TUESDAY, Oct. 7 (HealthDayNews) -- There are about 9.5 million cancer survivors in the United States, with almost two of three cancer patients living more than five years after their diagnosis.

But many cancer survivors have questions about the effects that diet and exercise may have on their health.

To help answer those questions, the American Cancer Society issued revised nutrition and physical activity recommendations for cancer survivors. They appear in a report published in the September/October issue of CA: A Cancer Journal for Clinicians.

The recommendations for cancer survivors include:

• Physical activity may help even people with advanced cancer by increasing appetite and reducing constipation and fatigue.
• Being overweight can increase the risk of cancer recurrence and may affect overall survival.
• A standard multivitamin and mineral supplement in amounts equivalent to 100 percent of the Daily Value can help cancer survivors meet their nutrient needs when it's difficult for them to eat a healthy diet.
• Some supplements, such as those that contain high levels of folic acid or antioxidants, may be harmful during cancer treatment.
• While a vegetarian diet does offer health benefits, there's no direct evidence that such a diet can prevent cancer recurrence. Cancer survivors who eat a vegetarian diet need to ensure they get adequate nutrition intake.
• Alcohol can have both positive and negative effects. These include increasing the risk of new cancers in survivors while reducing the risk of heart disease.

The report also reviews many of the best known dietary regimens and supplements frequently touted as alternatives to standard cancer care. The report concludes that there is little or no scientific evidence to support their use.

More information

Here's where to learn more about cancer survivors.