Diet may help preserve cognitive function
April 14, 2020
Science Daily/NIH/National Eye Institute
According to a recent analysis of data from two major eye disease studies, adherence to the Mediterranean diet -- high in vegetables, whole grains, fish, and olive oil -- correlates with higher cognitive function. Dietary factors also seem to play a role in slowing cognitive decline. Researchers at the National Eye Institute (NEI), part of the National Institutes of Health, led the analysis of data from the Age-Related Eye Disease Study (AREDS) and AREDS2. They published their results today in the journal Alzheimer's and Dementia.
"We do not always pay attention to our diets. We need to explore how nutrition affects the brain and the eye" said Emily Chew, M.D., director of the NEI Division of Epidemiology and Clinical Applications and lead author of the studies.
The researchers examined the effects of nine components of the Mediterranean diet on cognition. The diet emphasizes consumption of whole fruits, vegetables, whole grains, nuts, legumes, fish, and olive oil, as well as reduced consumption of red meat and alcohol.
AREDS and AREDS2 assessed over years the effect of vitamins on age-related macular degeneration (AMD), which damages the light-sensitive retina. AREDS included about 4,000 participants with and without AMD, and AREDS2 included about 4,000 participants with AMD. The researchers assessed AREDS and AREDS2 participants for diet at the start of the studies. The AREDS study tested participants' cognitive function at five years, while AREDS2 tested cognitive function in participants at baseline and again two, four, and 10 years later. The researchers used standardized tests based on the Modified Mini-Mental State Examination to evaluate cognitive function as well as other tests. They assessed diet with a questionnaire that asked participants their average consumption of each Mediterranean diet component over the previous year.
Participants with the greatest adherence to the Mediterranean diet had the lowest risk of cognitive impairment. High fish and vegetable consumption appeared to have the greatest protective effect. At 10 years, AREDS2 participants with the highest fish consumption had the slowest rate of cognitive decline.
The numerical differences in cognitive function scores between participants with the highest versus lowest adherence to a Mediterranean diet were relatively small, meaning that individuals likely won't see a difference in daily function. But at a population level, the effects clearly show that cognition and neural health depend on diet.
The researchers also found that participants with the ApoE gene, which puts them at high risk for Alzheimer's disease, on average had lower cognitive function scores and greater decline than those without the gene. The benefits of close adherence to a Mediterranean diet were similar for people with and without the ApoE gene, meaning that the effects of diet on cognition are independent of genetic risk for Alzheimer's disease.
https://www.sciencedaily.com/releases/2020/04/200414084316.htm
Mediterranean diet ingredient may extend life
Olive oil in the diet may also help mitigate aging-related diseases
February 21, 2020
Science Daily/University of Minnesota Medical School
Researchers at the University of Minnesota Medical School discover a potential new way in which diet influences aging-related diseases.
Doug Mashek, PhD, a professor in the Departments of Medicine and Biochemistry, Molecular Biology and Biophysics, leads a team of researchers who discovered that olive oil in the Mediterranean diet may hold the key to improving lifespan and mitigating aging-related diseases. Over the last eight years, with the help of multiple grants from the National Institutes of Health, their research findings were recently published in Molecular Cell.
Early studies on the diet suggested red wine was a major contributor to the health benefits of the Mediterranean diet because it contains a compound called resveratrol, which activated a certain pathway in cells known to increase lifespan and prevent aging-related diseases. However, work in Mashek's lab suggests that it is the fat in olive oil, another component of the Mediterranean diet, that is actually activating this pathway.
According to Mashek, merely consuming olive oil is not enough to elicit all of the health benefits. His team's studies suggest that when coupled with fasting, limiting caloric intake and exercising, the effects of consuming olive oil will be most pronounced.
"We found that the way this fat works is it first has to get stored in microscopic things called lipid droplets, which is how our cells store fat. And then, when the fat is broken down during exercising or fasting, for example, is when the signaling and beneficial effects are realized," Mashek said.
The next steps for their research are to translate it to humans with the goal of discovering new drugs or to further tailor dietary regimens that improve health, both short-term and long-term.
