High intake of dietary fiber and whole grains associated with reduced risk of non-communicable diseases
January 10, 2019
Science Daily/The Lancet
Observational studies and clinical trials conducted over nearly 40 years reveal the health benefits of eating at least 25g to 29g or more of dietary fiber a day, according to a series of systematic reviews and meta-analyses.
People who eat higher levels of dietary fibre and whole grains have lower rates of non-communicable diseases compared with people who eat lesser amounts, while links for low glycaemic load and low glycaemic index diets are less clear. Observational studies and clinical trials conducted over nearly 40 years reveal the health benefits of eating at least 25g to 29g or more of dietary fibre a day, according to a series of systematic reviews and meta-analyses published in The Lancet.
The results suggest a 15-30% decrease in all-cause and cardiovascular related mortality when comparing people who eat the highest amount of fibre to those who eat the least. Eating fibre-rich foods also reduced incidence of coronary heart disease, stroke, type 2 diabetes and colorectal cancer by 16-24%. Per 1,000 participants, the impact translates into 13 fewer deaths and six fewer cases of coronary heart disease.
In addition, a meta-analysis of clinical trials suggested that increasing fibre intakes was associated with lower bodyweight and cholesterol, compared with lower intakes.
The study was commissioned by the World Health Organization to inform the development of new recommendations for optimal daily fibre intake and to determine which types of carbohydrate provide the best protection against non-communicable diseases (NCDs) and weight gain.
Most people worldwide consume less than 20 g of dietary fibre per day. In 2015, the UK Scientific Advisory Committee on Nutrition recommended an increase in dietary fibre intake to 30 g per day, but only 9% of UK adults manage to reach this target. In the US, fibre intake among adults averages 15 g a day. Rich sources of dietary fibre include whole grains, pulses, vegetables and fruit.
"Previous reviews and meta-analyses have usually examined a single indicator of carbohydrate quality and a limited number of diseases so it has not been possible to establish which foods to recommend for protecting against a range of conditions," says corresponding author Professor Jim Mann, the University of Otago, New Zealand.
"Our findings provide convincing evidence for nutrition guidelines to focus on increasing dietary fibre and on replacing refined grains with whole grains. This reduces incidence risk and mortality from a broad range of important diseases."
The researchers included 185 observational studies containing data that relate to 135 million person years and 58 clinical trials involving 4,635 adult participants. They focused on premature deaths from and incidence of coronary heart disease, cardiovascular disease and stroke, as well as incidence of type 2 diabetes, colorectal cancer and cancers associated with obesity: breast, endometrial, esophageal and prostate cancer. The authors only included studies with healthy participants, so the findings cannot be applied to people with existing chronic diseases.
For every 8g increase of dietary fibre eaten per day, total deaths and incidence of coronary heart disease, type 2 diabetes and colorectal cancer decreased by 5-27%. Protection against stroke, and breast cancer also increased. Consuming 25g to 29g each day was adequate but the data suggest that higher intakes of dietary fibre could provide even greater protection.
For every 15g increase of whole grains eaten per day, total deaths and incidence of coronary heart disease, type 2 diabetes and colorectal cancer decreased by 2-19%. Higher intakes of whole grains were associated with a 13-33% reduction in NCD risk -- translating into 26 fewer deaths per 1,000 people from all-cause mortality and seven fewer cases of coronary heart disease per 1,000 people. The meta-analysis of clinical trials involving whole grains showed a reduction in bodyweight. Whole grains are high in dietary fibre, which could explain their beneficial effects.
The study also found that diets with a low glycaemic index and low glycaemic load provided limited support for protection against type 2 diabetes and stroke only. Foods with a low glycaemic index or low glycaemic load may also contain added sugars, saturated fats, and sodium. This may account for the links to health being less clear.
"The health benefits of fibre are supported by over 100 years of research into its chemistry, physical properties, physiology and effects on metabolism. Fibre-rich whole foods that require chewing and retain much of their structure in the gut increase satiety and help weight control and can favourably influence lipid and glucose levels. The breakdown of fibre in the large bowel by the resident bacteria has additional wide-ranging effects including protection from colorectal cancer." says Professor Jim Mann.
While their study did not show any risks associated with dietary fibre, the authors note that high intakes might have ill-effects for people with low iron or mineral levels, for whom high levels of whole grains can further reduce iron levels. They also note that the study mainly relates to naturally-occurring fibre rich foods rather than synthetic and extracted fibre, such as powders, that can be added to foods.
Commenting on the implications and limitations of the study, Professor Gary Frost, Imperial College London, UK, says, "[The authors] report findings from both prospective cohort studies and randomised controlled trials in tandem. This method enables us to understand how altering the quality of carbohydrate intake in randomised controlled trials affects non-communicable disease risk factors and how these changes in diet quality align with disease incidence in prospective cohort studies. This alignment is seen beautifully for dietary fibre intake, in which observational studies reveal a reduction in all-cause and cardiovascular mortality, which is associated with a reduction in bodyweight, total cholesterol, LDL cholesterol, and systolic blood pressure reported in randomised controlled trials... There are some important considerations that arise from this Article. First, total carbohydrate intake was not considered in the systematic review and meta-analysis... Second, although the absence of association between glycaemic index and load with non-communicable disease and risk factors is consistent with another recent systematic review, caution is needed when interpreting these data, as the number of studies is small and findings are heterogeneous. Third, the absence of quantifiable and objective biomarkers for assessing carbohydrate intake means dietary research relies on self-reported intake, which is prone to error and misreporting. Improving the accuracy of dietary assessment is a priority area for nutrition research. The analyses presented by Reynolds and colleagues provides compelling evidence that dietary fibre and whole grain are major determinants of numerous health outcomes and should form part of public health policy."
https://www.sciencedaily.com/releases/2019/01/190110184737.htm
Maternal stress leads to overweight in children
January 9, 2019
Science Daily/Helmholtz Centre for Environmental Research - UFZ
Researchers were able to identify mother's perceived stress during the first year of the child's life as a risk factor for developing overweight in infancy. Researchers found this to have long-lasting effects on girls' weight development in particular.
Overweight is unhealthy. Yet more and more people in Germany are overweight, particularly children. As part of the LiNA mother-child study coordinated by the Helmholtz Centre for Environmental Research (UFZ), researchers were able to identify mother's perceived stress during the first year of the child's life as a risk factor for developing overweight in infancy. According to the study recently published in the BMC Public Health specialist magazine, researchers from the UFZ, the University of Bristol and the Berlin Institute of Health found this to have long-lasting effects on girls' weight development in particular.
In Germany, nearly ten percent of children aged two to six are overweight, of which three percent are classified as obese. High-caloric diets and too little exercise are known to be risk factors for obesity. "Maternal stress is also thought to contribute to the development of obesity in children," explains nutritionist Dr Kristin Junge from the Department of Environmental Immunology at the UFZ. "In terms of child development, the period between pregnancy and the first years of life is particularly sensitive to external influences, which may lead to illness or obesity." And this may include psychological influences such as maternal stress. In their current study, UFZ researchers are investigating whether and how perceived maternal stress during pregnancy and the first two years of life, affects the child's weight development up to the age of five. To do so, they analysed data available from the LiNA mother-child study.
LiNA is a long-term study in which sensitive childhood development phases are investigated with special consideration given to lifestyle, environmental pollution and the subsequent occurrence of allergies, respiratory diseases and obesity. Since 2006, UFZ researchers in cooperation with the Städtisches Klinikum St. Georg in Leipzig, and more recently with the Universitätsklinikum Leipzig, have been following several hundred mother-child pairs from pregnancy onwards to investigate the effects of environmental influences and lifestyle habits on health and well-being. As part of the research, regular surveys are completed, pollutant measurements are taken in the living environment, and the mothers and children undergo clinical examinations. The current UFZ study is based on data from 498 mother-child pairs from the LiNA study. Using the data for height and weight, the researchers determined the children's Body Mass Index (BMI) and standardised the results by age and gender. Mothers' perceived stress was assessed by validated questionnaires and included topics such as worries and fears, feelings of tension, general satisfaction as well as coping with daily demands. "We compared the data on mothers' perceived stress during pregnancy and in the first two years of the child's life with the child's BMI development up to the age of five, and investigated whether there was a correlation," explains biochemist Dr Beate Leppert, the study's lead author.
