Overview
Homocysteine is an amino acid, a building block of protein, formed as a result of methionine metabolism. According to the American Association for Clinical Chemistry, methionine, an essential amino acid, must be derived from the diet. In healthy individuals, homocysteine converts to other products, while an accumulation of the amino acid causes negative effects on the body. A fasting blood sample is tested for homocysteine levels with normal findings ranging from 4 to 14 micromoles per liter.
Significance
Homocysteine levels predict and screen for coronary, cerebral and peripheral vascular disease for people with a high risk of developing heart attack or coronary artery disease. Some individuals may not have any lifestyle-based risk factors such as smoking, obesity or high cholesterol, however excess homocysteine can still lead to heart disease because of genetic inheritance. According to the American Heart Association, elevated levels of the amino acid may contribute to development of atherosclerosis, a condition that affects the lining of blood vessels causing build-up of plaque and the hardening and narrowing of arteries. Additionally, an increased tendency to develop blood clots exists with homocysteine elevation.
Effects
Besides increasing the risk for atherosclerosis, blood clotting and causing vascular disease, elevated homocysteine levels play a role in other conditions as well. According to the “Mosby’s Manual of Diagnostic and Laboratory Tests” by Drs. Kathleen Deska Pagana and Timothy J. Pagana, individuals with high levels are at a five-times increased risk for stroke, dementia and Alzheimer’s disease. Additionally, it also appears to be a risk factor for osteoporosis-related fractures in older men and women.
Causes
Causes of excess homocysteine levels are either genetic or acquired. According to the American Academy of Family Physicians, a diet deficient in folic acid, vitamin B6 and vitamin B12 results in high homocysteine levels. Without these vitamins, homocysteine cannot be changed into other usable amino acids and therefore accumulates in the blood.
Furthermore, due to the connection of excess homocysteine and dietary deficiency, blood testing may be recommended for individuals with known malnutrition such as the elderly, alcohol and drug abusers, or those with malabsorption issues, according to the American Association for Clinical Chemistry.
Additionally as stated by the AAFP, conditions such as low thyroid hormone levels, kidney disease, a skin condition called psoriasis and certain medications can possibly cause high homocysteine levels.
Considerations
Meat contains elevated levels of homocysteine; therefore fasting for up to 12 hours prior to the test is required to obtain an accurate reading. Drs. Pagana and Pagana also state several factors may interfere with actual levels of the amino acid, such as age and gender. Homocysteine levels increase as people age and men tend to have higher levels than women, most likely on account of greater muscle mass. The AACC adds that following menopause, homocysteine concentration increases for women as a result of decreased hormone estrogen production.
Prevention/Solution
The simplest way to prevent an excess or return homocysteine levels to an acceptable range is through dietary changes. Increasing folic acid, or folate, and B vitamins will decrease homocysteine in the blood. Folic acid can be found in leafy green vegetables such as spinach, as well as beans, lentils, asparagus and fruits such as strawberries or citrus fruits. Breakfast cereals and grain products serve as good sources for folate as well. Vitamin B6 can be found in bananas, potatoes and chicken, while vitamin B12 is present in dairy products, organ meats, red meats and some seafood.
About this Author
Based in Chicago, Jojo Genden is passionate about sharing her health and wellness expertise through writing since 2008. She holds a Bachelor of Science in biology from Rockford College, and a Bachelor of Science in nursing from Edinboro University of Pennsylvania. Genden is a registered nurse in the state of Illinois with a background in intensive care.
