Written by Greg Arnold, DC, CSCS. In the Framington study of 2000 patients, those with the highest homocysteine blood levels had an increased risk of mini strokes compared to those with the lowest homocysteine blood levels.

Homocysteine (Hcy) is an amino acid that is not used directly by the body but must be converted into cysteine and taurine, which are important amino acids for the heart, liver and glutathione production (1).  If Hcy is not broken down, its level can increase and pose a number of health risks, including increased risks for cardiovascular disease (2), (3) and a doubling of risk for Alzheimer Disease (4).

When looking at how elevated Hcy levels are associated with an increased risk of stroke (5) and Alzheimer disease (6), research has started to focus on both blood vessel and nerve cell health. Now a new study (7) has found that high homocysteine levels do indeed play a role in brain and blood vessel health.

In the study, nearly 2,000 patients (average age of 59) participating in the Framingham Health Study (8) underwent an MRI and had their Hcy levels measured. The MRI scans were read by medical professionals who did not know the patients’ age, sex, Hcy levels and exposure to stroke risk factors.  The researchers calculated brain volumes of different parts of the brain using mathematical models applied in previous research (9).

The researchers found “a strong, independent, cross-sectional association” between higher Hcy levels and lower total brain volume, as well as “an increased risk” of mini-strokes (called “subclinical infarcts” (SBI)) for patients with the highest blood levels of Hcy (14.3 micromoles per Liter) compared to those with the lowest Hcy levels (6.5 micromoles/Liter).  Specifically, white matter measurements were decreased by 13% while SBI measurements were increased by 51% in the highest Hcy group compared to the lowest Hcy group. These findings agreed with previous research regarding Hcy levels and both stroke (10) and SBI (11).

For the researchers, “our findings suggest that [Hcy levels] may have a sustained role in the changes of brain aging and dementia, affecting not only the incidence of…stroke and dementia…but also the prevalence of subclinical brain MRI changes in an apparently healthy population.”

Source: Seshadri, Sudha, Philip A. Wolf, Alexa S. Beiser, Jacob Selhub, Rhoda Au, Paul F. Jacques, Mitsuhiro Yoshita, Irwin H. Rosenberg, Ralph B. D’Agostino, and Charles DeCarli. “Association of plasma total homocysteine levels with subclinical brain injury: cerebral volumes, white matter hyperintensity, and silent brain infarcts at volumetric magnetic resonance imaging in the Framingham Offspring Study.” Archives of neurology 65, no. 5 (2008): 642-649.

©2008 American Medical Association. All rights reserved.

Posted August 22, 2008.

References:

  1. LEF (2003). Life Extension Foundation’s Guide to Disease Prevention and Treament, Life Extension Media. Fourth Edition. p. 419-421.
  2. Towfighi A.  Factors Associated with the Steep Increase in Late Midlife Stroke Occurrence among US Men.  Jou Stroke Crebrovasc Dis 2008; 17(4): 165-168.
  3. Towfighi A.  Factors Associated with the Steep Increase in Late Midlife Stroke Occurrence among US Men.  Jou Stroke Crebrovasc Dis 2008; 17(4): 165-168.
  4. “High Homocysteine Levels May Double Risk of Dementia, Alzheimer’s Disease, New Report Suggests” posted on the National Institutes of Health website.
  5. Bostom AG, Rosenberg IH, Silbershatz H; et al. Nonfasting plasma total homocysteine levels and stroke incidence in elderly persons: the Framingham Study. Ann Intern Med. 1999;131(5):352-355.
  6. Seshadri S, Beiser A, Selhub J; et al. Plasma homocysteine as a risk factor for dementia and Alzheimer’s disease. N Engl J Med. 2002;346(7):476-483.
  7. Seshadri S.  Association of Plasma Total Homocysteine Levels With Subclinical Brain Injury.   Arch Neurol.2008; 65: 642-649.
  8. Feinleib M, Garrison RJ, Stallones L, Kannel WB, Castelli WP, McNamara PM. A comparison of blood pressure, total cholesterol and cigarette smoking in parents in 1950 and their children in 1970. Am J Epidemiol. 1979;110(3):291-303.
  9. DeCarli C, Maisog J, Murphy DG, Teichberg D, Rapoport SI, Horwitz B. Method for quantification of brain, ventricular, and subarachnoid CSF volumes from MR images. J Comput Assist Tomogr. 1992;16(2):274-284.
  10. Eikelboom JW, Hankey GJ, Anand SS, Lofthouse E, Staples N, Baker RI. Association between high homocyst(e)ine and ischemic stroke due to large- and small-artery disease but not other etiologic subtypes of ischemic stroke. Stroke. 2000;31(5):1069-1075.
  11. Matsui T, Arai H, Yuzuriha T; et al. Elevated plasma homocysteine levels and risk of silent brain infarction in elderly people. Stroke. 2001;32(5):1116-1119.