Free Radicals and a Colorful Plate of Food
When I was eight I performed a simple experiment in biology that has affected me ever since, and perhaps even influenced my decision to research, among other areas, the process of aging. I left my fielder’s mitt out in the bright Colorado sun for a week one summer. It wasn’t long, only a week, and it certainly couldn’t have rained as that only happens in Colorado in April and May. What I beheld when I finally inspected my glove (I admit that the experiment was pure neglect and not a result of childhood genius) was hard, dry, bleached, wrinkled leather that I could barely wear, let alone use to field grounders. It looked like my one year old mitt was seventy-five. The following morning after an overnight application of neatsfoot oil I was astounded: my mitt looked young again, maybe not one, but three years old. The hard, dry membranes had been transformed almost new again. After rehydration, the gap between looking one and three was due to accelerated aging.
My mitt had been exposed to oxidation. If it had been in a vacuum, despite the sunlight, the damage would not have been as bad.
But light plus air had been a double whammy. In a nutshell, in the presence of sunlight, the chemical bonds between two oxygen atoms, tightly bound as the stable molecule O2 in the air, had uncoupled. Each oxygen atom was left without a mate. We call these oxygen species “free radicals,” which sounds like something out of the sixties: they are free, though not happy about it. Like a newcomer at Club Med, free radicals are also frenetically looking for partners with which they can couple, in order to satisfy their intense need for an electron.
We now recognize that this oxidative process plays a major role not only in aging, but also in the disease process. Cancer, hardening of the arteries (think of my mitt), wrinkles, cataracts, arthritis, stroke, emphysema, and Crohn’s disease are only a few of the disorders attributed to free radicals. Oxygen radicals are created not just on the surface of the body where sun meets air but also within the tissues. Fortunately we have mechanisms for neutralizing or scavenging free radicals, but sometimes the rate at which we create them is greater than our ability to sop them up.
Free radicals come from several sources. Immune cells called phagocytes engulf bacteria and other debris, and create free radicals to literally zap them and render them harmless so the cell can digest them. But those free radicals are left around to damage our own tissues. Sunlight and other radiation are important sources. In fact, the smooth elastic baby-like skin on an octogenarian’s bottom looks supple mainly because it has only rarely been exposed to sunlight. Chemicals and other drugs are important sources, including pesticides and herbicides, along with smoked and barbecued foods, the peroxidized fats in meats and aged cheeses, alcohol, cigarette smoke and air pollution.
Free radical scavenging can be accomplished not only by our internal enzymes evolved for this purpose, but also from antioxidants in plants we ingest. It is a good bet that if a fruit or vegetable is brightly colored, it is loaded with antioxidants. Pigments like lycopenes that make tomatoes red, limonenes in citrus, and carotenoids in carrots, squash and sweet potatoes are all antioxidants with activity against different free radicals. Naturally people think, “If a little is good, more must be better.” Many of you may be ingesting antioxidants in all colors and shapes with the hopes of avoiding cancer and heart disease. The medical research, however, does not bear this out; in fact, in one study, smokers taking beta-carotene actually developed more lung cancer than those taking placebos. On the other hand, studies show that people who take more fresh fruits and vegetables in their diets have important reductions in both of these disorders.
In Ayurvedic medicine there is a principle called “the fallacy of the active ingredient” which holds that if you try to isolate the active principle from the whole, you lose the benefit and you risk developing side effects. An Ayurvedic physician would say that taking the beta-carotene out of the carrot isolates it from the many other elements in the whole food that may have synergistic beneficial effects.
So if you want to avoid looking like my baseball mitt prematurely, shun the creators of free radicals listed above like they were the devil. Indeed they are: free radicals are the trident precipitating our eventual demise and yet, because they also mediate immune functions, metabolism and other healthy responses, we cannot live without them. In fact, people who take too many free radicals may suffer from fatigue, because they impair the body’s ability to mobilize certain metabolic pathways, according to Denham Harmon, the physician who initially proposed their connection with aging.
Ancient Ayurvedic texts recommend eating plenty of fruits and vegetables of every conceivable color. This advice had a scientific logic. Plants contain thousands of “active ingredients” such as natural alkaloids, flavonoids, and terpinoids, and in this lies their intelligence, their prana, or life force. Take your produce fresh if you can, not frozen, canned or packaged. Cook vegetables to make them more digestible, but don’t cook them to death. You want them to retain the precious information they carry to your cells. They may have antioxidants you need, they may even have something else you need but that we don’t yet even know about. Until science tells you otherwise you can feel good about picking your antioxidants the Ayurvedic way: in the produce department with your heart, intuition and common sense, and not in the drug store with your intellect.
Jay Glaser, MD is a board-certified internist.