Herbs and spices have been grown and used since antiquity to preserve and flavor foods. The ability of herbs and spices to delay food spoilage is due in large part to their rich content of antioxidants. The unique flavors associated with different herbs are provided by the aromatic ingredients of their essential oils and oleoresins while their pungency is due to their alkaloids. In addition, some herbs such as paprika and turmeric, add a red or yellow color, respectively, to food.

Freshly picked herbs add a rich and vigorous flavor to different foods. Dried herbs usually smell and taste somewhat differently from their fresh counterparts. During the drying of herbs there is usually a loss in the fragrant oils leaving the non-volatile bitter elements to dominate. Furthermore, the flavor of most dried herbs diminish with time. Any bottles containing herbs that are older than 12 months should be discarded.

With the current emphasis on eating more healthful diets that are low in fat and salt, people are turning to various herbs and spices to flavor their food. The culinary herbs and spices that are used to enhance the flavor of vegetables, soups, stir-frys, and pasta dishes can be derived from the bark, buds, flowers, leaves, fruit, seeds, rhizome, or roots of a plant.

Immigrants to the United States carried with them their own cultural cooking and uniquely flavored ethnic dishes. The popularity of Italian, Mexican, Greek, Chinese, Indian, Thai, and other ethnic dishes has resulted in an increased variety of herbal seasonings. For example:

• Oregano is essential in the preparation of Italian and Spanish food and is commonly used to flavor pizza;
• Chili pepper is commonly used in many Italian, Mexican, and Indian dishes;
• Italians use sweet basil for flavoring beans and many of their tomato dishes.
• Thyme has a prominent place in French cuisine.
• Rosemary is a common ingredient in Italian and French dishes.
• Cinnamon, cloves, cumin, ginger, and turmeric are common ingredients in Indian dishes.
• Lemon grass, coriander, and ginger add unique flavors to Oriental cuisine.

For centuries garlic has been used in Greek, Italian, Mexican, Indian, and Oriental dishes. Garlic can be used in a variety of dips, vegetable dishes, soups, and some baked goods. Likewise, onions or dehydrated onion can be used to enhance the flavor of most vegetables, salads, soups, gravies, and many entrees.

Herbs and Heart Health

There are a few herbs such as garlic, onions, and ginger that provide some help for persons with hyperlipidemia, or an abnormal tendency to form blood clots. Ginger adds a nice spicy flavor to stir-fried vegetables, bakery products, and fruit salads. Ginger contains a number of terpenoid and phenolic compounds that inhibit the formation of blood clots (1)

Garlic has been used medicinally for many centuries. The compound producing much of the activity of garlic is allicin, which is released when intact cells of a clove are cut or crushed. Allicin inhibits the growth of a wide variety of bacteria, moulds, yeasts (including Candida), and viruses (2). The regular use of garlic can also be useful in lowering the risk of heart attacks and strokes since it lowers both total and LDL cholesterol levels and triglyceride levels, without affecting HDL cholesterol levels. On average, consuming one-half to one clove of garlic per day for three to six months reduces elevated blood cholesterol levels by about ten percent of its initial value (3). Garlic also possesses anti-clotting activity and inhibits platelet clumping due in part to the presence of sulfur compounds produced from the breakdown of allicin (4).

The odor-modified garlic extract (Kyolic) has been found to be just as effective as fresh garlic for lowering blood cholesterol levels. The use of enteric-coated garlic pills, which dissolve in the intestinal tract, are another way to cut down on odor problems while still enjoying the benefits of garlic. Data also suggests that garlic may be useful for patients with mild hypertension. (5)

Onions contain many sulfur compounds that are identical or similar to those found in garlic. However, garlic is considered a more potent herb since it contains about three times the level of sulfur compounds found in onions. Onions are also considered anticlotting agents since they possess substances with fibrinolytic activity. A whole family of sulfur compounds known as a-sulfinyl disulfides isolated from onions have been shown to strongly inhibit platelet clumping (6). However, onion consumption does not appear to modify blood lipid levels. Onion extracts have also been useful in the treatment of asthma and bronchitis, since they decrease the likelihood of bronchial spasms (7).

Ground linseed can be added to breakfast cereals or bakery products, providing a nutty flavor to the food. The regular use of ground linseed can lower both total cholesterol and LDL cholesterol levels about 10 percent as well as producing a substantial decrease in platelet clumping, without altering HDL cholesterol and triglyceride levels (8). Linseed has a very low saturated fat content, and a high content of polyunsaturated fat (especially omega-3 fatty acids), phytosterols, in addition to a rich content of soluble fiber. Fenugreek is a common feature of Indian recipes. The rich content of saponins and soluble fiber in fenugreek explains its usefulness in lowering blood cholesterol levels. In addition, the terpenoids found in lemon grass, and the herbs belonging to the genus Lamiaceae (mint family) block cholesterol synthesis (9).

