In general, the body absorbs nutrients best from foods in which the nutrients are diluted and dispersed among other substances that may facilitate their absorption. Taken in pure, concentrated form, nutrients are likely to interfere with one another’s absorption or with the absorption of nutrients in foods eaten at the same time. Documentation of these effects is particularly extensive for minerals: Zinc hinders copper and calcium absorption, iron hinders zinc absorption, calcium hinders magnesium and iron absorption, and magnesium hinders the absorption of calcium and iron. Similarly, binding agents in supplements limit mineral absorption.
Although minerals provide the most familiar and best-documented examples, interference among vitamins is now being seen as supplement use increases. The vitamin A precursor beta carotene, long thought to be nontoxic, interferes with vitamin E metabolism when taken over the long term as a dietary supplement. Vitamin E, on the other hand, antagonizes vitamin K activity and so should not be used by people being treated for blood-clotting disorders. Consumers who want the benefits of optimal absorption of nutrients should use ordinary foods, selected for nutrient density and variety. 32
The British government, in May 2003, went quite a bit further than the textbook authors, bluntly warning consumers in the United Kingdom that some over-the-counter vitamin and mineral supplements can actually endanger health, especially if taken in high doses. The British food standards agency, following a four-year safety review by independent scientific advisors, concluded that “long-term use of six substances, vitamin B6, beta-carotene, nicotinic acid (niacin), zinc, manganese, and phosphorus, might also cause irreversible health damage.”33
Sir John Krebs, chairman of the food agency, said “While in most cases you can get all the nutrients you need from a balanced diet, many people choose to take supplements. But taking some high-dose supplements over a long period could be harmful.”34
A recent study published in the British medical journal The Lancet looked closely at the effects of regularly taking vitamin E and betacarotene pills as a supplement to prevent heart disease. “Vitamin E and beta-carotene pills are useless for warding off major heart problems, and beta-carotene, a source of vitamin A, may be harmful,” an Associated Press (AP) summary of the study reported.35
Researchers at the Cleveland Clinic Foundation gleaned similar conclusions from analysis of the pooled results of 15 key studies involving nearly 220,000 people–far more than needed to be statistically sound. “The public health viewpoint would have to be that there’s really nothing to support widespread use of these vitamins,” said Dr. Ian Graham, of Trinity College, Ireland.36
According to the AP: “The researchers found that vitamin E did not reduce death from cardiovascular or any other cause and did not lower the incidence of strokes. Beta-carotene was linked with a 0.3 percent increase in the risk of cardiovascular death and a 0.4 percent increase in the risk of death from any cause.”
Because the pills didn’t help, however, does not mean that vitamin E or beta-carotene themselves are not helpful in preventing disease. It only means that commercially produced pills that contain these substances in concentrated form may not help. Said the AP:
The idea that antioxidant vitamins might ward off heart trouble was plausible. Test tube studies indicated that antioxidants protect the heart’s arteries by blocking the damaging effects of oxygen. The approach works in animals, and studies show that healthy people who eat vitamin-rich food seem to have less heart disease.
However, experts say that perhaps antioxidants work when they are in food, but not when in pills. 37
Gulping jarfuls of orange, pink, or blue artificially concentrated vitamin tablets in an effort to offset the increasing nutritional poverty of our corporate/commercial food supply may actually end up making things worse, not better.
“Whenever the diet is inadequate, the person should first attempt to improve it so as to obtain the needed nutrients from foods,” say Whitney and Rolfes.38
Great advice, but how can we follow it if the foods available at our supermarkets have few or no nutrients? If the trend lines over the past 50 years continue to hold true, it would seem that our food supply system is heading inexorably toward a diet made up largely of “nonfoods” that contain increasingly fewer measurable nutrients, except for the relatively dangerous ones of fat, salt, and sugar.
Twenty or more years from now, if these trends aren’t halted, will the “food” offered commercially in chain stores be nothing more than an attractively colorful but inert, sweet- or salty-tasting physical solid we swallow to give ourselves the illusion of eating, while we try hopelessly to obtain our real nourishment by juggling a smorgasbord of pills? “Hey, Jack, come on over for Thanksgiving dinner, we’re having roast pill, with non-gravy!”
Whatever the future holds, for the past 50 years the nutrients have been leaching out of nearly everything we eat, leaving a vacuum that commercially produced vitamin pills can’t fill.
And, as the saying goes, “nature abhors a vacuum.”
Something else is already filling it.
MARY WASHINGTON IS A PRETTY YOUNG WOMAN, with wide, innocent-looking eyes and a quiet, disarming voice. You wouldn’t think she’d scare anybody, but judging from her story in the Westsider, a Michigan newspaper, she sure made some folks nervous.
Covering the consumer beat, she’d been assigned to investigate a new supermarket phenomenon. As she told her readers:
Going to the grocery to buy meat has probably been the same routine for years: Pick your favorite pork chops, chicken, steak, etc. and prepare it at home, as usual. But what if that routine could threaten your life?
People with high blood pressure, heart problems, or allergies had better start reading the package meat labels closely, because there’s something new in chain store food most consumers aren’t aware of.
I went to the meat section of my two local grocery stores, and did some shopping around. I found that meat, especially boneless pork chops and boneless chicken, now has the words ‘seasoned,’ or ‘preseasoned’ in almost-invisible small print on the label. This disturbed me, so I went to the store butcher at [the first store] and asked what seasoning is in this meat. 1
Adopting a deadpan tone to match her innocent demeanor, she continued:
He looked at me as if I was crazy, and asked why I was so concerned. I told him my mother has high blood pressure and if she is unaware that seasoning is in this meat, it could make her ill. Ordinary salt is actually sodium chloride—and sodium is something people with hypertension (high blood pressure) should avoid.
According to the Family Health and Medical Guide, “a reduction in sodium intake is particularly important for persons with hypertension.”