Diet And Exercise Can Lower Cancer Risk

One out of three Americans will get cancer before they die, CBS News correspondent Kelly Wallace reports. Who is at highest risk?

Someone with a family history, who smokes, has a high-fat diet and doesn't exercise, says oncologist Dr. David Nanus, who has been treating cancer patients for more than 20 years.

"If you're obese or overweight, you have an increased incidence in a number of cancers — colon cancer, prostate cancer, breast cancer," Nanus says.

According to the American Cancer Institute, about one-third of cancer deaths in 2006 were related to nutrition, physical inactivity and being overweight or obese — and therefore, could have been prevented.

So what can you do to reduce your risk?

Start by eating a diet that contains lots of fruit and vegetables. For example, studies show broccoli, especially broccoli sprouts, may help prevent colon and rectal cancer.

You can control your lifestyle, but not your family history. Five to 10 percent of all cancers are strongly hereditary. There are genetic tests for some kinds of cancers including breast, colon, and ovarian.

"It's important if you know you're from a cancer family, then you need to get screening," Nanus says.

Nanus believes those mammograms after age 40, and colonoscopies after age 50, may be the most powerful weapon in the battle against cancer.

"The biggest problem is the fear factor," he says. "People are so afraid of being diagnosed with cancer they wait." Nanus says waiting even three months can mean the difference between life and death.