Onions, rosemary, sage, thyme, and other herbs contain substantial levels of flavonoids. The flavonoid content of a herb can vary from plant to plant based upon where the herb was grown, the maturity of the plant when harvested, the actual cultivar, and the part of the herb used. Flavonoids act as antioxidants, protect LDL cholesterol from being oxidized, inhibit the formation of blood clots, as well as having anti-inflammatory and anti-tumor activity. Flavonoid intake is inversely associated with incidence of heart disease and stroke.

Herbs and Managing Diabetes

Diabetes is a disease characterized by elevated blood sugar levels. The unregulated blood sugar may result from either a lack of insulin or a reduction in its effectiveness. Careful dietary habits and regular exercise are essential components in the management of type II diabetes. In addition, there are a few herbs that lower blood glucose levels and may be useful therapeutic adjuncts in the management of diabetes.

The consumption of fenugreek seeds, which contain high levels of soluble fiber, can also lower blood sugar levels in people with diabetes. Research in India found that glucose tolerance improved, urinary glucose excretion decreased 70%, and insulin responses were reduced in people with diabetes after defatted fenugreek was used for 10 days. Total serum cholesterol, LDL cholesterol, and triglyceride levels, but not HDL cholesterol, all significantly decreased by about 20% when fenugreek was added to the diet (10). These changes in blood lipids are important factors for a person with diabetes who usually has elevated blood lipids.

Linseed, cinnamon, and other herbs may also provide benefits to people with diabetes. Subjects consuming bread containing 25 percent linseed meal showed an almost 30 percent improvement in a glucose tolerance test compared with those who ate plain bread (11). An extract from cinnamon has been found to enhance insulin activity (12). It has been suggested that cinnamon may find use in adult-onset diabetes. Preliminary studies have reported improved glucose tolerance or anti-diabetic activity from a number of other herbs including garlic, onions, bay leaves, cloves, cumin, and turmeric (13). Further research is needed to validate these findings and discover if there is any clinical significance to the hypoglycemic effects of these herbs.

Herbs and Cancer Prevention

A number of commonly used herbs have been identified as possessing cancer-protective properties. These include:

• linseed
• members of the Allium family (garlic, onions, chives, leeks),
• members of the Lamiaceae family (basil, mint, oregano, peppermint, rosemary, sage,, thyme),
• members of the Zingiberaceae family (turmeric, ginger), and
• members of the Umbelliferae (parsley) family, such as anise, caraway, celery, chervil, coriander, cumin, dill, fennel, and parsley.

Garlic has been shown to especially reduce the development of stomach, and colon cancer. A prospective study in Iowa revealed that risk of colon cancer was 32 percent less in those with the highest garlic consumption compared to those with the lowest consumption (14). The rich content of sulfides, disulfides and trisulfides in garlic provides its cancer preventive properties. Also, a Dutch study revealed that stomach cancer for those consuming the highest level of onions (at least half an onion a day) was about 50 percent lower than that in persons consuming no onions (15).

Linseed, turmeric, and ginger have all been suggested to inhibit cancer growth. Linseed contains a very rich supply of lignans, which are thought to reduce the risk of breast cancer. Turmeric and ginger contain curcuminoids which inhibit also cancer development.

Paprika or pimiento is a long, sweet, nonpungent species of capsicum. The spice is made by grinding the dried, ripe fruit to yield a mildly pungent, red powder. The red color is due to capsanthin, a carotenoid, a pigment that protects cells against oxidative damage... Paprika is commonly used as a garnish on white vegetables and other dishes. Paprika is used in the manufacture of tomato sauce, soups, salad dressings, and in pickled products. Persons with a high intake of carotenoids typically have a reduced risk of cancer (16).

Cayenne pepper or chili pepper is used in chili powder blends, soups and many Italian, Mexican and Indian dishes. Extensive cultivation over centuries of time has produced a large variety of peppers, differing in size, shape and pungency. The pepper has been used as a gastrointestinal stimulant and an aid to digestion. Cayenne pepper contains high levels of capsaicin, an irritating phenolic compound, and other active principles (600 to 13, 000 parts per million of capsaicinoids) which provide it with a strong stimulatory effect.. Excessive amounts may cause severe irritation of mucous membranes. Consumption of red pepper increases gastric acid secretion, and may cause a gastric ulcer (17) or aggravate symptoms of a duodenal ulcer (18). Chili and its extracts are also reported to cause cancer and promote the growth of tumors (19,20).

Cayenne pepper belongs to the capsicum family and is quite different from the white or black pepper, Piper nigrum, that is used with table salt at most meals. The research data for black pepper is fragmentary and conflicting. Black pepper contains compounds that are suspected of causing bladder cancer but not oral or esophageal cancer while animal studies have shown that black pepper induces glutathione-S-transferase (a beneficial phase 2 enzyme), suppresses DNA adducts, and decreases lipid peroxidation (21).

CONCLUSION

A variety of commonly used culinary herbs have the potential for use in the treatment of elevated blood lipids and blood glucose, while some provide protection against cancer. Herbs have been described as both a friend of physicians and the praise of cooks.

References

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