Hyperhomocysteine: High Levels of Homocysteine Increase Dementia Risk

Homocysteine Has Been Connected with an Increased Risk of Alzheimer's Disease
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What Is Homocysteiene?

Homocysteine is an amino acid in our bodies. It is naturally present but levels vary and can be influenced by vitamins, medical conditions and other factors.

What Is Hyperhomocysteine?

Hyper means high; thus, hyperhomocysteine is a high level of homocysteine. Increased levels of homocysteine have been associated with a higher risk of heart problems, stroke, bone fractures and dementia.

What Causes High Levels of Homocysteine?

High levels of homocysteine have been associated with aging, a decline in kidney functioning, poor ability to absorb (or low intake of) certain vitamins including folate/folic acid, vitamin B12 and vitamin B6, as well as some medical conditions and medications.

How Are Higher Levels of Homocysteine Connected to Dementia?

Several research studies have been conducted and have consistently found a correlation between higher levels of homocysteine and the following:

How Can We Change our Homocysteine Levels?

Vitamin supplementation has been shown to reduce homocysteine levels. This includes vitamin B12, vitamin B6, and folic acid (vitamin B9).

Has Vitamin Supplementation Been Shown to Decrease Dementia Risk?

It appears clear that higher levels of homocysteine are associated with an increased risk of developing dementia.

Additionally, vitamin supplementation has been shown to be effective in reducing homocysteine levels. The question that follows here is: Does the vitamin supplementation also improve cognition?

While one study suggests that there is little benefit to vitamin B supplements, other research found significant benefits.

Research results include the following:

  • Administration of vitamin B6, vitamin B12 and folic acid improved the cognitive functioning of middle-aged and older participants whose homocysteine levels were high at the beginning of the study.
  • People with mild cognitive impairment were given vitamin B supplements to decrease homocysteine levels. Researchers found that the rate of brain atrophy (shrinkage) decreased in those who were receiving the extra vitamins as compared to individuals who did not receive the supplements.
  • In a similar study with people who had mild cognitive impairment, vitamin B supplementation was associated with a slower rate of cognitive decline.


More research needs to be conducted on homocysteine levels and cognition, but there does appear to be a connection. Additionally, adequate levels of B vitamins have multiple physical benefits as well.

As a reminder, be sure to consult with your physician before making any changes in your diet, including vitamin supplementation, since unanticipated interactions can occur with other medications and health conditions.


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International Journal of Geriatric Psychiatry. Volume 27, Issue 6, pages 592–600, June 2012. Cognitive and clinical outcomes of homocysteine-lowering B-vitamin treatment in mild cognitive impairment: a randomized controlled trial. http://onlinelibrary.wiley.com/doi/10.1002/gps.2758/abstract

Journal of the American Geriatric Society. 2015 Jun;63(6):1158-63. Cognitive Status According to Homocysteine and B-Group Vitamins in Elderly Adults. http://www.ncbi.nlm.nih.gov/pubmed/26031567

Journal of Nutrition, Health & Aging. 2012 Aug;16(8):687-94. Conversion from mild cognitive impairment to dementia: influence of folic acid and vitamin B12 use in the VITA cohort. http://www.ncbi.nlm.nih.gov/pubmed/23076510

Neurobiology of Aging. 2015 Jan;36 Suppl 1:S203-10. Higher homocysteine associated with thinner cortical gray matter in 803 participants from the Alzheimer's Disease Neuroimaging Initiative. http://www.ncbi.nlm.nih.gov/pubmed/25444607

Nutritional Neuroscience. 2014 Jun 18. B vitamin supplementation improves cognitive function in the middle aged and elderly with hyperhomocysteinemia. http://www.ncbi.nlm.nih.gov/pubmed/24938711

Nutrition Reviews. 2015 Oct;73(10):723-35. Assessing the association between homocysteine and cognition: reflections on Bradford Hill, meta-analyses, and causality. http://www.ncbi.nlm.nih.gov/pubmed/26293664

PLOS One. September 8, 2010. Homocysteine-Lowering by B Vitamins Slows the Rate of Accelerated Brain Atrophy in Mild Cognitive Impairment: A Randomized Controlled Trial. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0012244

University of North Carolina. Folic acid for vascular outcome reduction in transplantation. Accessed November 25, 2015. http://www.cscc.unc.edu/favorit/faq.htm#5

Quest Diagnostics. Homosysteiene. June 2013. http://www.questdiagnostics.com/testcenter/testguide.action?dc=TS_Homocysteine

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