High-protein diets that include a lot of iron-containing foods, such as the increasingly popular Atkins diet, may not be the best choice for everybody, according to a new study out of the Medical University of South Carolina. Analyzing population-based data from U.S. National Health and Nutrition Examination Surveys, Mainous and colleagues found that people with elevated levels of serum transferrin saturation - an indicator of iron overload - who consume high levels of dietary iron, have an increased risk of cancer and cancer mortality.

Specifically, they found that people with elevated levels of transferrin saturation who ingest more than 18 mg of iron per day have a 2.24 times greater relative risk of cancer than those who have normal transferrin saturation levels and report low dietary iron intake. Having high transferrin saturation with a normal diet did not carry increased risk. The authors point out that a substantial proportion of adults in the United States - approximately 7 percent of the adult U.S. population - has transferrin saturation levels greater than 41 percent, and are at increased risk.

The authors suggest that simple dietary restrictions may help to reduce the cancer risk associated with high transferrin saturation. They add that these findings call into question the strategy of the addition of iron to food by manufacturers.

Transferrin Saturation, Dietary Iron Intake, and Risk of Cancer
By Arch G. Mainous III, et al

March/April 2005 Annals of Family Medicine tip sheet

Annals of Family Medicine is a peer-reviewed research journal that provides a cross-disciplinary forum for new, evidence-based information affecting the primary care discipline. Launched in May 2003, the journal is sponsored by six family medical organizations, including the American Academy of Family Physicians, the American Board of Family Practice, the Society of Teachers of Family Medicine, the Association of Departments of Family Medicine, the Association of Family Practice Residency Directors and the North American Primary Care Research Group. Annals is published six times each year and contains original research from the clinical, biomedical, social and health services areas, as well as contributions on methodology and theory, selected reviews, essays and editorials. A board of directors with representatives from each of the sponsoring organizations oversees Annals. Complete editorial content and interactive discussion groups for each published article can be accessed free of charge on the journal\'s Web site, http://www.annfammed.org.

Contact: Angela Lower
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American Academy of Family Physicians
http://www.annfammed.org.