Treating Pain Gingerly
Researchers have discovered that the drugs that treat pain and inflammation by inhibiting the COX-2 enzyme are mirrored by a number of natural compounds. Ginger, for example, has traditionally been used to treat pain and inflammation. Constituents of ginger (Zingiber officinale)—10-gingerol, 6-shogaol and 8-paradol—have been shown to have potent inhibitory effects on COX-2 in the test tube.1
In a recent randomised, double-blind, placebo-controlled, six-week study of 261 patients with osteo-arthritis, researchers tested a proprietary ginger extract combined with a proprietary extract of Alpinia galanga (Siamese ginger, Java galangal), another member of the ginger family.2 These extracts resulted in only modest pain reduction and even caused nausea.
In an earlier Danish randomised, controlled trial on persons with osteoarthritis, the same ginger extract used alone showed no significant pain reduction either.3 Although ginger may have COX-2 inhibitory effects, it may not be a strong enough natural panacea for aches and pains.
Doing Double Duty
One phytochemical that deserves attention for its cancer protection is D-glucaric acid, which is present in broccoli and apples.4 Not only has D-glucarate been shown to prevent the development of cancer in lab animals, it also improves blood cholesterol parameters. It inhibits an enzyme that can 'undo' the body's detoxification processes.5
D-glucarate is available in two supplement forms: calcium and potassium hydrogen D-glucarate. Cancer studies using animals having chemical-induced cancer have shown a protective effect primarily with calcium D-glucarate,6,7 but there is some evidence that the potassium version works as effectively.8 Scientists credit both with reducing total and LDL cholesterol, without diminishing the benefits of HDL cholesterol.4
To date, no published human studies show a cholesterol-altering or cancer-modifying effect of D-glucarate. Also, it may interact with prescription drugs because it modifies detoxification processes.
Nosing Out Colds
Zinc is a key player in optimising the immune system,9 specifically speeding up recovery from the common cold. Studies on zinc gluconate in lozenges began in the mid-1980s.10 Numerous studies since then have found either moderate effectiveness or ineffectiveness in reducing the severity and duration of colds.11
In one study, however, zinc acetate lozenges tasted "identical" to placebo and produced a significant reduction in the duration and severity of colds. The average daily dose was 80mg of zinc for four to five days.12 Because zinc lozenges can produce side effects, such as nausea, a distasteful metallic taste and diarrhea, researchers have been testing a 'homeopathic' intranasal zinc called Zicam. In the first study, subjects with severe colds showed a marked reduction in the severity and duration of their colds.13
In a more rigorous study, subjects exposed to a specific rhinovirus and treated with intranasal zinc had no symptom relief.14 An important note: In studies where zinc had a positive effect on colds, the effect was due to supplementation, not from diet-derived intake.15
Anthony Almada, BSc, MSc, is a nutrition and exercise biochemist and has collaborated on more than 50 university-based clinical trials. He is the co-founder of EAS and founder and chief scientific officer of IMAGINutrition in Laguna Niguel, California.
1. Tjendraputra E, et al. Effect of ginger constituents and synthetic analogues on cyclooxygenase-2 enzyme in intact cells. Bioorg Chem 2001;29:156-63.
2. Altman, RD, Marcussen KC. Effects of a ginger extract on knee pain in patients with osteoarthritis. Arthritis Rheum 2001;44:2531-8.
3. Bliddal H, et al. A randomised, placebo-controlled, cross-over study of ginger extracts and ibuprofen in osteoarthritis. Osteoarthritis Cartilage 2000;8(1):9-12.
4. Walaszek Z, et al. D-glucaric acid content of various fruits and vegetables and cholesterol-lowering effects of dietary D-glucarate in the rat. Nutr Res 1996;16:673-81.
5. Dwivedi C, et al. Effect of calcium glucarate on beta-glucuronidase activity and glucarate content of certain vegetables and fruits. Biochem Med Metab Biol 1990;43:83-92.
6. Abouissa H, et al. Relative efficacy of glucarate on the initiation and promotion phases of rat mammary carcinogenesis. Anticancer Res 1995;15:805-10.
7. Walaszek Z, et al. Metabolism, uptake, and excretion of a D-glucaric acid salt and its potential use in cancer prevention. Cancer Detection Prev 1997;21:178-90.
8. Yoshimi N, et al. Inhibition of azoxymethane-induced rat colon carcinogenesis by potassium hydrogen D-glucarate. Int J Oncol 2000;16: 43-8.
9. Rink L and Gabriel P. Extracellular and immunological actions of zinc. BioMetals 2001;14:367-83.
10. Eby GA, et al. Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study. Antimicrob Agents Chemother 1984;25:20-4.
11. Jackson J, et al. Zinc and the common cold: a meta-analysis revisited. J Nutr 2000;130:1512S-5S.
12. Prasad AS, et al. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. Ann Intern Med 2000;133:245-52.
13. Hirt M, et al. Zinc nasal gel for the treatment of common cold symptoms: a double-blind, placebo-controlled trial. Ear Nose Throat J 2000;79:778-80, 82.
14. Turner RB. Ineffectiveness of intranasal zinc gluconate for prevention of experimental rhinovirus colds. Clin Infect Dis 2001;33:1865-70.
15. Takkouche B, et al. Intake of vitamin C and zinc and risk of common cold: a cohort study. Epidemiology 2002;13:38-44.