AWIS Chicago

Evening Seminar: Loyola Female Researchers Poke Holes in Prevailing Theories about Exercise and Cancer

The Chicago Science Writers organization kindly invited AWIS Chicago to join them for an evening seminar.  The featured speakers were Dr. Amy Luke and Dr. Kathy Albain from Loyola University.  Continue reading to learn more about their research and the evening’s presentations.

Reality Check: Women Researchers Poke Holes in Prevailing Theories about Exercise and Cancer

December 3rd, 2009 at 6pm

Two Loyola University Health System female researchers described their groundbreaking research about what is driving the obesity epidemic and why there are racial disparities in cancer survival.

About the Speakers:
Epidemiologist Amy Luke has found that, contrary to prevailing belief, the number of calories burned in physical activity is not a key factor in rising rates of obesity.  Dr. Luke’s research focuses on nutritional epidemiology.  She received a PhD from University of Chicago and is now an associate professor and the Director of Research in the Preventative Medicine and Epidemiology department at Loyola University Chicago’s Stritch School of Medicine.

The following is a press release from Loyola University summarizing Dr. Luke’s presentation and recent research.

Physical Activity May not be Key to Obesity Epidemic, Loyola Study Finds

MAYWOOD, Ill. — A recent international study fails to support the common belief that the number of calories burned in physical activity is a key factor in rising rates of obesity.

Researchers from Loyola University Health System and other centers compared African American women in metropolitan Chicago with women in rural Nigeria. On average, the Chicago women weighed 184 pounds and the Nigerian women weighed 127 pounds.

Researchers had expected to find that the slimmer Nigerian women would be more physically active. To their surprise, they found no significant difference between the two groups in the amount of calories burned during physical activity.

“Decreased physical activity may not be the primary driver of the obesity epidemic,” said Loyola nutritionist Amy Luke, Ph.D., corresponding author of the study in the September 2008 issue of the journal Obesity. Luke is an associate professor in the Department of Preventive Medicine and Epidemiology at Loyola University Chicago Stritch School of Medicine.

Physical activity is defined as anything that gets your body moving. U.S. government guidelines say that each week, adults need at least 2 _ hours of moderate aerobic activity (such as brisk walking) or 75 minutes of vigorous activity (such as jogging). Adults also should do muscle-strengthening activities, such as weight-lifting or sit-ups, at least twice a week.

Physical activity has many proven benefits. It strengthens bones and muscles, improves mental health and mood, lowers blood pressure, improves cholesterol levels and reduces the risk of cardiovascular disease, diabetes, breast cancer and colon cancer.

But Loyola research suggests that weight control might not be among the main benefits. People burn more calories when they exercise. But they compensate by eating more, said Richard Cooper, Ph.D., co-author of the study and chairman of the Department of Preventive Medicine and Epidemiology.

“We would love to say that physical activity has a positive effect on weight control, but that does not appear to be the case,” Cooper said.

The recent study included 149 women from two rural Nigerian villages and 172 African American women from the west side of Chicago and suburban Maywood.

Adjusted for body size, the Chicago women burned an average of 760 calories per day in physical activity, while the Nigerian women burned 800 calories. This difference was not statistically significant.

Diet is a more likely explanation than physical activity expenditure for why Chicago women weigh more than Nigerian women, Luke said. She noted the Nigerian diet is high in fiber and carbohydrates and low in fat and animal protein. By contrast, the Chicago diet is 40 percent to 45 percent fat and high in processed foods.

Results of the new study are similar to those of a 2007 study of men and women in Jamaica. Researchers from Loyola and other centers found there was no association between weight gain and calories burned during physical activity.

“Evidence is beginning to accumulate that dietary intake may be more important than energy expenditure level,” Luke said. “Weight loss is not likely to happen without dietary restraint.”

Other centers involved in the study of Chicago and Nigerian women include University of Ibadan in Nigeria, Howard University, Johns Hopkins Bloomberg School of Public Health and University of Wisconsin.

Dr. Kathy Albain discussed how African Americans have higher mortality rates from certain cancers that are not due to poverty or inferior health care. Dr. Albain also described her research on a 21-gene test that is enabling many breast cancer patients to safely forgo chemotherapy.  Dr. Albain received her MD at University of Michigan, she is now a Professor of Medicine and Hematology/Oncology at Loyola University.

Below is a partial summary of Dr. Albain’s talk in the form of a press release from Loyola University.  Her study involving a 21-gene test for breast cancer patients will be published later in December and is currently embargoed.

Why Are African Americans Less Likely to Survive Certain Cancers?  Contrary to Prevailing Theory, the Reason isn’t Solely Due to Poverty or Inferior Healthcare, Loyola Study Finds

MAYWOOD, Il. — African Americans are more likely than other races to die from breast, prostate and ovarian cancers, but this disparity is not due to poverty or inferior healthcare, a first-of-its-kind study has found.
Researchers followed more than 19,000 patients who were enrolled in cancer clinical trials conducted by the Southwest Oncology Group, a National Cancer Institute-funded clinical trials national cooperative. Patients of all races received the same advanced treatments by the same doctors.

“It was a level playing field for everyone, with the same quality care,” said lead author Dr. Kathy Albain. “So our findings cast doubt on a prevailing theory that African Americans have lower cancer survival rates because of poverty, poor access to quality care or other socioeconomic factors.” Albain is a breast and lung cancer specialist at Loyola University Health System’s Cardinal Bernardin Cancer Center.

If poverty or other socioeconomic factors were to blame, then the survival gap should exist for all cancers. But the study, published in the Journal of the National Cancer Institute, found there was no statistically significant association between race and survival for lung and colon cancers, leukemia, lymphoma or myeloma.

“The good news for African Americans is that for most common cancers, they have the same survival rates as all other races,” Albain said.
The cancers that did show survival gaps — breast, prostate and ovarian — are gender-related. The findings therefore suggest that the survival gap is due to a complex interaction of biologic factors in the tumor and inherited variations in common genes that control metabolism of drugs and hormones, Albain said. People with different patterns of these genes metabolize cancer drugs and their own hormones differently, and experience different side effects.

“We are actively conducting new research based on these findings to explore interactions among tumor biology, treatment, sex, race, inherited genes and survival,” Albain said.

Dr. Patrick Stiff, director of the Cardinal Bernardin Cancer Center, said: “This groundbreaking study will provide investigators with a road map for future research that will improve outcomes of patients of all races and socioeconomic status.”
Researchers identified 19,457 adult cancer patients enrolled in 35 Southwest Oncology Group clinical trials who were followed for at least 10 years after treatment. Twelve percent of the patients were African American. During the course of the study, African Americans were 49 percent more likely than other races to die from early-stage, postmenopausal breast cancer; 41 percent more likely to die from early stage, premenopausal breast cancer; 61 percent more likely to die from advanced-stage ovarian cancer and 21 percent more likely to die from advanced-stage prostate cancer.

Albain is a professor in the Department of Medicine, Division of Hematology/Oncology, Loyola University Chicago Stritch School of Medicine. Her co-authors are Joseph Unger and John Crowley of the Southwest Oncology Group Statistical Center, Dr.Charles Coltman of the University of Texas Health Science Center and Dr. Dawn Hershman of Columbia University College of Physicians and Surgeons.
The study was funded by the National Cancer Institute.

For more information, contact Jim Ritter, Loyola Office of  Media Relations.

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