With increasing interest in “functional foods” among scientists and health professionals, herbs and spices have been receiving greater attention for their potential to confer benefits beyond basic nutrition. Research suggests that some herbs or spices may aid in appetite suppression, increase insulin sensitivity or lipid metabolism, or reduce risk of cancer or Alzheimer’s disease. Emerging potential health benefits of these conveyers of good taste are welcome news for “foodies,” who have proclaimed the value of enjoying flavorful food, independent of nutritional benefits.
Herbs and spices have been used for centuries for culinary purposes and are the foundation of many traditional medicinal practices. “Old World” civilizations such as Egypt, Greece, and Rome established an international spice trade with Ethiopia dating back to 4500-1900 BC. Ancient Egyptians used garlic cloves to decorate their tombs, and relied on cinnamon and cardamom, among others, for spicing foods. Grecians noted the potential benefit of herbal remedies, including rosemary, for improving memory. Mint was touted as a digestive aide. In fact, the first plant monograph, or scholarly article, was published by a Greek physician and botanist.
Perhaps most recognized for their use of herbs and spices as medicinal elements are the peoples of China and Eastern India, some of whose traditional practices (such as homeopathy and Ayurveda) are now beginning to find their way into mainstream Western medicine. The food traditions of these cultures also make rich use of herbs and spices. Ginger, garlic, and red pepper are identified with traditional Chinese foods. Ginger, turmeric, garlic, and cumin are combined to make curry, an Indian food favorite.
Americans, perhaps now more than ever, are trying to balance their enjoyment of food with their health goals. The time is ripe to explore the science—and whet the appetite—about herbs and spices that can promote health. This article will focus primarily on capsaicin (found in red pepper), curcumin (found in turmeric), cinnamon, and ginger—herbs and spices of current interest for their potential health benefits.
Red Pepper (Capsaicin)
Eating hot red or chili peppers has been known to make people sweat. While pepper lovers may be seeking the thrill of the fire, they may also be receiving unexpected benefits. An increase in body temperature or heart rate upon ingestion of hot red pepper is believed to be an indicator of increased metabolic rate. In fact, research has shown that capsaicin (a capsaicinoid, the class of active ingredients in red or chili peppers that imparts pungency, or heat) accelerates energy expenditure and increases lipid oxidation by activating the sympathetic nervous system.
Human studies also suggest that consuming capsaicin decreases energy and fat intake and increases satiety. In one study, capsaicin was provided in tomato juice or in capsular form. Both forms of capsaicin reduced energy intake and increased satiety. These effects were more pronounced in the tomato juice group compared to capsules, demonstrating the possible sensory effect, i.e., “spiciness,” of capsaicin on appetite.
Long-term studies of the effectiveness of capsaicin on weight and energy expenditure have been limited due to its pungency, especially in doses strong enough to show an effect. However, some research has demonstrated the usefulness of capsaicin analogues (capsinoids), derived from a non-pungent cultivar of sweet red pepper, in raising oxygen consumption and body temperature. Still, more research needs to be completed before recommendations related to weight loss or maintenance benefits can be made.
Turmeric, a popular spice contained in curry powder, has been studied primarily for the potential health benefits of its active polyphenolic component, curcumin. Curcumin gives turmeric its yellow pigment, which lends itself for use not only as a dietary spice, but also as a coloring agent. According to the Food and Agriculture Organization (FAO) of the United Nations, the U.S. imports nearly 2400 metric tons (roughly 5.3 million pounds) of turmeric annually for use as a food preservative and as a flavoring and coloring agent.
Curcumin has been studied for its potential to reduce risk of cancer, osteo- and rheumatoid arthritis, and Alzheimer’s disease. In animal studies, curcumin has been shown to inhibit growth of cancer-causing proteins, and in human studies it has been shown to reduce inflammation, another possible anti-cancer mechanism. Curcumin’s anti-inflammatory properties may additionally be useful in alleviating symptoms of arthritis.
Curcumin has also demonstrated potent antioxidant activity, which has led to consideration of a possible protective role against Alzheimer’s disease. Animal studies have suggested that curcumin protects against damage by amyloid B-proteins. Human research on curcumin and Alzheimer’s disease is in its infancy, although a double-blind, placebo-controlled trial in humans with mild to moderate Alzheimer’s disease is currently underway.
Cinnamon is a widely used spice perhaps most notable for its use in baked treats and warm winter beverages. However, significant attention is being directed toward its potential in diabetes management. Research has suggested that cinnamon may lower blood glucose levels, increase insulin sensitivity, and/or improve lipid profiles. Because these benefits have not been demonstrated consistently, scientists are digging deeper to understand why and how the effects of cinnamon may vary among different segments of the population. Research will likely continue, given the promising results of many studies and because cinnamon is well-tolerated, safe, and inexpensive.