First year of life particularly influential
And the study results show: There is actually a correlation. If mothers' perceived stress was high during the child's first year of life, there was a high probability that her child would develop a higher BMI in the first five years of their life. "The effects of maternal stress seem to have a long-term impact," says Kristin Junge. The correlation between perceived maternal stress in the child's first year of life and an increased BMI was especially evident in girls. "It seems that daughters of stressed mothers in particular are at increased risk of becoming overweight," says Dr Saskia Trump, senior author of the current study,who now works at the Berlin Institute for Health Research. "There are studies that demonstrate that psychological factors such as perceived maternal stress may be experienced less intensely or may be better compensated by boys." Perceived maternal stress during pregnancy or during the child's second year of life showed little evidence for an effect on the weight development of either gender. "The first year of life seems to be a sensitive phase and a characteristic factor for the tendency to be overweight," says Dr Junge. After all, mothers and children usually spend the entire first year together -- a lot of time in which the mother's perceived stress and/or associated behaviour is experienced by the child. "During this time, special attention should therefore be paid to the mother's condition," adds Dr Trump.
Identified stress factors
But what causes perceived maternal stress in the first place? To answer this question, researchers examined further data from the mother-child study and searched for possible influencing factors, such as household income, level of education, and the quality of the living environment. The results showed that mothers with a considerably higher perceived stress level were often exposed to high levels of traffic or noise, had poor living conditions or had a low household income. Maternal stress caused by difficult living conditions or an unfavourable living environment can lead to children becoming overweight in the long term. "Stress perceived by mothers should be taken seriously," says Dr Junge. "Midwives, gynaecologists, paediatricians and GPs should be particularly attentive to signs of stress in the first year following the child's birth." After all, if mothers are helped early on or are offered support, we may be able to kill two birds with one stone: To improve maternal well-being and also prevent their children becoming overweight. Following from this study, the UFZ team will continue to investigate whether the effects of perceived maternal stress also extend beyond the age of five.
https://www.sciencedaily.com/releases/2019/01/190109102419.htm
Intermittent fasting could improve obese women's health
January 8, 2019
Science Daily/University of Adelaide
Research shows that obese women lost more weight and improved their health by fasting intermittently while following a strictly controlled diet.
The study, published in the journal Obesity, involved a sample of 88 women following carefully controlled diets over 10 weeks.
"Continuously restricting their diet is the main way that obese women try to tackle their weight," says Dr Amy Hutchison, lead author from the University of Adelaide and the South Australian Health and Medical Research Institute (SAHMRI).
"Unfortunately, studies have shown that long-term adherence to a restricted diet is very challenging for people to follow, so this study looked at the impact of intermittent fasting on weight loss.
"Obese women who followed a diet in which they ate 70% of their required energy intake and fasted intermittently lost the most weight.
"Other women in the study who either fasted intermittently without reducing their food intake, who reduced their food intake but did not fast, or did not restrict their diet at all, were not as successful in losing weight," says Dr Hutchison.
The study also checked the effect of the different diets on the women's health. Women who fasted intermittently as well as restricting their food improved their health more than those who only restricted their diet or only fasted intermittently.
"By adhering to a strict pattern of intermittent fasting and dieting, obese women have achieved significant weight loss and improvements in their health such as decreased markers for heart disease," says Dr Hutchison.
Participants who fasted intermittently ate breakfast and then refrained from eating for 24 hours followed by 24 hours of eating. The following day they fasted again.
All participants of the study were women who were overweight or obese with a Body Mass Index (BMI) in the 25-40 range and aged between 35 and 70 years. They followed a typical Australian diet consisting of 35% fat, 15% protein and 50% carbohydrate.
"The most successful participants lost approximately 0.5 to 1 kg per week for each week of the study," says Dr Hutchison.
"This study is adding to evidence that intermittent fasting, at least in the short term, may provide better outcomes than daily continuous diet restriction for health and potentially for weight loss," says Associate Professor Leonie Heilbronn from the University of Adelaide and SAHMRI.
"While the study confirms that intermittent fasting is more effective than continuous diet restriction, the underlying signal for limiting people's appetite, which could hold the key to triggering effective weight loss, requires further research."
New trials now being undertaken will examine the effectiveness of long-term fasting on both men and women.
https://www.sciencedaily.com/releases/2019/01/190108125526.htm
Twofold overweight risk for five-year-olds given milk cereal drinks in infancy
December 19, 2018
Science Daily/University of Gothenburg
In five-year-old children, the risk for overweight is almost twice as high if they at 12 months had consumed milk cereal drinks every day, a study in the journal Acta Paediatrica shows.
"Milk cereal drinks are not bad as such; how it's used is the problem. That is, when it's seen not as a meal but as an extra, to supplement other food," says Bernt Alm, Associate Professor of Pediatrics at Sahlgrenska Academy, University of Gothenburg, Sweden.
The researchers behind the study have previously linked consumption of milk cereal drinks at age six months to high body mass index (BMI) at ages one year and one and a half years. The study now presented is of the same group of children, several years later.
The follow-up study comprised 1,870 children in Halland County, Sweden, whose particulars were taken from the Halland Health and Growth Study. Height and weight data have been recorded by the child health services, while the information on their food and beverage intake comes from the parents.
Among the five-year-olds, 11.6 percent were overweight and 2.3 percent had obesity. The risk for overweight or obesity proved to be almost double (factor 1.94) if the children had formerly, at age 12 months, been daily consumers of milk cereal drinks. This risk elevation was independent of other factors.
Examples of other conditions found to make overweight more likely were if the parents had low educational attainment, if they smoked, and if there was a history of obesity in the family. Heredity was the strongest single factor.
In Sweden, children commonly drink milk cereal drinks once to five times a day from age six months. In the study in question, 85 percent of the children had been daily consumers at 12 months of age.
The Swedish milk cereal drinks consists of milk and flour, and is nutritionally close to porridge, and usually enriched with vitamins and minerals. Similar products exist elsewhere in the world, but are not as common.
"Milk cereal drinks are nutritious and good, and has been used for hundreds of years in Sweden. Getting rid of it isn't a panacea. But if, for example, the child has other risk factors for overweight, such as heredity, perhaps not using milk cereal drinks should be considered," Alm says.
https://www.sciencedaily.com/releases/2018/12/181219115552.htm
Gut hormone increases response to food
Ghrelin promotes conditioning to food-related odours
December 12, 2018
Science Daily/McGill University
The holiday season is a hard one for anyone watching their weight. The sights and smells of food are hard to resist. One factor in this hunger response is a hormone found in the stomach that makes us more vulnerable to tasty food smells, encouraging overeating and obesity.
New research on the hormone ghrelin was published on today in Cell Reports on Dec. 4, 2018, led by Dr. Alain Dagher's lab at the Montreal Neurological Institute and Hospital of McGill University.
Previous research by Dr. Dagher's group and others demonstrated that ghrelin encourages eating and the production of dopamine, a neurotransmitter that is important for reward response. In the current study, researchers injected 38 subjects with ghrelin, and exposed them to a variety of odours, both food and non-food based, while showing them neutral images of random objects, so that over time subjects associated the images with the odours.
Using functional magnetic resonance imaging (fMRI), the researchers recorded activity in brain regions known to be involved in reward response from dopamine. They found that activity in these regions was higher in subjects injected with ghrelin, but only when responding to the images associated with food smells. This means that ghrelin is controlling the extent to which the brain associates reward with food odours.
Subjects also rated the pleasantness of the images associated with food odour, and the results showed that ghrelin both reduced the response time and increased the perceived pleasantness of food-associated images, but had no effect on their reaction to images associated with non-food odours.
People struggling with obesity often have abnormal reactivity to the food-related cues that are abundant in our environment, for example fast food advertising. This study shows that ghrelin may be a major factor in their heightened response to food cues. The brain regions identified have been linked to a neural endophenotype that confers vulnerability to obesity, suggesting a genetically-based hypersensitivity to food-associated images and smells.
