What is Oxidative Stress?

Oxidative stress has become something of a health buzz-word in recent years. It is getting blamed for everything from heart problems, to cancer, to aging. Yet for all the talk, not many people know what oxidative stress is.

Oxidation is surprisingly familiar. We see it all the time. We just don’t don’t usually call it oxidation. When we cut an apple in half and it turns brown, that is oxidation. When iron rusts, that’s oxidation. Oxidation also happens inside the body. Just like iron rusting and apples going gooey, oxidation inside the body causes damage. This damage is what doctors call oxidative stress.

But… let’s back up a bit. Just what is oxidation? Well, it starts with oxygen. Oxygen is unbalanced. Each oxygen atoms has seven electrons, in a space that is able to fit eight electrons. So oxygen is constantly ‘stealing’ electrons to fill that last spot and make itself balanced. This is called oxidation.

Oxygen isn’t the only chemical that causes oxidation; it’s just the best known. Many other chemicals do the same thing. Free radicals are chemicals inside the body that cause oxidation. Some free radicals come from outside the body, some are created inside the body. All of them cause problems.

Oxidative Stress
All of the cells in the body, and all the pieces of the cells, are made of chemicals that are held together by electrons. When a free radical steals an electron from the cell membrane, it damages the cell and might create a hole in the membrane. Over time, free radicals do more and more damage to different parts of the cell. This damage hurts the cell, and prevents the cell from doing its job. Eventually, the damage will cause the cell to die. This is oxidative stress.

If enough of your cells die, organs in your body will develop problems, and you will get sick. Many lung conditions are caused by oxidative stress, because lungs need to deal with free radicals from the environment and from inside the body. Of course, its not just the lungs that can be damaged by oxidative stress. Every organ in the body is susceptible to oxidative stress, and most of what we think of as ‘signs of aging’ are actually the results of long-term oxidative stress on the body.

Thankfully, the body doesn’t take oxidative stress lying down. There is an extensive system for combating and controlling oxidative stress. Free radicals that are created inside the body are carefully controlled and converted into other chemicals or flushed from the body. Special chemicals called ‘anti-oxidants’ are made by the body just to give extra electrons to free radicals and prevent them from causing oxidative stress. Cells constantly repair and fix damage done by the free radicals that the body isn’t able to stop in time.

When everything goes well, the body’s defenses against oxidative stress are very effective. Over time, damage does accumulate, but very slowly. When the body is able to protect against oxidative stress, people stay healthy and don’t develop diseases associated with old age early in life. Most people will develop one or two of the age associated diseases, and stay generally healthy until they die.

Unfortunately, many things can cause problems for the body’s defenses. There are more free radicals in the environment than ever before, so people are being exposed to higher amounts of external free radicals, which makes it harder for the body to protect itself. Many people don’t eat a healthy diet with enough anti-oxidants, so the body may not have everything it needs to protect itself. Finally, some genetic conditions can change the balance of free radicals and anti-oxidants, crippling or overwhelming the body’s defense.

How Does Oxidative Stress Relate to MTHFR?
MTHFR anomalies increase the amount of oxidative stress on the body. At first, researchers weren’t sure why this happened. There was no reason they could see for MTHFR anomalies to cause high levels of oxidative stress, and they couldn’t find any other reason for the high oxidative stress in people with MTHFR anomalies. For a few years, all they could say was that yes, MTHFR causes oxidative stress.

In 2009, a study was published in the Proceedings of the National Academy of Sciences of the United States (PNAS) which finally explained how MTHFR causes oxidative stress. This study found that homocysteine creates free radicals, the chemicals that cause oxidative stress. And researchers have known for years that MTHFR anomalies create high levels of homocysteine. So MTHFR anomalies don’t cause oxidative stress directly, but the increase in oxidative stress is a secondary effect, caused by the high levels of homocysteine.

Unfortunately, when levels of oxidative stress get high, the body doesn’t have enough anti-oxidants to prevent significant damage from occuring. Many people with MTHFR anomalies develop age-related diseases at unusually young ages, or are increased risk for age-related diseases as they get older.

A further affect of high levels of oxidative stress is the decrease in the amount of glutathione available to the body. Glutathione is one of the most important anti-oxidants, and when oxidative stress is high, like when a person has an MTHFR anomaly, glutathione levels drop. Since glutathione also clears heavy metals from the body, this can also lead to long term heavy metal poisoning, and it’s associated problems.

What Kinds of Health Problems are Caused by Oxidative Stress?
Oxidative stress causes a wide variety of health problems. Some of the most common ones can be:

  • Kidney damage
  • Cataracts
  • Ischemic bowel disease
  • Hardening of the arteries
  • Cancer
  • Diabetes
  • Alzheimer’s Disease
  • Asthma
  • Hyperoxia
  • Rheumatoid Arthritis
  • Angioplasty
  • Psoriasis


More on the connection between MTHFR, oxidative stress, and glutathione.

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