Following a diet designed to lower blood pressure during middle age may help women avoid memory loss later in life, new research shows.

The claim comes from a new study, published in the journal Alzheimer’s and Dementia, looking at how the DASH diet (Dietary Approaches to Stop Hypertension) could potentially improve cognitive function for women as they age.

The findings are particularly important, as women make up more than two-thirds of all people diagnosed with Alzheimer’s disease, the most common and prevalent form of dementia.

“Subjective complaints about daily cognitive performance are early predictors of more serious neurocognitive disorders such as Alzheimer’s,” senior study author Yu Chen, PhD, MPH, professor in NYU Langone’s Department of Population Health, said in a news release. “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.”

Here’s what to know about the DASH diet, how it might help prevent cognitive decline in women, and how best to follow the eating plan for its health benefits—which go far beyond cognition.

For the new study, researchers at NYU’s Grossman School of Medicine tracked the diet patterns of over 5,000 women enrolled in the decades-long New York University Women’s Health Study.

These women, who were 46 years of age on average between 1985 and 1991 when the study began, completed health questionnaires from these years until 2018–2020. Those whose diets most closely resembled a DASH diet—which includes plenty of fruits, vegetables, lean proteins, and low-fat dairy—were 17% less likely to have cognitive impairment in 2018–2020, at an average age of 79.

According to experts, this outcome is impressive, but not necessarily surprising.

“These results reinforce the advice we give to our patients: improve your cardiovascular health to improve your brain health” Anna Nordvig, MD, neurologist at Well Cornell Medicine’s Alzheimer’s Disease and Memory Disorders Program, who was not affiliated with the study, told Health. “Vascular cognitive impairment is a common issue and we actually have more treatments to prevent it from progressing—like controlling blood pressure.”

To understand the study’s findings, it’s important to first grasp the concept of the DASH diet. This eating pattern was developed in the early 1990s by researchers at the National Heart, Lung, and Blood Institute as a means of lowering blood pressure.

“The DASH diet promotes foods rich in nutrients that play a key role in regulating blood pressure by promoting flexible blood vessels and facilitating muscle contraction,” Veronica Rouse, RD, CDE, founder of The Heart Dietitian, told Health. 

“The diet is also low in unhealthy saturated fats, which can raise blood cholesterol levels,” added Rouse. “Furthermore, the diet emphasizes whole grains, fruits, vegetables, and lean proteins, all of which can support overall heart health.”

Often compared to a Mediterranean diet, a DASH diet revolves around prescribed numbers of servings of healthy, anti-inflammatory food groups each day. A 2,000-calorie daily DASH diet, for example, advises the following each day:

• 4–5 servings of fruit
• 4–5 servings of vegetables
• 6–8 servings of grains
• 6 or fewer servings of meats, poultry, and fish
• 2–3 servings of low-fat or fat-free dairy
• 2–3 servings of fats and oils

Because salt is a known contributor to hypertension, DASH dieters are encouraged to eat no more than 1,500 milligrams of sodium each day. Sweets, full-fat dairy, fatty meats, and sugary beverages are also kept to a minimum.

Since its creation in the ’90s, research has shown that a DASH diet really does live up to its name.

A 2018 study in JAMA found that 20 years after its inception, numerous trials had confirmed that a DASH diet consistently and significantly lowers blood pressure in a variety of populations. A large systematic review also showed that the diet reduced inflammatory markers in the blood—a known factor in the development of heart disease.

As the researchers behind the Alzheimer’s and Dementia study discovered, women whose eating habits most closely resembled a DASH diet were less likely to experience cognitive impairment.

To make this determination, the researchers divided the group into quartiles. Women in the top quartile of DASH-like eating ultimately had the lowest number of subjective cognitive complaints. These complaints were defined as “self-reported impairments in daily cognitive performance characterized by a greater frequency of memory loss.”

Experts say that, since a DASH diet can promote flexible blood vessels and reduce inflammation, it stands to reason that it could benefit the brain as well as the heart.

“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.