Maximize Antioxidants in Your Salad Bowl

Healthnotes Newswire (June 2, 2005)—Raw or steamed vegetables, and salads that include onions, fresh herbs, and dressings made from pure extra-virgin olive oil provide high antioxidant values, reports the British Journal of Nutrition (2005;93:257–66). Certain salad ingredients also add more antioxidants than others, and certain cooking methods decrease them.

Antioxidants are compounds that protect cells from damage by free radicals. Free radicals are electrically charged, highly reactive particles that damage cells throughout the body by triggering oxidative reactions. Oxidative free-radical damage is believed to be a central cause in the degenerative changes associated with aging, including those that leave us more vulnerable to cancer and heart disease. Vitamins C, E, and A are well-known antioxidant nutrients, as are the minerals zinc and selenium. Bioflavonoids are another group of potent antioxidants widely found in the plant world. Some bioflavonoids are pigments that give plants their color. Fruits and vegetables are especially rich in vitamin, mineral, and bioflavonoid antioxidants. Numerous studies have demonstrated that eating a diet rich in fruits and vegetables can prevent chronic diseases, including heart disease and cancer.

In the current study, 27 different vegetables and 21 different herbs and spices were studied for their antioxidant value, as demonstrated by their ability to neutralize free radicals. The effects of various cooking procedures on the antioxidant value of some of the vegetables were measured. Some of the vegetables and herbs were evaluated in combinations designed to resemble typical salads, and several oils and vinegars were also tested.

Artichoke, beet, broccoli, garlic, one variety of leek, radish, and red chicory had the highest antioxidant values of the vegetables tested; among the herbs and spices, cumin had the highest antioxidant value by far, followed by sage, rosemary, marjoram, and thyme. Steaming vegetables led to a drop in antioxidant values of 20 to 30%, but boiling led to nearly 80% reductions. Salads were made with combinations of lettuce, tomato, onion, carrot, and cucumber. Adding onion increased the salad antioxidant value significantly, and so did adding fresh herbs to the salad, such as lemon balm and marjoram. Pure extra-virgin olive oil was found to have a high antioxidant value; however, the presence of crushed garlic or other herbs in the olive oil reduced its antioxidant value by 40 to 80%.

The results of this study suggest that to maximize the antioxidant value of vegetables, they should be eaten steamed or raw, in combinations that include fresh herbs, spices, and dressings made from pure extra-virgin olive oil. Recommendations to eat more vegetables can be modified by using specific instructions that reflect these findings.

Maureen Williams, ND, received her bachelor’s degree from the University of Pennsylvania and her Doctorate of Naturopathic Medicine from Bastyr University in Seattle, WA. She has a private practice in Quechee, VT, and does extensive work with traditional herbal medicine in Guatemala and Honduras. Dr. Williams is a regular contributor to Healthnotes Newswire.

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