Women with diets during middle age designed to lower blood pressure were about 17 percent less likely to report memory loss and other signs of cognitive decline decades later, a new study finds.
Led by researchers from NYU Grossman School of Medicine, the new findings suggest that a mid-life lifestyle modification – adoption of the Dietary Approaches to Stop Hypertension, or DASH diet – may improve cognitive function later in life for women, who make up more than two-thirds of those diagnosed with Alzheimer's disease, the most prevalent form of dementia.
The findings, published online today in the journal Alzheimer's & Dementia , have implications for the approximately 6.5 million Americans over age 65 diagnosed with Alzheimer's disease in 2022. That number is expected to more than double by 2060.
"Subjective complaints about daily cognitive performance are early predictors of more serious neurocognitive disorders such as Alzheimer's," said Yu Chen, PhD, MPH, professor in the Department of Population Health and senior author of the study. "With more than 30 years follow-up, we found that the stronger the adherence to a DASH diet in midlife, the less likely women are to report cognitive issues much later in life."
The DASH diet includes a high consumption of plant-based foods that are rich in potassium, calcium, and magnesium and limits saturated fat, cholesterol, sodium, and sugar. Longstanding research shows that high blood pressure, particularly in midlife, is a risk factor for cognitive decline and dementia.
How the Study was Conducted
The investigators analyized data from 5,116 of the more than 14,000 women enrolled in the NYU Women's Health Study, one of the longest running studies of its kind that examines the impact of lifestyle and other factors on the development of the most common cancers among women, as well as other chronic conditions.
The researchers queried the study participants' diet using questionnaires between 1985 and 1991 at study enrollment when the participants were, on average, 49 years old. The participants were followed for more than 30 years (average age of 79) and then asked to report any cognitive complaints. Participants that did not return questionnaires were contacted by phone.
Self-reported cognitive complaints were assessed using six validated standard questions that are indicative of later mild cognitive impairment, which leads to dementia. These questions were about difficulties in remembering recent events or shopping lists, understanding spoken instructions or group conversation, or navigating familier streets.
Of the six cognitive complaints, 33 percent of women reported having more than one. Women who adhered most closely to the DASH diet had a 17 percent reduction in the odds of reporting multiple cognitive complaints.
"Our data suggest that it is important to start a healthy diet in midlife to prevent cognitive impairment in older age", said Yixiao Song , a lead author of the study.
"Following the DASH diet may not only prevent high blood pressure, but also cognitive issues," said Fen Wu, PhD, an senior associate research scientist and co-led the study.
According to the investigators, future research is needed across multiple racial and ethnic groups to determine the generalizability of the findings.
The study is supported by the National Institutes of Health, grant U01 CA182934.
Other investigators from NYU Grossman School of Medicine include Sneha Sharma, Tess V. Clendenen, Sandra India-Aldana, PhD, MPH, Yelena Afanasyeva, MS, Karen L. Koenig, PhD, Anne Zeleniuch-Jacquotte,PhD; and Yian Gu, MD, PhD, Columbia University.
