Are Some Plant Foods More Healthy than Others?
Some plant foods have as much as 1,000 times the antioxidant compounds found in others, according to a study published this month in the Journal of Nutrition.1
A group of researchers in Norway concluded that fruits, berries, and whole grains contributed more than 80% of total antioxidants in the diet of a typical Norwegian. Vegetables, beans, nuts, and seeds were also considered to be significant dietary sources of antioxidants.
Foods with the highest amounts of antioxidants per ounce included blueberries, pomegranates, walnuts, and dried apricots. Some fruits and vegetables, including carrots, potatoes, and watermelon, had nearly no antioxidant activity.
Antioxidants are chemicals that eliminate potentially toxic molecules in the body called free radicals. Free-radical damage is thought to be important in the development of a number of diseases, including heart disease, cancer, and Alzheimer’s disease.
The major dietary antioxidants are vitamins C, E, and A; selenium; and the carotenes; but many others also exist in smaller amounts. It is not known whether the minor antioxidants in foods have the same effects as those seen with the major agents. On the other hand, many studies have shown that consuming foods high in antioxidants provides greater protection against disease than taking antioxidants in supplement form. This implies that some of the lesser-known antioxidants found in food may work somehow in harmony with the better-known vitamins and minerals.
There are a couple of potential flaws in this study. First, there is no universally accepted laboratory method for determining antioxidant content of foods. Therefore, it isn’t likely the test used by the authors would identify all the different classes of antioxidants in foods. Second, foods grown in different areas or with different cultivation techniques may have different characteristics, so these results from Norway may not be entirely applicable to American-grown foods.
This study suggests some strategies for people looking to maximize the benefits of a plant-based diet. Whole-grain flours are uniformly higher in antioxidants than the refined white flours made from the same grains. Leafy green vegetables pack more antioxidant punch than potatoes and other root veggies. Citrus fruits and berries have more free radical-fighting potential than do apples or melons.
While some foods are higher in antioxidant potential than others, there does not appear to be any food that matches the high antioxidant activity of supplements such as vitamin C or vitamin E. However, the fact that diets rich in plant foods protect against the development of heart disease, cancer, and other diseases suggests that one does not have to take large amounts of antioxidants to obtain good results. Apparently, the complex mixture of antioxidants and other compounds present in natural foods can provide benefits that are not easily duplicated by a handful of pills.
1. Halvorsen BL, Holte K, Myhrstad MC, et al. A systematic screening of total antioxidants in dietary plants. J Nutr 2002;132:461–71.
Matt Brignall, ND, is in practice at the Seattle Cancer Treatment and Wellness Center and at the Evergreen Integrative Medicine Clinic in Kirkland, WA. He specializes in integrative treatment of cancer. He is a contributor to Healthnotes and Healthnotes Newswire.
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