Energy-dense foods may increase post-menopausal cancer risk

17 Aug 2017 --- A new study in the Journal of the Academy of Nutrition and Dietetics has revealed a link between high dietary energy density in food and obesity-related cancer in normal weight post-menopausal women.
Current research shows that an estimated 30 percent of cancers could be prevented through nutritional modifications.

To find out how the ratio of energy to food weight, otherwise known as dietary energy density (DED), contributes to cancer risk, researchers looked at DED in the diets of post-menopausal women. They discovered that consuming high DED foods was connected to a 10 percent increase in obesity-related cancer among normal weight women.

The findings could lead to updated dietary recommendations “To keep your overall dietary energy density [low] choose foods that have fewer calories per gram weight of the food – foods such as vegetable, fruit, or higher water foods such as soups, and other foods such as brown rice and other whole grain,” advises lead investigator Dr. Cynthia A. Thomson, Ph.D., speaking to NutritionInsight. “High energy density foods include higher fat foods such as pastries, butter and whole-fat cheese.”

“Expanding from DED, individuals should consider the pattern of intake – diets rich in plant foods, healthy fats, fiber such as the Mediterranean diet, pesco-vegetarian diets and the DASH dietary pattern have all been associated with lower risk of select cancers,” Thomson adds.

Increased risk
DED is a measure of food quality and the relationship of calories to nutrients. The more calories per gram of weight a food has, the higher its DED. Whole foods – including vegetables, fruits, lean protein and beans – are considered low-DED foods because they provide a lot of nutrients using very few calories. Processed foods, like hamburgers and pizza, are considered high-DED foods because you need a larger amount to get necessary nutrients. Previous studies have shown that regular consumption of foods high in DED contributes to weight gain in adults.

In order to gain a better understanding of how DED alone relates to cancer risk, researchers used data on 90,000 postmenopausal women from the Women’s Health Initiative including their diet and any diagnosis of cancer. The team found that women who consumed a diet higher in DED were 10 percent more likely to develop an obesity-related cancer, independent of body mass index. In fact, the study revealed that the increased risk appeared limited to women who were of a normal weight at enrollment in the program.

“The demonstrated effect in normal-weight women in relation to risk for obesity-related cancers is novel and contrary to our hypothesis,” explains Thomson. “This finding suggests that weight management alone may not protect against obesity-related cancers should women favor a diet pattern indicative of high energy density.”

Although restricting energy-dense foods may play a role in weight management, investigators found that weight gain was not solely responsible for the rise in cancer risk among normal weight women in the study. They hypothesize that the higher DED in normal-weight women may cause metabolic dysregulation that is independent of body weight, which is a variable known to increase cancer risk.

Thomson shared some potential limitations of the study with NutritionInsight: “Certainly […] women self-report their diet and most of us have a tendency to report a healthier diet or under-report total caloric intake – so this is not an exact science. Further, we did not have information on water intake and water is a no energy/gram beverage and as such can support lower overall energy intake.”

While further study is needed to understand how DED may play a role in cancer risk for other populations such as young people and men, this information may help persuade postmenopausal women to choose low DED foods, even if they are already at a healthy body mass index.

“Among normal-weight women, higher DED may be a contributing factor for obesity-related cancers,” says Thomson. “Importantly, DED is a modifiable risk factor. Nutrition interventions targeting energy density as well as other diet-related cancer preventive approaches are warranted to reduce cancer burden among postmenopausal women.”

The study, “Association between Dietary Energy Density and Obesity-Associated Cancer: Results from the Women’s Health Initiative,” by Cynthia A. Thomson, Tracy E. Crane, David O. Garcia, Betsy C. Wertheim, Melanie Hingle, Linda Snetselaar, Mridul Datta, Thomas Rohan, Erin LeBlanc, Rowan T. Chlebowski, and Lihong Qi, appears in the Journal of the Academy of Nutrition and Dietetics published by Elsevier.

By Paul Creasy