Most of us are aware that carrying excess weight can have serious consequences, such as increasing our risk of type 2 diabetes or heart disease. However, it is not as widely known that being overweight or obese has also been shown to increase the risk of several cancers. Now, the largest study of its kind solidifies the obesity-cancer link with 10 common forms of cancer. The study found that more than 12,000 cases of these 10 cancers each year are attributable to being overweight or obese. With approximately 5 times as many people in the US vs UK, we could estimate based on the numbers, that the US would see roughly 60,000 cases of these 10 cancers being attributed to weight each year.
Using health care data from more than 5 million adults in the UK, researchers found that for each 5 kg/m² increase in Body Mass Index (BMI), there was a higher risk of cancer of the:
- uterus (62% increase)
- gallbladder (31%)
- kidney (25%)
- cervix (10%)
- thyroid (9%)
- leukemia (9%)
Higher BMI also increased the overall risk of liver (19%), colon (10%), ovarian (9%) and breast cancers (5%), but the effects on these cancers varied by underlying BMI and by individual-level factors such as sex and menopausal status.
There was a lot of variation in the effects of BMI on different cancers–the risk of cancer of the uterus, for example, increased significantly with BMI, but for other cancers, there was a modest increase in risk, or no increase at all. The study provides sufficient evidence that obesity is a significant cause of unnecessary suffering and death from many forms of cancer, and calls for measures aimed at reducing obesity.
We asked Dr. Laura Machado, expert weight loss surgeon in Sacramento CA, to comment on the study’s findings. She said, “anecdotally I have always heard that my bariatric surgery patients can’t remember the last time they had a cold. As they maintain their weight loss and enjoy many health improvements, their immune system is clearly functioning better. The recent UK study linking obesity and cancer serves as further evidence on how obesity impacts many of our defense mechanisms.
The disease of obesity impacts our immune system, not just for colds and flu, but for the cancer fighting scavenger systems in our body. These systems are stressed, like many other systems when a patient is overweight and don’t function as well. Combine that with higher hormone levels and the higher rates of cancer are to be expected.
This information is useful for patients to take seriously, particularly if they already have a family history of some cancers. Being overweight will only further increase their risk. Treating and preventing obesity continues to be one of the single most effective health improvement strategies a patient can make for themselves.”
Related Reading: Obesity Raises Risk of Death from Breast Cancer