What is homocysteine?
Homocysteine is made in the body from another amino acid, methionine. As meat, cheese and some other proteins are especially rich in methionine, we tend to eat this amino acid every day.Why does the body make homocysteine and what does a high level tell us? It s all to do with a fundamental process upon which your life depends. We hrst encountered it in the introduction to this book. It’s called methylation. . tbody To understand methylation we need to know a bit abolt:lehow Chemistry. You eat 10 tons of food in your lifetlme and, Somehow, this turns into you. Your body is quite literally a sea of chemicals, a hairy bag of salty soup concocted out of millions of them, from glucose to fats, and amino acids to hormones and neurotransmitters.
For example, when you are under stress, the body makes more adrenalin to keep you going. When you go to bed, the body releases melatonin to help you sleep. When you’ve got a cold or flu the body makes more glutathione, which turns your immune cells into cold-busting warriors. These are just three examples of literally hundreds of thousands of adjustments the body makes every second to keep you healthy and alive.
But how on earth does the body keep everything in balance? This is where methylation comes in. In the methylation process ‘methyl groups’, which are made of one carbon and three hydrogen atoms, are added to, or subtracted from, other molecules. This is how the body actually makes the substances it needs, or breaks down those it doesn’t by transforming one biochemical into another.
Methylation happens over a billion times a second. It is like one big dance, with biochemicals passing methyl groups from one partner to another.
Take noradrenalin. The brain produces this chemical to keep you happy and motivated. However, if you are under stress, it adds a methyl group to noradrenalin in the adrenal glands to make adrenalin, which gives you a burst of energy and aggression known as the ‘fight or flight syndrome’.
This is how homocysteine is made in the body. When you eat a piece of fish containing methionine, it’s incorporated into your bloodstream and inside your cells and a methyl group is taken away from the methionine, leaving you with homocysteine. Ideally, the body adds a different methyl group back to homocysteine to convert it into an extraordinarily important chemical called S-adenosyl methionine (SAMe, pronounced ‘Sammy’, for short). SAMe is a natural anti-depressant, anti-arthritic and liver-protecting agent in your body. It also becomes a methyl donor in its own right, readily giving up its methyl group to help alter other body chemicals.
Homocysteine can also be converted to another extremely important body chemical, glutathione. Glutathione is the body’s best anti-ageing antioxidant and detoxifying agent. A low glutathione level is, like a high homocysteine level, linked to increased risk of death from all common causes. So methylation is also the key to slowing the ageing process and keeping your body free of toxic chemicals.
It is also thought that methylation plays a critical role in protecting us from certain serious diseases. Methyl groups are added to and subtracted from our DNA. When not enough methylation is going on, our DNA cannot properly repair itself, which puts us at higher risk from cancer and autoimmune diseases such as rheumatoid arthritis or lupus.