In the battle against dementia, there may be a simple weapon we’ve had in our armoury all along: taking a daily multivitamin. New scientific research has suggested that a dietary supplement could prevent cognitive decline in people over the age of 65, keeping their brain sharp for an extra two years.
The study of 2,200 men and women found those who took a multivitamin every day slowed their ageing by 60 per cent, or 1.8 years. They had improved global cognition, episodic memory and executive function, compared to those taking a placebo. The multivitamins contain vitamins A, C, D, E, K and B minerals such as zinc, selenium and magnesium, as well as a couple of antioxidants.
“We knew these supplements could be beneficial for brain health, but no one had ever tested them in the way we were proposing,” says the author of the study, Laura D Baker, professor of internal medicine, neurology and public health sciences at Wake Forest University, North Carolina. “This amazing finding needs to be replicated in further studies, but if it’s true, the treatment could be available to everybody on a worldwide basis. Multivitamins are inexpensive and accessible.”
According to YouGov, around half of us already take a supplement once a week or more and the supplement market is rising; it’s due to hit £559 million in 2025.
Yet for many years, debate has long raged over the use and efficacy of supplements.
The only previous study of long-term multivitamin use, the Physicians Health Study II, which ran from 1997 to 2011, did not show any particular protection against cognitive decline. Earlier this year, an editorial in the Journal of the American Medical Association stated: “People are wasting money thinking there has to be a magic set of pills that will keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising.”
Right now, the only recommendation the NHS makes for adults generally is to take 10 micrograms of Vitamin D in autumn and winter. So why might these findings – published in Alzheimer’s and Dementia, the journal of the Alzheimer’s Association – change the approach of the medical community?
“The educated hypothesis is that the over-65s are at sub-optimum micronutrient status for a variety of reasons,” says Baker. “We don’t absorb nutrients in the same way as we age. Generally in the US, we eat a terrible diet of processed food, carbs and saturated fats but not many nutrient-rich foods.” The UK will face similar issues – not only is our diet increasingly processed, but we face the same issues as we age: declining chewing ability, loss of appetite, slower metabolism and a decline in production of stomach acid which helps break down food.
The research showed that multivitamins particularly led to improvements in people with cardiovascular disease. “Cardiovascular disease is always associated with faster cognitive decline,” says Baker. “The disease itself may rob the body of micronutrients at a faster rate, so you need to consume more. Secondly, medication changes absorption of micronutrients.
“Our hypothesis is that taking a multivitamin on a regular basis has helped heart disease patients overcome some of their medical conditions.”
However, Baker cautions further research, with a larger and more diverse group of participants needed before we recommend all midlifers to start taking supplements. “This study was made through a national recruitment drive by mail or advertising in the media and that tends to recruit a certain type of person. We want to make sure our sample is diverse in terms of sex, ethnicity, but also rural.”
The multivitamin involved in the research was Centrum Silver, containing the aforementioned wide-spectrum mix of vitamins and minerals, as well as carotenoids lutein and lycopene – antioxidants which are thought to protect the skin and eyes. This specific combination was not present in the less-optimistic Physicians’ Study, and there are studies which back up the efficacy of ingredients found in the formulation.
“There’s enough evidence to say, with the heavy doses of the B vitamins and the addition of lutein and lycopene, that it’s a pretty decent mix,” says Baker. “You also have to consider the possibility it’s not any single ingredient, it’s the combination.”
Nishtha Patel is a clinical nutritionist, who believes the addition of B vitamins may be useful. “A lack of B12 – vital for keeping red blood cells and nerves healthy – can give symptoms of cognitive decline similar to dementia,” she says. “And if you are taking medication, this makes a difference to how nutrients are assimilated.” For example, drugs such as metformin, which are used to treat type 2 diabetes, deplete B12.
“B vitamins have been extensively researched for maintaining levels of the compound, homocysteine,” says public health nutritionist Dr Emma Derbyshire, from the Health & Food Supplements Information Service. Homocysteine is an amino acid and high levels are a risk factor for heart disease. “If levels of homocysteine rise too high, for example, this can impact on the health of the blood vessels in the brain, with a potential impact on blood flow,” says Derbyshire. “Vitamins can also act as antioxidants in the brain and reduce the risk of inflammation, which can increase the risk of poor brain health.”
However, cautions Derbyshire: “Multivitamins are not intended for treating disease, they are aimed to help bridge nutritional gaps in the diet. In this current study, the participants did not have dementia. It may be that micronutrient levels were low in these participants and topping up vitamins and minerals helped to improve brain health.”