We are often asked whether synthetic or natural nutrients are better for health. The function of a nutrient depends upon its chemical structure, not upon its source. A molecule of vitamin C is the same as any other molecule of vitamin C, whether it's made in a soft, green, leafy biological factory or in a shiny, manmade, stainless steel factory. However, advocates of natural vitamins and other nutrients suggest that these substances are often associated in plants with other valuable nutrients, such as bioflavonoids with vitamin C, so that it is better to use nutrients derived from natural sources.
Let's consider why a plant contains nutrients such as vitamins C and E. These vitamins and many other nutrients (for example, vitamins A, B-1, B-5, B-6, PABA, the amino acid cysteine, the minerals zinc and selenium, and others) are antioxidants—that is, they block certain uncontrolled spontaneous oxidation reactions that, if left unchecked, would damage various plant structures, including the DNA, their genetic blueprints.
Unsaturated fatty acids and structures containing large quantities of them (such as cell membranes and plant seeds) are particularly susceptible to these damaging oxidations. When these fatty acids become oxidized via exposure to air or to chemical oxidizers, they turn rancid.
Both the uncontrolled oxidation of the fat and the further chemical degradation of these chemically unstable rancid fats leads to the creation of highly chemically reactive and dangerous entities: free radicals. Their chemical reactivity is very promiscuous; they can attack any molecule in your body and are implicated as a major cause of cancer, cardiovascular disease, and aging. A lethal dose of x-rays kills because the x-rays produce free radicals in matter.
Some free radicals are more potent oxidizers than fluorine. These are so ubiquitous that every air-breathing organism on this planet is equipped with a battery of special enzymes and antioxidant nutrients to protect itself from damage by free radicals. Without these enzymes and antioxidants, ordinary air would quickly kill us, as well as all plants and microbes.
In a scientific study, it was found that plant seeds were less likely to germinate as the degree of oxidation of their lipids (fats and oils) increased (expressed mathematically as a negative-slope straight-line relation); almost all seeds germinated at low levels of fat oxidation, but none did so at high levels. The very high levels of antioxidants such as vitamins C and E contained by plant seeds are necessary so that the seeds can germinate.
But plants also contain many other substances to protect themselves from other enemies, such as animals that might eat them. For example, wheat germ (the embryo in a seed of wheat) contains not only high levels of vitamin E but also high levels of estrogens—female hormones. These hormones act as birth control pills that interfere with the reproductive cycle of female animals and also reduce the libido of male animals eating too much wheat, thereby reducing the number of offspring such animals produce.
Cold pressed wheat germ oil also contains considerable quantities of these hormones, so that if a man were to take large doses—say 2,000 IU a day—of natural vitamin E in the form of cold pressed wheat germ oil, he could suffer a reduced libido or even degeneration of the testicles. Indeed, there are more estrogens in a single slice of whole wheat bread than there are in a pound of DES (diethylstilbesterol)-treated calves' liver.
About 98 percent of the plant matter on this planet dies before it is eaten either by animals or by insects or by microbes because of contained toxins. Even plants that have been specially bred to be nontoxic, like potatoes and tomatoes, contain toxins that we can detoxify in small quantities at a time but that could kill us in large amounts, such as if we were taking megadoses of potato or tomato extracts. Highly purified natural vitamins, such as vacuum-distilled vitamin E, are nearly free of such toxins, but then there can be no advantage from possible unknown cofactors accompanying these vitamins.
In one study of the bioavailability of synthetic vitamin C versus natural vitamin C, the synthetic C turned out to be slightly more bioavailable (usable by the body). One reason for this is that the natural vitamin C is bound to certain plant structures it protects. In order for us to be able to get at this C, our digestive system must break down these plant structures. No such barriers exist in the use of synthetic vitamin C.
Bioflavonoids, which are synergistic in function with vitamin C, are contained in only very small quantities in crude vitamin C plant extracts. These bioflavonoids are, however, available inexpensively as relatively pure extracts that may also contain insignificant amounts of natural vitamin C.
Many people are allergic to plant substances contained in natural vitamins. We have heard of numerous cases of allergic reactions to products advertised as containing natural C, but never to pure synthetic C crystals.
Finally, synthetic vitamins are less expensive than natural vitamins. Natural vitamin C is a very expensive laboratory curiosity; it costs over $1,000 per kilogram. So-called natural vitamin C sold in health food stores is really almost entirely synthetic vitamin C plus a trace of natural C and other plant extractables, sometimes including allergens and insignificant amounts of plant toxins. When you pay a premium for "natural" vitamin C, you are shelling out your money to pay for a fantasy.
But don't worry about the slightly lower bioavailability of natural vitamin C extract; there is so little of it in so-called natural vitamin C that the impaired absorption is irrelevant. The scientific studies showing beneficial uses for vitamins have, in almost all cases, used synthetic vitamins, so that it is possible to attribute the results to a single vitamin under study. As a result, we generally use synthetic vitamins and consider them to be far more cost-effective than natural vitamins (the exception is vitamin B-12, which is most economically produced by fermentation).
A list of scientific literature on this topic is available. Send a stamped, self-addressed envelope to this publication, referring to the date of this issue.
Sandy Shaw and Durk Pearson are consulting scientists, authors, and TV personalities. Copyright © 1981 by Durk Pearson and Sandy Shaw.