Which foods do you eat together? How you combine them may raise dementia risk

Study finds 'food networks' centered on processed meats, starches may raise risk

April 22, 2020

Science Daily/American Academy of Neurology

t's no secret that a healthy diet may benefit the brain. However, it may not only be what foods you eat, but what foods you eat together that may be associated with your risk of dementia, according to a new study published in the April 22, 2020, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study looked at "food networks" and found that people whose diets consisted mostly of highly processed meats, starchy foods like potatoes, and snacks like cookies and cakes, were more likely to have dementia years later compared to people who ate a wider variety of healthy foods.

"There is a complex inter-connectedness of foods in a person's diet, and it is important to understand how these different connections, or food networks, may affect the brain because diet could be a promising way to prevent dementia," said study author Cécilia Samieri, PhD, of the University of Bordeaux in France. "A number of studies have shown that eating a healthier diet, for example a diet rich in green leafy vegetables, berries, nuts, whole grains and fish, may lower a person's risk of dementia. Many of those studies focused on quantity and frequency of foods. Our study went one step further to look at food networks and found important differences in the ways in which food items were co-consumed in people who went on to develop dementia and those who did not."

The study involved 209 people with an average age of 78 who had dementia and 418 people, matched for age, sex and educational level, who did not have dementia.

Participants had completed a food questionnaire five years previously describing what types of food they ate over the year, and how frequently, from less than once a month to more than four times a day. They also had medical checkups every two to three years. Researchers used the data from the food questionnaire to compare what foods were often eaten together by the patients with and without dementia.

Researchers found while there were few differences in the amount of individual foods that people ate, overall food groups or networks differed substantially between people who had dementia and those who did not have dementia.

"Processed meats were a 'hub' in the food networks of people with dementia," said Samieri. "People who developed dementia were more likely to combine highly processed meats such as sausages, cured meats and patés with starchy foods like potatoes, alcohol, and snacks like cookies and cakes. This may suggest that frequency with which processed meat is combined with other unhealthy foods, rather than average quantity, may be important for dementia risk. For example, people with dementia were more likely, when they ate processed meat, to accompany it with potatoes and people without dementia were more likely to accompany meat with more diverse foods, including fruit and vegetables and seafood."

Overall, people who did not have dementia were more likely to have a lot of diversity in their diet, demonstrated by many small food networks that usually included healthier foods, such as fruit and vegetables, seafood, poultry or meats.

"We found that more diversity in diet, and greater inclusion of a variety of healthy foods, is related to less dementia," said Samieri. "In fact, we found differences in food networks that could be seen years before people with dementia were diagnosed. Our findings suggest that studying diet by looking at food networks may help untangle the complexity of diet and biology in health and disease."

One limitation of the study was that participants completed a food questionnaire that relied on their ability to accurately recall diet rather than having researchers monitor their diets. Another limitation was that diets were only recorded once, years before the onset of dementia, so any changes in diet over time were unknown.

https://www.sciencedaily.com/releases/2020/04/200422214038.htm

Eating red meat and processed meat hikes heart disease and death risk

Eating red meat and processed meat hikes heart disease and death risk

February 3, 2020

Science Daily/Northwestern University

A large study links red and processed meat with higher risk of heart disease and death. Eating two servings of red meat, processed meat or poultry -- but not fish -- per week was linked to a 3 to 7 percent higher risk of cardiovascular disease. Eating two servings of red meat or processed meat -- but not poultry or fish -- per week was associated with a 3 percent higher risk of all causes of death.

After a controversial study last fall recommending that it was not necessary for people to change their diet in terms of red meat and processed meat, a large, carefully analyzed new study links red and processed meat consumption with slightly higher risk of heart disease and death, according to a new study from Northwestern Medicine and Cornell University.

Eating two servings of red meat, processed meat or poultry -- but not fish -- per week was linked to a 3 to 7% higher risk of cardiovascular disease, the study found. Eating two servings of red meat or processed meat -- but not poultry or fish -- per week was associated with a 3% higher risk of all causes of death.

"It's a small difference, but it's worth trying to reduce red meat and processed meat like pepperoni, bologna and deli meats," said senior study author Norrina Allen, associate professor of preventive medicine at Northwestern University Feinberg School of Medicine. "Red meat consumption also is consistently linked to other health problems like cancer."

"Modifying intake of these animal protein foods may be an important strategy to help reduce the risk of cardiovascular disease and premature death at a population level," said lead study author Victor Zhong, assistant professor of nutritional sciences at Cornell, who did the research when he was a postdoctoral fellow in Allen's lab.

The paper will be published Feb. 3 in JAMA Internal Medicine.

The new findings come on the heels of a controversial meta-analysis published last November that recommended people not reduce the amount of red meat and processed meat they eat. "Everyone interpreted that it was OK to eat red meat, but I don't think that is what the science supports," Allen said.

"Our study shows the link to cardiovascular disease and mortality was robust," Zhong said.

What should we eat?

