Recent news articles have been touting the benefits of B vitamins for slowing cognitive decline, citing research from a number of respected sources. While there is some connection between cognitive decline and diminished levels of folate and vitamins B6 and 12, there is still some question as to whether increasing their dosage can treat, slow, or halt intellectual decline.
Research into B vitamins and cognitive decline
A study published in the February 2015 Journal of the Academy of Nutrition and Dietetics addressed this question concerning the role folate, vitamin B6, and vitamin B12 play, if any, in the development of mild cognitive impairment (MCI) and possible dementia. Noting that existing work in this field had merely been observational in nature with few controls, the study followed more than 7,000 women over a five-year period. The women were given a food frequency questionnaire at the start of the study, and then self-reported B vitamin intake for the duration. Upon completion, 238 showed signs of mild cognitive impairment and 69 demonstrated probable dementia.
It was determined that folate intake below recommended daily allowances increased the risk of MCI/dementia. However, it also found that there was no correlation between vitamins B6 and B12 intake levels and MCI/dementia, nor was there any indication that interactions among these nutrients had any effect.
Importance of B vitamins
It has long been known that a folate deficiency can have an impact on cognitive ability; however, that does not mean that increasing intake beyond recommended allowances necessarily slows or halts MCI. Rather, maintaining the recommended folate level works as a preventive measure. The RDA of folate for individuals 14 and older is 400mcg of dietary folate equivalents (DFE); pregnant and lactating women need to consume 600 and 500mcg, respectively. While a healthy balanced diet will deliver the RDA for folates, for some individuals may require supplements to help reach target levels.
When B vitamins (this includes folic acid) are at recommended levels, they restrict the overproduction of homocysteine, a naturally occurring amino acid, high levels of which have been associated with brain shrinkage and the development of Alzheimer’s disease in the elderly. When homocysteine levels are elevated, increased doses of B vitamins can bring them down, thereby slowing its effects. However, there is no evidence that increasing B vitamin intake has any effect beyond that, including improving cognition. Furthermore, when homocysteine levels are normal, B vitamins had no impact.
Foods with Vitamin B6
In essence, failure to maintain healthy levels of B vitamins allows homocysteine levels to rise, hastening cognitive decline. For those looking for a super pill to improve their cognitive abilities, forget about a B vitamin magic bullet. However, to slow the gradual decline that can come with aging, eating a healthy diet and making sure minimum RDAs of folic acid, vitamin B6, and vitamin B12 are maintained is well-worth remembering.