Mediterranean Diet Cuts Dementia Risk for APOE4 Carriers by 35%

A recent study has revealed that adhering to a Mediterranean diet can significantly lower the risk of dementia by at least 35% in individuals with two copies of the APOE4 gene, a primary risk factor for Alzheimer’s disease. The study followed over 5,700 participants for a span of 34 years, with findings published in the journal Nature on March 25, 2024. Lead author, Yuxi Liu, a research fellow at Brigham and Women’s Hospital and Harvard Medical School in Boston, emphasized the diet’s focus on vegetables, fruits, nuts, whole grains, legumes, fish, and olive oil, while limiting alcohol and red and processed meats.

The results indicated that individuals with two copies of the APOE4 gene experienced the most pronounced benefits. Liu noted, “Not only did following a baseline Mediterranean diet reduce the probability of developing dementia by 35 per cent in people with two APOE4 genes, but higher adherence to the diet further reduced their risk.” This highlights the diet’s potential to mitigate genetic predispositions to Alzheimer’s.

Dietary Impact on Metabolic Profiles

One of the study’s critical findings is the unique metabolic profiles of those carrying the APOE4 gene. Liu explained that metabolic processes, including nutrient digestion and energy production, rely heavily on the quality of nutrients included in a diet. “Improving metabolic function in people with APOE4 through diet might explain, or at least partially explain, the huge fall in dementia risk we saw in our study,” she stated.

Echoing Liu’s findings, neurologist Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Florida, said this research could reshape perceptions surrounding genetic risk factors for Alzheimer’s. “Hopefully this will change the current dogma that having two copies of the APOE4 is a ‘fait accompli’ for developing Alzheimer’s,” he remarked, advocating for a holistic approach to risk mitigation that includes diet alongside other lifestyle changes such as exercise and stress management.

Previous Research and Future Directions

This study is not the first to link the Mediterranean diet with reduced dementia risk. A 2023 study involving over 60,000 participants in the United Kingdom found that adherence to a Mediterranean diet correlated with a 23% lower risk of dementia. Another study that focused on brain tissue revealed that consumption of foods from both the Mediterranean and MIND diets led to nearly a 40% reduction in the presence of Alzheimer’s markers in the brain.

Liu’s research underscores that even minor dietary adjustments can yield significant health benefits. For instance, incorporating just one category of recommended foods can reduce amyloid buildup in the brain, effectively making individuals appear four years younger in terms of brain health.

The MIND diet, which combines principles from the Mediterranean diet with specific brain-healthy foods such as dark leafy greens and berries, has also shown promise in enhancing cognitive function.

The potential for lifestyle changes to modify dementia risk was illustrated by the case of Simon Nicholls, a patient in Isaacson’s clinical trial. With two copies of the APOE4 gene, Nicholls implemented several lifestyle adjustments, including diet, exercise, and stress management. Remarkably, within a year, he showed a reduction in amyloid and tau levels in his blood, and scans revealed an increase in the volume of his hippocampus, a critical area for memory.

Despite these promising findings, the future of such research could be at risk. Both the Nurse’s Health Study and the Health Professionals Follow-Up Study have provided invaluable data over decades. These studies have led to significant discoveries, including the dangers of trans fats and links between obesity and breast cancer. However, federal funding for these studies has been halted, raising concerns over the preservation of decades of biodata. “We’re going to take 50 years of research and all this biodata and just destroy it?” questioned Martha Dodds, a nurse involved in the study.

As the medical community continues to explore the relationship between diet and genetic risk factors for Alzheimer’s, this study highlights the importance of dietary choices in mitigating health risks. The findings encourage a broader discussion on the role of lifestyle modifications in preventing cognitive decline, especially for those genetically predisposed to dementia.