Sun and a vitamin D-rich diet reduce the risk of breast cancer by up to 43 percent
Attested by a study among 70,000 women: the crucial aspect is sufficient UVB radiation; diet or food supplements merely have a supporting function
Veldhoven, 20 June 2011 (SRF). Regular sun exposure and a vitamin D-rich diet reduce the risk of developing breast cancer by around 32 to 43 percent. The deciding factor in prevention is exposure to adequate UVB rays. Admittedly food that is rich in vitamin D, such as fish, dairy products, eggs and certain types of oils or food supplements, can boost the effects of the sun, but used alone they have little effect on the occurrence or progression of the disease. These are the findings of researchers from the French National Institute for Health and Medical Research (Institut National de la Santé et de la Recherche Médicale[INSRM]) in Paris, obtained during a study published in the professional journal "Cancer Epidemiol Biomarkers".
In this study, scientists observed around 70,000 women over a period of ten years. During this period, 2,871 cases of breast cancer were diagnosed. According to the study, women who live in sunny regions such as Provence and who eat a vitamin D-rich diet have a far lower risk of developing breast cancer than women who have less sun exposure, who live in cloudier areas and who ingest less vitamin D through their food or food supplements.
The conclusion of the research group: "A high dose of vitamin D via exposure to sunlight and nutrition is necessary in order to obtain a sufficient protective effect against breast cancer. However, this value is very difficult for women to achieve in northern countries as the sunlight in these regions is not strong enough to ensure a sufficient supply of vitamin D.". Furthermore, the scientists explain, following the menopause it is far more difficult to achieve the protective effect from the combination of sun and a vitamin-D rich diet.
The Sunlight Research Forum (SRF) is a non-profit organisation based in the Netherlands. Its aim is to make the latest medical and scientific evidence on the effects of moderate exposure to UV radiation available to the general public.
Pierre Engel, Guy Fagherazzi, Sylvie Mesrine, Marie-Christine Boutron-Ruault, Francoise Clavel-Chapelonet: "Joint Effects of Dietary Vitamin D and Sun Exposure on Breast Cancer Risk: Results from the French E3N Cohort"; in: Cancer Epidemiol Biomarkers Prev 2011;20:187-198. Published Online First December 2, 2010
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