July 2007

Top 10 Culinary Herbs and Spices: Flavorful and Functional
By Sharon Palmer, RD
Today’s Dietitian
Vol. 9 No. 7 P. 36

“An herb is a friend of physicians and the praise of cooks.”
— Emperor Charlemagne, 9th century

Not long ago, a bland diet was a staple in clinical dietetics. But new research is turning up the heat on zesty herbs and spices, pointing out that a spicier life may be a healthier one. These findings seem to support what people have been saying for centuries—culinary herbs and spices may treat all manner of maladies. And the science is rolling in at a time when many Americans are enamored with all that is ethnic, bold, and beautiful on their dinner plates.

The American Spice Trade Association reports that the hottest trend in spices today is the “hot spices”—black and white pepper, red pepper, and mustard seed—reporting that these spices now comprise 41% of U.S. spice usage, with an increase of 71% in tonnage since the late 1970s.

Researchers are exploring the possible therapeutic uses for a long list of herbs and spices used in cooking. “The benefits of culinary herbs and spices are primarily due to their antioxidant, antimicrobial, and antiviral effects,” says Karen Siegel, MPH, MS, RD, a nutrition consultant specializing in the traditional Chinese medicine practices of acupuncture and herbal therapy in Houston, Tex.

Tieraona Low Dog, MD, education director for the program in integrative medicine at the University of Arizona, reported at the fourth annual Nutrition and Health Conference sponsored by the University of Arizona Program in Medicine and Columbia University’s Rosenthal Center for Complementary and Alternative Medicine that spices and culinary herbs are best known for turning ordinary foods into mouthwatering delicacies. But these exotic plants also contain a vast array of powerful phytochemical compounds that may help in the prevention of serious diseases such as cancer, heart disease, and infection.

The leaf of a plant used in cooking is generally referred to as a culinary herb; any other part of the plant, such as the buds, bark, roots, berries, seeds, and the stigma of a flower, is called a spice. Typically, fresh herbs and spices contain higher levels of antioxidants than dried or processed products. For example, fresh garlic is 11/2 times more powerful than dry garlic powder.

In a recent study of 26 common spice extracts, researchers discovered that the phenolic compounds in the spices contributed significantly to their antioxidant capacity.1 Studies have also shown that the intake of herbs can contribute greatly to the total intake of plant antioxidants. For example, salad dressings containing herbs and spices can increase the antioxidant capacity of a salad.2

The following 10 culinary herbs and spices show particular promise for promoting good health.

1. Curcumin, the Super Spice
One spice that is reaping much attention is curcumin, which is found in turmeric and curry powder. The components of turmeric and curcumin and related compounds called curcuminoids appear to have antioxidant, anti-inflammatory, antiviral, antibacterial, and antifungal properties, with potential activity against cancer, diabetes, arthritis, Alzheimer’s disease, and other chronic diseases.3

“Curcumin seems to be a very good anticarcinogen. It is linked to reduced susceptibility to cancer with a decreased occurrence of leukemia and cancers of the prostate, breast, and colon, which is most intensively studied. We know that it promotes wound healing because it is an antioxidant and anti-inflammatory,” says Greg Cole, PhD, associate director of GRECC (Geriatric Research, Education & Clinical Center) Research at the Greater Los Angeles VA Medical Center and associate director of the UCLA Alzheimer’s Disease Research Center.

“It appears to be very helpful in the process of inflammation in the diseases of aging, including emphysema, diseases of the cardiovascular system, congestive heart failure, gastrointestinal issues such as colon cancer and irritants, and Alzheimer’s disease. There’s no question it can work as an antioxidant. The National Cancer Institute decided it was worth studying extracts of turmeric enriched in curcumin, and it appears that it is pretty safe at reasonable doses. What we don’t know is how much to take and the treatment window. We don’t have clinical trial data to say this is what you have to do.”

2. Cracking Into Nutmeg
Within the apricotlike fruit of the tree myristica fragrans lies a kernel. The dried covering of that kernel yields the fragrant spice nutmeg. According to Low Dog, nutmeg displays bactericidal activity toward Helicobacter pylori and Escherichia coli (E. coli) O157:H7. In addition, animal studies demonstrate antidepressantlike activity. But nutmeg lovers need to be cautious, as 1 to 2 ounces of nutmeg have been known to cause prolonged delirium and toxicity.

