Thursday, May 5, 2022 (HealthDay News) — A diet rich in antioxidants provided by leaves, vegetables, and colorful fruits is good for your body, and now new research shows it protects your brain, too.
In the study, people whose blood contained the highest amounts of the three major antioxidants were less likely to develop all-cause dementia than those whose blood contained the lowest levels of these nutrients.
“The takeaway is that a healthy, antioxidant-rich diet of dark leafy greens and orange-colored fruits with or without antioxidant supplementation may reduce the risk of dementia,” said Dr. Luigi Ferrucci, scientific director of the US National Institute on Aging. NIA), which funded the study.
“But the only way to prove the relationship between antioxidants and brain health is to conduct a long-term, randomized clinical trial to see if more people who take a carefully controlled amount of antioxidant supplements develop dementia over time,” Ferrucci added.
For this new research, study author May Beydoun of the NIA in Baltimore and colleagues studied nearly 7,300 people, ages 45 to 90, who had a physical exam, interview, and blood test for antioxidant levels.
The individuals were divided into three groups, depending on the level of antioxidants in their blood, and were followed for an average of 16 years and up to 26 years.
The researchers found that those with the highest amount of the antioxidants lutein and zeaxanthin in their blood were less likely to develop dementia than those with the lowest levels. Lutein and zeaxanthin are found in green leafy foods such as kale, spinach, broccoli, and peas.
Each standard deviation increase (a measure of how scattered data are relative to the mean) of antioxidant levels in the study was associated with a 7% decrease in dementia.
For those with high levels of another antioxidant called beta-cryptoxanthin, each standard deviation increase was associated with a 14% lower risk of dementia. Beta-cryptoxanthin is found in orange-colored fruits, including oranges, papayas, tangerines and persimmons.
“Experts believe that taking antioxidants may help protect body cells – including brain cells – from damage,” Ferrucci said.
The effect of antioxidants on dementia risk was reduced somewhat when the researchers also took into account education, income, and physical activity. The study authors said these factors may help explain the relationship between antioxidant levels and dementia.
The study also only measured blood at one time and may not reflect the participants’ antioxidant levels over their lifetime.
“It’s important to keep in mind that experts don’t yet know how much antioxidants we need each day through our diet and supplementation for a healthy brain,” Ferrucci said.
He added that identifying ways to prevent the development of dementia is an important public health challenge, but results from previous studies have been mixed.
Researchers said the antioxidants may help protect the brain from oxidative stress that can cause cell damage.
“Population studies that follow healthy people over many years for dementia enable us to look for potential risk factors as well as protective factors, such as dietary choices and lifestyles,” Ferrucci noted.
The results were published online May 4 in the journal Neurology.
Yoko Hara, director of aging and Alzheimer’s prevention at the Alzheimer’s Drug Development Foundation, said the study was unique in its use of blood markers rather than reminding the patient of the foods they ate.
Hara also noted that the association between antioxidants and dementia in this study decreased when other factors were accounted for.
“It’s not that they weren’t involved, it’s the faculty that I think is part of the many different things you can do for good brain health,” said Hara, who was not involved in this study.
Hara said her organization recommends seven steps to brain health.
These include good nutrition, with an emphasis on a Mediterranean diet, getting seven to eight hours of sleep each night, and exercising at a moderate intensity for at least 150 minutes a week.
Other steps are relieving stress, engaging with the community, continuing to learn and managing chronic diseases that have been linked to a risk of dementia, including diabetes and hypertension (high blood pressure).
“These are conditions where if you leave it untreated you also harm your brain health and possibly harm [increasing] Alzheimer’s disease risk, as well as the risk of dementia in general. If you have these conditions, you really want to control them with lifestyle interventions or, if that is not enough with lifestyle interventions, your doctor will likely prescribe medications so that your blood pressure and glucose levels are well managed.” What we recommend.”
The US Centers for Disease Control and Prevention offers more on dementia.
SOURCES: Luigi Ferrucci, MD, PhD, scientific director, US National Institute on Aging, Bethesda, Md.; Yoko Hara, Ph.D., director of Aging and Alzheimer’s Prevention, Alzheimer’s Drug Development Foundation, New York City; NeurologyAnd May 4, 2022, online