"We want to understand the biology, and then translate it to humans, hopefully changing the paradigm of healthcare from someone going to eight different doctors to treat his or her eight different disorders," Mashek said. "These are all aging-related diseases, so let's treat aging."
https://www.sciencedaily.com/releases/2020/02/200221125120.htm
Mediterranean diet for one year promotes gut bacteria linked to 'healthy aging'
It may help curb advance of frailty and cognitive decline, suggest researchers
February 17, 2020
Science Daily/BMJ
Eating a Mediterranean diet for a year boosts the types of gut bacteria linked to 'healthy' ageing, while reducing those associated with harmful inflammation in older people, indicates a five-country study, published online in the journal Gut.
As ageing is associated with deteriorating bodily functions and increasing inflammation, both of which herald the onset of frailty, this diet might act on gut bacteria in such a way as to help curb the advance of physical frailty and cognitive decline in older age, suggest the researchers.
Previous research suggests that a poor/restrictive diet, which is common among older people, particularly those in long term residential care, reduces the range and types of bacteria (microbiome) found in the gut and helps to speed up the onset of frailty.
The researchers therefore wanted to see if a Mediterranean diet might maintain the microbiome in older people's guts, and promote the retention or even proliferation of bacteria associated with 'healthy' ageing.
They analysed the gut microbiome of 612 people aged 65 to 79, before and after 12 months of either eating their usual diet (n = 289) or a Mediterranean diet (n = 323), rich in fruits, vegetables, nuts, legumes, olive oil and fish and low in red meat and saturated fats, and specially tailored to older people (NU-AGE diet).
The participants, who were either frail (n=28), on the verge of frailty (n=151), or not frail (n=433) at the beginning of the study, lived in five different countries: France, Italy, Netherlands, Poland, and the UK.
Sticking to the Mediterranean diet for 12 months was associated with beneficial changes to the gut microbiome.
It was associated with stemming the loss of bacterial diversity; an increase in the types of bacteria previously associated with several indicators of reduced frailty, such as walking speed and hand grip strength, and improved brain function, such as memory; and with reduced production of potentially harmful inflammatory chemicals.
More detailed analysis revealed that the microbiome changes were associated with an increase in bacteria known to produce beneficial short chain fatty acids and a decrease in bacteria involved in producing particular bile acids, overproduction of which are linked to a heightened risk of bowel cancer, insulin resistance, fatty liver and cell damage.
What's more, the bacteria that proliferated in response to the Mediterranean diet acted as 'keystone' species, meaning they were critical for a stable 'gut ecosystem,' pushing out those microbes associated with indicators of frailty.
The changes were largely driven by an increase in dietary fibre and associated vitamins and minerals -- specifically, C, B6, B9, copper, potassium, iron, manganese, and magnesium.
The findings were independent of the person's age or weight (body mass index), both of which influence the make-up of the microbiome.
And while there were some differences in the make-up of a person's gut microbiome, depending on country of origin to start with, the response to the Mediterranean diet after 12 months was similar and consistent, irrespective of nationality.
The study findings can't establish a causative role for the microbiome in health, added to which some of the implications are inferred rather than directly measured, say the researchers.
"The interplay of diet, microbiome and host health is a complex phenomenon influenced by several factors," they emphasise.
"While the results of this study shed light on some of the rules of this three-way interplay, several factors such as age, body mass index, disease status and initial dietary patterns may play a key role in determining the extent of success of these interactions," they explain.
Older people may have dental problems and/or difficulty swallowing, so it may be impractical for them to eat a Mediterranean diet, they add. But the beneficial bacteria implicated in healthy ageing found in this study might yet prove useful therapeutic agents to ward off frailty, they suggest.
https://www.sciencedaily.com/releases/2020/02/200217192025.htm
Weight loss and health improvements with Mediterranean, fasting & Paleo diets
January 23, 2020
Science Daily/University of Otago
There were some weight loss and health benefits for overweight adults who followed the Mediterranean, Intermittent Fasting and Paleo diets, though adherence to the diets dropped off considerably during the one-year study, new University of Otago research shows.