"Fish, seafood and plant-based sources of protein such as nuts and legumes, including beans and peas, are excellent alternatives to meat and are under-consumed in the U.S.," said study coauthor Linda Van Horn, professor of preventive medicine at Feinberg who also is a member of the 2020 U.S. Dietary Guidelines Advisory committee.

The study found a positive association between poultry intake and cardiovascular disease, but the evidence so far isn't sufficient to make a clear recommendation about poultry intake, Zhong said. Still, fried chicken is not recommended.

The new study pooled together a large diverse sample from six cohorts, included long follow-up data up to three decades, harmonized diet data to reduce heterogeneity, adjusted a comprehensive set of confounders and conducted multiple sensitivity analyses. The study included 29,682 participants (mean age of 53.7 years at baseline, 44.4% men and 30.7% non-white). Diet data were self-reported by participants, who were asked a long list of what they ate for the previous year or month.

Key findings:

• A 3 to 7% higher risk of cardiovascular disease and premature death for people who ate red meat and processed meat two servings a week.

• A 4% higher risk of cardiovascular disease for people who ate two servings per week of poultry, but the evidence so far is not sufficient to make a clear recommendation about poultry intake. And the relationship may be related to the method of cooking the chicken and consumption of the skin rather than the chicken meat itself.

• No association between eating fish and cardiovascular disease or mortality.

Limitations of the study are participants' dietary intake was assessed once, and dietary behaviors may have changed over time. In addition, cooking methods were not considered. Fried chicken, especially deep fat-fried sources that contribute trans-fatty acids, and fried fish intake have been positively linked to chronic diseases, Zhong said.

https://www.sciencedaily.com/releases/2020/02/200203114328.htm

Whole grains decrease colorectal cancer risk, processed meats increase the risk

Report analyzing the global research finds hot dogs and other processed meats increase risk of colorectal cancer, eating more whole grains and being physically active lowers risk

September 7, 2017

Science Daily/American Institute for Cancer Research

Major new report finds strong evidence of links between lifestyle and colorectal cancer risk. Physical activity and whole grains lowers risk of this cancer; too much alcohol and red meat, processed meats and obesity increase the risk. An estimated 47 percent of US colorectal cancers could be prevented each year with lifestyle changes.

Diet, Nutrition, Physical Activity and Colorectal Cancer also found that hot dogs, bacon and other processed meats consumed regularly increase the risk of this cancer. There was strong evidence that physical activity protects against colon cancer.

"Colorectal cancer is one of the most common cancers, yet this report demonstrates there is a lot people can do to dramatically lower their risk," said Edward L. Giovannucci, MD, ScD, lead author of the report and professor of nutrition and epidemiology at the Harvard TH Chan School of Public Health. "The findings from this comprehensive report are robust and clear: Diet and lifestyle have a major role in colorectal cancer."

The new report evaluated the scientific research worldwide on how diet, weight and physical activity affect colorectal cancer risk. The report analyzed 99 studies, including data on 29 million people, of whom over a quarter of a million were diagnosed with colorectal cancer.

Other factors found to increase colorectal cancer include:

·      Eating high amounts of red meat (above 500 grams cooked weight a week), such as beef or pork

·      Being overweight or obese

·      Consuming two or more daily alcoholic drinks (30 grams of alcohol), such as wine or beer

Lowering Risk with Fiber, Activity and Grains

The report concluded that eating approximately three servings (90 grams) of whole grains daily reduces the risk of colorectal cancer by 17 percent.

It adds to previous evidence showing that foods containing fiber decreases the risk of this cancer.

For physical activity, people who are more physically active have a lower risk of colon cancer compared to those who do very little physical activity. Here, the decreased risk was apparent for colon and not rectal cancer.

In the US, colorectal cancer is the third most common cancer among both men and women, with an estimated 371 cases diagnosed each day. AICR estimates that 47 percent of US colorectal cancer cases could be prevented each year through healthy lifestyle changes.

Notes Giovannucci: "Many of the ways to help prevent colorectal cancer are important for overall health. Factors such as maintaining a lean body weight, proper exercise, limiting red and processed meat and eating more whole grains and fiber would lower risk substantially. Moreover, limiting alcohol to at most two drinks per day and avoidance or cessation of smoking also lower risk."

Fish, Fruits and Vegetables, Emerging Evidence

The report found other links between diet and colorectal cancer that were visible but not as clear. There was limited evidence that risk increases with low intake of both non-starchy vegetables and fruit. A higher risk was observed for intakes of less than 100 grams per day (about a cup) of each.

Links to lowering risk of colorectal cancer was with fish and foods containing vitamin C. Oranges, strawberries and spinach are all foods high in vitamin C.

The research continues to emerge for these factors, but it all points to the power of a plant-based diet, says Alice Bender, MS, RDN, AICR Director of Nutrition Programs. "Replacing some of your refined grains with whole grains and eating mostly plant foods, such as fruits, vegetables and beans, will give you a diet packed with cancer-protective compounds and help you manage your weight, which is so important to lower risk."

"When it comes to cancer there are no guarantees, but it's clear now there are choices you can make and steps you can take to lower your risk of colorectal and other cancers," said Bender.

https://www.sciencedaily.com/releases/2017/09/170907093623.htm