The influence of B vitamins on cognitive function, heart health, cancer and even gastric bypass recovery has been highlighted in new research.
Experts say it is hard to study the B vitamins in isolation, with four B vitamins cooperating in many critical activities in cells.
This, they say, makes it hard to tease out exactly how each one affects health, whether positively or negatively.
Here, we look at how the five of the most researched B vitamins impact health and disease.
- Type 2 diabetes risk not lowered by high-dose vitamin D supplements
- Vitamin D associated with good type 2 diabetes management
B12, folate and cognitive health
One area that has been a particular area of research is the link between B vitamins and cognitive health.
As people get older, around half of people have a reduced ability to absorb food-bound B12. This affects nerve health which can add to the risk of developing dementia.
Expert Irwin H. Rosenberg, Jean Mayer University Professor Emeritus at Tufts University, said: “The contribution of vitamin B12 deficiency to cognitive decline and the vascular disease that results in many cases of dementia is under-diagnosed and under-reported.”
“Age-related cognitive decline is not just Alzheimer’s. We’ve lumped together many kinds of brain dysfunction under one name. And in doing so, we’ve overlooked how critical blood vessels-and by extension, nutrition-are to preserving brain function.”
Much of the research and treatment around dementia has focussed on the build-up of harmful proteins in the brain, but this won’t work if the cause of dementia symptoms is a B12 deficiency.
Rosenberg says that testing to identify whether cognitive decline may be caused by a B12 deficiency is vital.
He said: “Unlike changes that we are unable to see in patients being given expensive anti-amyloid antibody drugs to treat Alzheimer’s disease, there is actually evidence that fairly early in the course of cognitive decline we can slow the process if the underlying cause is elevated homocysteine or B12-related deficiency.
“We hope to convince cardiologists, neurologists, and internists to measure B12 and homocysteine levels as part of the evaluation of cognitive impairment. Even the modest effects from vitamins that cost pennies a day can be very meaningful in those who will benefit, especially when you compare vitamin supplementation to costly drugs that are getting much more attention yet may have the same or even less benefit.”
- Fasting triggers changes in the gut and brain that could help delay dementia
- Dementia risk reduced by using semaglutide, study reveals
B12 and dementia
Paul Jacques, professor at the Friedman School of Nutrition Science and Policy, and colleagues are currently conducting a study looking at data from 2,500 people, all of whom were dementia free in the 1990s and all of whom received B12, MMA, and homocysteine testing for the last 20 years or more.
Jacques said: “The risk of dementia and late-stage Alzheimer’s begins to increase when one is 75 years old or older, but evidence suggests that some of the pathological changes associated with dementia and Alzheimer’s may start to develop 20+ years before clinical symptoms and diagnosis occurs.
“This study should give us a good handle on whether B12is related to cognitive decline and dementia. If so, hopefully we can identify a simple, inexpensive intervention that could be started years in advance and before real damage occurs.”
Jacques is also looking at the role folate (B9) may play in the development of cognitive issues, specifically the influence high levels of folate might have on B12 and cognitive health.
- Certain populations would benefit from more vitamin D than current recommendations, experts say
- Vitamin D associated with reduced risk of cancer mortality
Heart disease, cholesterol, and stroke
While B vitamins may have a possible role in heart disease and stroke prevention, the ability to use them as a form of treatment is still limited.
Riboflavin (B2) was found in the 2000s to reduce blood pressure very effectively but is only effective in reducing blood pressure specifically in patients with the MTHFR 677 TT genotype.
Vitamins B6, B12, and folate help the body rid itself of homocysteine, which in large volumes had been linked to an increased risk of heart attacks and strokes, as well as dementia.
However, trials in the 1980s showed that B6, B12, and folate supplementation didn’t decrease heart attacks, but did slightly lower the risk of strokes.
Niacin (B3) can lower LDL (the ‘bad cholesterol’) and raise HDL (the ‘good cholesterol’) but it has to be taken in such large doses that it often causes very uncomfortable flushing, like hot flashes, meaning that people often can’t tolerate taking it, and other drug options are available that lower blood LDL that do not have such unpleasant side effects.
Chronic inflammation and B6
One promising area is the role vitamin B6 may play in reducing inflammation, which could impact many chronic diseases from heart disease to diabetes to arthritis to dementia.
This involves B vitamins taken at an appropriate pharmaceutical level under the care of a clinician as B6 can be toxic in large amounts.
