What do civil rights activist Rosa Parks, American illustrator Norman Rockwell, and former president Ronald Reagan have in common? Each of these individuals is among the more than three million people per year who have been impacted by Alzheimer’s disease in the US. Alzheimer’s is a progressive disease causing memory loss and confusion, for which medications and management strategies may help to temporarily ease dementia symptoms. Because there is not yet a cure for Alzheimer’s, prevention strategies are also important.
One prevention strategy is healthful eating. No one diet can completely prevent the onset of Alzheimer’s. However, large-scale studies on the eating habits of people who both do and do not go on to develop Alzheimer’s has given scientists some clues as to which eating patterns may be linked with a lower risk of the disease.
The Mediterranean Diet and Alzheimer’s Dementia
In a 2016 review article, Australian researchers analyzed more than a dozen longitudinal and prospective studies (where participants are observed over a long period of time) to determine the link between eating patterns and cognitive health. In the 18 studies, encompassing nearly 60,000 adults total, the scientists found that closely following a Mediterranean diet was associated with “slower rates of cognitive decline, reduced conversion to Alzheimer’s disease, and improvements in cognitive function.” More specifically, the Mediterranean diet was linked with better memory, executive function (which controls behavior, planning and reasoning), and visual constructs.
Similarly, a 2021 study following 16,160 Spanish adults for two decades found that following a Mediterranean diet was linked with a 20% lower risk of developing dementia over the 20+ year study. However, the results were not statistically significant when looking at Alzheimer’s dementia specifically.
How the Mediterranean Diet Relates to Alzheimer’s Risk Factors
While research on the gut microbiome is still young, scientists understand that the microbial community in our gut can influence the development of neurodegenerative diseases, such as Alzheimer’s. A new study published in 2021 suggests that anti-inflammatory diets that favor fruits and vegetables, foods containing omega-3 fatty acids (fatty fish, walnuts), whole grains, lean protein and spices, such as the Mediterranean diet, might be linked with an improved gut microbiome, thereby potentially reducing the risk of Alzheimer’s down the road.
Diet may be especially important for people who accumulate plaque in their brains, thus putting them at a higher risk of Alzheimer’s. In a 2018 study, researchers analyzed the eating patterns and buildup of Aβ (small pieces of protein that can accumulate in the brain, potentially creating plaques and causing brain cells to be destroyed) in 77 older adults who were already on the path to Alzheimer’s disease (by being ﬂagged as being Aβ accumulators). Those who most closely followed a Mediterranean diet had signiﬁcantly less Aβ accumulation over time. The authors suggest that improving your Mediterranean diet score by just 1 point (0-9 point scale) may result in a 20% decrease in Aβ accumulation over 1 year, and up to a 60% decrease over 3 years.
Mediterranean Diet vs the “MIND Diet” for Alzheimer’s
If the Mediterranean may be protective for Alzheimer’s dementia, might the “MIND diet” be better? In a much publicized 2015 study, researchers studied the relationship between eating patterns and Alzheimer’s in 923 retired adults in Chicago over an average of 4.5 years. The scientists rated participants’ diets based on how closely they adhered to the Mediterranean diet, the DASH diet, and the MIND diet.
The ‘M’ in MIND Diet stands for Mediterranean. In fact, the MIND diet is actually a hybrid of the Mediterranean diet and the DASH diet (a healthy diet used to treat high blood pressure that emphasizes fruits, vegetables, whole grains, low fat dairy, and limited sweets and salt).
Those most closely following the Mediterranean diet were 54% less likely to develop Alzheimer’s dementia (more than any other diet group). The group most closely following the MIND diet (which shares many similarities with the Mediterranean diet) was 53% less likely to develop Alzheimer’s dementia than the group with the lowest MIND diet scores, and even those moderately following the MIND diet were at a 35% lower risk.
In other words, with similar foods come similar brain benefits. No matter what you want to call it, enjoying a balanced diet of whole grains, legumes, fruits, vegetables, fish, olive oil and nuts is a smart way to protect your body and brain for the long haul.