News Bites: Breast, Eye and Colon Health

Calcium, Vitamin D and Breast Cancer

Getting enough calcium and more vitamin D could provide benefits beyond maintaining a healthy bone mass. Findings from a recently published study suggest that younger women with higher intakes of these two nutrients have a lower risk of developing pre-menopausal breast cancer (1).

In this study, Harvard researchers evaluated the calcium and vitamin D intake of 10,578 pre-menopausal and 20,909 post-menopausal women who participated in the Women's Health Study. They compared the nutrient intake of women who developed breast cancer during an average 10-year follow-up, with the intake of women who remained breast cancer free.

Pre-menopausal women with the highest intake of calcium had a 39% lower risk compared with those consuming the least. For vitamin D, the risk was reduced by about 35%, again in younger women who consumed the most. A protective effect was not seen among the post-menopausal group.

Anti-Cancer Vitamin D Especially Important

Results of a four year long clinical trial in women 55 and older, point to vitamin D as a particularly important anti-cancer nutrient (2). Participants in the trial received 1400-1500 mg supplemental calcium per day alone, supplemental calcium plus 1100 IU vitamin D, or placebo. The investigators found that the incidence of cancer (many types) was lower in the Calcium plus D group than in the placebo subjects. That incidence was not significantly lower, however, in women who took calcium without vitamin D.

Vitamin D for Macular Health?

Vitamin D, according to new findings, may also be important for macular health (3). Investigators focused on participants of the 3rd National Health and Nutrition Examination Survey who had photographs taken of their retinas, their blood levels of vitamin D assessed, and who answered a questionnaire about their diet. Eleven percent of the surveyed group had AMD.

When participants were split into five groups based on the level of vitamin D in blood, those in the highest group had a 40% lower risk of developing early AMD than those with the lowest blood levels. People who drank D-fortified milk daily decreased their risk, as did people who took supplemental vitamin D consistently and didn't drink milk everyday.

Vitamin D's Anti-Inflammatory Actions Key

Emerging evidence has implicated chronic inflammation as a culprit in the development of AMD. The authors of this study theorize that vitamin D may intervene in the macular disease process by helping to reduce inflammation. This vitamin has been shown to block pro-inflammatory immune cells and recently was found to lower a biomarker of inflammation, C-reactive protein. The vitamin D and AMD connection needs to be confirmed by further research, but these preliminary findings are promising.

Green Tea May Halve Colorectal Cancer Risk

Finally, investigators from Vanderbilt University in collaboration with Shanghai Cancer Institute, NIH and the National Cancer Institute, report that regularly drinking green tea may cut the risk of colorectal cancer in half (4). The research team looked at green tea consumption and colorectal cancer risk among nearly 70,000 Chinese women aged 40 to 70. At the study's start - and in subsequent surveys - the risk reduction was most evident among those who consistently drank tea over the six-year period they were followed.

References

1. Lin J, et al. Intakes of calcium and vitamin D and breast cancer risk in women Arch Internal Med 167:1050-59, 2007.
2. Lappe JM, et al. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr 85:1586-91, 2007.
3. Parekh N et al. Association between vitamin D and age-related macular degeneration in the Third National Health and Nutrition Examination Survey. Arch of Ophthalmol 125:661-69, 2007.
4. Yang G et al. Prospective cohort study of green tea consumption and colorectal cancer risk in women. Cancer Epidemiol Biomarkers and Prev 16:1219-23, 2007.