Several Diets Found to Lower the Risk for Cognitive Decline: Daily Dose

Patient Care brings primary care clinicians a lot of medical news every day—it’s easy to miss an important study. The Daily Dose provides a concise summary of one of the website's leading stories you may not have seen.

On March 6, 2026, we reported on a study published in JAMA Neurology that examined the associations of 6 healthy patterns with subjective cognitive decline (SCD) and objective cognitive function.

The study

Researchers conducted a prospective cohort study based on the Nurses’ Health Study (NHS, 1986-2014), NHSII (1991-2017), and the Health Professionals Follow-Up Study (HPFS, 1986-2012). Investigators enrolled 159 347 adults (mean age, 44 years; 82.6% women) with available data on diet and cognitive function. Data analyses were performed from September 2024 to November 2025, according to the study.

The diets included the Dietary Approaches to Stop Hypertension (DASH)-style diet, the Healthful Plant-Based Diet Index (hPDI), the Alternate Healthy Eating Index 2010 (AHEI-2010), the Planetary Health Diet Index (PHDI) and the reversed empirical dietary indices for hyperinsulinemia (rEDIH) and inflammatory pattern (rEDIP).

Researchers assessed SCD through several questions on perceived changes in cognitive processes like memory and attention, while cognitive function was measured through telephone-based assessments in the Nurses’ Health Study.

The findings

The researchers reported that higher adherence to all 6 diets decreased the risk for SCD. The DASH-style diet had the greatest effect, lowering the risk by 41% (RR = 0.59; 95% CI, 0.57-0.62), followed by the:

• hPDI (RR = 0.76; 95% CI, 0.65-0.85);

• rEDIH (RR = 0.76; 95% CI, 0.73-0.8);

• PHDI (RR = 0.8; 95% CI, 0.75-0.86);

• AHEI-2010 (RR = 0.84; 95% CI, 0.8-0.89); and

• rEDIP (RR = 0.89; 95% CI, 0.85-0.93).

Authors’ comments

“These findings support the importance of healthy eating as part of midlife brain-health strategies and motivate pragmatic and implementation research to translate these findings into scalable programs.”

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