With the ageing population predicted to double by 2050, it’s of prime concern to optimise older consumers’ health span, including supporting cognitive health. Dietary habits and vitamin intake are one way to do that. For instance, vitamin B complex aids with cellular energy, methylation, DNA synthesis and repair, immune system, and steroid hormone activities. Further, the B vitamins play important roles in homocysteine metabolism, which is linked to cognitive performance.
Vitamin B6 (pyridoxine), B9 (folate), and B12 (cobalamin) make up the core part of the vitamin B complex involved with homocysteine metabolism. Thus, vitamin B supplementation and its neuro-protective properties may improve the cognitive performance of the ageing population. To better understand the correlation between vitamin B supplementation and cognitive performance among the elderly aged 60 years old or older, researchers analysed the US National Health and Examination Survey (NHANES) survey data from 2011- 2012 and 2013-2014, focusing on cognitive functions. The results were published in Neuropsychiatr Dis Treat (DOI: 10.2147/NDT.S337617).
As part of the NHANES survey, participants had interviews at home; they also went to a mobile examination centre (MEC) for a physical check-up—including CERAD [Consortium to Establish a Registry for Alzheimer’s disease], word learning and recall modules, AF [Animal Fluency test], and DSST [Digit Symbol Substitution Test]—to look at divergent cognitive domains. As explained by researchers, “Individuals who had missing data in vitamin B6, B9, and B12 intakes, body mass index (BMI), poverty income ratio (PIR), alcohol use, education level, hypertension, and cardiovascular diseases were excluded (n=516).” Researchers analysed the data of 2,421 people total, 46.54% male and 53.46% female representing ‘Mexican American’ (3.12%), ‘Other Hispanic’ (3.27%), ‘Non-Hispanic White’ (81.29%), ‘Non-Hispanic Black’, and ‘Other races.’ Researchers further grouped participants into low cognitive performance (LCP) or normal cognitive performance (NCP) groups based on their CERAD, AF and DSST scores. “Respective cut-off values for CERAD, AF and DSST were 5, 13 and 35”, they added.
When looking at vitamin B intake, researchers noted they “obtained vitamin B6, B9 and B12 consumption from the Dietary Interview-Total Nutrient Intakes dataset.” They further differentiated among groups meeting the recommended dietary allowance (RDA) or higher versus those taking lower levels of vitamins compared to the RDA—Vitamin B6 ≥1.7mcg/day or <1.7mcg/day; Vitamin B9 ≥400mcg/day and <400mcg/day; and Vitamin B12 ≥2.4mcg/day and <2.4 mcg/day. The levels below RDA were used as the reference group for results analysis.
The current research results included 337, 398 and 563 participants in the LCP group following CERAD, AF and DSST tests, respectively. Interestingly, participants in the LCP group were generally older, aged 70 years old or older; and were found to have significantly more heart-related problems than the NCP group. When looking at vitamin consumption, the LCP group had more participants following the RDA recommendations for all the vitamin B groups – 6, 9, and 12.
The results from CERAD showed vitamin B6 consumption was not significantly correlated with the risk of LCP; higher levels of vitamin B9 and B12 consumption were linked to minimised risk of LCP. Similar results were found for AF tests. When looking at the DSST test, researchers found that meeting the RDA of vitamin B6 lowered the risk of LCP by 31.7%; higher levels of vitamin B9 and B12 intake also reduced the risk of LCP.
When looking at subgroup analyses, researchers found vitamin B6 consumption benefited most older adults aged between 60 and 69 years old and ‘Non-Hispanic Black’ race; vitamin B9 benefitted most participants aged 60 to 69 years old, older men, older women, and the elderly from the ‘Non-Hispanic white’ race; and vitamin B12 showed benefits for older participants ages 60 – 69, 70 – 79 and ≥80 years old (both men and women), ‘Non-Hispanic white’ and ‘Non-Hispanic black’ races.
Researchers concluded: “Our findings suggest that vitamin B9 and vitamin B12 intakes strongly correlate with cognitive performances among elderly participants. Individuals who consumed adequate vitamin B9 and vitamin B12 are associated with significantly better cognitive performances across all three cognitive tests, including immediate and delayed memory recall, categorical verbal fluency, processing speed, sustained attention, and working memory. Of the three cognitive tests, adequate vitamin B9 and vitamin B12 consumption display the greatest protective effects using the DSST test. Furthermore, adequate vitamin B6 intake is only associated with better cognitive performance when evaluated by the DSST test, implying the prominent role of B vitamins in maintaining normal processing speed, sustained attention, and working memory among elderly people. Further, the relations between 3 B vitamins and cognitive performance vary across different sex, race, and age groups of people.”