April 24, 2008

6 Min Read
Science Beat

Calcium and Vitamin D Together Prevent Colon Cancer Recurrence
Calcium prevents recurrence of colon cancer more effectively in people with higher levels of vitamin D than in people with lower levels, according to a new study published in the Journal of the National Cancer Institute (2003;95:1765?71).

Vitamin D is a fat-soluble vitamin produced in skin exposed to sunlight and activated in the liver and kidney. It is also obtained through the consumption of foods such as fortified dairy products, eggs and fish. Vitamin D increases the intestinal absorption of calcium and decreases its output in the urine, leaving more calcium available to the bones and possibly other tissues of the body. The results of some animal and human studies have suggested that vitamin D might protect against colon and other cancers, but other studies have found no such effect. A number of studies have demonstrated that high intake of calcium reduces the risk of colon cancer. There is some evidence that vitamin D and calcium might have a synergistic cancer-preventive effect in the colon, but the interactions between these two nutrients in the colon are not well understood.

The current study examined the effect of calcium supplementation and vitamin D levels on the risk of recurrence of colon cancer. The 803 participants had all had colon cancer in the past, but had no detectable cancer at the beginning of the study. Participants were randomly assigned to receive either 1,200 mg of calcium per day or a placebo. They were monitored for recurrence of colon cancer over a four-year period. Vitamin D levels in the blood were measured at the beginning and end of the study and a median vitamin D level was calculated. The risk of recurrence of colon cancer was evaluated separately for those whose vitamin D levels were at or below the median and for those whose levels were above the median.

In people with higher vitamin D levels, those receiving calcium had a significantly lower risk of recurrence than those receiving placebo, but in those with lower vitamin D levels, calcium showed no significant protective effect.

The results of this study suggest that calcium supplementation and higher vitamin D levels together, but not independently, protect against recurrence of colon cancer. Future studies are needed to evaluate the joint effect of calcium and vitamin D on colon cancer risk in people who have never had colon cancer. The effect of vitamin D supplementation and optimal levels of calcium and vitamin D intake remain to be determined.


Geranium Oil Fights Post-Shingles Pain
People suffering from pain following an outbreak of shingles may get relief by using topical geranium oil (Pelargonium spp.), according to a preliminary study in The American Journal of Medicine (2003;115:586?7). This finding is encouraging for the thousands of individuals who are stricken each year with this difficult-to-treat condition.

Shingles is caused by infection with the varicella-zoster virus, the same virus that causes chicken pox. The initial manifestation of shingles is a cluster of painful blisters that appear on an area of the skin, and usually heal within three to ten days. In a significant minority of cases, the skin lesions are followed by chronic and sometimes debilitating pain (post-herpetic neuralgia) around the area where the skin lesions occurred. This chronic pain appears to be due to the persistence of the virus in the root of the nerve that supplies that area of the skin.

Shingles develops most often in people with decreased immune function, such as the elderly or those with HIV or cancer. Prescription oral anti-viral medications such as acyclovir may reduce the pain in some individuals. Topical capsaicin may also provide relief. While these treatments may take days or weeks to be effective, the new study suggests that geranium oil may help in a matter of minutes.

In the study, 30 adults with post-herpetic neuralgia were assigned to receive one of five topical treatments. The groups received (1) 100 percent geranium oil, (2) 50 percent geranium oil in mineral oil, (3) 10 percent geranium oil in mineral oil, (4) mineral oil only or (5) 0.025 percent capsaicin cream. Measurements of spontaneous and evoked pain using a scale of 0 (no pain) to 100 (worst possible pain) were taken at 2, 10, 15, 20, 30, 45 and 60 minutes following application of the respective topical treatment.

Pain was reduced in all participants receiving geranium oil, and the degree of pain reduction was proportional to the amount of geranium oil in the topical mixture. Thus, those using 100 percent geranium oil had greater pain relief than those using 10 percent geranium oil. All groups receiving geranium oil had significant reductions in spontaneous and evoked pain, compared with those using plain mineral oil. A few minor skin reactions occurred in those using geranium oil, but all reactions resolved within one hour.

Some physicians have reported benefits from giving people with post-herpetic neuralgia injections of vitamin B12 daily or up to several times a week. Oral vitamin B12 does not appear to have the same benefit. Topical peppermint oil (Mentha piperita) or licorice (Glycyrrhiza glabra) may also be useful. Although the current study is preliminary, topical geranium oil is relatively safe and may provide faster pain relief than other treatments.


Bee Propolis May Improve Fertility in Women with Endometriosis
Women with endometriosis who have been unable to get pregnant may have a more successful outcome by taking bee propolis, according to a preliminary study in Fertility and Sterility (2003;80:S32).

Endometriosis is a disease where cells from the uterine lining become implanted within the pelvic cavity, causing adhesions, menstrual irregularities, painful periods, premenstrual syndrome and infertility. The diagnosis can be difficult, since surgery is the only way to accurately identify endometriosis. Studies suggest that 7 percent to 10 percent of all women in the United States have endometriosis.

In the new preliminary study, 40 women with mild endometriosis and primary infertility (i.e., they had never been pregnant) who had unsuccessfully tried to get pregnant for at least two years were assigned to receive 500 mg twice a day of bee propolis or placebo for nine months. The number of pregnancies was recorded during the treatment period.

Women taking bee propolis had a significantly higher pregnancy rate than those taking the placebo: 60 percent and 20 percent, respectively. No adverse effects were reported by the women taking bee propolis, which is the resinous substance collected by bees from the leaves and bark of trees.

Test tube studies, although preliminary, suggest that propolis may have strong anti-inflammatory effects. The pain associated with endometriosis is often due to the body?s inflammatory response to the endometrial lesions in the pelvic wall. Propolis may help decrease this inflammatory reaction, thereby reducing pain. It is unknown how propolis affects fertility.

Several studies also suggest that oral propolis is useful in treating the common cold and intestinal parasites. Other studies have shown that topical propolis helps against genital herpes, cold sores, dental caries, periodontal disease and rheumatoid arthritis.


Maureen Williams, N.D., has a private practice in Quechee, Vt.
Darin Ingels, N.D., is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000).

Copyright ? 2004 Healthnotes, Inc.

Natural Foods Merchandiser volume XXV/number 3/p. 120-121

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