Association between malnutrition and hyperhomocysteine in Alzheimer's disease patients and diet intervention of betaine.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease, which is associated with malnutrition and hyperhomocysteine. The current study aimed to analyze the relationship between malnutrition and hyperhomocysteine in AD patients, and effects of diet intervention with betaine on the disease.

METHODS: The nutritional statuses of the AD patients were assessed by short form mini nutritional assessment (MNA-SF). The levels of Hcy, tau hyperphosphorylation, synaptic proteins, blood inflammatory factors were measured by enzymatic cycling assay, Western blot and ELISA. The cognitive function was measured by AD assessment scale (ADAS-cog).

RESULTS: There was a significant difference in mental status between normal people and AD patients (P<.05). Overall, malnutrition was reported in a larger proportion of AD patients and high level of Hcy was closely associated with malnutrition. Betaine decreased the levels of phosphorylated tau, elevated PP2Ac activity and inhibited Aβ accumulation (P<.05). The levels of IL-lβ and TNF-α were significantly higher in the untreatment group while much lower in the intervention group (P<.05). After intervention of betaine treatment, the expression level of Hcy can be restored and betaine can effectively suppress inflammation as well as trigger an increase in memory-related proteins. ADAS-Cog suggested that significant improvement was found after the intervention of betaine.

CONCLUSIONS: AD was associated with both malnutrition and higher levels of Hcy. Betaine could restore Hcy expression to normal level in AD patient, which might ameliorate memory deficits.