Studies suggest that, besides perking up our palates, culinary herbs and spices may be powerful weapons against a variety of diseases-from Alzheimer's to cancer and diabetes. Here's a rundown of some of the most promising functional flavourings.
An exciting new study suggests that cinna-mon, made from tree bark, may help to slow or even reverse Alzheimer's disease, the most common form of dementia. Researchers at Tel Aviv University in Israel fed an extract of cinnamon called CEppt to mice bred with Alzheimer's.
After four months, they noticed a significantly reduced number of amyloid plaques (a hallmark of the disease) in the animals' brains, as well as improvement in cognitive deficits such as impaired memory (PLoS One, 2011; 6: e16564). But more research is needed to see whether the results also apply to humans, and to find out how much cinnamon-or CEppt-is needed to have any useful effects.
Earlier studies have suggested that cinnamon-even in small amounts-might also be useful for type 2 diabetes. In one randomized controlled trial, researchers in Pakistan split 60 type 2 diabetics into six groups: groups 1, 2 and 3 consumed 1, 3 and 6 g/day of cinnamon, respectively (1 g is about a quarter of a teaspoon), while groups 4, 5 and 6 were given placebo capsules matching the number of capsules consumed by the first three groups.
After 40 days, all doses of cinnamon significantly reduced blood glucose, triglycerides, and LDL ('bad') and total cholesterol levels, whereas no significant changes were noted in the placebo groups.
The results "suggest that the inclusion of cinnamon in the diet of people with type 2 diabetes will reduce risk factors associated with diabetes and cardiovascular diseases", the researchers concluded (Diabetes Care, 2003; 26: 3215-8).
Cinnamon also appears to have anti-inflammatory, antimicrobial and antitumour effects (Crit Rev Food Sci Nutr, 2010; 50: 822-34).
Like cinnamon, sage has been studied for its effects on Alzheimer's disease-with encouraging results. In one double-blind randomized control-led trial, a liquid extract of the herb (60 drops/day) was given to patients with mild-to-moderate Alzheimer's for four months.
At the end of the study, the group taking the sage extract had better cognitive function scores compared with the placebo group. They also showed less agitation, according to the researchers (J Clin Pharm Ther, 2003; 28: 53-9).
Another study looked at the possible mechanisms behind sage's apparent anti-Alzheimer's effect, and concluded that rosmarinic acid-sage's active ingredient-could play a major role, as it exerts neuroprotective and antioxidative effects against the amyloid-beta-induced toxicity characteristic of Alzheimer's (J Pharmacol Exp Ther, 2006; 317: 1143-9).
Other research suggests that sage might be an effective treatment for hyperlipidaemia-abnormally high levels of lipids (fats) in the blood. Compared with a placebo, sage leaf extract (one 500-mg capsule every eight hours for two months) signifi-cantly lowered triglycerides, and LDL ('bad'), very-low-density lipoprotein (VLDL, also 'bad') and total cholesterol levels, while increasing levels of HDL ('good') cholesterol-with no adverse effects (Phytother Res, 2011 Apr 19; doi: 10.1002/ptr.3506).
Curcumin, the yellow pigment in this popular Indian spice, is showing promise against a broad range of diseases and particularly cancer. Labora-tory studies have found that curcumin can kill human cancer cells of the breast, prostate, pancreas, stomach, colon and oesophagus (Int J Oncol, 2009; 35: 867-72; J Huazhong Univ Sci Technolog Med Sci, 2011; 31: 530-4; Anticancer
Res, 2001; 21: 873-8), while animal research suggests that the compound has an impact on all three stages of cancer development-its initiation, promotion and progression (Altern Med Rev, 2009; 14: 141-53). Although these findings may not apply to people, preliminary trials in cancer patients are encouraging. In one, 15 patients with advanced colorectal cancer were given a turmeric supplement (equivalent to 36- 180 mg of curcumin) every day for up to four months. Five patients saw their condition stabilize, while another showed signs of cancer regression (Clin Cancer Res, 2001; 7: 1894-900).
