Homocysteine has become an important marker of cardiovascular health risk. At high levels, it has been shown to damage the vessels of the heart and promote blood clot formation, which can result in heart disease and stroke.

Many of us are unaware of our homocysteine levels, as there are no symptoms when they are too high, and testing is not routinely performed.

Many natural healthcare practitioners use homocysteine as an important component of cardiovascular screening tests. If these amino acid levels are found to be outside the optimal range, there are several important nutrients that can lower levels and help prevent cardiovascular disease.

What is Homocysteine?

It is an amino acid that comes from the digestion of proteins. It is formed from methionine, an essential amino acid found abundantly in animal protein such as meat, seafood, dairy, and eggs. Once it is formed from methionine, it is metabolized in two ways: it is either recycled back into methionine or it is converted into another amino acid, cysteine. Both of these actions require folate (or folic acid), pyridoxine (B6), and cobalamin (B12) in order to work effectively. Inadequate levels of these nutrients prevent homocysteine breakdown and can lead to persistently high levels.

Why Are High Levels of Homocysteine Are Unhealthy?

When present in high levels, it has been linked to heart disease and stroke. High circulating homocysteine appears to cause injury to the delicate cells of the coronary arteries. Continued cellular injury leads to vascular inflammation, which ultimately causes scarring and hardening of the arteries known as atherosclerosis. This process results in thicker and less elastic artery walls and a narrowing of arterial openings, thus reducing blood flow.

Secondly, it has effects on the action of blood platelets, promoting blood clot formation. Large clots can travel through the body to the cardiac arteries of the heart, causing a heart attack, or to the vessels of the brain, causing a stroke. Further, recent evidence has also shown that even slightly elevated levels of this amino acid above normal ranges can double the risk of developing Alzheimer's disease.

Causes of High Homocysteine

Because protein-rich diets are high in methionine, they consequently produce high levels of homocysteine. For this reason, diets rich in animal protein but low in fruits and leafy vegetables tend to promote high homocysteine levels. In addition, insufficient consumption of green vegetables results in inadequate intake of B vitamins and folic acid, which are essential for the breakdown of this amino acid. High stress levels can also contribute to high circulating homocysteine.

The body's levels of neurotransmitters epinephrine (adrenaline) and norepinephrine increase when exposed to stress. The body uses the methionine-homocysteine pathway to break these neurotransmitters down and return to a non-stressed state. Researchers have also noticed a correlation between coffee consumption and high homocysteine levels. It seems that as coffee intake goes up, so too does homocysteine.

How Do I Know If I Have High Homocysteine?

There are no physical symptoms of high homocysteine; levels can only be checked via blood tests. These tests are usually not routinely performed by physicians and are often overlooked in favour of other cardiovascular risk markers such as cholesterol levels or blood pressure measurements. Normal levels of homocysteine should range between 5-15 mmol/L, although it is suggested that levels less than 7-8 mmol/L are preferable.

Homocysteine Support Options

Conventional Treatment 

Since there are no medications that directly reduce its levels, conventional treatment usually consists of attempts to increase dietary intake of B vitamins and folic acid in order to indirectly promote homocysteine breakdown.

Naturopathic Treatment

Naturopathic treatment is similar in dietary approach. Emphasis is on increased consumption of foods rich in B6, B12, and folic acid. Folate-rich foods include beans and legumes,broccoli, asparagus, and leafy greens such as spinach. B6 and B12 are found in most meats and fortified cereals, and B6 is additionally found in bananas, sweet potato, and spinach. In addition, it is recommended that methionine-rich foods such as red meat and dairy be avoided. It is advisable to reduce foods high in animal protein to a daily max of 3-4oz (120g).

Lifestyle interventions are also important. In particular, modulating stress levels through breathing exercises, meditation, and yoga will help reduce homocysteine formation. Exercise is excellent for reducing stress and has been shown to reduce homocysteine levels by as much as 12%.

As explained above, vitamin B6 and B12 are essential for the recycling, conversion, and ultimately the breakdown of excess it in the blood. Since levels of homocysteine increase with age and our ability to absorb vitamin B12 decreases with age, it is especially important for older individuals to supplement appropriately.

  1. Vitamin B 12

Vitamin B12 is absorbed differently depending on how it is taken. Oral doses should be sublingual, that is, they should be dissolved under the tongue and not swallowed. For even better absorption, concentrated doses of B12 can be injected into the muscle of the arm. This procedure is commonly performed by naturopathic doctors in the office.

2. 5-Methyltetrahydrafolate (5-MTHF)

Folate is especially important for the breakdown of excess it. Recent studies have shown that simply taking a folic acid supplement is not sufficient to increase blood levels enough to affect homocysteine.

Instead, it is recommended that an active form of folic acid, specifically 5-methyltetrahydrofolate (5-MTHF), be taken. This is effective at much lower doses than regular folate, so less is more.

3. Trimethylglycine (TMG)

TMG or trimethylglycine, also known as glycine betaine, is a compound found in quinoa, spinach, lamb and beets, where it was first discovered. It is especially important for the recycling of homocysteine back into methionine, thus reducing total homocysteine levels. Therapeutic doses are usually achieved through supplementation.

4. SAMe

SAMe, like homocysteine, is also synthesized from methionine. Not only does it promote the conversion of homocysteine to cysteine, but it also increases the action of folate, which is essential for homocysteine reduction.

5. N-acetyl-cysteine (NAC)

NAC, also known as N-acetyl-cysteine, has been shown to reduce homocysteine levels by promoting its conversion to cysteine. This is accomplished by dislodging homocysteine from its protein carrier in blood, making it more susceptible to breakdown.

6. Omega-3 Fatty Acids

Omega-3 fatty acids have a wide variety of benefits when it comes to heart health; however, their effects on it are relatively new discoveries. While the mechanism of how this action occurs is still unknown, studies have shown that supplementation with omega-3s causes a reduction in blood levels of homocysteine.

7. Taurine

Taurine is another nutrient well studied in cardiovascular disease. Research suggests that this amino acid might actually block the absorption of methionine, which ultimately prevents its breakdown into homocysteine.