It is no longer a secret that obesity is a risk factor for cancer. Due to metabolic changes and the sedentary lifestyle they entail, there is a real causal link between the two variables. However, less is known about the effect of transient obesity in adolescence on the risk of cancer in adulthood. Is this also a risk factor? A new observational study, published in the medical journal The Lancet, tells us a little more about this.
Existing but moderate risk
In this study, the researchers hypothesized that adolescent obesity could increase their incidence of cancer when they are in their forties. Between 1967 and 2010, more than two million Israeli man and women participated in the study. Just over 100,000 of them were excluded on the basis of exclusion criteria or due to loss of control during the study. Of the remaining patients, the statistical analysis shows an increase in the relative risk (compared to the ‘normal’ risk in the general population) of an average of 26% (the actual value lies between 18-35%) in men. No association was found in women because of two inverse associations with breast and cervical cancer, according to researchers. Excluding these cancers, the relative risk is 27% (the actual value is 13-44%) for all other cancers.
If obesity was very high, the relative risk of cancer was even higher in both sexes after 10 years. The authors concluded that the increasing prevalence of obesity in adolescents and the possible link between obesity and cancer may increase the burden on society for obesity-related cancers in the future. This underlines the importance of a focus on prevention.
The importance of prevention
A recent German study points in the same direction: obesity in adolescence increases the risk of cardiovascular disease and cancer in adulthood. That is why prevention is extremely important. However, several problems arise. Although we know most of the behaviors that must be adopted in order to prevent disease (non-smoking, low alcohol consumption, exercise, a balanced diet and maintaining a healthy weight, as pointed out in a recent British Medical Journal study), we are far from successful in encouraging people to adopt these behaviors. But this is a major new public health challenge. In addition, nudges “Indirect suggestions that, without coercion, can influence the motivation, encouragement, and decision-making of groups and individuals at least as effective, if not more effectively, than direct orders, legislation or enforcement” may be helpful in finding solutions to these problems. In fact, they are already addressing public health and obesity problems.
Nevertheless, this is a complex health, economic and political problem. Indeed, in our political systems, in addition to the biological, psychological and neurological factors that drive us to eat too much (and poorly), this pandemic is also a consequence of the problem of food production, availability and the environment.