High Homocysteine Levels Linked to Alzheimer's

High circulating homocysteine levels, especially with increasing age, may be linked with cognitive impairment, according to researchers from the third National Health and Nutrition Examination Survey.

Recent studies have shown that extremely high serum homocysteine levels may be associated with Alzheimer's disease and dementia after multiple strokes. Researchers in this current study assessed the relationship between homocysteine levels and short-term memory recall in a group of elderly people and found an independent relationship between very high homocysteine levels and poor performance on cognitive tests.

Approximately 1,300 men and women over age 60, with no prior history of stroke, participated in the study that ran from 1991 to 1994. The participants' serum levels of nutrients, cholesterol, folate and homocysteine were measured and factors of gender, age, years of education, income and ethnicity were controlled in the data assessment.

The researchers found that story recall was weaker in subjects with a combination of low folate and high homocysteine than in those whose homocysteine levels were normal or low. Homocysteine levels increased with age and were accompanied by a comparable decline in folate.

The status of folate in the participants' blood was critical, as folate has been shown to significantly modify homocysteine levels.

The researchers concluded that there was an independent association between the highest levels of homocysteine and poorer recall. Among participants with the highest levels of serum homocysteine, the odds of passing a word delayed-recall test were identical whether their folate levels were high or low.

Other sources: American Journal of Clinical Nutrition