Breaking the Link

African Americans, obesity and cancer

Together - Summer 2009

By Rachel Winters

Between 1988 and 2004, the number of Americans who were overweight or obese grew, even as fast food outlets added healthier items to their menus and more people signed up for health club memberships. According to the Centers for Disease Control and Prevention, the obesity epidemic is greater among African Americans, with 76% considered overweight or obese, compared to 66% of the general population.

The Connection Between Cancer and Obesity

Obesity increases the risk of cancer because fat cells cause the hormone androgen to turn into the hormone estrogen (in both men and women.) Some forms of estrogen can increase the risk of cell mutations throughout the body, and cell mutation leads to cancer.

“Rates for some cancers, such as breast, colon and endometrial cancers, would drop if obesity rates fall,” says Danielle Baham, M.S., R.D., L.D., senior clinical dietitian in M. D. Anderson’s Clinical Nutrition Department. “We can help by letting people know about simple things they can do to lose weight and fight cancer.” Making little changes can have a huge impact on individuals and on communities.

Cancer in the African American Community

According to the U.S. Department of Health and Human Service’s Office of Minority Health, African Americans are 33% more likely to die from all types of cancer than whites, which means that African Americans have the highest overall cancer death rates of any racial or ethnic group.

“African American women get breast cancer at younger ages than the general population, and African American men get prostate cancer much earlier than men of other races,” says Richard Hajek, Ph.D., senior research scientist at the Center for Research on Minority Health. “Both of these cancers are related to obesity, making weight control a priority for cancer prevention in this community.”

A “Nu” Study Sheds Light on the Issue

Hopeful news for African Americans -- data from M. D. Anderson’s A Nu-Life study showed that a healthy lifestyle can help protect the body against cancer.

The study looked at whether a low-fat, high-fiber diet would lower the level of estrogen hormones in young African American women ages 25 to 45. 

“A Nu-Life was a study of what happens to your body when you change your eating habits,” says Beverly Gor, Ed.D., one of the study’s principal investigators. “The data shows that changes in diet can lower hormone levels.”

What A Nu-Life Means for Men

Another M. D. Anderson study, The WHEL Study (Women’s Healthy Eating and Living Study), looked at whether diet affected breast cancer survivors’ risk of getting cancer again. The data showed that that being active and eating healthy reduced estrogen levels, which meant reduced risk for breast cancer recurrence. So what do these studies mean for men?

“We believe that healthy eating and staying active also would reduce estrogen levels in men, and thus their risk for prostate cancer,” says Hajek, a co-investigator for both the WHEL Study and A Nu-Life study. “We hope to conduct that research in the future.”  

Barriers to Reaching Diet and Exercise Goals

Early focus groups with study participants before the study began provided valuable information about cultural norms that might affect a person’s body weight.

“We learned that part of the issue is that African Americans consider a larger body to be acceptable,” Gor says.

“It’s a cultural thing,” Baham says. “And when being heavier isn’t seen as a risk, you are less likely to focus on weight control activities such as exercise and healthy eating.”

The A Nu-Life study focus groups also pointed out other more specific barriers to healthy eating.

“We found that time is a big issue,” Gor says. “People may know that they should eat better, but they often didn’t have enough time to put together a healthy meal. We heard that they didn’t always have time to go to the grocery store. Running through a drive-through was more convenient. Many people also were concerned that healthy eating would mean a larger grocery bill.”

According to the American Cancer Society, one-third of African American adults do no physical activity, and African American women more likely than men to be physically inactive.

“Based on what we’ve seen, some barriers preventing African Americans from being physically active may be the lack of affordable gym memberships and safe walking trails in urban communities,” Baham says.

While obesity statistics, especially for African Americans, might sound scary, each person can usually do something to reduce their own risks. The truth is that weight is controllable with changes in diet and exercise. No fancy gym equipment or shots of wheat grass are required.