New light shed on who benefits most from weight-loss jabs
New light shed on who benefits most from weight-loss jabs
New research indicates that individuals with specific genetic differences related to appetite and digestion may achieve greater weight reduction when using medications like Wegovy and Mounjaro for obesity treatment. Published in the Nature journal, the study highlights how genetic factors could explain variations in weight loss outcomes and the severity of side effects, such as nausea and vomiting, experienced by different patients.
These drugs work by mimicking natural gut hormones that suppress hunger, leading to a feeling of satiety. While genetics might contribute to the effectiveness of the treatments, experts emphasize that other elements—including biological sex, age, and geographic origin—also play a role. The study analyzed data from 15,000 participants who had enrolled in gene-testing through 23andMe, tracking their responses to weight-loss therapies.
Genetic variants linked to weight loss and side effects
Researchers identified genetic patterns suggesting a connection between certain variants and the drugs’ success rate. Professor Ruth Loos, from the University of Copenhagen, noted that a specific variant was associated with both increased weight loss and nausea. Individuals with this variant typically lost around 0.76kg (1.6 lbs) more, and those carrying two copies saw double the effect.
“The study found a genetic variant associated with weight loss, which was also associated with nausea. People lose more weight if they have this variant,” said Prof Loos.
The variant is more common in people of European descent, with 64% possessing one copy and 16% having two. In contrast, only 7% of African Americans carry a copy. The research also uncovered another variant tied to severe side effects like vomiting, potentially causing up to 1% of users to experience nausea 15 times worse than average.
Broader factors influencing results
Dr Marie Spreckley from the University of Cambridge stressed that genetics is just one piece of a larger puzzle. She pointed out that lifestyle choices, like exercise and diet, along with medical support and pre-existing conditions, significantly impact outcomes. Women, for instance, are more than twice as likely to lose 15% of their body weight on Mounjaro compared to men, according to earlier findings.
Demographic factors such as race and age also correlate with weight loss. While the reasons for these links remain unclear, younger individuals, those of white or Asian descent, and others appear to benefit more. Additionally, the type of medication, dosage, and duration of treatment are all linked to greater weight reduction.
Path to precision medicine
If validated, integrating genetic data with clinical information could lead to personalized treatment strategies, a concept known as precision medicine. However, Professor Naveed Sattar, a metabolic health specialist at the University of Glasgow, cautioned that the findings are still preliminary. “These results are scientifically interesting, but they’re far from altering clinical practice,” he said.
“What we really need now is more robust trial data to better define the balance of benefits and harms with these and many other emerging therapies,” Prof Sattar added.
Currently, the NHS provides Wegovy and Mounjaro to a small fraction of people with obesity and related health issues, while most individuals purchase these drugs privately through online pharmacies. Over 1.6 million UK residents have tried weight-loss medications in the last year, and this number is growing. Yet, the study’s implications for real-world application remain to be confirmed through further research.