3. Sweet, Sweet Cinnamon
Cinnamon, the seasoning that’s as comforting as grandma’s apple pie, has been studied not only for its antioxidant capacity and antimicrobial effects but also for its role in insulin activity. Cinnamon’s active ingredients are polyphenol polymers, which scientists think may act like insulin. In three trials involving 164 patients with type 2 diabetes, researchers evaluated the efficacy of cinnamon supplementation. Two of the studies reported modest improvements in lowering blood glucose levels with cinnamon supplementation in small patient samples, while one trial showed no significant difference between the cinnamon and placebo in lowering blood glucose levels. Researchers concluded that cinnamon has a possible modest effect in lowering plasma glucose levels in patients with poorly controlled type 2 diabetes.4

4. Hot Pepper
There may be a host of health benefits in the heat of pepper. Cayenne pepper (ground red pepper), which gets its name from the city of Cayenne in French Guiana, is a concentrated source of capsaicin, the powerful phytochemical that gives chiles their heat and appears to have chemopreventative activity. Data also suggest that the major capsaicinoids of peppers target a variety of pathways involved in cancer development and inflammation.5 Low Dog reported that capsaicin and its relatives are also powerful analgesics.

5. Fields of Garlic
The perceived health benefits of garlic, a species in the onion family, have long been passed down through the generations in many cultures. Garlic contains substances now being studied for their anticancer effects, including allicin, allixin, allyl sulfides, quercetin, and organosulfur compounds. There is some evidence that consuming one half to one full clove of garlic daily may have a cholesterol-lowering effect of up to 9%. Also, 7.2 grams of aged garlic extract has been associated with anticlotting (in vivo studies), as well as modest reductions in blood pressure. However, a new National Institutes of Health-funded clinical trial recently published in the Archives of Internal Medicine found that consumption of garlic, in any form, did not reduce cholesterol levels in patients with moderately high levels.

6. Oh, Oregano
Dining on fresh green herbs like oregano can offer the same benefits as eating fruits and vegetables, thanks to generous levels of phytochemicals and antioxidants. In one study, oregano had the highest antioxidant activity among 27 culinary herbs and 12 medicinal herbs tested, ranking even higher than fruits and vegetables. Oregano also presents antimicrobial activity against pathogens like Salmonella typhimurium, E. coli, Staphylococcus aureus, and Staphylococcus epidermidis.6,7

7. La Vie en Rosemary
Native to the Mediterranean, rosemary has been prized for its medicinal strengths throughout history. Today, we know that rosemary, like other green herbs, possesses antioxidant and antimicrobial activities linked to its polyphenol composition. Animal studies have demonstrated its chemopreventative action. Even the aromatherapy effects of this fragrant herb have been studied regarding its relationship to relieving pain and improving mood.2,8

8. Exotic Ginger
Ginger, a mixture of several hundred known constituents, including gingerols, beta-carotene, capsaicin, caffeic acid, curcumin, and salicylate, has a long history of medicinal use that dates back 2,500 years. Today, it is being studied for numerous uses, such as an aid for pain, nausea, and vomiting. According to Low Dog, dried ginger may be efficacious for nausea and vomiting associated with pregnancy with little risk of harm, but there have been contradictory studies for efficacy in motion sickness and chemotherapy-related nausea and vomiting.

Some compounds in ginger have potent antioxidant and anti-inflammatory activities. In addition, ginger exhibits cancer preventive activity in experimental carcinogenesis. Epidemiologic data suggest that populations consuming foods rich in polyphenols such as ginger have lower incidences of inflammatory disease.2,9

9. Cool Mint
Peppermint, one of the most widely consumed single-ingredient herbs in teas, has been used in traditional medicine for centuries. The phenolic constituents of the leaves include rosmarinic acid and several flavonoids, such as eriocitrin, luteolin, and hesperidin. The main volatile components of the essential oil of peppermint are menthol and menthone. Peppermint has significant antimicrobial and antiviral activities, strong antioxidant and antitumor actions, and some antiallergenic potential. Some animal model studies show a relaxation effect on gastrointestinal tissue, analgesic and anesthetic effects in the central and peripheral nervous system, immunomodulating actions, and chemopreventive potential.10

