Multivitamins may slow memory loss
Seniors who took a daily pill at a low dosage showed improved instant recall.
American researchers have found that multivitamins can slow memory loss for people aged over 60.
A study conducted by researchers at Harvard and other universities found a daily pill improved episodic memory by about three years. Episodic memory is measured by instant recall.
The biggest improvement was seen over the first year of the trial, then plateaued, although improvement was sustained across three years.
The study authors emphasise that one pill showed benefits and that more was not necessarily better. High doses could be damaging.
In the study 3,500 people aged 60 and older were given a daily multivitamin. Results showed this led to 3.1 years less cognitive aging than for those assigned a placebo.
The researchers said the fact that two separate randomised trials with different methodologies showed significant benefits of multivitamins compared to placebo was “remarkable”.
Other trials have generally tested just one or a few micronutrients, not a multivitamin with more than 20 essential vitamins and minerals.
Lead author JoAnn Manson said it was unlikely there was a “magic bullet” or single nutrient. So, when considering supplements, we should consider the pill’s combined nutrients.
“Several micronutrients are known to be important for optimal brain health, and a deficiency of one or more of those essential vitamins and minerals could accelerate cognitive ageing,” she said.
“Some people may have a deficiency in one and others may have a deficiency in another. So, taking a multivitamin containing more than 20 of these micronutrients will tend to benefit more people than taking a single isolated micronutrient.”
However, it doesn’t mean that every single ingredient in the multivitamin is a major contributor to these benefits.
“It’s possible it was only a few of the vitamins and minerals,” she said. “Some of the top candidates are vitamin B12, other B vitamins, vitamin D, lutein, zinc, and magnesium.”
Both studies showed people with a history of cardiovascular disease benefited most. At the start of the study, they had worse memory performance than others. After a year on the pill, they recovered to a comparable level.
The researchers said there are many nutritional factors that are important in reducing risk of cardiovascular disease, and it’s likely that people with a history of cardiovascular disease have lower nutrient status, at least for certain selected nutrients.
“That may be why they’re benefiting more. It’s also possible that, because of medications they’re taking or other needs that they have, they benefit more from the multivitamins. We want to drill down more deeply on those findings,” Dr Manson said.
The researchers warned multivitamins and other dietary supplements are not a substitute for a healthy diet or a healthy lifestyle, but as a complementary strategy.
“Clinicians are sometimes concerned that recommending dietary supplements will lead to complacency about healthy diets and regular physical activity,” Dr Manson said.
“Nothing is going to replace a healthy lifestyle in terms of fending off chronic diseases and achieving a longer health-span. It is really important that people understand that.”
Further research is needed to determine who will benefit most from the pills and to understand the biological mechanisms involved.
One possible mechanism could relate to micronutrient receptors in the hippocampus, which has a major role in memory.
As it is differentially affected by age, the detection of the cognitive effects of multivitamins in older adults might be most obvious with tasks that are hippocampus-dependent.
