Written by Angeline A. De Leon, Staff Writer. This longitudinal study demonstrated the health benefits of vitamins B12, B6, folate and riboflavin in reducing cognitive decline in the elderly .
One of the major challenges facing global public health today is finding new strategies to prevent the cognitive decline associated with advancing age. A concentration of studies are showing that certain nutritional deficiencies, including deficits in B-vitamins such as folate 1 and vitamin B12 2, may contribute directly to cognitive dysfunction. However, clinical benefits of B-vitamin supplementation are mixed 3, and the individual roles of B-vitamins, particularly vitamin B6, in cognition remain relatively unstudied.
In Ireland, a study by Hughes and colleagues (2017) conducted the first longitudinal examination of the effects of dietary intake and biomarker status of four key B-vitamins (folate, vitamin B12, vitamin B6, and riboflavin) on the cognitive health of older adults. A total of 155 healthy senior participants (aged 60-88), verified for normal vitamin B12 levels and the absence of vitamin-B supplementation, completed assessment procedures at baseline and again at the 4-year follow-up period. Baseline assessment involved the following initial measurements:
- Cognitive Function Test: The Mini-Mental State Examination (MMSE), a widely used cognitive screening tool designed to measure global cognitive function, was employed to assess orientation, attention, concentration, and recall. Based on a 30-point scale, scores less than 25 indicate cognitive impairment and scores less than 20 indicate dementia.
- Dietary Assessment: Dietary intake of B-vitamins from natural and fortified food was estimated using a 4-day food diary (a recorded account of variable daily nutritional intake over 4 consecutive days), in combination with a food frequency questionnaire (a self-report measure on the frequency of consumption of food groups or branded products specially fortified with B-vitamins).
- Laboratory Analysis: Participants provided a fasting 30 mL blood sample, which was chemically analyzed to obtain individual biomarker concentrations of folate, vitamin B12, vitamin B6, and riboflavin.
At follow-up, the MMSE was readministered to evaluate participants for cognitive decline (defined as a decrease of more than 0.56 points per year on the MMSE).
Statistical analyses of the data indicated significant correlations between dietary intake and corresponding baseline blood biomarker concentrations for three of four B-vitamins of interest: folate (r = 0.579, p < 0.001), vitamin B6 (r = 0.306, p < 0.001), and riboflavin (r = -0.414, p < 0.001).
Furthermore, results showed vitamin B6 to be the only B-vitamin that was predictive of cognitive decline: Subjects with lower vitamin B6 biomarker status (measured by plasma concentrations of pyridoxal-5-phosphate (PLP) less than 43.3 nmol/L) showed about 3.5 times higher risk of cognitive decline (Odds Ratio, OR = 3.48; 95% CI: 1.58-7.63; p < 0.05). Likewise, those with lower dietary intake of B6 (0.9-1.4 mg/day) showed higher odds for cognitive decline as well (OR = 4.22; 95% CI: 1.28-13.90; p = 0.018).
The association between lower baseline vitamin B6 status (based on dietary intake and biomarker status) and accelerated cognitive decline over a 4-year period coincides with vitamin B6’s known role in various nervous system functions 4. This exploratory study, therefore, confirms early evidence of vitamin B6 as a critical protective factor in maintaining cognitive health in older adults. To substantiate current findings on the relationship of B-vitamins and the cognitive health of older adults, future research in the form of well-designed randomised controlled trials would be valuable.
Source: Hughes CF, Ward M, Tracey F, et al. B-Vitamin intake and biomarker status in relation to cognitive decline in healthy older adults in a 4-year follow-up study. Nutrients. 2017; 9(1):53. DOI: 10.3390/nu9010053.
© 2017 by the authors; licensee MDPI, Basel, Switzerland. Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
Posted April 3, 2017.
Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program.
References:
- Doets EL, Ueland PM, Tell GS, et al. Interactions between plasma concentrations of folate and markers of vitamin B 12 status with cognitive performance in elderly people not exposed to folic acid fortification: the Hordaland Health Study. British Journal of Nutrition. 2014;111(06):1085-1095.
- Clarke R, Birks J, Nexo E, et al. Low vitamin B-12 status and risk of cognitive decline in older adults. The American journal of clinical nutrition. 2007;86(5):1384-1391.
- Wald DS, Kasturiratne A, Simmonds M. Effect of folic acid, with or without other B vitamins, on cognitive decline: meta-analysis of randomized trials. The American journal of medicine. 2010;123(6):522-527. e522.
- Guilarte TR. Vitamin B6 and cognitive development: recent research findings from human and animal studies. Nutrition reviews. 1993;51(7):193-198.
