Weight-loss jab Mounjaro may help slash food cravings by suppressing brain signals that are linked to eating control, according to a first-of-its-kind study.
Researchers in the US placed electrodes in the brain of a patient on the drug to study its impact on the region that is associated with pleasure, motivation and reward.
Mounjaro, also known as tirzepatide, is a GLP-1 agonist, a type of medication that mimics the hormone glucagon-like peptide-1 to help manage blood sugar levels and promote weight loss.
The study included three severely obese patients who all struggled to control their eating habits. The researchers at the University of Pennsylvania analysed the brain activity, recorded directly with electrodes implanted in the brain.
They found episodes of intense food preoccupation and cravings were linked to low-frequency brain signals, known as delta-theta activity, in the nucleus accumbens, a part of the brain’s reward system.
In two patients, electrical stimulation to areas of the brain reduced this signal.
The third patient was given Mounjaro to manage diabetes following weight-loss surgery, which also resulted in reductions in food cravings.
Researchers also recorded a decline in delta-theta brain activity in the patient who was on Mounjaro. However, these brain signals and food cravings returned a few months later.
Weight-loss jab Mounjaro may help slash food cravings by suppressing brain signals that are linked to eating control, according to a first-of-its-kind study (File image)
The findings, published in the journal Nature Medicine, suggest that the drug may tackle food cravings by affecting the brain signal biomarkers associated with eating control.
Reacting to the study, Dr Simon Cork, a senior lecturer in physiology at Anglia Ruskin University called for caution. He said: ‘This study specifically looked at a marker of brain activity associated with periods of “binge eating” in patients with obesity associated with food preoccupation.
‘This is important because this is a specific condition associated with obesity. We know from animal studies that directly record from neurons in this region of the brain that GLP-1 does suppress activity of this region of the brain, and this suppression is likely to be associated with the reduction in “food noise” that patients with obesity often report,’ he added.
‘It is also likely to be one of the reasons why this drug class is seeing increased interest in combating addictive conditions, such as alcohol and drug abuse.
‘So while this study is methodologically very interesting, it has to be clear that this is only one patient with a very specific condition associated with obesity and so shouldn’t necessarily be generalised to the entire population.’
Mounjaro – dubbed the King Kong of weight-loss jabs – is approved for use in the NHS to treat type 2 diabetes and manage weight. But while the health service has started its rollout for obesity, tight restrictions govern which patients are eligible.
The drug, made by the American pharmaceutical firm Eli Lilly, is approved for use in the NHS for those with a body mass index (BMI) of more than 35 and – crucially – at least one weight-related illness. Over three years the NHS expects to give the jabs to 240,000 people.
