It is generally believed that higher fat consumption increases incidence of cancer. Detailed analysis of studies now refute this blanket assumption. Breast cancer, now we know, is more related to total calorie intake than to fat in diet. Generally, in cultures where female children grow faster and have earlier menstruation, the incidence of breast cancer is higher; this indicates that when female body cells multiply faster, they also tend to become carcinogenic. Taller women with larger breast sizes have higher chances of developing breast cancer. In China where breast cancer remains low, age at menarche is still around 18 years and breast size is generally small. Multiple factors contribute to differences in incidence of breast cancer: reproductive patterns, physical activity, adiposity, alcohol intake and use of hormones. It is no longer just the fat in diet. In Pakistan, an alarming condition is emerging. The use of hormones in cattle to increase milk production contaminates the dairy products and as a result the consumers are getting a big dose of these hormones. The menstruation age is decreasing which means that at later age, the incidence of breast cancer will increase substantially.

Colon cancer remains connected to consumption of red meat and fat from animal sources. Components of red meat such as heat-induced carcinogens and readily available iron may be responsible. Though studies regarding prostate cancer are not conclusive, the connection with red meat and animal fat intake (which yields the culprit alpha linolenic acid) is considered established. Men over 40 remain at higher risk of prostate cancer if they continue to consume large quantities of red meat.