New Delhi, March 24 A new study suggests that greater adherence to a healthy diet, such as the Dietary Approaches to Stop Hypertension (DASH), may lower the risk of self-perceived cognitive decline and support better brain function.
The DASH diet is considered a heart-healthy diet, emphasizing the intake of fruits, vegetables, whole grains, and low-fat dairy. It also promotes fish and poultry and restricts salt and fatty red meat.
The findings, published in The Journal of the American Medical Association (JAMA) Neurology, also show that the link between a healthy diet and cognitive health was "more pronounced" when followed during midlife, between the ages of 45-54.
The researchers, including those from Harvard and Zhejiang universities in the US and China, said that while healthier diets are believed to benefit cognitive health, few studies systematically examine multiple dietary patterns within the same settings.
The team analyzed diet and cognitive function data of over 1.5 lakh participants – with the majority being women – taken from the US' Nurses' Health Study (NHS, 1986-2014), NHS-II (1991-2017), and the Health Professionals Follow-Up Study (1986-2012).
The Healthful Plant-Based Diet Index (hPDI) and the Planetary Health Diet Index (PHDI) were among the six diets studied.
"The results reveal that healthy diets, exemplified by the DASH diet for blood pressure control and diets with lower hyperinsulinemia and inflammation potentials, were associated with a lower SCD (subjective cognitive decline) risk and better cognitive function," the authors wrote.
Hyperinsulinemia is characterized by abnormally high levels of insulin in the blood, often associated with type 2 diabetes or insulin resistance.
Greater adherence to all six dietary patterns was associated with a lower risk of self-perceived cognitive decline.
The DASH diet showed the strongest link, followed by hPDI, reversed empirical dietary indices for hyperinsulinemia (rEDIH) and PHDI.
Greater adherence to the DASH diet at ages 45 to 54 showed the strongest link with subjective cognitive decline and a higher cognition measured objectively.
Key food groups associated with better cognitive function included vegetables and fish, along with lower consumption of red and processed meats, the researchers said.