Dementia is more likely to occur in those who are older, relatively poorly educated, inactive, and have deposits of the protein ApoE. Researchers now believe the onset of dementia is significantly more likely in those with lower than usual foliate levels.

Researchers tracked the development of dementia in 518 people over 2 years (2001-2003). Participants were over the age of 65. Blood test were taken periodically to assess their level of foliate, vitamin B12, and the protein homocysteine over time.

The higher the levels of foliate at the beginning of the study, the higher was the vitamin B12 levels, and the lower the levels of homocysteine. By the end of the study those participants who had a decrease in their level of foliate. Of the subjects, 45 participants had developed dementia. Of those, 34 had Alzheimer’s disease, 7 had vascular dementia, and 4 had ‘other’ types of dementia. People who were foliate deficient at the beginning of the study were almost 3.5 times more likely to develop dementia.