Association between Dietary Energy Density and Obesity-Associated Cancer: Results from the Women’s Health Initiative
Dr Rachel Nicholls, Health Promotion Advisor, Cancer Society of New Zealand
A diet high in energy dense foods (those high in fats and/or added sugars and/or low in fibre) contribute to increasing rates of obesity globally. With obesity related to some cancers, the question arises whether energy dense foods themselves can increase the risk of obesity-related cancer.
This study investigated the association between energy dense foods as a risk factor for obesity-related cancers. The dietary energy density (DED) in the diets of over 92,000 post-menopausal women were examined and incidence and obesity related cancers were documented over an average 14.6 year follow-up period.
A strength of the study was the large sample size. Limitations included baseline only recording of dietary intake and not taking in to account some factors that may have contributed to participant cancer risk including occupation and beverage consumption.
What were the findings?
The researchers had expected to find that higher baseline DED would be associated with increased risk of obesity-associated cancers and that these effects would be stronger among participants who were obese (BMI ≥30). Although they did find that DED was associated with a 10% increased risk of obesity-related cancers, this risk was limited to women of normal weight at study entry (BMI 18.5 -24.9).
The authors concluded that being a healthy weight may not necessarily protect against obesity-related cancers should women consume a high energy dense diet.
What are the implications?
Although the link between diet, lifestyle and cancer are complex, research continues to underscore the importance of healthy diet and body weight in cancer prevention. Strategies to support people to make healthy choices remain the cornerstone of obesity-related cancer prevention.
NB: this commentary does not necessarily reflect the view of the NZ Cancer Society.