Intermittent fasting -- whereby participants limit their energy intake to about 25 per cent of their usual diet (500kcal for women and 600kcal for men) on two self-selected days per week, led to slightly more weight loss than the other diets. The Mediterranean diet also improved blood sugar levels.
Co-lead author Dr Melyssa Roy, a Research Fellow in the Department of Medicine, says the amount of weight loss was modest -- on average two to four kilograms for the 250 participants, but for those choosing the fasting or Mediterranean diets, clinically significant improvements in blood pressure were also seen.
The aim of the research was to examine how effective all three diets were in a "real world" setting, where participants self-selected which diet they wished to follow, without any ongoing support from a dietitian.
Dr Roy says the evidence shows that for some people the Mediterranean, fasting or paleo (Paleolithic) diets can be "healthful, beneficial ways to eat."
"This work supports the idea that there isn't a single 'right' diet -- there are a range of options that may suit different people and be effective. In this study, people were given dietary guidelines at the start and then continued with their diets in the real world while living normally. About half of the participants were still following their diets after a year and had experienced improvements in markers of health.
"Like the Mediterranean diet, intermittent fasting and paleo diets can also be valid healthy eating approaches -- the best diet is the one that includes healthy foods and suits the individual."
The Mediterranean diet encouraged consumption of fruit, vegetables, whole-grain breads and cereals, legumes, nuts, seeds and olive oil with moderate amounts of fish, chicken, eggs and diary and red meat once a week or less.
The paleo diet consists of mostly less-processed foods with an emphasis on eating fruit and vegetables, animal proteins, nuts, coconut products and extra-virgin olive oil. While "original" Paleo diets strictly exclude all legumes, dairy and grains, this study used a modified version including some dairy as well as up to one serving daily of legumes and grain-based food.
Co-lead author Dr Michelle Jospe, a Postdoctoral Fellow in the Department of Medicine, says the results showed people found the Mediterranean diet to be the easiest to adhere to.
"Our participants could follow the diet's guidelines more closely than the fasting and paleo diets and were more likely to stay with it after the year, as our retention rates showed."
Most of the 250 participants (54 per cent) chose the fasting diet, while 27 per cent chose the Mediterranean and 18 per cent the paleo. After 12 months, the Mediterranean diet had the best retention rate with 57 per cent of participants continuing, with 54 per cent still fasting and 35 per cent still on the paleo diet.
After 12 months, the average weight loss was 4.0kg for those choosing the fasting diet, 2.8kg on the Mediterranean diet and 1.8kg on the paleo diet.
Reduced systolic blood pressure was observed among those participating in the fasting and Mediterranean diets, together with reduced blood sugar levels in the Mediterranean diet.
Dr Jospe explains participants who said they were still following their diet at 12 months lost even more weight, showing the importance of choosing a diet that is sustainable.
She believes the results of this study are relevant to the thousands of people following self-chosen diets with little supervision and indicates more realistic outcomes.
https://www.sciencedaily.com/releases/2020/01/200123170721.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
A hypocaloric Mediterranean diet and daily exercise maintain weight loss
November 5, 2018
Science Daily/Universitat Rovira i Virgili
Following a Mediterranean diet low in calories and engaging daily physical activity have been demonstrated to result in reduce body weight and cardiovascular risk in overweight patients and patients with metabolic syndrome, and to maintain these benefits after one year.
Overweight or obese patients, particularly those with metabolic syndrome, are often told to lose weight by changing their lifestyle. The aim of these recommendations is to reduce their cardiovascular risk; however, there is no scientific evidence that this beneficial effect can be maintained in the long-term. Although low fat and low carbohydrate diets have proven effective in losing weight and improving cardiovascular risk, the benefits tend to diminish after a year. Following a Mediterranean diet low in calories and engaging daily physical activity have been demonstrated to result in reduce body weight and cardiovascular risk in overweight patients and patients with metabolic syndrome, and to maintain these benefits after one year.
