Can this weight loss drug also help protect against diabetes and cancer? Study of 16 lakh people sheds light

New research has revealed that GLP-1 weight loss and diabetes drugs may reduce the risk of certain obesity-related cancers. Find out which cancers may benefit and which may not.

GLP-1 drugs (like semaglutide, etc.), currently popular for weight loss and blood sugar control, have garnered significant attention. A major study published in JAMA Network Open in 2024 has introduced a new dimension: can these drugs also reduce the risk of certain obesity-related cancers? The answer, in some cases, is yes, but not universally.

What was the Study's True Objective?

Researchers focused on 13 types of cancer directly linked to obesity. These included cancers of the intestine (colon), liver, pancreas, kidney, and uterus. The direct question was: if people with type-2 diabetes take GLP-1 drugs, do they develop these cancers less frequently compared to those taking insulin or metformin? To answer this, health records of over 1.6 million diabetic patients in the US were examined and followed for 15 years. Initially, none of them had these cancers.

The Strongest Results: GLP-1 vs. Insulin

When GLP-1 drugs were compared with insulin, the difference was clear. GLP-1 users had a lower risk of 10 out of the 13 cancers. The risk of gallbladder cancer was approximately 65% lower. The risk of pancreatic cancer was less than half. Significant improvements were also observed for liver cancer and a type of brain tumour (meningioma). This suggests that the choice of medication for diabetes treatment can also impact long-term cancer risk.

Where No Benefit Was Observed

The news wasn't uniformly good. GLP-1 drugs showed no significant benefit for postmenopausal breast cancer and thyroid cancer. There was a slight indication for stomach cancer, but it was not conclusive. This clearly indicates that these drugs are not a magical bullet for cancer prevention.

GLP-1 vs. Metformin: The Story Changed

When GLP-1 drugs were compared with metformin, the benefit was almost non-existent. GLP-1 did not emerge as clearly superior for any cancer. Conversely, there was a slightly higher risk of kidney cancer, which warrants further research. In simple terms, GLP-1 appeared better than insulin but not better than metformin.

Why Might This Be Happening?

GLP-1 drugs promote weight loss, reduce inflammation, and help insulin work more effectively – all factors linked to cancer risk. On the other hand, insulin can lead to weight gain and higher circulating insulin levels, which may promote certain tumours. Metformin works differently, hence its distinct effects.

What Does This Study Mean?

This study provides indications, not definitive proof. It cannot be concluded that GLP-1 drugs should be taken for cancer prevention. However, it does highlight that in type-2 diabetes, the choice of medication can impact not only sugar levels but also long-term health.