"Obesity is becoming more common around the world and it's well known to cause health problems such as heart disease and diabetes," says Dr. Dagher. "This study describes the mechanism through which ghrelin makes people more vulnerable to hunger-causing stimuli, and the more we know about this, the easier it will be to develop therapies that counteract this effect."
https://www.sciencedaily.com/releases/2018/12/181212121907.htm
Study links frequent red meat consumption to high levels of chemical associated with heart disease
Findings reveal tripling of blood levels of TMAO from red meat diet, but dietary effects can be reversed
December 11, 2018
Science Daily/NIH/National Heart, Lung and Blood Institute
Researchers have identified another reason to limit red meat consumption: high levels of a gut-generated chemical called trimethylamine N-oxide (TMAO), that also is linked to heart disease. Scientists found that people who eat a diet rich in red meat have triple the TMAO levels of those who eat a diet rich in either white meat or mostly plant-based proteins, but discontinuation of red meat eventually lowers those TMAO levels.
TMAO is a dietary byproduct that is formed by gut bacteria during digestion and is derived in part from nutrients that are abundant in red meat. While high saturated fat levels in red meat have long been known to contribute to heart disease -- the leading cause of death in the United States -- a growing number of studies have identified TMAO as another culprit. Until now, researchers knew little about how typical dietary patterns influence TMAO production or elimination.
The findings suggest that measuring and targeting TMAO levels -- something doctors can do with a simple blood test -- may be a promising new strategy for individualizing diets and helping to prevent heart disease. The study was funded largely by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health. It will be published Dec. 10 in the European Heart Journal, a publication of the European Society of Cardiology.
"These findings reinforce current dietary recommendations that encourage all ages to follow a heart-healthy eating plan that limits red meat," said Charlotte Pratt, Ph.D., the NHLBI project officer for the study and a nutrition researcher and Deputy Chief of the Clinical Applications & Prevention Branch, Division of Cardiovascular Sciences, NHLBI. "This means eating a variety of foods, including more vegetables, fruits, whole grains, low-fat dairy foods, and plant-based protein sources such as beans and peas."
"This study shows for the first time what a dramatic effect changing your diet has on levels of TMAO, which is increasingly linked to heart disease," said Stanley L. Hazen, M.D., Ph.D., senior author of the study and section head of Preventive Cardiology & Rehabilitation at the Cleveland Clinic. "It suggests that you can lower your heart disease risk by lowering TMAO."
Hazen estimated that as many as a quarter of middle-aged Americans have naturally elevated TMAO levels, which are made worse by chronic red meat consumption. However, every person's TMAO profile appears to be different, so tracking this chemical marker, Hazen suggested, could be an important step in using personalized medicine to fight heart disease.
For the study, researchers enrolled 113 healthy men and women in a clinical trial to examine the effects of dietary protein -- in the form of red meat, white meat, or non-meat sources -- on TMAO production. All subjects were placed on each diet for a month in random order. When on the red meat diet, the participants consumed roughly the equivalent of about 8 ounces of steak daily, or two quarter-pound beef patties. After one month, researchers found that, on average, blood levels of TMAO in these participants tripled, compared to when they were on the diets high in either white meat or non-meat protein sources.
While all diets contained equal amounts of calories, half of the participants were also placed on high-fat versions of the three diets, and the researchers observed similar results. Thus, the effects of the protein source on TMAO levels were independent of dietary fat intake.
Importantly, the researchers discovered that the TMAO increases were reversible. When the subjects discontinued their red meat diet and moved to either a white meat or non-meat diet for another month, their TMAO levels decreased significantly.
The exact mechanisms by which TMAO affects heart disease is complex. Prior research has shown TMAO enhances cholesterol deposits into cells of the artery wall. Studies by the researchers also suggest that the chemical interacts with platelets -- blood cells that are responsible for normal clotting responses -- in a way that increases the risk for clot-related events such as heart attack and stroke.
TMAO measurement is currently available as a quick, simple blood test first developed by Hazen's laboratory. In recent published studies, he and his colleagues reported development of a new class of drugs that are capable of lowering TMAO levels in the blood and reducing atherosclerosis and clotting risks in animal models, but those drugs are still experimental and not yet available to the public.
https://www.sciencedaily.com/releases/2018/12/181211084948.htm
High childhood BMI linked to obesity at age 24 in women
December 3, 2018
Science Daily/Penn State
Girls who gain weight more rapidly between the ages of 5 and 15 are more likely to be obese at age 24, according to researchers.
"This highlights the importance of prevention efforts in childhood and adolescence," said Emily Hohman, assistant research professor of the Center for Childhood Obesity Research. The center is a college-wide collaboration of researchers from Penn State and elsewhere focused on evidence-based research that can be applied to treatment and prevention programs.
The Penn State researchers completed a follow-up study using data collected from a 10-year longitudinal observational study done by other researchers. In the original study, the researchers gathered 197 non-Hispanic white girls all 5 years in age.
The original study found four different BMI trajectory groups based on patterns of growth between the ages of 5 and 15. The four groups were classified as accelerated weight gain from ages 5 to 15; accelerated weight gain from 5 to 9 followed by a leveling-off; weight tracked along the 60th percentile; and weight tracked along the 50th percentile. The previous study had found that the first group -- accelerated weight gain from ages 5 to 15 -- had higher fasting insulin, blood pressure and triglycerides at age 15 than the other groups.
The follow-up study tracked down 182 of the 197 original participants when they were 24 years old, 10 years after last contact. The researchers sent surveys that asked the women to self-report their weight, height, education level, dieting, relationship, student and work status. The women who reported having a child were excluded from the follow-up.
The researchers found the accelerated weight gain from ages 5 to 15 group had a 93 percent rate of overweight or obesity at age 24 compared to just 20 to 37 percent in the other three groups.
"There is a need for prevention in young adulthood, too," said Hohman. "Kids are going off to college, getting their first jobs, and leaving home. This is another critical window where long-term health habits can develop, and obesity risk might increase."
A high BMI throughout childhood is associated with negative health outcomes in adulthood including obesity, cancer, cardiovascular disease and diabetes, according to the paper, which was made available online in July 2018 ahead of peer-review and publication this month in Eating Behaviors.
"We found that about 20 to 30 percent of girls who did not have accelerated weight gain in childhood or adolescence ended up having overweight or obesity at age 24," said Hohman.
This shows how eating behaviors and lifestyle choices can impact BMI as well.
For future work, the researchers plan to test additional psychological and physiological measures in person.
"We would love to bring the women back in to get additional data on eating behaviors and health," said Hohman. "We just need to find the funding."
https://www.sciencedaily.com/releases/2018/12/181203162739.htm
A Mediterranean diet in pregnancy is associated with lower risk of accelerated growth
December 3, 2018
Science Daily/Barcelona Institute for Global Health (ISGlobal)
Over 2,700 women and their children participated in this study that highlights the benefits of a healthy diet.
The Mediterranean diet is characterised by a high content of fruits, vegetables, olive oil, legumes and nuts. This healthy diet pattern has been associated with lower obesity and cardiometabolic risk in adults, but few studies have focused on children.
This study, published in the Journal of Pediatrics, aimed at evaluating the association between adherence to a Mediterranean diet during pregnancy and growth patterns and cardiometabolic risk in early infancy.
The study was performed with data of over 2,700 pregnant women from Asturias, Guipúzcoa, Sabadell and Valencia, who are part of the INMA-Childhood and Environment cohort. The women filled in a questionnaire on dietary intake in the first and third trimester of pregnancy. In addition, the diet, weight and height of their offspring were followed-up from birth to age 4 years. Other tests such as blood analysis and blood pressure were also performed at age 4.
The results show that pregnant women with higher adherence to the Mediterranean diet had a 32% lower risk of having children with an accelerated growth pattern, as compared to offspring of women that did not follow such diet.
Sílvia Fernández, ISGlobal researcher and first author of the study, underlines that "mothers with lower adherence to the Mediterranean diet were younger, consumed more calories, and had higher probability of smoking and a lower education and social level," as compared to those women who did follow the diet."
"These results support the hypothesis that a healthy diet during pregnancy can have a beneficial effect for child development," concludes the study coordinator Dora Romaguera, researcher at ISGlobal and CIBEROBN. Regarding the mechanisms that underlie this association, the researcher mentions "possible epigenetic modifications that regulate fetal caridiometabolism, or shared eating patterns between mothers and children, although this deserves further investigation."
