Herbs have higher antioxidant activity than fruits, vegetables and some spices, including garlic, the researchers say. Their findings appear in a recent 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 Centgre in Beltsville, Maryland. "People should use more herbs for flavouring 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 three 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 four times more than blueberries, Wang says.
For example, one tablespoon of fresh oregano contains the same antioxidant activity as one mediumsized apple, she says.
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 flavour 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.