Homocysteine is an amino acid that is produced by the body, usually as a byproduct of consuming meat. Amino acids are naturally made products, which are the building blocks of all the proteins in the body.

Below are some cut and pasted sections of the study that were intriguing:

In cross-sectional studies, elevated plasma homocysteine levels have been associated with poor cognition and dementia. Studies of newly diagnosed dementia are required in order to establish whether the elevated homocysteine levels precede the onset of dementia or result from dementia-related nutritional and vitamin deficiencies.

Low serum levels of certain B vitamins (folate and vitamins B12 and B6) have been associated with elevated plasma homocysteine levels in several studies and with an increased risk of dementia in a few investigations. In our study, the observed association between plasma homocysteine and risk of dementia was not significantly altered by adjustment for the plasma levels of these vitamins (Table 3). Furthermore, after adjustment for age, sex, and APOE genotype, none of these vitamin levels were independently related to the risk of dementia or Alzheimer’s disease (data not shown).

Their Conclusion? An increased plasma homocysteine level is a strong, independent risk factor for the development of dementia and Alzheimer’s disease.

Here is a link to the article in The New England Journal of Medicine.