Hooshmand B, Refsum H, Smith AD, et al. - Researchers examined the influence of methylation status (ie, methionine to homocysteine ratio) on the risk of incident dementia, Alzheimer disease (AD), and the rate of total brain tissue volume loss during 6 years. They conducted a population-based longitudinal study including a sample of 2,570 individuals (aged 60 to 102 years) from the Swedish Study on Aging and Care in Kungsholmen; participants were dementia-free at baseline and had undergone comprehensive examinations and structural brain MRI on 2 to 3 occasions during 6 years. Participants with better B₁₂ or folate status had a higher methionine to homocysteine ratio, which was associated with decreased risk of incident dementia and AD. They observed a decreased rate of total brain tissue volume loss during 6 years in correlation to a higher methionine to homocysteine ratio. These findings support a possible value of a higher methionine to homocysteine ratio in reducing the rate of brain atrophy and decreasing the risk of dementia in older adults.