A healthy diet and exercise not only reduce the risk for heart disease, they can also help prevent many types of cancers.
Quitting smoking is the best thing you can do to reduce your chances of getting many types of cancer.
"The most important lifestyle factor when it comes to cancer is the use of tobacco," Brown said. "We would eliminate 60 percent of cancers, not just lung cancer, if people stopped smoking."
When it comes to tobacco use, Brown said it was an all-or-nothing proposition.
"No level of usage is safe. Just one cigarette is harmful," Brown said. "Also, smokeless tobacco is just as harmful."
Brown stressed that it's never too late to give up tobacco, even those who already have cancer.
"People who have cancer think, 'Well, the horse is out of the barn; why stop now?' We know that cancer-survival rates improve when one stops smoking. Also, when you stop smoking, the risk of cancer goes down immediately and continues to decrease."
It's not just good for you to quit smoking, but also for those around you, Brown said. "It's just as important to reduce exposure to secondhand smoke."
There are 3,000 to 10,000 cases of lung cancer diagnosed each year in the United States as a result of secondhand smoke, Brown said.
DROP EXCESS POUNDS
Obesity is expected to surpass tobacco as the most significant cause of many cancers.
"Most people probably don't think about obesity as a cause of cancer, but weight control is very important to prevent various types of cancer," Brown said.
But don't look for the latest fad diet, health experts say. Research has shown that losing weight by dieting alone is not effective without adding some sort of exercise activity.
"Diet plus exercise will help sustain weight loss over the long run," Brown said.
Speaking of diet, experts recommend following nutritional guidelines to ensure you're getting the right amount of vitamins, protein, fiber and other nutrients. Diets high in red meat can contribute to higher risk of colon cancer. Conversely, high fiber can reduce the risk of colon cancer.
GET MORE SLEEP
Studies show that women who slept less than seven hours a day have a higher incidence of breast and colon cancer. Sleep is also important for boosting immunity and improving concentration.
"The message here is get your sleep," Brown said.
LIMIT SUN EXPOSURE
More than five sunburns can double one's risk of developing skin cancer.
"This is especially important for children. When you've had early exposure to the sun, the damage is done," Brown said.
Some sun exposure -- with a sunscreen of at least 15 SPF, 45 or higher if you're fair-skinned -- is important because sunlight provides vitamin D, an important nutrient that can also help prevent cancer.
"Too much sun causes skin cancer. Too little increases the risk of breast cancer," Brown said. "It's a balance."