The study did not find a correlation between Mediterranean diet in pregnancy and a reduction in cardiometabolic risk (blood pressure or cholesterol) in early infancy. "The effects on cardiometabolic risk could appear later in childhood," explains Fernández.
https://www.sciencedaily.com/releases/2018/12/181203101419.htm
Despite common obesity gene variants obese children lose weight after lifestyle changes
November 28, 2018
Science Daily/University of Copenhagen The Faculty of Health and Medical Sciences
Children who are genetically predisposed to overweight, due to common gene variants, can still lose weight by changing their diet and exercise habits, according to a new study.
Overweight and obesity constitute an increasing global problem that may lead to serious sequelae such as heart attacks, diabetes and cancer. In 2016, 124 million children and adolescents worldwide suffered from obesity. Now researchers from the University of Copenhagen and the Children's Obesity Clinic, the Department of Paediatrics at Holbæk Hospital have examined how genetics affect children and young people's ability to lose excess weight.
'We are trying to understand the genetic driving force behind overweight and whether this force also makes it impossible for some to lose weight. We show that a high genetic predisposition to overweight during childhood in fact had no influence on whether the children reacted to lifestyle intervention compared to children with low genetic predisposition to overweight. The 15 genetic variants we have studied are common in the population and are the ones that in general increase a child's risk of becoming overweight,' says Postdoc at the Novo Nordisk Foundation Center for Basic Metabolic Research at UCPH Theresia Maria Schnurr, who is one of the authors of the study.
The new research results have just been published in the scientific journal Obesity. The researchers' aim was to determine the influence of specific gene variants on children and adolescents' ability to lose weight. Therefore, they studied the 15 specific gene variants implicated in childhood obesity and which are common in the population. In the study, the researchers demonstrate that these genetic variants did not predict whether children and adolescents' were able to lose weight when they changed their lifestyle. So far only children with a rare genetic mutation in the MC4R gene do not seem to lose weight when undergoing lifestyle intervention.
Lifestyle Intervention Led to Weight Loss
The researchers examined 754 children and adolescents with overweight and obesity. The median age was 11.6 years. The genetic profile of all participants was mapped, and the researchers then calculated a genetic risk score for childhood overweight for each participant based on the 15 genetic variants. They all carried one or more of the 15 genetic variants associated with increased risk for obesity and overweight during childhood. To determine whether a genetic predisposition for overweight affected the children and adolescents' ability to lose weight the children had to implement a series of lifestyle changes.
They followed a treatment protocol developed at Holbæk Hospital. The protocol centres around the family with behavioural lifestyle changes. For example, the children and adolescents had to change their diet, means of transportation, physical activity, sedentary activity, amount of sleep, consumption of snacks and sweet things and social activities. The intervention lasted six to 24 months. Subsequently, the researchers followed up on the treatment and found that the lifestyle changes had affected the weight of the participants, despite their genetic disposition for overweight and obesity.
'Large parts of the population believes that when you have problematic genes it is game over. That is why it is very important we send a clear message that even though you have a genetic sensitivity this treatment can help people. We have discovered that it does not matter whether the children and adolescents have an increased genetic risk score or not. They can respond to treatment just as well. This means our treatment is efficient despite carrying common obesity risk genes. It gives hope to people with obesity and obesity related complications such as high blood pressure, cholesterol and fatty liver that we can in fact help them,' says one of the study's authors Jens-Christian Holm, doctor and head of the Children's Obesity Clinic, Holbæk Hospital.
Genetic Markers
The genetic variants the researchers have examined are common in the population and turned out not to have an effect on the ability to lose weight during the intervention. So far, the researchers did not find any biological markers for a poor response on lifestyle intervention except for the rare gene MC4R associated with poor response in terms of weight loss following a lifestyle intervention.
'MC4R is a rare genetic mutation and thus the question remains why around 75 percent of children in a group of children receiving the exact same treatment react more positively to the treatment compared to the remaining 25 percent of children not responding to lifestyle treatment. Identifying additional common genetic markers would help us understand the biological pathways that affect obesity and a person's reaction to lifestyle changes -- and thus in the long term help us provide even better treatments,' says Professor at the Novo Nordisk Foundation Center for Basic Metabolic Research Torben Hansen, last author of the study.
https://www.sciencedaily.com/releases/2018/11/181128115006.htm
Long-term exposure to road traffic noise may increase the risk of obesity
New evidence on the damaging effects of noise on health
November 16, 2018
Science Daily/Barcelona Institute for Global Health (ISGlobal)
Long term exposure to road traffic noise is associated with increased risk of obesity. This was the conclusion of a study involving the participation of the Barcelona Institute for Global Health (ISGlobal), a research centre supported by the "la Caixa" Banking Foundation. The study has been published in Environment International.
The authors of this study wanted to find out whether new research would confirm the results of the few earlier studies that had demonstrated associations between traffic noise and several markers for obesity. To do this, they studied 3796 adults who took part in the population-based Swiss SAPALDIA cohort study and had attended at least two follow-up visits between 2001 and 2011. The study is based on objective measures, such as the participants' weight, height, body mass index, waist circumference, and abdominal fat. These data were analysed together with estimates of exposure to transportation noise developed in the context of the Swiss SiRENE project.
"Our analysis shows that people exposed to the highest levels of traffic noise are at greater risk of being obese" explains ISGlobal research Maria Foraster, first author of the study. "For example, we observed that a 10 dB increase in mean noise level was associated with a 17% increase in obesity."
The study authors also analysed exposure to noise generated by aircraft and railway traffic and found no significant associations except in the case of long-term exposure to railway noise, which was associated with a higher risk of overweight but not of obesity.
The methodology and design of the study were chosen to allow the authors to look at the data from two different perspectives. Cross-sectional analysis was used to study the participant population at a specific time point in the study and to examine more objective measures. The longitudinal design, on the other hand, allowed the authors to evaluate how the risk of obesity evolved over the study period. The associations with traffic-related noise pollution were consistent in both cases. Overweight was only associated with exposure to traffic-related noise in the cross-sectional analysis. The authors found no association between noise exposure and body mass index measured continuously throughout the longitudinal analysis.
"Our study contributes additional evidence to support the hypothesis that traffic-related noise affects obesity because the results we obtained in a different population were the same as those reported by the authors of earlier studies. Nevertheless, more longitudinal studies are needed to confirm the association and to examine certain inconsistencies in the data which, to date, have prevented us from formulating an explanation accepted by the scientific community as a whole," explains Maria Foraster.
Unfortunately, sustained exposure to noise pollution is a widespread public health problem that is more serious than previously thought. Noise generates stress and affects our sleep. It alters hormone levels and increases blood pressure. Moreover, among other effects, sleep disturbance deregulates glucose metabolism and alters the appetite. "In the long term, these effects could give rise to chronic physiological alterations, which would explain the proven association between persistent exposure to traffic-related noise and cardiovascular disease or the more recently discovered associations with diabetes and obesity. Our findings suggest that reducing traffic-related noise could also be a way of combating the obesity epidemic" adds Maria Foraster.
https://www.sciencedaily.com/releases/2018/11/181116110615.htm
Should you eat a low-gluten diet?
November 15, 2018
Science Daily/University of Copenhagen The Faculty of Health and Medical Sciences
When healthy people eat a low-gluten and fiber-rich diet compared with a high-gluten diet they experience less intestinal discomfort including less bloating which researchers show are due to changes of the composition and function of gut bacteria. The new study also shows a modest weight loss following low-gluten dieting. The researchers attribute the impact of diet on healthy adults more to change in composition of dietary fibers than gluten itself.
An increasing number of people choose a low-gluten diet, even though they are not allergic to the dietary substance. This trend has sparked public debate about whether or not low-gluten diets are recommendable for people without allergies. Now, researchers from University of Copenhagen among others have looked into just that.
In an intervention study of healthy Danish adults, reported today in Nature Communications, an international team of scientists shows that a low-gluten but fibre-rich diet changes the community of gut bacteria and decreases gastrointestinal discomfort such as bloating and is linked to a modest weight loss. The changes in intestinal comfort and body weight relate to changes in gut bacteria composition and function.
"We demonstrate that, in comparison with a high-gluten diet, a low-gluten, fibre-rich diet induces changes in the structure and function of the complex intestinal ecosystem of bacteria, reduces hydrogen exhalation, and leads to improvements in self-reported bloating. Moreover, we observed a modest weight loss, likely due to increased body combustion triggered by the altered gut bacterial functions," explains the leading principal investigator of the trial, Professor Oluf Pedersen, Novo Nordisk Foundation Center for Basic Metabolic Research at University of Copenhagen.
