The study on multivitamins and biological aging involved 958 healthy participants with an average age of about 70 years, split into four groups taking different combinations of cocoa extract, multivitamin, or placebos. According to the researchers, the slowdown in biological aging from daily multivitamin use was measured using epigenetic clocks, specifically those used to estimate mortality risk. The team added that the effects appeared greater for people who had faster biological aging at the start of the study, possibly due to greater nutritional deficits. Previous work by Sesso and colleagues suggested daily multivitamins were associated with improved cognition and reductions in lung cancer and cataracts. A large study published last year found daily multivitamins did not help people live longer and might increase the risk of an early death.
Separate research indicates higher vitamin D levels in midlife are linked to lower levels of tau protein, a key Alzheimer's-related protein, in the brain years later. The study found no connection between higher vitamin D levels and amyloid beta protein, another marker of Alzheimer's disease. Martin David Mulligan from the University of Galway in Ireland said that these results suggest higher vitamin D levels in midlife may offer protection against developing tau deposits in the brain, and low levels could be a modifiable risk factor for dementia.
The study on vitamin D and dementia followed 793 people with an average age of 39 who did not have dementia, measuring blood vitamin D levels at the start and brain scans an average of 16 years later. The study defined high vitamin D levels as above 30 nanograms per milliliter, with around a third of participants below this and just five percent regularly taking supplements. Mulligan noted that these findings are promising, as they suggest a link between higher vitamin D levels in early middle age and lower tau burden 16 years later, with midlife being a time for impactful risk factor modification.
In related nutrition research, scientists have revealed that following a specific dietary regimen can slow the brain's aging process by more than two years. The research tracked more than 1,600 adults for approximately 12 years.
Health experts recommend adults over 65 take a daily supplement of 10 micrograms of vitamin D, especially if frail, housebound, or with little sun exposure. However, key questions remain unanswered, including what the slowdown in biological aging from daily multivitamins means in terms of actual health outcomes and clinical relevance. Dr. Howard Sesso, an epidemiologist at Mass General Brigham and senior author of the multivitamin work, stated that there are no known risks for taking a multivitamin in their two large clinical trials, but it is not known for sure who benefits and how. The authors of the multivitamin study emphasized that it is critical to determine the clinical relevance of their findings. It is also unclear whether the link between higher vitamin D levels and lower tau protein translates to a reduced risk of developing dementia.