The DASH Diet Could Benefit Women's Cognitive Health and Prevent Memory Decline as They Age.

New research suggests that a diet aimed at reducing blood pressure during middle age may prevent women from experiencing memory loss in their later years. This information is from a recent study published in the Alzheimer’s and Dementia journal, which explored the potential cognitive benefits of the DASH diet (Dietary Approaches to Stop Hypertension) for aging women.

This research is extremely relevant, given that women constitute over two-thirds of all Alzheimer’s disease diagnoses, the most prevalent form of dementia. “Complaints about daily cognitive performance are early signs of more severe neurocognitive disorders like Alzheimer’s,” stated senior study author Yu Chen, PhD, MPH, a professor in NYU Langone’s Department of Population Health. “After over 30 years of follow-up, we observed that women who adhered more closely to the DASH diet in their midlife were less likely to report cognitive problems later in life.”

The following article provides an overview of the DASH diet, its potential to prevent cognitive decline in women, and the proper ways to practice the diet for its many health benefits beyond just cognitive function.

In this study, researchers from NYU’s Grossman School of Medicine examined the dietary habits of over 5,000 women participating in the long-term New York University Women’s Health Study. These women, with an average age of 46 years between 1985 and 1991, completed health questionnaires up to the period 2018–2020. The data showed that women whose diets aligned closely with a DASH diet—rich in fruits, vegetables, lean proteins, and low-fat dairy—were 17% less likely to experience cognitive impairment in 2018–2020, at an average age of 79.

Experts express that while these findings are impressive, they are not unexpected. “These outcomes affirm our advice to patients: better cardiovascular health leads to better brain health” said Anna Nordvig, MD, a neurologist at Well Cornell Medicine’s Alzheimer’s Disease and Memory Disorders Program, who was not involved in the study. “Vascular cognitive impairment is a common problem and we have more effective treatments to prevent it from worsening—like controlling blood pressure.”

Understanding the study’s results necessitates familiarity with the DASH diet. Developed in the early 1990s by researchers at the National Heart, Lung, and Blood Institute, this eating plan was created as a method of reducing blood pressure.

“The DASH diet encourages consumption of nutrient-rich foods which play a crucial role in controlling blood pressure by promoting flexible blood vessels and facilitating muscle contraction,” stated Veronica Rouse, RD, CDE, founder of The Heart Dietitian. “The diet also limits intake of unhealthy saturated fats, which can increase blood cholesterol levels,” Rouse adds. “Additionally, the diet endorses whole grains, fruits, vegetables, and lean proteins, which all support overall heart health.”

Often compared with a Mediterranean diet, a DASH diet focuses on consuming prescribed numbers of servings of healthy, anti-inflammatory food groups per day. A 2,000-calorie daily DASH diet, for instance, recommends the following each day:

Since sodium is known to contribute to hypertension, DASH dieters are advised not to consume more than 1,500 milligrams of sodium daily. The diet also minimizes sweets, full-fat dairy, fatty meats, and sugary beverages.

Since the 1990s, research has consistently proven the DASH diet’s effectiveness in living up to its name. A 2018 JAMA study found that, 20 years after its creation, multiple trials have corroborated that the DASH diet can effectively and significantly reduce blood pressure among various populations. A thorough systematic review also revealed the diet’s ability to decrease inflammatory markers in the blood, which is a known factor in the development of heart disease.

The researchers of the Alzheimer's and Dementia study found that women who ate a diet similar to the DASH diet were less likely to exhibit cognitive impairment. To arrive at this conclusion, the researchers divided the group into quartiles. Women in the top quartile, who more closely followed a DASH-like eating pattern, were found to have the fewest number of subjective cognitive complaints, which included increased instances of memory loss.

Experts suggest that because the DASH diet promotes flexible blood vessels and decreases inflammation, it has the potential to benefit not only the heart but also the brain.

“The two most common causes of dementia are Alzheimer’s disease and cerebrovascular disease (stroke),” Raphael Wald, PsyD, a neuropsychologist with Marcus Neuroscience Institute, part of Baptist Health South Florida at Boca Raton Regional Hospital. told Health. “The greatest controllable risk factor for both of these forms of dementia is any vascular risk such as diabetes, hypothyroidism, poor diet, or hypertension.”

“Focusing on a diet that reduces hypertension would reduce vascular risks and subsequently reduce the risk for Alzheimer’s disease and vascular dementia,” added Wald.

As for why vascular problems impact cognition in such dramatic ways? It has partly to do with how blood vessels supply all-important oxygen to the brain. “Consistently maintaining a healthy blood pressure can support proper blood flow and oxygen delivery to the brain, which are crucial for preserving cognitive abilities,” said Rouse.

Nordvig likened a DASH diet for brain health to using high-quality fuel in a car. “People understand that more expensive, higher-octane gas keeps the engine cleaner. This is a good parallel to what food is to the body and to the brain,” she said. “Diet (and avoidance of toxins) throughout the lifespan, coupled with exercise and cognitive stimulation, are all critical to build and reinforce our neurons.”

Since women are more likely than men to experience cognitive decline in their later years, this new research on the diet-brain connection is especially pertinent.

That said, science has yet to uncover exactly why women are at higher risk. Wald points out that women tend to live longer than men, and since advanced age is a major factor in cognitive decline, this may be a primary underlying cause.

Regardless of the underlying mechanism, it’s possible that both men and women could benefit from a DASH diet for brain health. “Men suffer from hypertension just like women, and I would expect those men to benefit from the DASH diet too,” Nordvig said.

Want to get started on a DASH diet to boost brain and heart health? Consult a registered dietitian or visit the National Heart, Lung, and Blood Institute’s guide.