A new study on brain health has made a connection between individuals getting more Vitamin D and a reduced risk of developing Alzheimer’s Disease.
By Annie Schulman
What do eating cheese and napping in the sun have in common? Not only are they both enjoyable activities, they might help keep your brain healthy! Dairy products and sunlight both provide humans with Vitamin D. Scientists have begun looking into Vitamin D’s role in preventing Alzheimer’s Disease. You know what they say, an ice cream a day keeps the doctor away!
What is Alzheimer’s Disease?
Currently, over 55 million individuals worldwide have been diagnosed with Alzheimer’s Disease (AD), according to Alzheimer’s Disease International. But what exactly is AD? Alzheimer’s Disease is a type of dementia. Dementia is a word describing a range of symptoms an individual might be experiencing that have an impact on their daily life. These symptoms might include worsening memory, altered thinking, and/or acting in a way that is different from how one acted in the past. AD is a neurodegenerative disease. A neurodegenerative disease refers to a condition causing neurons, the cells that make up the brain and nervous system, to stop working or to die. Neurodegenerative diseases are progressive, meaning they worsen with time, and often are incurable. Alzheimer’s Disease is often first identified when individuals are in their mid-60s or older, and increasingly interferes with patients’ mental abilities as they age. Despite over $3 billion dedicated to AD research every year, as reported by the Alzheimer’s Impact Movement, Alzheimer’s Disease remains a medical mystery, with limited treatment options available to patients with this devastating disease. As a result, AD researchers have become increasingly interested in identifying potential ways to reduce the number of individuals who develop this disease.
Vitamin D: Food for your thoughts?
Vitamin D is a molecule that has long been associated with bone health. Vitamin D helps the body take in and store two minerals necessary for bone growth: phosphorus and calcium. However, a recent research study from the University of Calgary’s Hotchkiss Brain Institute in Canada and the University of Exeter in the UK shows Vitamin D might play a role in maintaining brain health. Vitamin D has been shown to help clean up the damaging brain-waste, called amyloid-beta plaques, that are thought to be associated with Alzheimer’s Disease progression.
What does science say about Vitamin D for brain health?
Researchers of this recent study were interested in seeing if patients who took Vitamin D were less likely to develop Alzheimer’s Disease in later life. The researchers used data from the National Alzheimer’s Coordinating Center database. This database contains information from over 40 Alzheimer’s research centers. These research centers collect information on participants over a long period of time. This allows researchers to learn about a patient’s cognitive status, or mental abilities, from year to year. In this case, patients ranged from normal cognitive status to dementia. Negative changes in cognitive status indicated to researchers that the participants might have developed dementia or Alzheimer’s Disease. Cognitive status is determined each year by giving patients standardized tests that reveal if the patient’s brain is healthy or affected by dementia.
In addition to cognitive status, researchers have access to information about the lives of the participants. In this study, researchers were specifically interested in whether patients took Vitamin D supplements or not, at any point in their life. They tracked 12,388 patients, and recorded which patients developed AD. Patients were broken down into two groups: patients who had taken Vitamin D (D+) and patients who had never taken Vitamin D (D-).
Researchers used 10 years’ worth of study data to track if patients developed AD. The researchers took into consideration the demographic factors of their patients, such as age, sex, race, years of education, and mental health diagnoses. Statistical calculations were used to think about these variables, and exclude them from Vitamin D’s relationship with dementia. This allowed the researchers to say that patients in the D+ group had a significantly lower likelihood of developing dementia within the 10 years. In five years, 31.6 percent of patients in the D- group experienced symptoms of dementia, while only 16.4 percent of patients in the D+ group reported dementia symptoms. Taking supplemental Vitamin D was associated with a 40 percent lower risk of developing dementia. This lower risk of dementia was true for both male and female groups. However, the researchers observed that the association with Vitamin D was even higher in females! Females exposed to Vitamin D were even more unlikely to develop AD, compared to males. The study had a couple of other key takeaways. The association between Vitamin D and AD was stronger for individuals who did not have mental disabilities compared to individuals that did. In addition, Vitamin D’s effect on individuals who had a genetic risk factor for AD, called the APOE e4 gene, was not as high as its effect on individuals who did not have this risk factor. Researchers are interested in discovering why this might be!
Dairy, sunlight, and next steps
It is important to keep in mind that this study showed an association between Vitamin D and AD risk. An association refers to a pattern in the data, where two variables seem to be related. In this case, Vitamin D exposure is related to decreasing symptoms of dementia. However, this study does not prove causation. Causation indicates one variable causes the other variable. This would mean Vitamin D exposure is directly responsible for lower AD rates. Additionally experimental studies would need to be performed in order to prove this idea.
With that being said, researchers are excited about the potential benefits Vitamin D might offer. While the science isn’t ready to say Vitamin D can absolutely reduce your risk of AD, this study certainly makes a case for ice cream and a beach day!
This study was published in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.
Alzheimer’s Disease International. Dementia Statistics. https://www.alzint.org/about/dementia-facts-figures/dementia-statistics/
Alzheimer’s Impact Movement. (2023). Investing in Alzheimer’s Research. https://alzimpact.org/research
Ghahremani, M., Smith, E. E., Chen, H.-Y., Creese, B., Goodarzi, Z., & Ismail, Z. (2023). Vitamin D supplementation and incident dementia: Effects of sex, APOE, and baseline cognitive status. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 15(1), e12404. https://doi.org/10.1002/dad2.12404
About the Author
Annie Schulman received her BA in Biology from Colby College. She currently works as a research assistant, and is always interested in reading the newest neuroscience research. When not in a laboratory, she enjoys running, skiing, and attempting to bake homemade bagels.