Ovarian cancer is associated with high dietary fat intake. But which type of fat is most to fear?
A meta-analysis of eight studies comprising 6,689 test subjects looked at dietary fat from three angles, total fat, saturated fat, and animal fat content. Compared to low-fat diets, a diet high in total fat was associated with a 24% higher risk of ovarian cancer, while a diet high in saturated fat from both animal and plant sources showed a 20% higher risk of ovarian cancer. The dubious winner of the contest was animal fat. A diet high in animal fat versus a diet low in animal fat carried a 70% higher risk of ovarian cancer. The researchers concluded, “Ovarian cancer risk associated with high animal fat intake appears significantly greater than that associated with the other types of fat intake studied.”
But animals come in many forms, and usually provide the primary source of protein for the building, maintenance and repair of bodily tissues. Researchers in Australia, where ranching and meat production are major industries, investigated the relative risk to ovarian cancer from consumption of various forms of animal protein. They investigated the association between intakes of total meat, red meat, processed meat, poultry, and fish and ovarian cancer risk. Their results suggested that low consumption of processed meat and higher consumption of poultry and fish may reduce the risk of ovarian cancer. But the devil is in the details.
You will note that, although their work looked at 2049 test subjects and 2191 control subjects, the Australian researchers only “suggested” that eating more poultry and fish “may” reduce the risk of ovarian cancer. The week enunciation of their results reflected the weakness of the findings. A frequent intake of poultry was associated with “borderline significant reductions” in risk as shown in the 2 case-control studies they examined as well as their meta-analysis of 7 additional studies. High fish intake was associated with a significantly reduced risk of ovarian cancer in the 2 case-control studies, but only a smaller, borderline significant reduction in the meta-analysis of 6 additional studies.
Given the high variability of dietary intake of meats among individuals, and biochemical individuality, the slight advantages vaguely implied by the analyses become meaningless. We are left with the much stronger suggestion that consumption of animal fats, and, specifically, high consumption, carries a significant risk of contributing to ovarian cancer.
Huncharek M1, Kupelnick B., Dietary fat intake and risk of epithelial ovarian cancer: a meta-analysis of 6,689 subjects from 8 observational studies, Nutr Cancer. 2001;40(2):87-91.
Kolahdooz F1, van der Pols JC, Bain CJ, Marks GC, Hughes MC, Whiteman DC, Webb PM; Australian Cancer Study (Ovarian Cancer) and the Australian Ovarian Cancer Study Group, Meat, fish, and ovarian cancer risk: Results from 2 Australian case-control studies, a systematic review, and meta-analysis. Am J Clin Nutr. 2010 Jun;91(6):1752-63. doi: 10.3945/ajcn.2009.28415. Epub 2010 Apr 14.