New research is matching diet with cognition. Two Harvard University studies have now concluded that a Mediterranean Diet and a diet high in nuts will decrease cognitive decline among elderly persons.
Med diet slows cognitive decline
Harvard University researchers followed 16,058 women over the age of 70 years old for six years. Their diets were followed for more than 13 years, as part of the Nurses’ Health Study.For six of those years, the researchers conducted phone interviews with each four times a year. These tested their cognitive status using the Telephone Interview for Cognitive Status (TICS) test. This tests cognition skills using memory recall, fluency and attention span tests.
The researchers found that those women who ate closest to a Mediterranean diet had significantly better cognitive scores as the women grew older. The differences in their cognitive scores calculated to about one to 1.5 years of aging – meaning the Med diet slowed their aging decline in cognition.
Nuts also slow cognitive decline
Another study by different researchers from Harvard University and Brigham and Women's Hospital confirmed that eating more nuts every day will increase cognitive skills among women.Using the same Nurses study as a foundation, the researchers followed 16,010 women 70 years old or older. In this study, 15,467 completed the final cognitive interview. And the TICS cognitive skills testing was utilized.
The researchers found those women who consumed at least five servings of nuts per week had higher cognitive scores compared to those who did not consume nuts. (Most nut serving sizes are about one ounce - about a small handful). The average difference in scores was 0.08 units, which is equivalent to two years of cognition decline during the aging process.
They could not correlate cognitive decline with long-term nut consumption, but the association was clear, as concluded by the researchers:
“Higher nut intake may be related to better overall cognition at older ages, and could be an easily-modifiable public health intervention.”
Cognitive link to heart disease
Both nut consumption and the Med diet has been associated with cardiovascular health and mortality in other research.A study from Harvard that calculated the results of 18 studies that included over 83,000 patients with various metabolic syndrome disorders found in their pooled analysis that nut consumption reduced the risk of ischemic heart disease by 36%, cardiovascular disease by 30%, strokes by 9%, and reduced death from all causes by 15%.
The relationship between the Med diet and cognition was confirmed in a study from the UK’s University of Exeter Medical School. This study reviewed 12 studies, and the researchers concluded that higher adherence to the Med diet was associated with less cognitive decline, better cognitive function and reduced risk of Alzheimer’s disease. They concluded:
“Published studies suggest that greater adherence to Mediterranean diet is associated with slower cognitive decline and lower risk of developing Alzheimer disease.”
Learn about the Ancestor’s Diet
REFERENCES:
Samieri C, Okereke OI, E Devore E, Grodstein F. Long-term adherence to the Mediterranean diet is associated with overall cognitive status, but not cognitive decline, in women. J Nutr. 2013 Apr;143(4):493-9. doi: 10.3945/jn.112.169896.O'Brien J, Okereke O, Devore E, Rosner B, Breteler M, Grodstein F. Long-term intake of nuts in relation to cognitive function in older women. J Nutr Health Aging. 2014;18(5):496-502. doi: 10.1007/s12603-014-0014-6.
Luo C, Zhang Y, Ding Y, Shan Z, Chen S, Yu M, Hu FB, Liu L. Nut consumption and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis. Am J Clin Nutr. 2014 May 21. pii: ajcn.076109.
Photo by Ian Scott