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Can multivitamins protect us against dementia and cognitive decline?

Can multivitamins protect us against dementia and cognitive decline?Apparently so. According to a new study published in the journal Alzheimer’s and Dementia, older people who take a daily multivitamin supplement for several years are far less likely to develop dementia, Alzheimer’s disease, and other types of cognitive decline. The new study supports earlier research where it has been seen that the different vitamins and minerals increase cerebral blood flow and protect neurons. It pays off to choose high-quality supplements to make sure that the nutrients are properly absorbed in the body.

According to the Alzheimer’s Association of the US, more than 6.5 million Americans suffer from Alzheimer’s disease, and one in three older people dies of Alzheimer’s disease or a related type of dementia. In Denmark, there are around 90,000 people with Alzheimer’s disease or some kind of dementia, and these conditions are the 4th-leading cause of death. Alzheimer’s disease and other types of dementia normally take several years to develop. Most people are diagnosed after they reach the age of 80 years. Dementia also occurs among younger people, though.
More and more people in Denmark and around the world are affected by Alzheimer’s disease and dementia. The problem represents a huge human and socio-economic health burden. Recent science has therefore focused on what causes the problem and how diet and certain nutrients can protect both older and younger people against cognitive decline.

The study: Multivitamin supplementation for three years improves cognitive skills

The new study (COSMOS-Mind) was conducted in a collaboration between Wake Forest University School of Medicine and Brigham and Women’s Hospital in Boston, USA. The trial included more than 2,200 men and women aged 65 years and older. The study participants represented the broad variety of the American population with regard to geography, race, ethnicity, social status, etc. The scientists specifically compared the effect of taking cocoa extract or multivitamins every day to see if the treatments were able to lower the risk of developing, dementia, heart disease, stroke, cancer, and other diseases.
According to Professor Laura D. Baker, one of the investigators, cocoa beans contain a lot of flavonoids, which are antioxidants with a positive effect on cognitive skills. Vitamins and minerals are essential nutrients that are known to support countless functions in the body and brain. Older people are at risk of nutrient deficiencies because they often eat very little, have impaired nutrient uptake, slow enzyme processes, or take medicine. Moreover, the ageing process comes with an increased risk of oxidative stress, the condition where protective antioxidants are outnumbered by harmful free radicals. This may result in free radical damage to brain cells.
The study participants took the respective supplements for three years. At study start, once a year, and at the end of the study, they were asked over the phone to carry out different tests as a way of evaluating their memory and other cognitive skills.
While the cocoa extract did not have a significant impact on their cognitive skills, the multivitamins did. The scientists observed that three-year supplementation with multivitamins lowered the risk of cognitive decline by 60 percent, which corresponds with a 1.8-year delay. The advantage of taking multivitamins was greatest among the participants who already had cardiovascular diseases. This is an extremely important observation because cardiovascular diseases are already known to increase the risk of cognitive decline.
The new study is published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association. The scientists say that it is still too early to recommend multivitamin supplementation. More research and larger studies are needed to map out exactly how multivitamins can help improve elderly people’s cognitive skills.

B vitamins and cognitive functions

Vitamin B12 is important for blood formation, energy levels, the nervous system, and cognition. Lack of vitamin B12 is associated with fatigue, poor memory, and impairment of the other cognitive skills. In the case of a B12 deficiency, supplementation with the nutrient can lead to an improvement of the cognitive skills, according to a study that is published in Nutrients.
Vitamin B12, folic acid, and vitamin B6 are also important in that they participate in the body’s conversion of homocysteine into other amino acids. Elevated blood levels of homocysteine increase the risk of cardiovascular disease. They also increase the risk of oxidative stress in the brain and free radical attacks on neurons. The problem is not made any easier by the fact that cognitive impairment is insidious and is not normally associated with nutrient deficiencies.

B vitamins affect the brain’s blood flow and activity

At Swinburne University, Melbourne, scientists carried out two clinical studies of B vitamin supplementation. It was the first time that science looked at the effect of B vitamins with help from techniques that enabled the researchers to monitor changes in the cerebral blood flow. Both techniques showed that B vitamins increased the cerebral blood flow and the activity in the part of the brain that deals with attention and work memory.

Antioxidant and their effect

Multivitamins also contain antioxidants such as vitamins A, C, and E plus selenium and zinc. The different antioxidants counteract oxidative stress and neuronal damage caused by oxidative stress.

Choose multivitamins that the body can absorb

The quality of multivitamins varies a lot. Some tablets have been pressed with too much pressure during the manufacturing process and therefore fail to dissolve completely before being absorbed in the small intestine. Other multivitamins contain inorganic minerals that have poor absorption. Always choose a multivitamin preparation that has the right quality and contains organic minerals.

Also remember vitamin D and omega-3 fatty acids for cognitive improvement

It also takes sufficient amounts of vitamin D and omega-3 fatty acids to maintain cognitive skills.


Laura D. Baker et al. Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial. Alzheimer's & Dementia, 2022

Atrium Health Wake Baptist. Daily multivitamin may improve cognition and possibly protect against decline, study suggests. ScienceDaily 2022

A Ueno et al. Influences of Vitamin B12 Supplementation on Cognition and Homocysteine in Patients with Vitamin B12 Deficiency and Cognitive Impairment. Nutrients 2022

Shufeng Li et al. The preventive efficacy of vitamin B supplements on the cognitive decline of elderly adults: a systematic review and meta-analysis. BMC Geriatrics 16 June 2021

Gary Scattergood: Vitamin B clinical trials first to use neuroimaging technology. 2016

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