A daily multivitamin and mineral supplement can reduce cognitive decline in older people, according to a US study that is the first to show that they can benefit aging brain function.
The trial, which included more than 2,200 people over the age of 65, suggests that daily supplements can slow cognitive decline by about 60%, or almost two years, with the most substantial effects seen in older people with a history of cardiovascular diseases.
But while Alzheimer’s disease and dementia experts are encouraged by the findings, they caution that larger studies are needed to confirm the effect before recommending daily multivitamins to help protect older people from cognitive decline. Previous trials of dietary supplements have had no effect on the disease.
“We provide the first evidence in a long-term randomized controlled trial of elderly women and men that daily use of a safe, readily available, and low-cost mineral multivitamin can improve cognition,” the researchers wrote in Alzheimer’s and dementia the Journal of the Alzheimer’s Association. “This finding could have important public health implications for brain health and resilience to future cognitive decline.”
With aging populations around the world, dementia has become a major global health challenge, but there are no drugs that can cure any of the common types. In the UK, around 850,000 people live with dementia, the majority of which is Alzheimer’s disease or ‘vascular dementia’. People over 65, and people with diabetes, hypertension, high cholesterol and depression, are most at risk.
Researchers at Wake Forest University in North Carolina and Brigham and Women’s Hospital in Boston investigated whether a daily cocoa extract or multivitamin with minerals improved memory and other mental tasks in 2,262 people age 65 and older. The researchers assessed participants’ “global cognition” before and during the three-year trial using tests including word lists, number problems, verbal fluency and story recall.
Cacao extract is rich in substances called flavanols, and previous research has suggested that they may have some benefit for brain function. But the latest trial found that daily cocoa supplements made no difference to people’s cognitive performance. However, daily multivitamin and mineral supplements appeared to improve cognitive scores, particularly for those with cardiovascular disease, a known risk factor for dementia. The results suggest “greater relative improvement or greater protection against cardiovascular disease-related cognitive decline,” the authors wrote.
Professor Laura Baker, co-principal investigator of the Cosmos study at Wake Forest University, said it was too early to recommend daily multivitamins to prevent cognitive decline. “Although these preliminary findings are promising, additional research is needed in a larger and more diverse group of people. Additionally, we still have work to do to better understand why multivitamins may benefit cognition in older adults,” he said.
Professor Tara Spiers-Jones, group leader at the UK Dementia Research Institute at the University of Edinburgh, said the study was well conducted but noted that most people involved were highly educated white people.
“It will be important to confirm that the results hold in the wider population,” he said. “It is also not clear from this study whether the use of multivitamins will prevent diseases that affect cognition such as Alzheimer’s disease. Several dietary supplements have been tested as treatments for Alzheimer’s disease and so far none have effective state”.
Dr Maria Carrillo, Scientific Director of the Alzheimer’s Association, said: “This is the first large-scale, long-term positive study showing that multivitamin and mineral supplementation for older people can delay cognitive ageing. While the Alzheimer’s Association is encouraged by these results, we are not ready to recommend the widespread use of a multivitamin supplement to reduce the risk of cognitive decline in older adults.
“Independent confirmatory studies in larger and more diverse study populations are needed,” he added. “It is essential that future treatments and preventions are effective in all populations.”