Many people’s vitamin D levels do not fall within a healthy range, which can cause muscle weakness, fatigue, depression, bone pain and lower immune function. In fact, an estimated 60% of the world is vitamin D deficient and needs a supplement, Dr. Michael Holick, a professor of medicine, pharmacology, physiology & biophysics and molecular medicine at Boston University Chobanian & Avedisian School of Medicine, previously told HuffPost.
But if that alone isn’t enough to convince you to prioritize getting vitamin D, which you can do through foods like salmon, tuna, and milk, new research published in the journal “Neurology” this month may do the trick. The study suggests that people with high vitamin D levels in their 30s and 40s have lower dementia risk factors later in life.
The study investigates the potential impact of vitamin D levels in early midlife by examining the prevalence of tau protein and amyloid protein in the brain, “which are key hallmarks of Alzheimer’s disease,” Dr. Thomas M. Holland, physician-scientist and assistant professor at the Rush Institute for Healthy Aging at Rush University Medical Center in Chicago, told HuffPost via email. Holland is not affiliated with the study.
Researchers followed 793 people in their 30s and 40s with an average age of 39 over 16 years. Vitamin D levels were tested at the beginning of the study; those with levels below 30 nanograms per milliliter (ng/mL) were categorized as having low vitamin D; anything above was considered high.
After a follow-up at the end of the study, it was determined that participants in the high-vitamin D group were more likely to have lower tau levels in their brains.
“Researchers looked at two different types of scans of the brain called PET scans,” said Dr. David Gill, chief of the division of cognitive and behavioral neurology at the University of Rochester in New York. Gill is not affiliated with the study. “One looks at the amyloid protein [prevalence], and one looked at the tau protein [prevalence].”
Even though tau protein levels were lower in participants with high vitamin D, researchers found that those elevated levels did not impact levels of amyloid in the brain. This indicates someone with high vitamin D could still have elevated levels of amyloid protein, which, as mentioned above, is a characteristic of Alzheimer’s disease.
This study does have a “major limitation,” Dr. Jagan Pillai, a Cleveland Clinic neurologist and director of the Cleveland Alzheimer’s Disease Research Center, told HuffPost via email. Vitamin D levels were measured once at the beginning of the study “and after that PET scans were completed 15 or more years later,” said Pillai, who was not associated with the study..
“So, we don’t have any information in between,” Pillai added. It’s unknown if participants took supplements or followed a healthy lifestyle that helped them maintain healthy vitamin D levels, he noted. Because vitamin D levels were only measured once, it’s also unclear if someone shifted from having healthy levels to unhealthy levels (or the opposite) during the study’s time period.
While this study has solid data, it does not prove that vitamin D levels directly affect dementia risk, according to Gill. There are many studies on this topic, and they’re conflicting.
“Specifically, there’s been some studies to show that giving vitamin D might help improve memory a little bit, but those are also conflicting. There’s been all of this information out there without a firm understanding of whether there’s a real connection between low vitamin D and Alzheimer’s disease,” Gill said. “I don’t know this [study] answers that question, but it helps move us forward.”
So, does this mean having healthy vitamin D levels in your 30s and 40s will protect you from dementia? Not necessarily. But having healthy vitamin D levels can bolster many systems in your body, including the brain. And as research emerges about vitamin D and dementia risk, there are other changes you can make to take care of your cognition.
Anastasiia Voloshko via Getty Images
New research suggests that healthy vitamin D levels in midlife may be protective for your brain.
To lower your risk of dementia, there are certain rules you should follow in midlife and throughout your life.
Holland said the amyloid and tau brain proteins associated with dementia begin accumulating “15 to 20 years before the clinical symptoms of dementia or cognitive decline are detected.”
Anything we can do in midlife to support cognitive function and reduce the risk of dementia will “benefit us later in life,” Holland added. “We know that low vitamin D levels and other nutrient deficiencies are associated with neuroinflammation and potentially oxidative stress.” All of that can take a toll on your brain.
Throughout your life, you should work with your doctor to correct any vitamin deficiencies, whether that’s vitamin D, vitamin B12 or something else, according to Pillai.
Eating a nutrient-dense diet is also protective for the brain.
″For vitamin D specifically, adding in healthy protein sources, particularly fatty fish such as tuna, salmon, sardines and mackerel, can be beneficial,” Holland said.
“For overall brain health, incorporating foods such as dark leafy greens (i.e., kale, romaine lettuce, and spinach), berries (such as blueberries, strawberries, and blackberries), whole grains (like oatmeal, brown rice, and quinoa) and extra virgin olive oil is helpful, as these foods provide beneficial fatty acids and a wide range of supportive nutrients,” Holland continued.
Additionally, “we should be as physically active as possible,” Gill said.
This doesn’t mean signing up for a marathon, but can instead mean going for frequent walks in your neighborhood.
“We should be doing things that challenge us mentally to keep ourselves mentally active,” Gill added.
For older folks, staying challenged can be tough — working is one of the easiest ways to stay mentally active, Gill said. For those who no longer work, taking a class, playing cards with friends, volunteering or joining a book club are all good options.
“Really, anything that you enjoy that engages your brain can be a good thing,” Gill said.
Socializing is also important.
“Being social is important for a number of reasons. We know the opposite, being lonely, is bad for our memory over time. And so being social is good for us because it keeps our brain active, but also avoids loneliness,” Gill said.
Finally, you should address any issues you have that could lead to dementia down the line.
“We should treat the medical problems that can increase the risk of Alzheimer’s disease,” said Gill, noting that “the things that increase the risk of heart disease tend to increase the risk of Alzheimer’s disease.” Diabetes, high blood pressure, smoking and high cholesterol are all issues that you should work with your doctor to treat, Gill said.