Change in dietary fibre composition seems to be the cause
The researchers undertook a randomised, controlled, cross-over trial involving 60 middle-aged healthy Danish adults with two eight week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day).
The two diets were balanced in number of calories and nutrients including the same amount of dietary fibres. However, the composition of fibres differed markedly between the two diets.
Based on their observations of altered food fermentation patterns of the gut bacteria, the researchers conclude that the effects of low-gluten dieting in healthy people may not be primarily due to reduced intake of gluten itself but rather to a change in dietary fibre composition by reducing fibres from wheat and rye and replacing them with fibres from vegetables, brown rice, corn, oat and quinoa.
No basis for change of diet recommendation yet
A low-gluten diet has previously been proposed to diminish gastrointestinal symptoms in patients with inflammatory bowel diseases and irritable bowel syndrome, disorders which occur in up to 20 percent of the general Western population.
The present study suggests that even some healthy individuals may prefer a low-gluten diet to combat intestinal discomfort or excess body weight.
"More long-term studies are definitely needed before any public health advice can be given to the general population. Especially, because we find dietary fibres -- not the absence of gluten alone -- to be the primary cause of the changes in intestinal discomfort and body weight. By now we think that our study is a wake-up call to the food industry. Gluten-free may not necessarily be the healthy choice many people think it is.
Most gluten-free food items available on the market today are massively deprived of dietary fibers and natural nutritional ingredients. Therefore, there is an obvious need for availability of fibre-enriched, nutritionally high-quality gluten-free food items which are fresh or minimally processed to consumers who prefer a low-gluten diet. Such initiatives may turn out to be key for alleviating gastro-intestinal discomfort and in addition to help facilitating weight control in the general population via modification of the gut microbiota," concludes senior lead investigator, Professor Oluf Pedersen.
https://www.sciencedaily.com/releases/2018/11/181115115340.htm
Low-carb diets cause people to burn more calories
All calories are not alike, finds largest, longest macronutrient feeding trial to date
November 14, 2018
Science Daily/Boston Children's Hospital
Most people regain the weight they lose from dieting within one or two years, in part because the body adapts by slowing metabolism and burning fewer calories. A meticulous study now finds that eating fewer carbohydrates increases the number of calories burned. The findings suggest that low-carb diets can help people maintain weight loss, making obesity treatment more effective.
The study, known as the Framingham State Food Study, or (FS)2, tightly controlled what people ate by providing them with fully prepared food-service meals for a 20-week period. Researchers carefully tracked participants' weight and measured insulin secretion, metabolic hormones and total energy expenditure (calories burned).
"This is the largest and longest feeding study to test the 'Carbohydrate-Insulin Model,' which provides a new way to think about and treat obesity," says David Ludwig, MD, PhD, who is co-principal investigator with Cara Ebbeling, PhD. (Ludwig and Ebbeling are co-directors of the New Balance Foundation Obesity Prevention Center in Boston Children's Division of Endocrinology.) "According to this model, the processed carbohydrates that flooded our diets during the low-fat era have raised insulin levels, driving fat cells to store excessive calories. With fewer calories available to the rest of the body, hunger increases and metabolism slows -- a recipe for weight gain."
Comparing carb levels head to head
After careful telephone screening of 1,685 potential participants, Ebbeling, Ludwig and colleagues enrolled 234 overweight adults (age 18 to 65, body mass index of 25 or higher) to an initial weight-loss diet for about 10 weeks. Of these, 164 achieved the goal of losing 10 to 14 percent of body weight and went on to the study's maintenance phase.
These participants were then randomized to follow high-, moderate- or low-carbohydrate diets for an additional 20 weeks -- with carbs comprising 60, 40 and 20 percent of total calories, respectively. Carbs provided to all three groups were of high quality, conforming to guidelines for minimizing sugar and using whole rather than highly processed grains.
In all three groups, total calorie intake was adjusted to maintain weight loss, so participants' weight did not change notably. During this phase, the goal was to compare energy expenditure -- how the different groups burned calories at the same weight. Energy expenditure was measured by a gold-standard method using doubly labeled water.
Over the 20 weeks, total energy expenditure was significantly greater on the low-carbohydrate diet versus the high-carbohydrate diet. At the same average body weight, participants who consumed the low-carb diet burned about 250 kilocalories a day more than those on the high-carb diet.
"If this difference persists -- and we saw no drop-off during the 20 weeks of our study -- the effect would translate into about a 20-pound weight loss after three years, with no change in calorie intake," says Ebbeling.
In people with the highest insulin secretion at baseline, the difference in calorie expenditure between the low- and high-carb diets was even greater, about 400 kilocalories per day, consistent with what the Carbohydrate-Insulin Model would predict. Ghrelin, a hormone thought to reduce calorie burning, was significantly lower on the low- versus high-carb diet.
"Our observations challenge the belief that all calories are the same to the body," says Ebbeling. "Our study did not measure hunger and satiety, but other studies suggest that low-carb diets also decrease hunger, which could help with weight loss in the long term."
Ludwig and Ebbeling recently launched another clinical trial called FB4, in which 125 adults with obesity live in a residential center for 13 weeks. Participants are being randomized to one of three diets: very-low-carb, high carb/low sugar or high carb/high sugar diets, with their calorie intakes individually matched to their energy expenditure. Results are expected in 2021.
https://www.sciencedaily.com/releases/2018/11/181114120302.htm
Treating obesity: One size does not fit all
November 13, 2018
Science Daily/Brown University
Understanding the very different characteristics of subgroups of obese patients may hold the key to devising more effective treatments and interventions, new research found.
Analyzing data from more than 2,400 obese patients who underwent bariatric weight-loss surgery, researchers identified at least four different patient subgroups that diverge significantly in eating behaviors and rate of diabetes, as well as weight loss in three years after surgery.
"There probably isn't one magic bullet for obesity -- if there is a magic bullet, it's going to be different for different groups of people," said Alison Field, chair of the department of epidemiology at the Brown University School of Public Health and lead author of the paper.
"There's a really diverse mix of people who get put into one group. A child who becomes very obese by age 5 is going to be very different from someone who gradually gains weight over time and at age 65 is obese. We need to recognize this diversity, as it may help us to develop more personalized approaches to treating obesity."
The findings were published on Tuesday, Nov. 13, in the journal Obesity.
Four groups of patients
This was the first study examine psychological variables, such as eating patterns, weight history and a range of biological variables, including hormone levels, to identify different types of obesity, Field said.
The team used an advanced computational model, called latent class analysis, to identify different groups of patients among more than 2,400 adults who underwent bariatric surgery between March 2006 and April 2009 -- either gastric bypass or gastric banding. They found four distinct groups.
Group one was characterized by low levels of high-density lipoprotein, the so called "good" cholesterol, and very high levels of glucose in their blood prior to surgery. In fact, 98 percent of this group's members were diabetic, in contrast with the other groups, where about 30 percent were diabetic, the study found.
Group two was characterized by disordered eating behaviors. Specifically, 37 percent had a binge eating disorder, 61 percent reported feeling a loss of control over "grazing" -- regularly eating food between meals -- and 92 percent reported eating when they weren't hungry.
Field found group three surprising, she said. Metabolically, they were fairly average, but they had very low levels of disordered eating -- only 7 percent reported eating when they weren't hungry compared to 37 percent for group one, 92 percent for group two and 29 percent for group four.
"Interestingly, no other factors distinguished this group from the other classes," the authors reported in the paper.
Group four comprised individuals who had been obese since childhood. This group had the highest body mass index (BMI) at age 18 with an average of 32, compared to an average of approximately 25 for the other three groups. A BMI above 30 is considered obese, while 25 is the start of the range defined as overweight. This group also had the highest pre-surgery BMI, an average of 58 compared to approximately 45 for the other three groups, the study reported.
Overall, in the three years following the bariatric procedure, men lost an average of 25 percent of pre-surgery weight and women lost an average of 30 percent. Field and colleagues found that patients in groups two and three benefited more from bariatric surgery than patients in groups one and four. Men and women with disordered eating lost the most, at an average of 28.5 percent and 33.3 percent, respectively, of pre-surgery weight.