Curcumin may also help against gastrointestinal condi-tions such as dyspepsia (indigestion), Helicobacter pylori infec-tion, peptic ulcer, irritable bowel syndrome, Crohn's disease and ulcerative colitis (Altern Med Rev, 2009; 14: 141-53). In one trial of
25 pepticulcer patients given 600 mg of curcumin five times a day for 12 weeks, nearly half had no ulcers after four weeks and, by the end of the study, 76 per cent were ulcer-free (Southeast Asian J Trop Med Public Health, 2001; 32: 208-15).
Other research indicates that curcumin might be useful for arthritis. In a preliminary ran-domized controlled trial, 1200 mg/day of curcumin effectively improved joint swelling, morning stiffness and walking time in patients with rheumatoid arthritis-findings supported by both animal and laboratory evidence (Altern Med Rev, 2009; 14: 141-53; Int J Mol Med, 2007; 20: 365-72).
Ginger is well known for its antiemetic properties-its ability to control nausea and vomiting. Indeed, studies show that not only is it superior to a placebo, but it is also just as effective as the antiemetic drug metoclopramide (Br J Anaesth, 2000; 84: 367-71).
More recent research, however, is focusing on ginger's anticancer potential. In a laboratory study by scientists at Georgia State University in Atlanta, GA, whole-ginger extract had significant effects in preventing cell growth and inducing cell death in a spectrum of prostate cancer cells. Furthermore, animal experiments with the extract showed tumour regression of 56 per cent-with no toxicity (Br J Nutr, 2011, Aug 18: 1-12; Epub ahead of print). However, these results may not necessarily apply to humans.
Ginger also has a wide range of anti-inflammatory actions (J Med Food, 2005; 8: 125-32), which suggests that it may be beneficial for conditions such as arthritis and asthma.
Could hot red pepper be the answer to the obesity problem? It could be one small piece of the puzzle, according to a new US study by Purdue University researchers. In this six-week trial, 25 non-overweight people-13 of whom liked spicy food and 12 of whom did not-consumed meals seasoned with ground cayenne pepper.
The researchers compared the effects of eating a plain meal or a spicy meal (seasoned with no more than 1 g, or half a teaspoon, of cayenne pepper) on calorie-burning and appetite. They discovered that the cayenne-spiced meals were associated with reduced hunger and higher calorie-burning after the meal, especially in those who did not consume the spice regularly (Physiol Behav, 2011; 102: 251-8).
"Dietary changes that don't require great effort to implement, like sprinkling red pepper on your meal, may be sustainable and beneficial in the long run, especially when paired with exercise and healthy eating," said study co-author Richard Mattes.
Red pepper appears to have other benefits, too. Capsaicin-the major pungent ingredient in red peppers-has been successfully used topically (in creams) to treat various pain conditions (Phytother Res, 2010; 24: 1877-85). It's also showing promise as an anticancer agent. A recent study revealed that capsaicin was able to inhibit the growth of human breast-cancer cells (Hum Exp Toxicol, 2011 Feb 7; Epub ahead of print).
Factfile: More healing herbs and spices
- Parsley. As well as being an effective breath freshener, parsley may also help to fendoff breast cancer-at least according to animal and test-tube studies (which may not apply to humans). Its flavonoid component apigenin reduced the incidence of mammary tumours in rats, and inhibited the growth of human breast-cancer cells (Cancer Prev Res [Phila], 2011; 4: 1316-24).
- Cumin. A recent rat study reported that cumin has "antistress, antioxidant, and memory-enhancing activities" (Pharm Biol, 2011; 49: 702-8). But, again, these results may not necessarily apply to humans.
- Coriander. This herb (also known as Chinese parsley) may aid in detoxification of the body. Researcher Dr Yoshiaki Omura found that patients excreted more toxic metals after consuming a Vietnamese soup containing this herb (Acupunct Electrother Res, 1995; 20: 195-229). Also, when patients with mercury deposits supplemented with coriander tablets (100 mg/day four times a day) for a few weeks, their heavy-metal deposits disappeared (Acupunct Electrother Res, 1996; 21: 133-60).
- Oregano. In a study comparing the antioxidant capacity of nine common herbs, oregano came out on top-in both dried and fresh forms (Int J Food Sci Nutr, 2011; 62: 219-25). Studies also suggest that oregano has antifungal and antibacterial properties (Curr Med Chem, 2003; 10: 813-29).
WDDTY 22 no 7, October 2011