Many people understand the importance of good nutrition, but believe that a daily vitamin pill will substitute for actually eating the fruits and vegetables that they know are good for them.
The more we learn about nutrition and the human body, however, the more we realize the importance of eating whole foods. That is why the American Dietetic Association and the U.S. Department of Agriculture still recommend that we eat two to four servings of fruit and three to five servings of vegetables a day.
Here is an example of what science has found. During the last 15 years, a number of studies have shown that people who eat a diet rich in beta-carotene have a lower rate of several kinds of cancer. Beta-carotene is an antioxidant chemical naturally found in foods such as sweet potatoes, winter squash and carrots, and is also available in a pure, synthetic form.
The pure form of beta-carotene has become a popular dietary supplement, either by itself or as an ingredient in multi-vitamin pills. A number of recent studies, though, have not shown that taking beta-carotene in pill form lessens the risk of cancer.
Why should a nutrient in a pill be less effective than the same nutrient obtained from food?