Oxygen and Eating Vegetables

Oxygen and Eating Vegetables

Dr. Thornburg

Oxygen must be very toxic; if you breathe it long enough, you will die. This well-worn joke contains an ironic truth. Oxygen is necessary to metabolize food fuels that you eat in the form of sugars, fats and proteins. But oxygen can also be toxic. The air we breathe contains about 20% oxygen and in the process of metabolizing the food we eat, potentially harmful forms of oxygen are generated. These include several toxic molecules called reactive oxygen species or ROS. These forms of oxygen are prone to oxidize and harm structural components within our cells, including DNA. The resulting damage can lead to a condition known as oxidative stress. Lessening oxidative damage is where eating vegetables comes in.

Most Americans would rather eat a burger with fries washed down with a caramel milkshake than a meal containing whole grains, red beans, and blueberries. However these two kinds of meals are very different in what they offer in the way of nutritional support for the body. The metabolism of the high fat burger and shake not only offers more calories than most people need in a single meal but results in the generation of oxidative stress.

The grain, beans and blueberries offer not only many more varieties of vitamins and minerals than does the burger-fries-shake combo, they also provide high levels of other molecules called anti-oxidants. Antioxidants are molecules that alleviate oxidative stress by "mopping up" the ROS and rendering them harmless. In addition to vitamins like E and C, other molecules with powerful antioxidant properties are also present in the grain, blueberry bean diet. These are classified as phenols or polyphenols because of a common feature of their chemical structure and they provide most of the antioxidant effect derived from vegetables.

For women about to become pregnant or for women already pregnant, a diet rich in vegetables is essential for building a healthy baby. Babies born with well grown bodies will carry low risks for acquiring chronic diseases later in life.

Oxidative stress is believed to accelerate aging and underlie the progression of heart disease, diabetes and many cancers. To prevent oxidative stress, our cells need to be continually awash in antioxidant molecules from a wholesome diet. Not only do whole grains, legumes and vegetables provide vitamins, minerals and multiple antioxidants that we need every day but perhaps hundreds of other helpful but unknown nutrients not found in pills or supplements.

Everyone agrees that people should continue breathing oxygen for as long as possible and scientific evidence suggests that a daily consumption of a variety of fruits, vegetables and grains is required to protect against the oxygen stress that accompanies our food habit. As it turns out, your mother was right, there is no substitute for eating your vegetables.

Kent Thornburg
November 2012


Kent L. Thornburg, Ph.D.
Interim Director, OHSU Moore Institute
M. Lowell Edwards Chair for Research
Professor and Associate Chief for Research, Division of Cardiovascular Medicine
Director, Heart Research Center