High Homocysteine … A Risk to Your Heart?
Heart disease rates in the United States are rapidly declining -- but we're not in the clear yet. Heart disease remains neck and neck with cancer as the number one killer of adults of all ages. Continuing research on dietary choices as well as lifestyle factors and medical facts is helping lead the way toward healthy hearts for all.
In fact, current research into a new potential risk factor for heart disease -- elevated blood levels of homocysteine -- is looking promising. This new information about homocysteine and the associated impact on heart disease risk could open up a whole new avenue of heart disease prevention.
Have you heard of this new heart disease marker? Do you know what it is? Test your knowledge of this relative newcomer to the risk factor scene with the questions that follow.
Q. What the heck is homocysteine?
an amino acid
a hormone
a blood fat
none of the above
A. The correct answer is "an amino acid."
The production of homocysteine in the body is part of a complex system related to the metabolism of dietary protein.
When the body metabolises the amino acid methionine, homocysteine -- another kind of amino acid -- is formed as a product of this process. Normally, most of the homocysteine is recycled as other amino acids. However, the body needs sufficient amounts of dietary vitamin B12 and folate to do this. Without enough B12 and folate in the diet, the recycling process becomes faulty, causing homocysteine levels in the blood to rise.
Elevated blood levels of total homocysteine (tHcy) often indicate that you're not getting enough folate or B12 from food or supplements. The optimal amount of these nutrients varies considerably from person to person. However, other factors, such as lack of certain enzymes or a genetic predisposition to high levels of homocysteine, also can be at fault.
What's so bad about too much homocysteine? Over the last two decades, studies have looked at how tHcy relates to numerous health conditions. Read on to find out what researchers have discovered . . .
Q. Which of the following health problems has NOT been linked to elevated homocysteine levels?
deep vein thrombosis (DVT)
varicose veins
coronary artery disease
stroke
A. The correct answer is "varicose veins."
Elevated tHcy, or hyperhomocysteinemia, has been linked to numerous vascular problems such as DVT, coronary artery disease, and stroke. However, exactly how hyperhomocysteinemia might contribute to these cardiovascular conditions is not completely understood. Studies suggest that abnormal levels of homocysteine in the blood may damage the lining of blood vessels, making veins and arteries more susceptible to blockage or blood clots. This, in turn, may increase the risk of coronary artery disease, stroke, pulmonary embolism, and DVT.
To date, varicose veins have not been associated with elevated homocysteine levels.
Researchers are exploring potential connections between elevated homocysteine and many other conditions. For example, preliminary studies have linked elevated blood levels of homocysteine to such conditions as osteoporosis, pregnancy complications, and cognitive dysfunction ranging from mild cognitive decline (age-related memory loss) to Alzheimer's disease.
Many questions remain regarding all of these connections. It has yet to be determined whether homocysteine is:
- the direct cause of these conditions, or
- a consequence of these conditions, or
- a marker for something else that causes them, such as a B vitamin deficiency.
To better understand the questions surrounding homocysteine, let's take a look at how all the interest in homocysteine began.
In the Beginning . . .
Researchers first began exploring homocysteine as a risk factor for cardiovascular disease in the late 1960s after a pathologist investigating the stroke deaths of two children with a rare hereditary disorder known as homocystinuria pointed to the excess homocysteine in each child’s system as the cause. He proposed that high tHcy was at the root of the artery blockage that led to the children's strokes. This hypothesis prompted numerous studies on how mild to moderately elevated tHcy affects the arterial health of the general population.
Since then, additional findings have supported the pathologist’s original hypothesis. Moderately elevated blood levels of homocysteine have been associated with an increased risk of vascular disease in the coronary, cerebral, and peripheral arteries. However, studies that included healthy subjects with a low risk of cardiovascular disease yielded less consistent results. Such studies tended to indicate a weak association or no association between elevated tHcy and cardiovascular disease.
So who should have their homocysteine levels checked? The next question reveals the answer . . .
Q: Should all people have their homocysteine levels screened?
Yes, everyone
No, only people over 40
No, only people over 65
No, only specific populations
A. The correct answer is "No, only specific populations."
Based on the available evidence, screening is recommended only for specific populations, which includes people with:
- family members who developed heart problems at a young age
- family members whose tests have revealed high tHcy, or who have homocystinuria
- known cardiovascular disease, a history of cardiovascular problems, or prior heart attacks
- a high risk of cardiovascular disease
- a diagnosis of homocystinuria
- demonstrated folate deficiency or symptoms of this deficiency
If you don’t fall into any of the above groups, screening for high homocysteine levels is not recommended. Considering the conflicting research on people with low risk of cardiovascular disease, screening results may only open the door to unanswerable questions.
If you do fall into any of the above categories, ask your healthcare provider about having your homocysteine levels checked. The test can be performed as part of a routine blood fats panel; however, keep in mind that some insurance plans might not cover it, so check with your provider.
Find out more about plasma tHcy testing at Lab Tests Online.
So, what should you do if you want to guard against high homocysteine while researchers continue to study its impacts? As mentioned earlier, your body needs sufficient levels of both vitamin B12 and folate to convert homocysteine in the blood. Read on to find out the best foods sources of these nutrients.
