Study Shows Weight Loss After Bariatric Surgery Reduces Cancer Risk in Women

In a study spanning four decades, researchers have established a strong link between weight loss achieved through bariatric surgery and a significant reduction in long-term cancer risks, especially among women. The study, led by Ted Adams, a prominent researcher in the field, sheds light on the potential benefits of these surgeries beyond weight management.

Obesity has long been associated with an elevated risk of cancer, but this study’s comprehensive analysis delves into the impact of weight loss resulting from bariatric surgery on cancer prevention. The study focused on over 22,000 patients who had undergone various bariatric procedures, including gastric bypass and sleeve gastrectomy, and compared their cancer incidence and outcomes with those of obese patients who hadn’t received such surgery.

The results were striking. The group that had undergone bariatric surgery exhibited a remarkable 25% lower overall risk of developing any form of cancer. Among female patients who had undergone the surgery, the risk of obesity-related cancers was slashed by an impressive 41%, emphasizing the potential protective effects of weight loss on female-specific cancers such as uterine, ovarian, and both pre- and post-menopausal breast cancer. Furthermore, these cancers were often detected at earlier stages in the surgery group, highlighting another potential benefit of weight loss interventions.

While the study’s findings are promising, the mechanisms driving this cancer risk reduction remain speculative. Adams suggests hormonal alterations could play a pivotal role, particularly in estrogen-related cancers. Excess fat tissue in obese individuals can lead to heightened estrogen levels, potentially fueling the development of hormone-driven cancers. Weight loss resulting from bariatric surgery may mitigate this hormonal imbalance, thus lowering cancer risks. Additionally, the reduction in insulin, another hormone, following weight loss could contribute to the observed effects.

However, it’s not just the weight loss itself that appears to influence cancer risk. Adams speculates that anatomical changes triggered by bariatric surgery, potentially affecting hormone release, could also play a role. Further research, including randomized studies, is warranted to unravel these complex interactions and confirm the precise mechanisms at play.

The implications of this study are profound for both patients and healthcare providers. While male patients didn’t exhibit a lowered cancer risk after bariatric surgery, the significant reduction seen in female patients underscores the potential benefits of this intervention. Adams stresses the importance of informed discussions between patients and healthcare professionals to determine the suitability of bariatric surgery based on individual health circumstances.

Looking ahead, researchers call for more investigations to comprehend the nuanced factors driving the link between bariatric surgery and cancer prevention. As newer weight-loss interventions like the drug Ozempic enter the scene, comparative studies could provide additional insights into their long-term impact on cancer risks.

While more research is needed to unveil the underlying mechanisms, the findings present a pivotal shift in understanding the multifaceted benefits of weight loss interventions beyond mere weight management.


Adams, TD, Meeks, H, Fraser, A, et al. Long-term cancer outcomes after bariatric surgery. Obesity (Silver Spring). 2023; 31(9): 2386-2397. doi:10.1002/oby.23812