Homocysteine is a breakdown product of protein metabolism when the amino acid Methionine is converted into toxic amino acid Homocysteine. Healthy methylation processes in body will ensure that homocysteine is converted back into methionine or into another harmless compound with the aid of ‘methyl group’ nutrients: vitamins B2, B3, B6, B12 and Folic Acid or Trimethylglycine (TMG also called Betaine) and Zinc. Those who lack these nutrients have poor methylation and most likely will retain homocysteine in their blood. High levels of homocysteine in blood leads to cardiovascular diseases, mental decline and psychological problems. A simple blood test can show the levels of homocysteine. Ideally it should not be higher than 7µmol/L.
Homocysteine is considered to be a cause for heart disease due to arterial damage it does, that may lead to heart attack and stroke. In fact, dangerously high levels of homocysteine (9µmol/L and above) increase the heart attack risk by 50% and the risk of stroke by 40%. High homocysteine level is also a risk factor for blood clots (Deeps Vein Thrombosis).
Research suggests that high homocysteine levels play a role in cognitive decline, mental disorders and even the development of Alzheimer’s disease. A Swedish study of 692 schoolchildren found that their monitored homocysteine level predicted their school grades. Another study has found that high levels of homocysteine doubles the likelihood of depression. Other studies show that people with Alzheimer’s and even with schizophrenia have poor methylation and consequently high levels of homocysteine in blood. In fact, homocysteine level above 14µmol/L amplifies the risk of developing Alzheimer’s disease by 150%!
There are also studies that show the connection between raised homocysteine and age related macular degeneration (AMD). One of these studies showed that those with homocysteine over 15µmol/L and low serum B12 have four times more likely to develop AMD.
Luckily, the defence against homocysteine is simple and inexpensive. Although genes do play a role in methylation, for example people with the C677T genotype consistently have higher levels of homocysteine than those with the normal C677C genotype, it is possible to change some chemical processes in body and improve methylation with healthy diet and lifestyle. As I mentioned earlier B vitamins are responsible for proper methylation. B6, Folic Acid, B2 and B12 or TMG with Zinc help to make S-adenosyl methionine (SAMe). SAMe does further methylation by donating its ‘methyl’ group to make neurotransmitters, phospholipids, repair DNA, etc. For some people the minimum required amount of B vitamins will be enough, while for those with lack of certain supporting enzymes and for elderly the requirement will be much higher.
The easiest way to provide enough of methyl group nutrients is to take supplements with above mentioned nutrients. A good quality multivitamin should be enough for those with homocysteine below 6µmol/L. Those with higher levels should take extra supplements. Dietary sources of methyl group are:
- B2 – eggs, almonds, brown rice, oats, barley, soybeans, spinach, kale and other leafy greens, mushrooms, whole milk, chicken and organ meats.
- B6 – brown rice, oats, barley, bananas
- B12 – meat, fish, dairy, eggs, seaweed
- Folic acid – pretty much all leafy greens
- Zinc – fish and seafood (especially oysters), nuts, seeds
- TMG – brown rice, barley, oats, spinach, beetroot
Lifestyle habits that hinder methylation include smoking, caffeine consumption and stress. Alcohol in small doses (not more than one small glass of wine – more than this amount will cause the opposite effect) and exercise improve levels of homocysteine.