The studies cited here have been excerpted from the inaugural issue of Research and Your Health, a new quarterly publication of the CHFA, which contains selected abstracts that focus on the value of natural products and health foods for both the prevention and treatment of cancer. The Canadian Health Food Association (www.chfa.ca) and InspireHealth (www.inspirehealth.ca) have partnered to create this educational resource. Translating the large and growing body of evidence in support of integrative care into a language and format that is readily understood by the average person – in simple, clear language with clear simple conclusions for action/self-care based on this evidence – is essential in engaging the public in their own health and healing and integrative approaches to care.
Herbal & specialty supplements
- Some can reduce the risks of developing lung and colorectal cancer
Millions of North Americans use dietary supplements with little knowledge about their benefits or risks. Therefore, the authors of this study examined associations of various herbal and specialty supplements with lung and colorectal cancer risk.
Men and women, 50 to 76 years, in the “Vitamins and Lifestyle” cohort completed a 24-page baseline questionnaire that captured duration (years) and frequency (days per week) of use of commonly used herbal/specialty supplements. Supplement exposure was categorized as “no use” or “any use” over the previous 10 years. The number of lung (665 individuals) and colorectal cancers (428 individuals) were obtained from the American Surveillance, Epidemiology, and End Results (SEER) cancer registry.
Any use of glucosamine and chondroitin, which have anti-inflammatory properties, over the previous 10 years, was associated with significantly lower lung cancer risk (26% and 28% risk reduction) and colorectal cancer risk (27% and 35% risk reduction). Other supplements that reduced the risk of colorectal cancer included fish oil (35% risk reduction), methylsulfonylmethane (54% risk reduction) and St. John’s wort (65% risk reduction). In contrast, garlic pills were associated with a statistically significant 35% elevated colorectal cancer risk.
These results suggest that some herbal/specialty supplements may be associated with reducing the risk of developing lung and colorectal cancer. Additional studies examining the effects of herbal/specialty supplements on risk for cancer and other diseases are needed.
Some herbal and specialty supplements can reduce the risks of developing lung and colorectal cancer
Satia JA, Littman A, Slatore CG, Galanko JA, White E. Cancer Epidemiol Biomarkers Prev. 2009 May;18(5): 1419-28. Email: email@example.com. supplements with lung and colorectal cancer risk.
- One or more cups of green tea per day may help prevent ovarian cancer
The link between caffeinated drinks like coffee and tea and risk of ovarian cancer is still unknown. This study included 781 women who were diagnosed with epithelial ovarian cancer between 2002 and 2005 and 1,263 similar women without cancer (control group) from Washington State, USA. Each participant completed questionnaires that measured how much caffeinated and non-caffeinated coffee, tea and cola they consumed. Each participant was also interviewed about reproductive and hormonal exposures. The researchers analyzed the data to look at ovarian cancer risk and consumption of coffee, tea, cola and total caffeine intake.
The results showed no association between ovarian cancer risk and caffeinated coffee, decaffeinated coffee, black tea, decaffeinated tea, herbal tea or total caffeine. However, women who reported drinking at least one cup of green tea per day had a 54 percent lower risk of ovarian cancer. This association between high levels of green tea consumption and a lower risk of developing cancer applied to early and advanced ovarian cancer. Green tea is a common beverage in countries with low ovarian cancer rates. Studies to assess its potential to prevent cancer should be expanded.
Song, YJ, A. R. Kristal, K. G. Wicklund, K. L. Cushing-Haugen and M. A. Rossing. Cancer Epidemiology, Biomarkers & Prevention. 2008 Mar; 173: 712-716.
- Vitamin D and calcium reduce cancer risk
In the past, numerous observational studies* have found that taking vitamin D and calcium supplements reduces the risk of many common cancers. This study was designed as a randomized clinical trial, which is considered the gold standard of clinical studies. The purpose of this study was to determine the efficacy of calcium alone and calcium plus vitamin D supplementation in reducing cancer risk of all types. This was a four-year, population-based, double-blind, randomized placebo-controlled trial (i.e. gold-standard clinical study).
The primary outcome was bone fracture incidence and the secondary outcome was cancer incidence; 1179 women were randomly selected from the population of healthy, postmenopausal women aged >55 years in rural Nebraska, USA. Subjects were randomly assigned to receive 1400-1500 mg supplemental calcium per day alone, supplemental calcium plus 1100 IU vitamin D per day, or placebo (sham medication; e.g. sugar pills).
The results showed that cancer incidence was lower in calcium + vitamin D supplemented women than in the placebo control subjects. Cancer risk was reduced by 47 percent in the calcium-only group and by 60 percent in the calcium + vitamin D group.
When the analysis was confined to cancers diagnosed after the first 12 months of supplementation, the cancer risk was reduced by 77 percent in the calcium + vitamin D group. Improving calcium and vitamin D nutritional status substantially reduces all-cancer risk in postmenopausal women.
*Observational study: Study where the assignment of subjects into a treated group versus a control group is outside the control of the investigator.
Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Am J Clin Nutr. 2007 Jun; 85(6):1586-91.
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