June 17, 2020
French researchers report that diets high in processed meats and starchy foods, especially when they are consumed together, are tied to an increased risk of dementia. The findings underscore the importance of diet for long term brain health.
“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,” said study author Cécilia Samieri, of the University of Bordeaux in France. “Many of those studies focused on quantity and frequency of foods. Our study went one step further to look at food networks” — or the kinds of foods that people tend to eat in combination — “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.”
For the study, in the journal Neurology, the researchers looked at 209 older men and women, average age 78, who had Alzheimer’s disease or other forms of dementia. They compared them with 418 of their peers of similar age, sex and educational level who did not have memory or thinking problems. All were part of a large and ongoing dementia study of men and women living in the cities of Bordeaux, Dijon and Montpellier in France.
The study volunteers had filled out detailed food questionnaires five years earlier, before any signs of memory impairment were present, in which they described what foods they ate over the course of a year. They rated how often they ate specific foods, ranging from less than once a month to more than four times a day.
They were also given medical checkups every two to three years, including tests of memory and thinking skills.
Researchers found that many of the adults, with or without dementia, ate many of the same foods. But they found that those with dementia tended to eat a lot of processed— foods like ham, sausage, pepperoni, hot dogs and deli meats – and to eat them together with starchy, high-carbohydrate foods like potatoes, cookies and cakes.
“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,” Dr. Samieri said. “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.”
People without dementia also ate a fair amount of meat, including processed meats, but when they ate meat, they “were more likely to accompany meat with more diverse foods, including fruit and vegetables,” Dr. Samieri said. Alcohol consumption was about the same in both the dementia and dementia-free groups: about nine drinks per week, on average.
Overall, those without dementia tended to have more diversity in their diets. They also tended to eat meals containing a mix of healthier foods like fruit, vegetables, seafood, poultry and unprocessed meats. “We found that more diversity in diet, and greater inclusion of a variety of healthy foods, is related to less dementia,” Dr. Samieri said.
Many earlier studies have found that the foods we eat may influence our risk for dementia. The traditional Mediterranean diet, for example, high in fruits, vegetables, whole grains and fish and moderate amounts of red wine, has been tied to a lower risk of developing Alzheimer’s disease. Similarly, the MIND diet, which favors foods like berries, nuts, leafy greens, chicken and fish and discourages foods like red meat, butter, cheese and sweets, has also been linked to a lower risk of dementia.
Many factors besides diet play an important role in who ultimately develops Alzheimer’s disease, including the genes you inherit and advancing age. Still, the findings add to a growing body of evidence that what you eat may help keep the brain young.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Cécilia Samieri, Abhijeet Rajendra Sonawane, Sophie Lefèvre-Arbogast, et al: “Using Network Science Tools to Identify Novel Diet Patterns in Prodromal Dementia.” Neurology, April 22, 2020