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Aug. 1 (UPI) -- Eating strawberries daily may improve cognitive function in older adults, as well as lower blood pressure and boost antioxidant capacity, a new study finds. "That's an important preventive measure for different chronic diseases," the study's principal investigator, Dr. Shirin Hooshmand, told UPI in an email. She is a professor in the School of Exercise and Nutritional Sciences at San Diego State University.
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Results of the randomized clinical trial were presented in July at Nutrition 2023, the annual meeting of the American Society of Nutrition. The study adds to earlier research demonstrating the cardiovascular, metabolic and cognitive health benefits of strawberry consumption.
"Prior to conducting our clinical study, some of the similar effects were shown in animal studies and some human studies," but in different populations and with different research designs, Hooshmand said.
The double-blind, placebo-controlled study enrolled 35 healthy men and women between the ages of 66 and 78. They consumed 26 grams of freeze-dried strawberry powder, which is equivalent to two daily servings of strawberries, or a control powder for eight weeks each.
After strawberry intake, cognitive processing speed increased by 5.2%, systolic blood pressure decreased by 3.6% and total antioxidant capacity jumped by 10.2%. Waist circumference decreased by 1.1% during the control and intervention arms of the trial. Participants consuming the control powder experienced an increase in serum triglycerides, while the intervention arm did not.
Hooshmand said she is encouraged that a simple dietary change, like incorporating strawberries daily, may improve cognitive function and reduce cardiovascular risk factors such as hypertension.
Strawberries contain many bioactive compounds. In addition to providing 100% of daily vitamin C needs, they are a source of heart-healthy nutrients like folate, potassium, fiber and polyphenols.
Previous clinical trials have linked strawberry consumption to improvements in several markers for cardiovascular disease, including reduced total and LDL cholesterol and lower blood pressure.
The connection between strawberry consumption and brain health also has been investigated in clinical and population-based studies.
In studies conducted at Rush University in Chicago, strawberries and pelargonidin, a biochemical primarily found in the fruit, were associated with a reduced risk of Alzheimer's dementia.
Long-term observational studies, including the Health Professionals Study and the Nurses' Health Study, found that people who consumed strawberries had lower rates of cognitive decline.
"An emerging area of research for strawberries has been metabolic health," according to the website of the California Strawberry Commission's Health Research Round-Up.
"Epidemiological research has linked strawberry consumption to a reduced risk for diabetes. Data from the Women's Health Study revealed that, compared to women who rarely or never ate strawberries, those who ate at least two servings of strawberries each week had a 10% lower risk of developing diabetes."
In addition, "the ability of strawberry intake to impact digestive health is a new area of study for the California Strawberry Commission. Several studies that were recently published or are underway are looking closely at how strawberry consumption might impact the gut microbiome and, in turn, other aspects of health."
John "Wesley" McWhorter, national spokesman for the Academy of Nutrition and Dietetics, told UPI in a recent interview that the study's findings are not surprising.
"The results are very consistent with what we've seen in the data the past several years, which is whole foods are wonderful for you."
Dietary guidelines recommend that half of an individual's plate of food be filled with fruits and vegetables. Strawberries contain fiber, which is very beneficial for decreasing the risk of chronic diseases such as diabetes and heart disease, said McWhorter, who is also director of lifestyle medicine for Houston-based Suvida Healthcare, a primary care practice serving Hispanic seniors and their families in Texas and Arizona.
"If you add strawberries in a diet, you'll see positive improvements."
Consuming other fruits, vegetables, seeds, legumes and whole grains can make a difference, too. Eating a variety of these foods in different colors helps ensure that you're supplying the body with an array of nutrients, he said.
"Often times, we're looking for a magic-pill solution," he said, instead of following the science, which clearly shows that "the more fiber-rich foods we have in our diet, the better our overall health will be."
This research and several other studies on berries have demonstrated that powerful substances called flavonoids increase blood flow in the body by dilating veins. Increasing the antioxidant capacity in the blood helps relax the arteries and protects the cardiovascular system from plaque build-up, Taylor C. Wallace, CEO of the Think Healthy Group, a food science and nutrition consulting firm in Washington, told UPI in an email.
He's also editor of the Journal of Dietary Supplements, deputy editor of the Journal of the American Nutrition Association and a member of the American Society of Nutrition.
"Increases in flow-mediated dilation is often correlated to decreased blood pressure," Wallace said.
"Decreases in waist circumference are also associated with lower blood pressure. Cognition, which is the primary outcome of the study, is often improved when you see improvements in cardiovascular function," he said.
"The cerebrovascular and cardiovascular systems are very akin in their response to diet. Vascular disease has been thought to contribute up to half of all cases of dementia in older adults, which is marked by memory loss."
Wallace added that "colorful fruits and vegetables such as strawberries have been shown to promote cardiovascular and brain health, and red-purple dark colored berries are showing superior effects."
