Elevated Dietary Fat & Cholesterol May Increase Breast Cancer Risk
Posted Jan 12 2011 10:23am
The concept that diet can impact breast cancer risk stems from population-based studies, which have shown that breast cancer incidence is several times higher in Western countries compared to other countries. Additionally, studies have shown that different dietary patterns are linked to different levels of breast cancer risk. One component of diet that is thought to be linked to breast cancer risk is dietary fat consumption; however, the studies to date have shown inconsistent results. A new breast cancer study in mice published a few days ago examined this relationship further.
For this study, breast cancer researchers fed 4-week old mice susceptible to breast cancer either a Western diet (20% fat, 17% protein, 48% carbohydrates) or a standard chow diet (4.5% fat, 23% protein, 50% carbohydrates) for 8 weeks. Breast cancer development and blood cholesterol levels were measured at 8 and 12 weeks of age. The breast cancer researchers reported
Mice fed a the high-fat, high-cholesterol Western diet developed more tumors than mice fed the standard chow diet, which was low in fat and had negligible amounts of cholesterol.
Breast cancer tumors were approximately 1.5 times larger in mice fed the Western style diet compared to mice fed the standard chow diet.
Mice fed the high-fat, cholesterol-rich diet also showed a tendency for increased lung metastasis.
Breast cancer tumor development was more advanced and markers of breast cancer tumor aggression were elevated in mice fed the Western diet.
Blood vessel growth in the tumors (needed for tumor growth) was enhanced in mice fed the Western diet compared to mice fed the standard chow diet.
Blood cholesterol levels were reduced and apparently taken up and used by the breast cancer tumors for continued development in mice fed the high-fat diet.
This is a fascinating and important paper that begins to better define the role of cholesterol in breast cancer development. According to these study results, breast cancer tumors appear to absorb cholesterol from the blood stream and immediately use it for blood vessel growth and overall breast cancer tumor growth. This utilization of cholesterol for breast cancer tumor growth might be a major part of the link between a high-fat, Western-style diet and increased breast cancer risk. Because of the apparent importance of cholesterol for breast cancer development, the study authors suggest that cholesterol-lowering agents might have a future role in breast cancer treatments. Additionally, these results indicate the importance of developing and following a healthy diet to reduce breast cancer risk.