- A link between diet, obesity, and cancer has been identified
- Registered dietitian nutritionists (RDNs) play a major role in cancer prevention and cancer care
- Dietary and lifestyle changes as guided by RDNs can help in the treatment and prevention of obesity-related cancers
Making lifestyle and dietary changes as recommended by registered dietitian nutritionists (RDNs) can help reduce prevalence, incidence, and progression of obesity-related cancers and support cancer patients in recovery.
Nearly one-third of cancer cases were found to be associated with dietary and other modifiable risk factors, especially in the case of obesity-related cancers like breast, colorectal, endometrial, ovarian, kidney, esophageal, gallbladder, and pancreatic cancers.
In the issue of the Journal of the Academy of Nutrition and Dietetics, food and nutrition practitioners and other health professionals studied in-depth about the relationship between nutrition, obesity, and cancer treatment and prevention, and survival and to identify research gaps for future research.
Link between Cancer and Obesity
In previous studies, diet was linked to cancer and obesity increases the risk of several types of cancer and other chronic diseases such as type 2 diabetes, cardiovascular disease, hypertension, and chronic inflammation.
Over the last 50 years, the prevalence of obesity has tripled in the US. Also, it was found that excess body fat can increase the risk for 13 types of cancer.
Stephen D. Hursting, Ph.D., MPH, the lead investigator, professor, Department of Nutrition, the University of North Carolina at Chapel Hill, and colleagues reviewed the multiple mechanisms underlying the link between obesity and cancer.
"Obesity-associated metabolic perturbations are emerging as major drivers of obesity-related cancer, including alterations in growth factor signaling, inflammation, and angiogenesis," explained Dr. Hursting.
"Preclinical evidence suggests that dietary interventions, such as calorie restriction, intermittent fasting, low-fat diet and the ketogenic diet, have the potential to reverse some of these obesity-associated alterations; however, more clinical data are needed to confirm translation to human subjects," said Dr. Hursting.
Link between Obesity and PDAC
Obesity and type 2 diabetes are the major risk factors for pancreatic ductal adenocarcinoma (PDAC), which is one of the deadliest cancers. However, the underlying molecular mechanisms and interactions are still unknown.
In this study, the research team highlights the risk factors for developing PDAC and found that there are some research gaps and opportunities.
Consuming dietary energy density (DED) foods was linked to weight gain in adults and was also linked to higher risk of any obesity-related cancer. However, DED is a modifiable risk factor.
DED is the intake of food weight (grams) and is the ratio of energy calculated in kilocalories or kilojoules and is a measure of diet quality.
"The finding suggests that weight management alone may not protect against obesity-related cancers if women favor a diet pattern indicative of high energy density. Higher DED in normal-weight women may promote metabolic dysregulation independent of body weight, an exposure known to increase cancer risk," said Cynthia A. Thomson, PhD, RD, professor, Mel and Enid Zuckerman College of Public Health, The University of Arizona.
Impact of Nutrition Interventions
Nutrition interventions can target energy density, and other diet-related cancer preventive approaches can reduce the cancer burden.
A pilot intervention was conducted for 46 cancer survivors who were 60 years and older by Wendy Demark-Wahnefried, Ph.D., RD, professor of Nutrition Science, the University of Alabama at Birmingham, and colleagues.
They found that the gardening intervention was safe and feasible and was well accepted among the survivors, which improved reassurance of worth and reduced weight gain around central adiposity.
The team also found an increase in the consumption of fruits and vegetables by approximately one serving per day.
Role of Registered Dietitian Nutritionists
Nancy J. Emenaker, Ph.D., MEd, RDN, LD, and Ashley J. Vargas, Ph.D., MPH, RDN are registered dietitian nutritionists from the National Institutes of Health who have reviewed the scientific evidence associated with diet and cancer.
They explain the disparities in the nutrition and cancer scientific literature and the issues that the registered dietitian nutritionists (RDNs) face when explaining it to the patients.
"RDNs are uniquely positioned to provide balanced, evidence-based information from peer-reviewed literature to help at-risk, and cancer patients understand the strength of the evidence guiding individual health decisions," observed Dr. Emenaker and Dr. Vargas.
"RDNs play such an important role in both cancer prevention and cancer care. Our profession is involved in research to investigate diet-cancer relationships, as well as supporting individuals and communities in making lifestyle changes for cancer prevention and treatment. RDNs are integral in providing quality care by implementing evidence-based interventions," added Linda Snetselaar, Ph.D., RDN, LD, endowed chair and professor, Department of Epidemiology, College of Public Health, University of Iowa, and Editor-in-Chief of the Journal of the Academy of Nutrition and Dietetics.