Expert Q&A: The Anti-Cancer Diet
An interview with Karen Collins, MS, RD.
Why is keeping a normal body weight so important to cancer prevention?
We know that being overweight or obese is strongly linked to an increased
risk of several common cancers – like cancers of the colon, breast,
kidneys, esophagus, endometrium, and pancreas to name a few. We think there
could be several reasons why.
Excess body fat, especially around the waist, is linked with insulin
resistance and high insulin levels. Although people associate insulin with
blood sugar and diabetes, researchers think that high levels of insulin may
promote the growth of cancer cells. Excess fat also seems to trigger
inflammation throughout the body, which seems to encourage cancer growth.
Excess body fat can pose a specific risk to older women. After menopause,
excess weight is associated with higher levels of estrogen. That can promote
the development and growth of estrogen-sensitive cancers of the breast and
How does physical activity affect a person’s cancer risk?
We now think that physical activity has a vital role in lowering cancer
risk. It can directly reduce insulin resistance, inflammation, and the levels
of reproductive hormones. Indirectly, it can help achieve and maintain weight
loss, as well as prevent the weight gain that many adults experience as they
The current recommendations from the American Institute for Cancer Research
are at least 30 minutes a day of moderate physical activity. And if you can,
you should aim for 60 minutes a day – or 30 minutes of more vigorous activity.
You’ll achieve even better cancer protection and weight control.
Does meat or any other type of food contribute to the risk of cancer?
There’s a pretty convincing link between red meats and colon cancer, and
possibly other cancers as well. It’s not just the fat. Although choosing lean
meat is good for nutrition, it’s not enough to reduce the cancer risk.
However, you don’t have to give it up completely. Eating up to 18 ounces of
red meat a week seems to be safe. You just want to make meat an occasional food
instead of one that you eat daily.
Eating processed meat -- which is salted, cured, smoked, or treated with
preservatives -- seems to have an even greater risk of colon cancer. So you
should try to limit that as much as you can.
You should also be careful of how much sodium you get – more than 2,400
milligrams a day seems to increase the risk of stomach cancer. Eating
fewer processed foods can help with that. Alcohol also increases the risk of
several cancers, so from a cancer perspective, the less you drink the better.
Women should have no more than one drink a day and men no more than two.