Targeted treatments
Identifying these different groups of patients and understanding their characteristics should help obesity research and treatment, Field said. At the extreme end of treatment -- procedures such as bariatric surgery -- it's important to identify who would benefit most from surgery and those for whom the benefits likely won't outweigh the surgical risks, she said.
"One of the reasons why we haven't had stronger findings in the field of obesity research is that we're classifying all of these people as the same," Field said. "It may very well be that there are some incredibly effective strategies out there for preventing or treating obesity, but when you mix patients of different groups together, it dilutes the effect."
Field added that obesity researchers need to test a variety of interventions in a more targeted, personalized manner. For example, mindfulness might be quite effective for people who are overstimulated by the sights and smells of food but might not be effective for people in group three who don't eat when they're not hungry, she said.
In the future, Field hopes to use the same statistical analysis methods on a more general population of overweight individuals to see if the same, or similar, subgroups exist among people at weights less than those defined as obese.
She and her colleagues are now developing a mobile app to measure what influences individuals' eating behaviors in real time. Field hopes the app can eventually be used to provide tailored interventions. She has a beta version of the app, and hopes to move forward in fully developing and testing it.
https://www.sciencedaily.com/releases/2018/11/181113080923.htm
How many calories do you burn? It depends on time of day
November 8, 2018
Science Daily/Cell Press
Researchers have made the surprising discovery that the number of calories people burn while at rest changes with the time of day. When at rest, people burn 10 percent more calories in the late afternoon and early evening than in the early morning hours.
The findings reinforce the important role of the circadian clock in governing metabolism. They also help to explain why irregularities in eating and sleeping schedules due to shift work or other factors may make people more likely to gain weight.
"The fact that doing the same thing at one time of day burned so many more calories than doing the same thing at a different time of day surprised us," says Kirsi-Marja Zitting of the Division of Sleep and Circadian Disorders at Brigham and Women's Hospital and Harvard Medical School, lead author of the paper.
To determine changes over the course of the day in metabolism apart from the effects of activity, sleep-wake cycle, and diet, the researchers studied seven people in a special laboratory without any clues about what time it was outside. There were no clocks, windows, phones, or Internet. Study participants had assigned times to go to bed and wake up. Each night, those times were adjusted four hours later, the equivalent of traveling westward across four time zones each day for three weeks.
"Because they were doing the equivalent of circling the globe every week, their body's internal clock could not keep up, and so it oscillated at its own pace," co-author Jeanne Duffy, also in the Division of Sleep and Circadian Disorders at Brigham and Women's Hospital, explains. "This allowed us to measure metabolic rate at all different biological times of day."
The data showed that resting energy expenditure is lowest at the circadian phase the researchers designated as ~0°, corresponding to the dip in core body temperature in the late biological night. Energy expenditure was highest at circadian phase ~180°, about 12 hours later, in the biological afternoon into evening.
The researchers found that participants' respiratory quotient, which reflects macronutrient utilization, varies by circadian phase, too. This measure was lowest in the evening and highest in the biological morning.
The findings offer the first characterization of a circadian profile in fasted resting energy expenditure and fasted respiratory quotient, decoupled from effects of activity, sleep-wake cycle, and diet in humans, the researchers say.
"It is not only what we eat, but when we eat -- and rest -- that impacts how much energy we burn or store as fat," Duffy says. "Regularity of habits such as eating and sleeping is very important to overall health."
Duffy, Zitting, and their colleagues next will look at how appetite and the body's response to food varies with the time of day. They are also exploring how the timing, duration, and regularity of sleep influences those responses.
https://www.sciencedaily.com/releases/2018/11/181108142423.htm
Does a woman's weight gain during pregnancy affect children's bone health?
November 7, 2018
Science Daily/Wiley
A new study has examined whether managing weight during pregnancy might affect children's bone mass. In under/normal weight mothers, weight gain during pregnancy was associated with slightly increased bone mass at seven years of age in children, while in overweight/obese mothers, no beneficial effect of weight gain on bone mass was observed.
In the Journal of Bone and Mineral Research study, investigators analyzed prospective data from 2,167 mother-child pairs from Portugal. In under/normal weight mothers, weight gain during pregnancy was associated with slightly increased bone mass at 7 years of age in children, while in overweight/obese mothers, no beneficial effect of weight gain on bone mass was observed.
Given the well-known adverse implications of excessive weight gain during pregnancy for both the mother and child on various aspects of health, following the current recommendations on pregnancy weight gain should not have consequences on children's skeletal health.
"Until recently, it was a widely held scientific belief that any weight gain from the mother during pregnancy would have a beneficial effect on children's bone mass. Our study results corroborate that there is no benefit in gaining weight above the US Institute of
Medicine recommendations for pregnancy weight gain for children's bone mass, in both normal and overweight women prior to pregnancy," said lead author Dr. Teresa Monjardino, of the Universidade do Porto, in Portugal.
https://www.sciencedaily.com/releases/2018/11/181107082520.htm
Nuts for nuts? Daily serving may help control weight and benefit health
November 5, 2018
Science Daily/American Heart Association
Eating Brazil nuts and other varieties of nuts daily may prevent weight gain and provide other cardiovascular benefits, according to two separate preliminary studies.
One study analyzed the influence of eating nuts and peanuts on long-term body weight in U.S. men and women. The other study examined whether eating Brazil nuts could increases a sense of fullness and improve glucose and insulin responses.
In the analysis of nuts' impact on weight, researchers followed health professionals who were free of chronic disease at the start of the study. They found that eating a one one-ounce serving of any type of nuts or peanuts, in place of foods generally considered low in nutritional value, was associated with a lower risk of long-term weight gain and obesity.
Nut consumption was assessed through a food-frequency questionnaire submitted to participants every four years in three different established study groups of 25,394 men in the Health Professionals Follow-up Study, 53,541 women in the Nurse's Health Study and 47,255 women in the Nurse's Health Study II in follow-up research.
Findings revealed that:
· Eating a daily serving of any type of nut or peanuts was associated with less risk of weight gain or becoming obese over the four-year intervals.
· Substituting one serving a day of any type of nuts in place of one serving of red meat, processed meat, French fries, desserts or potato chips was associated with less weight gain over the four-year intervals.
A serving of nuts is defined as one ounce of whole nuts or two tablespoons of nut butter. "People often see nuts as food items high in fat and calories, so they hesitate to consider them as healthy snacks, but they are in fact associated with less weight gain and wellness," said Xiaoran Liu, Ph.D., first author of the study and a research associate in the nutrition department of Harvard School of Public Health in Boston, Massachusetts.
"Once people reach adulthood, they start to gradually gain about one pound a year of weight, which seems small. But if you consider gaining one pound over 20 years, it accumulates to a lot of weight gain," she said. "Adding one ounce of nuts to your diet in place of less healthy foods -- such as red or processed meat, French fries or sugary snacks -- may help prevent that slow, gradual weight gain after you enter adulthood and reduce the risk of obesity-related cardiovascular diseases."
Participants in the research on the influence of nuts on weight gain were mainly white and part of the health profession, but researchers believe even with this limitation the findings can be applied to a general population.
In the Brazil nut study, conducted at San Diego State University in 2017 through a grant from the American Heart Association, 22 healthy adults (20 women and two men) age 20 or older with a mean body mass index of 22.3, consumed either 36 grams of pretzels or 20 grams of Brazil nuts (about five nuts) in addition to their usual diet. The Brazil nuts and pretzels had approximately the same amount of calories and sodium. Participants ate either the nuts or the pretzels in two trials with a washout period of at least 48 hours to prevent carryover effects.
The study found:
· Both Brazil nuts and pretzels significantly increased a sense of fullness and reduced feelings of hunger, with the greatest sense of fullness experienced by the group eating Brazil nuts compared to those eating pretzels.
· Pretzel consumption caused a significant increase in blood glucose and insulin at 40-minutes after they were eaten, compared to the start of the trial, whereas eating Brazil nuts did not significantly increase blood glucose or insulin.
"While both Brazil nuts and pretzels increased a sense of fullness after they were eaten, eating Brazil nuts stabilized postprandial (after eating) blood glucose and insulin levels, which may be beneficial in preventing diabetes and weight gain," said Mee Young Hong, Ph.D, R.D., senior author of the study and professor in the School of Exercise & Nutritional Sciences at San Diego State University in San Diego, California.
