Sunday, May 09, 2010

Dietary Fat and Colon Cancer

New thinking on the possible link between food, or a particular component of food, and cancer is that the carcinogen (or whatever word fits here better) is a more powerful actor when it is introduced to a vulnerable body. This may be why the trends found in large population studies are weak, if they are evident at all. The "vulnerable" confounder is not being taken into account.

A body is vulnerable if:
  1. It has vulnerable genes (gene mutations, gene omissions)
  2. It has a compromised immune system (HIV/AIDS)
  3. It is very young (immature immune system)
  4. It is very old (related to 2.)
In this case-control study, when the population was considered as a whole, dietary fats were not associated with colon cancer:
Dietary Fats And Colon Cancer: Assessment Of Risk Associated With Specific Fatty Acids, International Journal of Cancer, 1997

And that was the news that made headlines.

However, analysis of the study's vulnerable population - those with a family history of colon cancer - revealed a strong positive association between dietary fat and colon cancer. The association was higher for unsaturated fats (both polyunsaturated and monounsaturated). Women who had both a family history and a high intake of unsaturated fat had over 3 times the risk, some over 9 times. Those are very high numbers; 3 times is 300%, 9 times is 900%.

Apart from those with a family history, another group that had a higher risk for colon cancer from fat intake were women whose fats were derived from food preparation (fried foods, bakery foods):
"In this study, we observed among women that fats from preparation appeared to increase risk more than fats from foods or fats eaten as additions."
So, if you're a woman who enjoys fried foods, especially fried in unsaturated fat (that includes olive oil) AND there's a history of colon cancer in your family, you may be stacking your cancer deck.

Another reason to eat the Paleo Vegetarian diet.

1 comment:

Mike said...

Or, another reason to avoid easily oxidizable vegetable and seed based PUFAs and MUFAs, and add saturated fat to one's diet.