Researchers Call Herbs Rich Source Of Healthy Antioxidants; Oregano Ranks Highest

Herbs have higher antioxidant activity than fruits, vegetables and some spices, including garlic, the researchers say. Their findings appear in a recent (Nov.) print issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the world’s largest scientific society.

“Some herbs should be considered as regular vegetables,” says Shiow Y. Wang, Ph.D., the study’s lead researcher and a biochemist with the USDA’s Beltsville Agricultural Research Center in Beltsville, Md. “People should use more herbs for flavoring instead of salt and artificial chemicals.”

Using various chemical tests, Wang studied and compared the antioxidant activity of 39 commonly used herbs grown in the same location and conditions. The study, which did not involve animal or human subjects, included 27 culinary and 12 medicinal herbs.

In what may be good news for pizza lovers and Italian food connoisseurs everywhere, the herbs with the highest antioxidant activity belonged to the oregano family. In general, oregano had 3 to 20 times higher antioxidant activity than the other herbs studied, says Wang.

On a per gram fresh weight basis, oregano and other herbs ranked even higher in antioxidant activity than fruits and vegetables, which are known to be high in antioxidants. In comparison to the antioxidant activities of a few select fruits and vegetables, the potency of oregano ranks supreme: Oregano has 42 times more antioxidant activity than apples, 30 times more than potatoes, 12 times more than oranges and 4 times more than blueberries, Wang says.

For example, one tablespoon of fresh oregano contains the same antioxidant activity as one medium-sized apple, she says. (For other herbs, please see last page of release.)

Adding a moderate amount of herbs may go a long way toward boosting the health value of a meal, especially as an alternative to salt and artificial additives, the researcher suggests.

Even if you’re not into oregano, other herbs also appear to pack a significant antioxidant punch. Among the more familiar, ranked in order, are dill, garden thyme, rosemary and peppermint.

The most active phenol component in some of the herbs with the highest antioxidant activity, particularly oregano, was rosmarinic acid, a strong antioxidant, the researcher says.

Antioxidants have become synonymous with good health. They are a class of compounds thought to prevent certain types of chemical damage caused by an excess of free radicals, charged molecules that are generated by a variety of sources including pesticides, smoking and exhaust fumes. Destroying free radicals may help fight cancer, heart disease and stroke, researchers believe.

Fruits and vegetables have long been viewed as a rich source of antioxidant compounds. Health officials have been urging consumers for years to eat more fruits and vegetables in order to gain the health benefits of antioxidants, but progress has been slow, according to researchers. Westerners still tend to favor diets that are rich in fats and carbohydrates, they say.

More recently, researchers have begun to formally study the health benefits of herbs and spices. The two differ mainly by source. Herbs typically come from the leaves of plants. Spices come from the bark, stem and seeds of plants. Both have been used for thousands of years to flavor foods and treat illness.

Now, herbs have emerged as a quick and easy way to get a concentrated source of antioxidants — without all the extra calories of whole foods, Wang says. She recently compared the antioxidant activity of herbs to a few select spices, including paprika, garlic, curry, chili, and black pepper. Herbs came out on top, she says.

Herbs can be consumed in a variety of ways. Some people prefer to drink herb extracts, which can be made by adding herbs to hot water to make potent antioxidant teas. Others use concentrated herbal oils available in some health food stories. Most of us prefer a little dash and sprinkle of the familiar leafy or powdered versions to add flavor to our favorite meats and vegetables.

In general, fresh herbs and spices are healthier and contain higher antioxidant levels compared to their processed counterparts. For example, the antioxidant activity of fresh garlic is 1.5 times higher than dry garlic powder, the researcher says.

Just as consuming too much of any food product can carry health risks, herbs should be used with moderation, she cautions.

Whatever form they take, herbs are no substitute for a balanced diet, Wang says. Pregnant women in particular should consult their physicians before taking herbal supplements, she adds.

Funding for this study was provided by the USDA.