Can we eat our way to better brain health? A new study suggests that steering toward a vitamin D-rich diet may be a wise move to help ward off memory-robbing dementia.

Published in the journal Alzheimer's and Dementia, the research tracked more than 1,700 people for nearly 6 years. It found that those consuming the highest amounts of vitamin D were 28% less likely to develop dementia than those consuming the lowest amounts.

The link between vitamin D intake and dementia risk had been established in earlier research. But the new study stands out by confirming it in a large group of people of various races and ethnic backgrounds, experts said.

"There has been some evidence suggesting protection from vitamin D for Alzheimer's disease and dementia, but in the past those studies were more in non-Hispanic or white populations," said study author Yian Gu, MD, PhD. She's an assistant professor of neurological sciences at Columbia University Vagelos College of Physicians and Surgeons in New York City.

"Our study population is multi-ethnic because we need to know whether this relationship with dementia is the same in different populations," Dr. Gu told Medical Daily. "We know dementia has no [effective] pharmaceutical treatments right now, so it's important for us to find preventive measures to delay the onset or prevent the disease."

Food choices tracked

Marked by the deterioration of memory, thinking skills and the ability to do everyday activities, dementia affects about 50 million people worldwide, with about 10 million new cases each year, according to the World Health Organization.

Risks increase with age, with the number of people living with Alzheimer's disease – the most common cause of dementia – doubling every five years after 65, according to the U.S. Centers for Disease Control and Prevention.

Dr. Gu and her team analyzed 1,759 people who were aged 65 or older when the study began. Hailing from diverse New York neighborhoods, participants filled out questionnaires detailing their food choices over an average follow-up period of 5.8 years.

Over the study period, 329 participants developed dementia. Researchers adjusted the results for other factors that could also influence dementia risk, such as age, gender, education and smoking, but still found a strong link between higher vitamin D intake and lower rates of dementia.

Dementia is far from the only condition linked to vitamin D. In COVID-19, low blood levels of vitamin D were found to be independent risk factors for ICU admission and death, according to new research. Meanwhile, a variety of chronic conditions such as heart disease, autoimmune disorders and diabetes have all been associated in recent years with vitamin D deficiency.

"A low level of vitamin D is linked with many negative outcomes," said Miroslaw "Mack" Mackiewicz, PhD. He is a program director in the Neurobiology of Aging and Neurodegeneration Branch at the U.S. National Institute on Aging, which helped fund the new dementia/vitamin D study.

Talk to your doctor

The research does not prove that eating a vitamin D-rich diet prevents dementia, only that it's linked to lower risk, Dr. Mackiewicz told Medical Daily. "It's incredibly difficult to design a study that would establish a causal link, but it should be part of our future research," he said.

According to the U.S. National Institutes of Health, people aged 14 to 70 should consume 600 IUs (international units) of vitamin D daily, increasing this to 800 IUs after 70. Vitamin D-rich foods include salmon, tuna, milk, yogurt and eggs.

"The takeaway message would be that keeping a healthy level of vitamin D is important," Dr. Mackiewicz said. "When you talk to your health professional and you're concerned about dementia, talking about vitamin D storage should be part of that conversation."

Maureen Salamon writes about health and medicine for websites, magazines and hospitals such as Medscape, St. Jude Children's Research Hospital, Weill Cornell Medicine and others.