Brazil nuts are one of the highest known food sources of selenium, a mineral which the researchers note in previous studies may be associated with improvements in insulin and glucose responses. Insulin is produced in the pancreas and is a catalyst for processing glucose into energy. Some people are insulin resistant or don't produce enough insulin, which means glucose can reach unhealthy levels and result in diabetes, a major risk factor for heart attacks and strokes.
"Our study allows researchers and clinicians to consider the possible beneficial role of Brazil nuts to help people feel full and maintain a healthy level of glucose, reducing the risk of obesity and diabetes," Hong said.
In the Brazil nut study, only 9 percent of the participants were men, so the findings should not be generalized to a male population according to Hong.
https://www.sciencedaily.com/releases/2018/11/181105081742.htm
How diet impact health and well-being
November 2, 2018
Science Daily/University of California - Santa Barbara
From the standpoint of heart health, the Tsimane are a model group. A population indigenous to the Bolivian Amazon, the Tsimane demonstrate next to no heart disease. They have minimal hypertension, low prevalence of obesity and and their cholesterol levels are relatively healthy. And those factors don't seem to change with age.
Also minimal is the incidence of Type-2 diabetes. Which leads scientists to consider the role of diet in the Tsimane's cardiovascular health -- and how it might be impacted over time as the population becomes more exposed to globalization and market forces.
That's where UC Santa Barbara anthropologists Thomas Kraft and Michael Gurven come in. They are part of the Tsimane Health and Life History Project, supported by the National Institutes of Health, which conducted the first systematic study that examines what the Tsimane consume on a regular basis and compares it to that of the Moseten, a neighboring population with similar language and ancestry, but whose eating habits and lifeways are more impacted by outside forces. The researchers' findings appear in the American Journal of Clinical Nutrition.
"Our prior work showed that the Tsimane have the healthiest hearts ever studied, so naturally there's a lot of interest in understanding why and how," said Michael Gurven, a professor of anthropology at UC Santa Barbara, co-director of the Tsimane Health and Life History Project and the paper's senior author. "The obvious first contender is, what are they eating? And are they eating what we think is best for heart health?
"We conducted a detailed analysis of the Tsimane diet and then compared it to what modern Americans typically eat, and to the diets that claim to be heart healthy," he continued. "Maybe the Tsimane just happen to follow one of those without knowing about them." These diets -- Paleo, Okinawan and DASH, among others -- are often promoted because of their proposed health benefits, and in the case of Paleo, that our bodies have evolved to benefit from particular types of food.
The connection to the Moseten is an added benefit of the study. Ethnolinguistically and genetically very similar to the Tsimane, the Moseten, an isolate in Bolivia, are much more acculturated in a number of ways than are the Tsimane. "They provide a forecast of what Tsimane health might look like 20 years from now," Gurven said. "They represent what is happening to many indigenous populations over time. To what extent may changes in their diet increase the prevalence of heart disease and diabetes?"
Using the same measurement strategy employed by the U.S. Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey, the researchers interviewed 1,299 Tsimane and 229 Moseten multiple times about everything they had eaten or drunk in the previous 24 hours. Using published and their own nutritional estimates for all items, and a variety of methods to estimate portion size, they provided a detailed breakdown of daily food intake.
The high-calorie (2,433-2,738 kcal/day) Tsimane diet was characterized by high carbohydrate and protein intake, and low fat intake (64, 21 and 15 percent of the diet, respectively). In addition, the Tsimane don't eat a wide variety of foods, relative to the average U.S. or Moseten diet. Almost two-thirds of their calories are derived from complex carbohydrates, particularly plantains and rice. Another 16 percent comes from over 40 species of fish, and 6 percent from wild game. Only 8 percent of the diet came from markets.
Despite the low dietary diversity, the researchers found little evidence of micronutrient deficiencies in the Tsimane's daily intake. Calcium and a few vitamins (D, E and K) were in short supply, but the intake of potassium, magnesium and selenium -- often linked to cardiovascular health -- far exceeded U.S. levels. Dietary fiber intake was almost double U.S. and Moseten levels.
Over the five years of study, the researchers saw the Tsimane's total energy and carbohydrate intake increase significantly, particularly in villages near market towns. Their consumption of food additives (lard, oil, sugar and salt) also has increased significantly. The Moseten, the researchers noted, consumed substantially more sugar and cooking oil than did the Tsimane.
The conclusion: A high-energy diet rich in complex carbohydrates is associated with low cardiovascular disease risk, at least when coupled with a physically active lifestyle (Tsimane adults average 17,000 or so steps per day, compared to Americans' 5,100). Moving away from a diet that is high in fiber and low in fat, salt and processed sugar represents a serious health risk for transitioning populations. Evidence of nutrition transition in Bolivia parallels trends in increasing body fat and body mass index among Tsimane, suggesting the low prevalence of cardiovascular disease -- as among the Tsimane -- may not persist.
According to Gurven, avoiding the pitfalls of changing diets and lifestyles will be critical for groups like the Tsimane. Many other indigenous populations in South America, Africa and Southeast Asia are in similar situations. And rates of obesity, type-2 diabetes and heart disease are high among indigenous groups whose lifeways are no longer traditional -- including many North American Indian and Australian aboriginal populations.
And for the Tsimane, change is not far on the horizon. "This is a key time," said Thomas Kraft, a postdoctoral researcher in anthropology at UC Santa Barbara and the paper's lead author. "Roads are improving in the area, as is river transport with the spread of motorized boats, so people are becoming a lot less isolated compared to the past. And it's happening at a pretty rapid pace."
Anecdotally, Gurven added, the Tsimane Health and Life History Project's biomedical team is seeing more diabetic patients among the Tsimane than they have previously. That's likely due to the increased regular intake of refined sugar and fat that occurred over the course of the study. As Kraft noted, with the Tsimane's ability to buy large kilo bags of sugar and liters of cooking oil, the researchers calculated a 300 percent rise in consumption of those products. "They're basically deep frying and adding lots of sugar to drinks when they can," he said.
And consuming a lot of calories. "But they're also physically active -- not from routine exercise, but from using their bodies to acquire food from their fields and the forest," added Gurven, "which is also an important lesson. You can't look at what you're eating irrespective of what you're doing with your body. If you're physically active, you can probably get away with more flexibility in the diet."
Calorie count aside, the high carbohydrate content of the Tsimane diet isn't "unprecedented," according to Kraft. "One of the other artery-protecting diets is the Okinawan diet from Japan. It comes out at about 85 percent carbohydrate. But a common feature they share is that pretty much across the board, they're complex carbohydrates -- it's sweet potatoes in the Okinawan diet; here it's plantains and manioc."
The Moseten diet has fewer total calories and less carbohydrates than the Tsimane diet, but the Moseten eat a broader range offoods, including more fruits, vegetables, dairy and legumes. The Moseten also buy more of their food, including soda, bread, dried meat and processed items. The Moseten diet could provide insight into the Tsimane diet of the future, the researchers suggest. "We're still analyzing their health indicators, but we expect the Moseten to show more risk factors related to diabetes and heart disease," said Gurven.
In addition to finding that the Tsimane consume more calories per day than the Moseten do, the researchers note the Tsimane are also more physically active (with much of their labor devoted to the hard work of slash and burn farming, hunting, fishing and foraging). They expend more energy activity, but may also have a higher resting energy expenditure due to higher rates of infection and persistent immune activity.
Overall, the findings suggest that no single diet protocol offers the key to health. The picture is much more complicated. "It definitely sheds light on the diversity of diets that are compatible with good cardiovascular health," said Kraft.
Added Gurven, "We're at a unique point in history where for many of us, our daily decisions are more about what not to eat. We have to work hard not to overeat. Throughout most of human history, it was the opposite. It was so hard to get those calories we needed to survive."
And in terms of the Tsimane's eagerness to incorporate sugar and other additives into their diets despite the associated health risks, "Telling folks to watch what they're eating, don't eat too much of this or that -- that mentality is hard to convey when getting food is unpredictable and a daily grind," Gurven continued. "Getting calories cheaply with less effort -- who wouldn't?"
https://www.sciencedaily.com/releases/2018/11/181102180757.htm
Childhood obesity linked to poor school performance and coping skills
November 2, 2018
Science Daily/American Academy of Pediatrics
Study suggests that childhood obesity, now at epidemic levels in the United States, may affect school performance and coping skills for challenging situations.
