WINSON-SALEM, N.C. — Picking the right meals today can help our minds tomorrow. Researchers from Wake Forest University find that adopting a modified ketogenic (high-fat and low-carb) Mediterranean diet may decrease the risk of developing Alzheimer’s disease.
Study authors compared a more traditional low-fat diet with a diet consisting of healthy fats and protein and less carbohydrates — which study authors classified as a modified Mediterranean ketogenic diet. This comparison revealed that the modified approach to eating showed robust changes in a biological pathway that has a link to Alzheimer’s disease.
Keto diets often focus heavily on meat, ranging from chicken to pork and steak. It can also include seafood, nuts, vegetables, and healthy fats from eggs and cheese. Alzheimer’s disease is the most common form of dementia, affecting over 6.5 million Americans. Estimates show that one in three U.S. seniors die with the disease or another form of dementia.
“We hope that better understanding this complex relationship between diet, cognitive status and gut health will lead to new interventions to prevent and treat Alzheimer’s disease,” says Suzanne Craft, Ph.D., professor of gerontology and geriatric medicine at Wake Forest University School of Medicine, in a university release.
This project builds on earlier research conducted by Prof. Craft’s team that found a modified ketogenic diet may be beneficial when it comes to stopping cognitive decline. This study was a randomized, single-site assessment involving a total of 20 adults (nine diagnosed with mild cognitive impairment and 11 with normal cognition). The team randomly instructed the participants to follow either the low-carbohydrate modified Mediterranean-ketogenic diet or a low-fat, higher carbohydrate diet for a period of six weeks. Then, following a six-week “washout” period, participants switched to the other diet.
Your gut balance appears to alter Alzheimer’s risk
Researchers collected stool samples from participants at the beginning and end of each diet period, as well as six weeks after the washout of the second diet, in an effort to analyze changes in each person’s gut microbiome — the collection of both good and bad bacteria in the gastrointestinal tract.
The research team reveals that participants with mild cognitive impairment (MCI) on the modified Mediterranean ketogenic diet showed lower levels of both gamma-aminobutyric acid (GABA) and GABA-producing microbes. People on this diet also displayed more GABA-regulating bacteria. For reference, GABA is the primary inhibitory neurotransmitter in the central nervous system. GABA dysfunction displays a connection to neuropsychiatric conditions including Alzheimer’s disease.
“Our study is the first to show that diet modulates GABA differently in MCI,” Prof. Craft adds.
The study also found participants with MCI who had curcumin in their diets showed lower levels of BSH-containing bacteria, which is a type of bacteria that regulates bile acids produced by the liver and gut. Lower levels often point to reduced gut motility, a phenomenon in which food and waste take longer to transit through the gut. Researchers have detected abnormal bile acid profiles among adults with Alzheimer’s.
“These findings provide crucial insight into how diet may affect the microbiome and improve brain health,” Prof. Craft concludes. “Larger studies are needed to assess the role diet interventions play in patients with cognitive impairment.”
The study is published in Alzheimer’s & Dementia.