Like the old stand-by saltine crackers, ginger ale is often-recommended as a remedy for nausea. Ginger, a potent root containing a matrix of constituents including gingerols, beta-carotene, capsaicin, and turmeric, is thought to act directly on the digestive tract and has been used for centuries for the treatment of nausea and vomiting. A review of studies assessing the effectiveness of ginger for nausea and vomiting found that, overall, ginger was more effective than placebo in treating nausea caused by motion sickness, morning sickness, chemotherapy, and surgery. A more recent review concluded that the effectiveness of ginger is limited to treatment of nausea caused by pregnancy. The effectiveness of ginger on the treatment of the numerous causes of nausea is still being explored.
The benefits of ginger may not stop at the gut. Recent studies also suggest that ginger may play a role in preventing inflammation, thereby possibly extending its usefulness to alleviating pain caused by arthritis. One intervention study of individuals with osteoarthritis found that reported pain levels were lower in the group taking a Chinese ginger extract versus placebo, producing pain relief similar to that achieved with ibuprofen.
Like curcumin, ginger also exhibits antioxidant properties. Its anti-inflammatory and antioxidant properties together suggest a potential role in reducing the risk of cancer. Animal studies show that the principal constituent of ginger, gingerol, inhibits carcinogenesis in the gastrointestinal tract, skin, and breast. Human studies are needed to further evaluate the efficacy of ginger in cancer prevention.
Spicing up Health Goals
Despite the potential for herbs and spices to contribute more than just flavor to our food, dietary recommendations do not yet make specific recommendations for herbs and spices. The science in many cases is only beginning to emerge, providing validation of traditional medicinal practices, and revealing more detailed questions that must be pursued such as the effective amount of a particular herb or spice that needs to be consumed in order to see a benefit. That said, promotion of a diet that includes herbs and spices is on par with current dietary guidelines from the U.S. and many other countries worldwide. The Dietary Guidelines for Americans 2005 recommend use of herbs and spices as a strategy for reducing sodium intake. Dietary recommendations in Greece devote particular attention to herbs as beneficial in their own right: “Oregano, basil, thyme and other herbs grown in Greece are a good source of antioxidant compounds and can be a tasteful substitute for salt in the preparation of various dishes.”
A sprinkling of herbs and spices on favorite foods can add a lot of flavor to life. Fullness of flavor may indeed impart specific health benefits. While the recipe for good health is still being written, the wisdom of many cultures, both ancient and modern, around the world tells us that there is value in simply enjoying food. Good food, good taste, and good health truly go hand-in-hand.
Herbs and Spices: What’s the Difference?
An herb is the leaf of a plant or shrub, or more broadly, “the part of a plant that is used in the diet for its aromatic properties,” and can be used fresh or dried. All other parts of the plant, including the buds, bark, root, seeds, berries or fruit, are referred to as spices. Examples of some common herbs are oregano, parsley, rosemary, sage, thyme, chives, and basil. Common spices include cloves (buds), cinnamon (bark), ginger (root), cumin (seeds), black peppercorn (berries), and paprika (fruit).
Herbs and Spices and Their Role in Food Safety
Many herbs and spices have long been used for their ability to reduce the growth of bacteria in foods. For example, it is known that certain herbs and spices—including clove, cinnamon, thyme, oregano, and rosemary—can function as antibacterial agents in food. Before refrigeration, food spoilage was a significant problem, especially in countries with hot climates. According to researchers, people who began adding spices to their meat in those times were reducing risk of foodborne illnesses without realizing it. Recent evidence points to another benefit for herbs and spices using the culinary technique – grilling. The use of marinades containing certain antioxidant spices such as rosemary and oregano has been shown to reduce production of potentially harmful heat-formed compounds associated with grilling meats. More research is needed to fully understand this protective property of spices and herbs.
Flavorful Food-Spice Combinations
Meat, Poultry, Fish
Beef: onion, pepper, thyme, marjoram
Pork: garlic, onion, sage
Chicken: ginger, oregano, rosemary, sage, tarragon
Fish: curry powder, dill, paprika
Carrots: cinnamon, cloves, nutmeg, marjoram, sage
Green Beans: dill, oregano, tarragon, thyme
Potatoes (or root vegetables such as rutabaga): dill, garlic, paprika, parsley, sage
Winter Squash/Sweet Potatoes: cloves, nutmeg, cinnamon, ginger
Adapted from Henneman A. Add a Little Spice (& Herbs) to Your Life! University of Nebraska-Lincoln Cooperative Extension.