A study of 200,000 European women has found that doing housework is more likely to protect you against breast cancer than job- or leisure-based physical activity.
The study is published in Cancer Epidemiology Biomarkers & Prevention.
The research was funded by Cancer Research UK and led by Petra Lahmann of the Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbrücke, in Nuthetal, Germany, and a widely constituted international team of researchers.
While much research extols the virtue of physical exercise as a way to reduce breast cancer risk, the evidence on precisely what type of activity is most beneficial is scanty.
Petra Lahmann and colleagues used data on over 200,000 premenopausal and postmenopausal women aged between 20 and 80, from 9 European countries.
They used statistical regression models to work out a metabolic-equivalent rate for the various forms of exercise the women undertook so that they could compare the “physical activity value” of the different forms of exercise.
They also took into account demographic, social and medical factors such as age, age when menstruation started, body mass index, education, geographical location, alcohol consumption, age at first pregnancy, oral contraception and hormone replacement therapy.
The women’s physical activities were classified into three groups: recreational, household, and occupational, and a total of all three was also calculated. The women were followed up over a 6.4 year period, during which time 3,423 invasive breast cancers occurred in the group.
The results suggest that total physical activity reduces risk of breast cancer only in postmenopausal women. However, and perhaps more surprisingly, housework on its own reduces breast cancer risk in both pre- and postmenopausal women – the former by 19 per cent and the latter by 29 per cent. The study found no significant link between reduced breast cancer risk and either leisure or work-related physical activity.
The women spent an average of 16 to 17 hours a week on household chores such as washing, cooking and cleaning.
The researchers mention in the study that their findings on housework and reduced breast cancer risk are in line with other research, but point to the low numbers of women in the study who were classed as “active” in job-related activity as to the possible reason why no link was found in that area.
Their main conclusion is that this study supports the growing body of evidence showing strong links between physical activity and reduced breast cancer risk. This is in line with the general message from Cancer Research UK who promote taking regular exercise and maintaining a healthy body weight as the main way to reduce cancer risk.
“Physical Activity and Breast Cancer Risk: The European Prospective Investigation into Cancer and Nutrition.”
Petra H. Lahmann, Christine Friedenreich, A. Jantine Schuit, Simonetta Salvini, Naomi E. Allen, Tim J. Key, Kay-Tee Khaw, Sheila Bingham, Petra H.M. Peeters, Evelyn Monninkhof, H. Bas Bueno-de-Mesquita, Elisabet Wirfält, Jonas Manjer, Carlos A. Gonzales, Eva Ardanaz, Pilar Amiano, José R. Quirós, Carmen Navarro, Carmen Martinez, Franco Berrino, Domenico Palli, Rosario Tumino, Salvatore Panico, Paolo Vineis, Antonia Trichopoulou, Christina Bamia, Dimitrios Trichopoulos, Heiner Boeing, Mandy Schulz, Jakob Linseisen, Jenny Chang-Claude, Francoise Clavel Chapelon, Agnès Fournier, Marie-Christine Boutron-Ruault, Anne Tjønneland, Nina Føns Johnson, Kim Overvad, Rudolf Kaaks, Elio Riboli.
Cancer Epidemiology Biomarkers & Prevention, 10.1158/doi:1055-9965.EPI-06-0582
Published online first on December 19, 2006
Written by: Catharine Paddock
Writer: Medical News Today