With this investigation, the researchers from the Human Nutrition Unit at the Universitat Rovira i Virgili, in collaboration with 23 other research groups in the PREDIMED-Plus study, have evaluated the changes in body weight, fat accumulation and different cardiovascular risk factors after one year in 626 patients. The results have shown that the lifestyle changes included in the study are effective in maintain clinically significant weight loss. Indeed, after 12 months of intervention, 33.7% of the patients following the hypocaloric Mediterranean diet and daily exercise showed a minimum of 5% weight loss. These patients also showed improvements in those parameters related with glucose metabolism and certain inflammatory markers, in contrast with those patients who did not follow the diet. Furthermore, for those patients with diabetes or at risk of diabetes, the benefits from these lifestyle changes were particularly high in terms of glucose control.
The researchers highlight that, in this study, the greatest weight loss has been found after 12 months, which illustrates that weight loss was maintained over time. In the light of these results, the researchers expect that this weight-loss maintenance in response to the PREDIMED-Plus lifestyle programme can provide the same or more benefits for cardiovascular disease (myocardial infarction, stroke or mortality from these causes) in the long term. In fact, this is the main objective of the PREDIMED-PLUS trial.
https://www.sciencedaily.com/releases/2018/11/181105105353.htm
Mediterranean diet and exercise can reduce sleep apnea symptoms
November 28, 2011
Science Daily/European Lung Foundation
Eating a Mediterranean diet combined with physical activity can help to improve some of the symptoms of sleep apnea, according to new research. The study, which is published online in the European Respiratory Journal, looked at the impact a Mediterranean diet can have on obese people with sleep apnea, compared to those on a prudent diet.
Obstructive sleep apnea syndrome (OSAS) causes frequent pauses of breathing to occur during sleep, which disrupts a person's normal sleeping pattern. It is one of the most prevalent sleep-related breathing disorders with approximately 2-4% of the adult population experiencing the condition. This percentage increases up to 20-40% with obesity, and weight loss is often an essential part of the recommended treatment plan.
The researchers, from the University of Crete in Greece, examined 40 obese patients suffering from OSAS. Twenty patients were given a prudent diet to follow, while the other 20 followed a Mediterranean diet. Both groups were also encouraged to increase their physical activity, mainly involving walking for at least 30 minutes each day.
In both groups, the patients also received continuous positive airway pressure (CPAP) therapy which involves wearing a mask that generates an air stream, keeping the upper airway open during sleep.
The researchers monitored the patients during a sleep study, known as polysomnography. This involved monitoring several markers for OSAS, including electrical activity in the brain, eye movements and snoring. The patients were examined at the start of the study and again 6 months later.
The results showed that people following the Mediterranean diet had a reduced number of disturbances, known as apneas, during the rapid eye movement (REM) stage of sleep, which usually accounts for approximately 25% of total sleep during the night.
The findings also revealed that people following the Mediterranean diet also showed a greater adherence to the calorie restricted diet, an increase in physical activity and a greater decrease in abdominal fat.
The results of this small sample did show an improvement during one stage of sleep for people with sleep apnea, however it did not show an overall improvement in severity of the condition. The authors suggest that further studies in a larger sample are required to fully understand the benefits of this diet.
Christopher Papandreou, lead author for the research, said: "This is the first study examining the impact of the Mediterranean diet in combination with physical activity on OSAS via changes in the human body. Our results showed that the number of disturbances during REM sleep was reduced more in the Mediterranean diet group than the other group. Recent reports have related an increase in disturbances during REM sleep with the risk of developing significant systemic consequences like diabetes type II. However, its clinical significance remains unclear. Finally, more studies are needed to examine the effect of the above diet on this sleep-related breathing disorder taking into account its anti-inflammatory and antioxidant properties."
http://www.sciencedaily.com/releases/2011/11/111102093043.htm
Mediterranean-style diets linked to better brain function in older adults
July 25, 2017
Science Daily/American Geriatrics Society
Eating foods included in two healthy diets -- the Mediterranean or the MIND diet -- is linked to a lower risk for memory difficulties in older adults, according to a new study.
The Mediterranean diet is rich in fruits, vegetables, whole grains, beans, potatoes, nuts, olive oil and fish. Processed foods, fried and fast foods, snack foods, red meat, poultry and whole-fat dairy foods are infrequently eaten on the Mediterranean diet.
