From cold exposure to GLP-1 medications and even mental health, brown fat is attracting fresh attention. Discover what researchers are investigating — and what it could mean for midlife health.
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Over half of U.S. adults say they would like to lose weight, according to data from Gallup.
Fat is often seen as the enemy of people looking to reduce their weight, both on the plate and on the scale. But did you know that not all fat is bad for you — and some can even help with weight loss?
‘Most people don’t realise that we actually have different types of fat in our bodies, and they don’t all do the same thing,’ says Dr Farah Latif, physician and medical director at Elevate Medical & Aesthetic Clinic. This is where brown fat steps in.
‘White fat is what we usually think of when we talk about body fat. It stores energy, whereas brown fat actually burns energy to produce heat and keep us warm,’ she explains.
We typically have much higher amounts of brown fat when we are babies, in order to help regulate our body temperature. But adults still have a small amount — and it can do more than just keep us warm.
In fact, recent research has suggested that there could even be a strong link between active brown fat and lower rates of mental health conditions like anxiety and depression, after examining data from 100,000 patients. Brown fat may also be linked to lower cardiovascular and metabolic disease risk.
Brown fat and weight loss
‘The interesting thing about brown fat is that it actually burns calories, so naturally there’s been a lot of interest in whether we can get it working harder to help with weight loss,’ Latif explains. ‘It also takes up glucose and fatty acids and may influence how the body handles these fuels, which is why researchers are so interested in its potential role in blood sugar regulation and metabolic health.’
And what’s more, research into ‘turning on’ or activating this brown fat is showing some potentially promising results.
Studies have shown that brown fat can be activated through cold exposure: when you get cold, brown fat starts burning energy to keep you warm. But this doesn’t mean you can just start taking cold showers or ice baths and expect the weight to fall off, warns Latif.
‘The amount of energy brown fat burns is relatively small, and we don’t currently have good evidence that activating brown fat alone produces meaningful weight loss in humans.’
‘What I find more interesting is whether activating brown fat could help the body manage blood sugar and fat more effectively, because that could potentially have benefits beyond simply losing weight,’ she instead suggests. ‘Research in this area is promising, but we’re not yet at the point where brown fat activation can be considered a treatment for metabolic disease.’
Brown fat and menopause
When entering perimenopause and menopause, many find that they suddenly find managing their weight much more difficult and can start to accumulate fat more easily, sometimes referred to as the ‘middle-age spread’.
However, Latif says, there is research suggesting that estrogen could play a role in how brown fat works, meaning hormonal changes around menopause might affect its activity.
‘Changes in oestrogen, muscle mass, sleep and activity levels all have an influence. But brown fat could be another piece of the puzzle when we’re trying to understand why our metabolism and body composition change as we age,’ she says.
‘I think it also shows why looking after muscle mass and metabolic health becomes so important during midlife, rather than focusing entirely on what the scales say.’
Brown fat and GLP-1s
Another area of emerging research revolves around brown fat and GLP-1 medications.
‘Preclinical studies, particularly in animal models, suggest that GLP-1 signalling may influence brown-fat thermogenesis and the ‘browning’ of white fat,’ says Latif. ‘But whether commonly used GLP-1 medications produce a meaningful brown-fat effect in humans remains uncertain.’
‘What I think is particularly exciting is that we’re starting to look at weight management in a much broader way,’ she adds. ‘We also need to think about what’s happening to their muscle, their blood sugar levels, their body composition and their health in the longer term.’
‘Especially as we get older, I think the conversation needs to shift towards helping people stay strong, maintain good metabolic health and reduce their risk of developing health problems, rather than focusing purely on weight loss.’