10. Verdant Basil
Basil (Ocimum basilicum), which comes from the Greek word for “king,” is one of the medicinal plants widely used in several countries, including Morocco, to reduce plasma cholesterol and the risk of atherosclerosis-related diseases. Basil extract appears to contain hypolipidemic and antioxidant substances that have shown some protection against carcinogen-induced cancers in mice.2,11

Suggestions for Spicing up the Diet
It’s not a stretch for dietitians to promote a zesty diet when crafting public health messages. In the 2005 revision of the Dietary Guidelines for Americans, the chapter on choosing a diet moderate in sodium recommends flavoring with herbs and spices.

Greece’s dietary guidelines are even bolder in making recommendations about the health benefits of culinary herbs. Their dietary guidelines not only refer to the usefulness of herbs as salt substitutes but also report that “oregano, basil, thyme and other herbs grown in Greece are good sources of antioxidant compounds.”

The American Institute for Cancer Research notes that herbs and spices should be used as flavor enhancers because of their health-protective phytochemicals, which can help fight cancer and other diseases, much like those found in fruits, vegetables, whole grains, and other plant-based foods.

“People are absolutely more interested in herbs and spices. They read about them, see them in functional foods and supplements, and have questions about them,” says Siegel. “Dietitians need to think of ways to reduce inflammation through the diet. They can make dietary recommendations about increasing aromatic spices and herbs to increase antioxidant levels.”

Scientists are quick to point out that more research on the potential health benefits of culinary herbs and spices needs to occur before specific recommendations for supplementing the diet can be made, but the public may find it beneficial to take a total health approach by including a variety of culinary herbs and spices in a diet focused on lean protein sources, whole grains, fruits, vegetables, nuts, and legumes. At the very least, people can sprinkle flavorful herbs and spices into foods without having to worry about pesky calories, fat, and sodium levels.

In the end, the fragrance and flavor of nature’s bounty of herbs and spices may be the ultimate reward.

— Sharon Palmer, RD, is a contributing editor at Today’s Dietitian and a freelance food and nutrition writer in southern California.

References
1. Shan B, Cai YZ, Sun M, et al. Antioxidant capacity of 26 spice extracts and characterization of their phenolic constituents. J Agric Food Chem. 2005;53(20):7749-7759.

2. Tapsell LC, Hemphill I, Cobiac L, et al. Health benefits of herbs and spices: The past, the present, the future. Med J Aust. 2006;185(4 Suppl): S4-S24.

3. Stix G. “Spice Healer — An ingredient in curry shows promise for treating Alzheimer’s, cancer and other diseases.” Scientific American.com. January 14, 2007. Available here.

4. Pham AQ, Kourlas H, Pham DQ. Cinnamon supplementation in patients with type 2 diabetes mellitus. Pharmacotherapy. 2007;27(4):595-599.

5. Macho A, Lucena C, Sancho R, et al. Non-pungent capsaicinoids from sweet pepper synthesis and evaluation of the chemopreventive and anticancer potential. Eur J Nutr. 2003;42(1):2-9.

6. Arcila-Lozano CC, Loarca-Pina G, Lecona-Uribe S, et al. [Oregano: properties, composition and biological activity.] Arch Latinoam Nutr. 2004;54(1):100-111.

7. More evidence that tomato sauce may lower prostate cancer risk. CA Cancer J Clin. 2002; 52:128-129.

8. Moreno S, Scheyer T, Romano CS, et al. Antioxidant and antimicrobial activities of rosemary extracts linked to their polyphenol composition. Free Radic Res. 2006;40(2):223-231.

9. Shukla Y, Singh M. Cancer preventive properties of ginger: A brief review. Food Chem Toxicol. 2007;45(5):683-690.

10. McKay DL, Blumberg JB. A review of the bioactivity and potential health benefits of peppermint tea. Phytother Res. 2006;20(8):619-633.

11. Amrani S, Harnafi H, Bouanani Nel H, et al. Hypolipidaemic activity of aqueous Ocimum basilicum extract in acute hyperlipidaemia induced by triton WR-1339 in rats and its antioxidant property. Phytother Res. 2006;20(12):1040-1045.