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GLP-1 drugs like Ozempic and Wegovy may help restore ‘natural killer’ cells that can reduce the risk of several types of cancer.Mario Tama/Getty Images
  • Results of a small study have found that drugs containing semaglutide, the active ingredient in Ozempic and Wegovy, may help reduce cancer risk.
  • The type 2 diabetes treatment was shown to restore anticancer cells which are less effective in people with obesity.
  • Experts say semaglutide’s anti-inflammatory properties and effect on blood sugar regulation may explain this link.

You might have heard semaglutide (sold under the brand names Ozempic and Wegovy) described as a ‘miracle’ weight loss aid. Now, new research suggests the drug may also help reduce cancer risk in people with obesity.

A small study conducted at Maynooth University in Ireland found that glucagon-like peptide (GLP-1) analogs like semaglutide can restore naturally occurring anticancer cells, known as natural killer (NK) cells.

The study authors note that people with obesity are at a greater risk of developing cancer due in part to their NK cells being “rendered useless”. They discovered that semaglutide restored the cancer-killing effect of NK cells independent of the drug’s main weight loss function, concluding that the treatment appears to be “directly kick-starting the NK cells’ engine”.

So, how do these NK cells fight cancer, why are they not as effective in people with obesity, and what do the results of this study mean for the treatment of obesity going forward?

Dr. Semiya Aziz, a UK doctor and general practitioner, describes these findings as significant.

“It would be fair to say that this is a very small cohort of people to build conclusions from, however, based on the results within this small cohort, the findings appear significant and could have important implications in understanding the relationship between obesity, the immune system, and cancer risk,” she surmises.

According to Aziz, what is most encouraging from the study, is that treatment with long-acting GLP-1 analogs, such as semaglutide, can potentially restore the functionality of NK cells in people with obesity, independent of weight loss effects of semaglutide.

“Natural killer (NK) cells are part of the innate immune system and play a crucial role in preventing cancer,” she explains. “They do this by recognizing and then destroying cancer cells through a process called cytotoxicity.”

It’s not entirely clear why NK cells are rendered less effective in people with obesity, but Aziz points to lower-grade inflammation and altered cellular metabolism as two possible causes.

Why does semaglutide appear to restore the function of NK cells, and in return reduce cancer risk in people with obesity? That’s not fully known either. “What we do know is that semaglutide promotes weight loss and obesity is a well-established risk factor for various types of cancers, including breast, colorectal, and endometrial cancer.”

Semaglutide has also been shown to have anti-inflammatory properties. “We already know that chronic inflammation can lead to the development and progression of cancers, therefore by suppressing inflammation, semaglutide may mitigate some of the factors that promote cancer development,” Aziz explains.

Another factor may be semaglutide’s effect on blood sugar levels. Intended for use as a type 2 diabetes treatment, the drug regulates blood sugar levels by stimulating the release of insulin and reducing the production of glucagon.

“Elevated blood glucose levels have been associated with an increased risk of certain cancers, such as liver, pancreatic, and colorectal cancer so achieving better glycemic control may contribute to a decreased cancer risk,” Aziz points out.

Dr. Stephen Lawrence, associate clinical professor at Warwick Medical School in the UK, says this study adds to a pool of evidence supporting opportunities to positively influence the body’s systems in people with obesity.

However, he notes that as it’s a small study it has limited statistical validity.

“The value of this study is best regarded as hypothesis-generating rather than having practical clinical implications,” he surmises. “I would hope the study will form a platform for the design of clinical trials which are powered to demonstrate the significance of interventions.”

Furthermore, Lawrence says it’s important to remember that obesity is not the only factor that may impair the immune system and increase our risk of cancer.

“A very important contributor to the development of cancer includes unhealthy lifestyle in its various forms, and so one non-pharmacological intervention could be to modify your lifestyle to reduce the risk of adverse outcomes,” he points out.

As Lawrence suggests, drugs like semaglutide may not be the best first-line approach when it comes to tackling obesity. Taking the drug won’t help you recognize – and eventually shift – the behaviors and habits that led to your weight gain or encourage you to create healthier habits.

“People with obesity carry a high metabolic risk, and so pharmacologically targeting the immune system without addressing the obesity is not a desirable or likely intended approach,” Lawrence points out.

When tackling obesity and improving your overall health, Aziz believes making small, achievable dietary changes should be your first port of call.

“By adopting a balanced and calorie-controlled diet that focuses on whole, plant-based nutrient-dense foods, we can naturally aid weight loss. It’s important to incorporate plenty of fruits, vegetables, lean proteins, whole grains, and healthy fats into your meals,” she advises.

Outside of the conventional weight loss advice, like moving more, managing sleep and stress, and seeking support from friends and family, Aziz says behavior and mindset are key.

“Focus on making sustainable changes, addressing emotional eating, and developing a positive relationship with food,” she suggests. “A great way to start is by practicing mindful eating and tuning into your body’s hunger and satiety cues trigger dietary awareness.”

Semaglutide may provide hope to people living with obesity, and it may seem promising that the drug carries the added benefit of reducing cancer risk. However, Aziz believes more research is needed.

“Although the study has discussed the potential benefits of semaglutide in reducing cancer risk through the restoration of NK cell function, it’s evident that more research is certainly needed to fully understand the clinical implications and long-term effects of semaglutide,” she notes.

“Furthermore the study doesn’t provide information on potential side effects or limitations of GLP-1 therapy, which highlights the need for further research, investigation, and clinical trials to assess the safety and efficacy of the drug.”

Until we have a more thorough understanding of semaglutide and its effects on the body, developing sustainable healthy habits that lead to weight loss – and in turn reduce your cancer risk – may be your best bet.