Vitamin B12 may slow brain aging

An important study appeared in JAMA Psychiatry (Journal of the American Medical Assoc.) in June 2016, providing additional evidence that high blood levels of vitamin B12 can slow the shrinking of the brain that commonly occurs after age 60.

Previous studies have also shown that vitamin B12 and other B vitamins (folic acid and vitamin B6) can slow the rate of brain atrophy, the actual shrinking of the brain. Older people are subject to mild cognitive impairment and increased risk of progression to Alzheimer's disease. Emerging scientific evidence suggests if you can slow or prevent the shrinking of the brain as you age, you may decrease your risk of dementia and Alzheimer's disease substantially.

Vitamin B12 is required to make a number of brain neurotransmitters and has been shown to have neuroprotective effects, which may directly slow brain shrinking. Taking vitamin B12 may slow down this atrophy by lowering the levels of homocysteine in the blood. High homocysteine is known to be extremely damaging to the brain and cerebrovascular blood vessels. Homocysteine is correlated to brain atrophy and the risk of Alzheimer's disease.

Other B vitamins matter as well. A study of individuals older than 70 who already had some form of MCI (mild cognitive impairment) revealed that taking folic acid/B6/B12 every day for two years slowed brain atrophy by 30%, and in a few cases by 50%. In most cases, these unusually high levels in the blood can be achieved by using a simple B vitamin supplement. Vitamin B is a water-soluble element and is absorbed and excreted very easily from the body, reducing the chance of retaining too much. Vitamin B12 is very safe and effective. Always check with your pharmacist if you are taking any prescription medications.

These studies are important because we know MCI is the step that precedes development of Alzheimer's disease. This is one reason why it is very important to prevent the brain from shrinking. Alzheimer's patients show an average brain shrinkage rate of 2.5 % per year, whereas the normal rate is only 0.5%. That is 5 times the normal rate. So anything that slows the brain from shrinking is to be considered an invaluable way to preserve cognition as we age.

Vitamin B12 cannot be made by the body, so we must regularly consume enough B12 to meet the necessary requirement. How much is enough? Current guidelines show 2.4 to 3 micrograms per day; this is very conservative. I believe we should consume 4.5 to 7 micrograms per day. Remember, this is a water-soluble substance and will pass through your system in 3-5 hours. The best food sources of B12 are meats, poultry, eggs, dairy, and fortified grains. Since B12 is not found in plants, vegetarians and vegans should consider adding a supplement.

Consuming enough vitamin B12 is only part of the solution. The other factor is the individual’s ability to absorb and assimilate the B12. You may have problems absorbing enough B12 if you have had stomach reduction surgery, suffer from intestinal illness such as Crohn’s disease, or take acid-reducing medications prescribed for heartburn.