Conclusion
This large prospective cohort study was well conducted. However, there are several facts that should be considered when interpreting the results.
•The study included previous smokers. Although the researchers say that smoking status had no effect on their findings, they also state that imprecise or incorrect categorisation of smoking status may have affected the results.
•The researchers highlight that the different protocols for measuring blood glucose levels may have affected the outcome.
•Information about the participants’ diet and lifestyle was not available, for example exercise levels, alcohol consumption or the many other genetic and medical risk factors that can also contribute to the risk of cancer.
•The 5 and 11% risk increases for men and women had only borderline significance.
Overall, this research provides some evidence that high blood glucose is associated with an increased risk of some types of cancer. However, it did not directly test or suggest that high blood sugar causes these cancers. Although the research did find an association between high blood sugar levels and cancer risk, there are many other lifestyle, medical and genetic factors that may contribute to a person’s likelihood of developing cancer, few of which were considered in this analysis.
It is now known that healthier diets and lifestyles are associated with a lower risk of cancer, and as part of this healthier lifestyle, lower sugar consumption is recommended.