Beta-carotene, the pigment that gives carrots and sweet potatoes their distinctive color, is also a valuable antioxidant. When you eat healthful orange and other brightly colored produce, your body converts the beta-carotene to vitamin A, which is essential for normal growth, good vision and a strong immune system.
But too much beta-carotene can be too much of a good thing. Certain molecules that derive from beta-carotene may actually block some vital actions of vitamin A, according to scientists at Ohio State University who recently published their findings in the Journal of Biological Chemistry.
If you eat excessive amounts of beta-carotene-rich foods, you could be getting more of the anti-vitamin A molecules, suggest researchers, who are continuing to study how the negative molecules are produced.