♦ The elderly who are suffering from mild cognitive impairment could improve their cognition function if their diet is supplemented with B vitamins such as B6, B12 and folic acid.

A recent study by researchers at Suwon Women’s University in GyungGi-do and Kyung Hee University in Seoul, South Korea has been examining how B vitamins might help alleviate if not improve cognitive function in those who suffer from mild cognitive impairment (MCI). The research was reported in the PubMed’s Journal of Nursing Scholarship ((Lee et al., 2016). It reverses some findings from earlier research on intervention studies with B vitamins which did not produce such improvements for those with dementia.

Subjects were given a daily regimen of various B vitamin supplements over 12 weeks and they were found at the end of the study to have lower levels of depression and there were also decreased levels of an important amino-acid metabolite called homocysteine. This particular amino-acid is associated although not wholly proved, with losses in brain function including depression, rising levels of anxiety and dementia.

The number of elderly in all countries is rising and with it comes rising levels of dementia. Mild cognitive impairment (MCI) is the transitional stage between normal aging and dementia according to the American Psychiatric Association (1994). The presence of MCI is a risk factor for the development of a full blown dementia (Morris, 2001; Kim et al., 2007). The wider implication from this latest study is that from a nursing perspective, vitamin supplementation could be an intervention that improves cognitive function by reducing serum homocysteine levels and so minimise development of dementia and even alleviate depression in elderly people in aged care facilities. The researchers also comment that it might mean reducing the incidence of cognitive disorders and depression in the elderly in aged care facilities which means they might adapt to such facilities better and even have an improved quality of life.

Homocysteine Levels Reduced By B Vitamins

Increasing levels of homocysteine have often been regularly reported to be associated with brain function loss, even atrophy and a leading factor for mild cognitive impairment (MCI). Other studies report that high homocysteine levels are linked to suspected and confirmed dementia. One study, the Framlingham has stated that when homocysteine levels are above 14 micromoles per litre of serum they had twice the risk from dementia.

Even now, a number of mechanisms have been proposed for the effects of homocysteine on cognitive decline. Raised homocysteine levels may produce DNA damage in the central nervous system as well as being implicated in vascular disease (Kruman et al., 2002; Irizarry et al., 2005).

It is hypothesized that the impairment of glutathione metabolism by homocysteine and raised levels of oxidative stress, increased levels of impaired DNA methylation, and associated epigenetic mechanisms might increase amyloid-b-peptide production and toxicity as witnessed in Alzheimer’s disease (Fuso et al., 2005). The raised concentrations of both homocysteic acid, which is an N-methyl-D-aspartate receptor agonist and a metabolite of homocysteine, may result in neuronal dysfunction (Gortz et al., 2004).

The interest in B vitamin supplementation comes from an understanding that both plasma and tissue concentration of homocysteine are directly linked to levels of vitamin B. The vitamin is a critical cofactor in homocysteine balance.

The Study

 In this study, 48 people over the age of 65 with MCI who were living in care homes were randomly split into two groups. One group received the B vitamin supplement whilst the other received the placebo. After 12 weeks, the participants receiving the supplement scored better on the Mini Mental State Examination-Korean test and the Geriatric Depression Scale Short Form Korea Version test compared to the control. The serum homocysteine levels were also reduced when B vits were fed too.

The discussion in the paper states:-

“The correlation between the serum homocysteine level and impaired cognitive function is still controversial, according to various studies.”

 “Some studies claimed that the influence of the serum homocysteine level on impaired cognitive function decreased after age adjustment, presenting impaired cognitive function as just one of the symptoms of aging.”

“The result of this study confirmed, however, that vitamin supplement intake was an effective intervention for cognitive function improvement in elderly people with MCI in aged care facilities.”

 “In future studies, to confirm the effects more effectively in elderly people with MCI in aged care facilities, the long-term intake of vitamin supplements and the repetitive evaluation of improvement at various time points should also be conducted as a nursing interventional study.”

References

American Psychiatric Association. (1994) Diagnostic and statistical manual of mental disorders (DSM-IV). 4th ed. Washington: APA.

Fuso, A., Seminara, L., Cavallaro, R.A., D’Anselmi, F., Scarpa, S. (2005) S-adenosylmethionine/homocysteine cycle alterations modify DNA methylation status with consequent deregulation of PS1 and BACE and beta-amyloid production. Mol. Cell Neurosci. 28 pp. 195–204.

Gortz, P., Hoinkes, A., Fleischer, W., Otto, F., Schwahn, B., Wendel, U., Siebler, M. (2004) Implications for hyperhomocysteinemia: not homocysteine but its oxidized forms strongly inhibit neuronal network activity. J. Neurol Sci. 218 pp. 109–14.

Irizarry, M.C., Gurol, M.E., Raju, S., Diaz-Arrastia, R., Locascio, J.J., Tennis, M., Hyman, B.T., Growdon, J.H., Greenberg, S.M., et al. (2005) Association of homocysteine with plasma amyloid beta protein in aging and neurodegenerative disease. Neurology. 65 pp. 1402–8.

Kim, J., Park, M. H., Kim, E., Han, C., Jo, S. A., & Jo, I. (2007). Plasma homocysteine is associated with the risk of mild cognitive impairment in an elderly Korean population. J. Nutrition, 137(9), pp. 2093-2097.

Kruman, I., Kumaravel, T.S., Lohani, A., Pedersen, W.A., Cutler, R.G., Kruman, Y., Haughey, N., Lee, J., Evans, M . et al. (2002) Folic acid deficiency and homocysteine impair DNA repair in hippocampal neurons and sensitize them to amyloid toxicity in experimental models of Alzheimer’s disease. Neurosci. 22 pp. 1752–62.

Morris, J.C., Storandt, M., Miller, J.P., McKeel, D.W., Price, J.L., Rubin, E.H., Berg, L. (2001) Mild cognitive impairment represents early-stage Alzheimer disease. Arch. Neurol. 58 pp. 397–405.

Lee, H.K., Kim, S.Y. Sok, S.R. (2016) Effect of Multivitamin Supplements on Cognitive Function, Serum Homocysteine Level, and Depression of Korean With Mild Cognitive Impairment in care Facilities. J. Nursing Scholarship. doi: 10.111/jnu.12201