The MIND diet is a version of the Mediterranean diet that includes 15 types of foods. Ten are considered "brain-healthy:" green leafy vegetables, other vegetables, nuts, berries, beans, whole grains, seafood, poultry, olive oil, and wine. Five are considered unhealthy: red meat, butter and stick margarine, cheese, pastries, sweets and fried/fast foods.
Researchers examined information from 5,907 older adults who participated in the Health and Retirement Study. The participants filled out questionnaires about their eating habits. Researchers then measured the participants' cognitive abilities -- mostly on their memory and attention skills.
The researchers compared the diets of participants to their performance on the cognitive tests. They found that older people who ate Mediterranean and MIND-style diets scored significantly better on the cognitive function tests than those who ate less healthy diets. In fact, older people who ate a Mediterranean-style diet had 35% lower risk of scoring poorly on cognitive tests. Even those who ate a moderate Mediterranean-style diet had 15% lower risk of doing poorly on cognitive tests. The researchers noted similar results for people who ate MIND-style diets.
This study suggests that eating Mediterranean and MIND-style diets is linked to better overall cognitive function in older adults, said the researchers. What's more, older adults who followed these healthy diets had lower risks for having cognitive impairment in later life, noted the researchers.
https://www.sciencedaily.com/releases/2017/07/170725154208.htm
Want a better memory? Try eating a Mediterranean diet
Eating a Mediterranean diet can slow down cognitive decline
August 9, 2016
Science Daily/Frontiers
The Mediterranean diet can improve your mind, as well your heart, shows a new study
The Mediterranean diet can improve your mind, as well your heart, shows a study published in the open-access journal Frontiers in Nutrition.
By sticking to the Mediterranean diet the study showed that people had slowed rates of cognitive decline, reduced conversion to Alzheimer's, and improved cognitive function.
The main foods in the Mediterranean diet (MedDiet) include plant foods, such as leafy greens, fresh fruit and vegetables, cereals, beans, seeds, nuts, and legumes. The MedDiet is also low in dairy, has minimal red meat, and uses olive oil as its major source of fat.
Leading author Roy Hardman from the Centre for Human Psychopharmacology Swinburne University of Technology Melbourne Australia and his colleagues evaluated all the available papers between 2000-2015 that investigated if and how a MedDiet may impact cognitive processes over time. In total, 18 out of the 135 articles met their strict inclusion criteria.
"The most surprising result was that the positive effects were found in countries around the whole world. So regardless of being located outside of what is considered the Mediterranean region, the positive cognitive effects of a higher adherence to a MedDiet were similar in all evaluated papers;" he said.
Attention, memory, and language improved. Memory, in particular, was positively affected by the MedDiet including improvements in: delayed recognition, long-term, and working memory, executive function, and visual constructs.
"Why is a higher adherence to the MedDiet related to slowing down the rate of cognitive decline? The MedDiet offers the opportunity to change some of the modifiable risk factors," he explained.
"These include reducing inflammatory responses, increasing micronutrients, improving vitamin and mineral imbalances, changing lipid profiles by using olive oils as the main source of dietary fats, maintaining weight and potentially reducing obesity, improving polyphenols in the blood, improving cellular energy metabolism and maybe changing the gut micro-biota, although this has not been examined to a larger extent yet."
Moreover, the benefits to cognition afforded by the MedDiet were not exclusive to older individuals. Two of the included studies focused on younger adults and they both found improvements in cognition using computerized assessments.
The researchers stress that research in this area is important due to the expected extensive population aging over the next 20-30 years. They envision that the utilization of a dietary pattern, such as the MedDiet, will be an essential tool to maintain quality of life and reduce the potential social and economic burdens of manifested cognitive declines like dementia.
"I would therefore recommend people to try to adhere or switch to a MedDiet, even at an older age," Hardman added.
Like many researchers, Hardman takes his research home: "I follow the diet patterns and do not eat any red meats, chicken or pork. I have fish two-three times per week and adhere to a Mediterranean style of eating."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/08/160809145258.htm