Analysis of data from the Age-Related Eye Disease Study (AREDS) and AREDS2, involving a total of around 8,000 older adults, has found that those with the greatest adherence to the Mediterranean diet had the lowest risk of cognitive impairment. High fish and vegetable consumption appeared to have the greatest protective effect. At 10 years, AREDS2 participants with the highest fish consumption had the slowest rate of cognitive decline.
A study involving 5,907 older adults (average age 68) found that those who ate Mediterranean and MIND-style diets scored significantly better on cognitive tests than those who ate less healthy diets, with adherence to a brain-healthy diet correlating with cognitive benefit in a dose-response way. Those who followed these healthy diets also had lower risk of cognitive impairment in later life.
An animal study comparing five diets shows that one diet really doesn't fit everyone, and what works for some may not be best for others.
There were four groups of genetically (almost-)identical animals, with genetic differences between any two of the groups translating to roughly the same as those of two unrelated people. The test diets included: an American-style diet (higher in fat and refined carbs, especially corn); Mediterranean (with wheat and red wine extract); Japanese (with rice and green tea extract); and ketogenic, or Atkins-like (high in fat and protein with very few carbs). The fifth diet was the control group.
One of the four genetic types did very poorly when eating the Japanese-like diet, developing signs of liver damage. Two types did well on the Atkins-like diet, but two did very badly (one became very obese, while the other became 'skinny-fat' — apparently a healthy weight but with a high percentage of body fat.
Two types became very obese, with signs of metabolic syndrome, on the American-style diet, while the other two were less negatively affected. With the Mediterranean diet, some groups were healthy, while others experienced some weight gain.
https://www.eurekalert.org/pub_releases/2017-11/tau-dsm113017.php
Barrington, W. T., Wulfridge, P., Wells, A. E., Rojas, C. M., Howe, S. Y. F., Perry, A., … Threadgill, D. W. (2018). Improving Metabolic Health Through Precision Dietetics in Mice. Genetics, 208(1), 399-417. Retrieved from https://www.genetics.org/content/208/1/399
Data from more than 25,000 female health professionals who participated in the Women's Health Study has revealed a 25% reduction in cardiovascular risk among those who consumed a diet rich in plants and olive oil and low in meats and sweets.
Changes in signals of inflammation accounted for 29% of the cardiovascular risk reduction), glucose metabolism and insulin resistance 27.9%, and body max index 27.3%. There were also connections to blood pressure, various forms of cholesterol, and other biomarkers, but these were less important.
https://www.eurekalert.org/pub_releases/2018-12/bawh-rew120718.php
Ahmad, S., Moorthy, V., Demler, O. V., Hu, F. B., Ridker, P. M., Chasman, D. I., & Mora, S. (2018). Assessment of Risk Factors and Biomarkers Associated With Risk of Cardiovascular Disease Among Women Consuming a Mediterranean Diet. JAMA Network Open, 1(8), e185708 - e185708. Retrieved from https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2717565
A study involving 116 healthy older adults (65-75) has found that higher levels of several key nutrients in the blood were associated with more efficient brain connectivity and better cognitive performance. In fact, the findings suggest that the level of nutrients governs the strength of the association between functional brain network efficiency and cognitive performance.
A pilot study involving 106 participants of the Rush Memory and Aging Project who had experienced a stroke followed participants for an average of 5.9 years, testing their cognitive function and monitoring their eating habits using food journals. It was found that those whose diets scored highest on the MIND (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay) diet score had substantially slower rates of cognitive decline than those who scored lowest.
Another study adds to the growing evidence that a Mediterranean diet is good for the aging brain.
The New York study used data from 674 non-demented older adults (average age 80). It found that those who closely followed such a diet showed significantly less brain shrinkage. Specifically, total brain volume was an average 13.11 milliliters greater, with grey matter volume 5 millilitres greater, and white matter 6.4 millilitres greater.
More evidence for the benefits of the Mediterranean diet for fighting age-related cognitive decline comes from a large 5-year study. The study involved 960 older adults, whose cognitive change was assessed over 4.7 years. Those who followed the MIND diet more rigorously showed an equivalent of being 7.5 years younger cognitively than those who followed the diet least.
The Mediterranean-DASH Diet Intervention for Neurodegenerative Delay is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. It requires at least:
A large meta-analysis has concluded that having diabetes increases the chance that a person with mild cognitive impairment will progress to dementia by 65%.
There was no consistent evidence that hypertension or cholesterol levels increased the risk of someone with MCI progressing to dementia. Smoking was similarly not associated with increased risk, although the reason for this probably lies in mortality: smokers tend to die before developing dementia.
A review of 19 studies involving over 162,000 people has found that adherence to the Mediterranean diet was associated with a 21% reduced risk of diabetes, with a greater effect (27%) for those at high risk for cardiovascular disease. The association was found in both European and non-European groups.
The research was presented at the American College of Cardiology's 63rd Annual Scientific Session.
http://www.eurekalert.org/pub_releases/2014-03/acoc-mdm032614.php