Researchers analyzed responses from 22,914 parents and caregivers of children aged 10-17 years who participated in the 2016 National Survey of Children's Health. The goal was to determine the independent association between body mass index (BMI) and five markers of "flourishing," or overall well-being as it relates to the development of positive psychosocial and coping skills.
"Childhood obesity is one of the biggest public health challenges we face today," said Natasha Gill, MD, FAAP, a Pediatric Emergency Medicine Fellow at the Alpert Medical School of Brown University and Hasbro Children's Hospital. "We know that children with obesity are at a greater risk for long-term health conditions that can last into adulthood, and we wanted to see whether obesity affects a child's immediate well-being as it relates to development of psychosocial skills and other signs of flourishing."
Adjusting for several confounding variables, including gender, child depression status, average sleep hours per night, average digital media exposure per day, highest parental education level, and household poverty status, Dr. Gill and her colleagues analyzed parents' responses to questions about whether their child:
· "Shows interest and curiosity in learning new things"
· "Works to finish tasks he or she starts"
· "Stays calm and in control when faced with a challenge"
· "Cares about doing well in school"
· "Does all required homework"
Researchers found that only 27.5 percent of children with obesity, defined as a BMI at or above the 95th percentile for children and teens of the same age and sex, were reported to have all five flourishing markers. This compares with 36.5 percent of those in the overweight range, with BMI at or above the 85th percentile, and 39 percent of children with normal BMI.
"The negative relationship between obesity and flourishing markers suggests that when compared to children with a normal BMI, obese youth may be less likely to develop healthy relationships, positive attitudes, a sense of purpose and responsibility, and interest in learning," Dr. Gill said. "Individual markers of flourishing have been shown to stay the same over time like a person's personality," she said, "so it may be important to monitor these markers in childhood to ensure optimal development into adulthood."
"We want all children to reach their maximum potential," she said. "If we can intervene early enough, we can promote positive physical, mental, and social development for these at-risk children and help them become responsible, hard-working members of society." She said her study's findings support the need for focused and coordinated efforts and resources from schools and health care providers that target obesity to improve overall well-being.
https://www.sciencedaily.com/releases/2018/11/181102083441.htm
Plant-based or vegan diet may be best for keeping type 2 diabetes in check
It is linked to improved wellbeing, quality of life, weight loss and lower blood glucose
Science Daily/October 30, 2018
BMJ
A predominantly plant-based or vegan diet may be best for keeping type 2 diabetes in check, not least because of its potential impact on mood, suggests a systematic review of the available evidence.
This diet is associated with improved psychological wellbeing, a reduction in some of the known risk factors for type 2 diabetes, and possibly some of those linked to cardiovascular disease, one of the main causes of early death in people with the condition, the findings indicate.
The International Diabetes Federation estimates that 642 million people will be living with diabetes by 2040. In the UK around 4.5 million people have been diagnosed with it; in the US the equivalent figure is more than 30 million.
Nearly 15 per cent of all global deaths are attributed to diabetes; and it killed 5 million people before the age of 60 in 2015. It is also frequently associated with depression, which in turn affects how well blood glucose levels are controlled.
While a predominantly plant-based diet-rich in fruits, vegetables, nuts, legumes, and seeds with no (vegan) or few animal products-has been linked to a significantly lower risk of developing type 2 diabetes, it's not clear if it might also be linked to improved mood and wellbeing.
To try and find out, the researchers trawled through the available evidence and found 11 relevant English language clinical trials, published between 1999 and 2017, comparing plant-based diets with other types of diet. The studies involved a total of 433 people in their mid-50s, on average.
Eight of the trials assessed the impact of a vegan diet and six included patients being given information on optimal nutrition to help them better understand the benefits of a plant based diet. The trials lasted for an average of 23 weeks.
A systematic critical analysis of the results showed that quality of life-both physical and emotional-improved only in those patients on a plant based/vegan diet. Similarly, depressive symptoms improved significantly only in these groups.
Nerve pain (neuropathy) eased in both the plant based and comparator diet groups, but more so in the former. And the loss of temperature control in the feet in those on the comparator diets suggests that eating predominantly plant based foods may have slowed the progressive nerve damage associated with diabetes, say the researchers.
Average (HbA1c) and fasting blood glucose levels fell more sharply in those who cut out or ate very few animal products and these participants lost nearly twice as much weight: 5.23 kg vs 2.83 kg. The fall in blood fats -- a known risk factor for cardiovascular disease -- was also greater in those on plant based/vegan diets.
The researchers point out several caveats to their findings, including the small sample sizes of the studies they reviewed and the reliance of the data on participant recall. But this review is the first to attempt to look at the psychological impact of a plant based diet in people with type 2 diabetes, and it draws on research from five different countries, they say.
In six of the studies, those following a plant based/vegan diet were able to cut down or discontinue the drugs they were taking for their diabetes and associated underlying conditions, such as high blood pressure.
Overall, the results indicated that even though the plant based diets were more difficult to follow, at least to begin with, participants stuck to them better than those in the comparator groups.
"Based on the evidence of the research analysis by this systematic review, it can be concluded that plant-based diets accompanied by educational interventions can significantly improve psychological health, quality of life, HbA1c levels and weight, and therefore the management of diabetes," write the researchers.
"Furthermore, plant-based diets could potentially improve diabetic neuropathic pain and the levels of total cholesterol, [low density lipoprotein] cholesterol and triglycerides in [type 2 diabetes].
https://www.sciencedaily.com/releases/2018/10/181030184510.htm
Childhood antibiotics and antacids may be linked to heightened obesity risk
These drugs may alter gut microbes associated with weight gain, say researchers
October 30, 2018
Science Daily/BMJ
Young children prescribed antibiotics and, to a lesser extent, drugs to curb excess stomach acid, may be at heightened risk of obesity, new research suggests.
These drugs, particularly if taken for lengthy periods, may alter gut microbes that have been associated with weight gain, explain the researchers.
The composition of gut bacteria (the microbiome) has been linked to various aspects of human health, including obesity. And certain drugs, such as antibiotics and acid suppressants-histamine 2 receptor antagonists (H2RA) and proton pump inhibitors (PPIs)-can alter the type and volume of bacteria in the gut.
To try and find out if exposure to these drugs in early childhood might increase the risk of obesity, the researchers looked at the medicines prescribed to 333,353 infants, whose medical records had been input into the US Military Health System database between 2006 and 2013, in the first two years of their lives.
In all, 241, 502 (72.5%) had been prescribed an antibiotic; 39,488 (just under 12%) an H2RA; and 11,089 (just over 3%) a PPI during this period. Some 5868 children were prescribed all three types of drug.
Some 46,993 (just over 14%) children became obese, of whom 9628 (11%) had not been prescribed any antibiotics or acid suppressants.
Boys, those born after a caesarean section, and those whose parents were below officer rank were more likely to become obese.
But after taking account of potentially influential factors, a prescription for antibiotics or acid suppressants was associated with a heightened risk of obesity by the age of 3 -- the average age at which obesity was first identified in these children.
A prescription for antibiotics was associated with a 26 per cent heightened risk of obesity. This association persisted, irrespective of antibiotic type, and strengthened with each additional class of antibiotic prescribed.
Acid suppressants were also associated with a heightened obesity risk, although to a lesser extent, and this association strengthened for each 30-day supply prescribed.
Although the largest study of its kind, it is nevertheless observational, and as such, can't establish cause. And potentially influential information on how much the children's mothers weighed, and whether they smoked or had other underlying conditions wasn't available.
And the researchers emphasise that the links between the individual, the environment, and obesity are complex, highlighting the "current difficulty of drawing clear conclusions about the interplay between exposure history, gut microbiota and propensity to develop obesity."
They add: "There is an important therapeutic role for microbiota-altering medications. The long term risks to health must be weighed against the short-term benefits."
But they also point out that over prescription of both antibiotics and acid suppressants, including in young children, is "a significant problem."
https://www.sciencedaily.com/releases/2018/10/181030184507.htm