Australian researchers report that brown fat — a unique form of fat that burns calories to produce heat — may also help stabilise blood sugar levels in adults.
Scientists at the Garvan Institute of Medical Research in Sydney monitored brown fat activity and blood glucose continuously in real time and found that people with more active brown fat experienced smaller swings in blood sugar. These results point to new directions for therapies that target brown adipose tissue to improve glucose control and reduce diabetes risk.
The global rise in type 2 diabetes, characterised by persistently elevated blood glucose, creates an urgent need for fresh approaches to glucose regulation beyond current treatments. Brown fat, unlike white fat which stores energy, consumes glucose and lipids to generate heat. Located in regions such as above the collarbone and around the neck, brown fat can be highly metabolically active and may influence whole‑body glucose balance.
Led by Dr Paul Lee and Associate Professor Jerry Greenfield from Garvan’s Diabetes and Metabolism Division, the team investigated whether brown fat activity influences short‑term glucose variability. “Brown fat takes up so much glucose that we wondered whether it could affect blood glucose concentration, and whether brown fat‑targeted approaches might help manage diabetes,” Dr Lee said.
The study followed 15 healthy adults over a 12‑hour period. Researchers used continuous glucose monitoring to track blood sugar and a simple, non‑invasive temperature sensor over the supraclavicular area (above the collarbone) to estimate brown fat activity. Because active brown fat produces heat just under the skin, collarbone skin temperature serves as a practical proxy for thermogenic activity.
Results showed a close temporal relationship between brown fat thermogenesis and blood glucose: heat production from brown fat and glucose levels rose and fell together. Crucially, participants with larger brown fat depots experienced smaller glucose fluctuations and often showed a drop in blood sugar following surges in brown fat activity.
By contrast, participants with smaller amounts of detectable brown fat tended to show brown fat activity that increased primarily in response to rising glucose, and they had greater glucose variability. Those without detectable brown fat had the largest swings in blood sugar.
Dr Lee summarised the pattern: “It looks like the more brown fat one has, the more influence it has on blood glucose. Our findings suggest brown fat may act as a glucose buffer, reducing blood glucose variation and potentially lowering metabolic stress that contributes to diabetes risk.”
In addition to the glucose‑linked thermogenic activity, the researchers observed a distinct daily rhythm: brown fat activity tended to rise at dawn, around the time participants woke. The team speculates this morning thermogenic surge could have evolved to generate heat and mobilise energy as the day begins.
The study is notable for its simultaneous, real‑time monitoring of glucose and brown fat activity under everyday conditions using a minimally invasive approach. While supraclavicular skin temperature is an indirect measure of brown fat, it provides a feasible way to study its dynamics alongside continuous glucose measurements.
Implications and cautions: Targeting brown fat could become part of future strategies to improve glucose stability and lower diabetes risk. If researchers can identify how brown fat activity is switched on and off during the day, that knowledge might reveal new drug targets. However, the investigators emphasise that brown fat is not a standalone cure for diabetes. A balanced diet, physical activity, and established metabolic care remain essential.
Funding: Supported by the Australian National Health and Medical Research Council, Diabetes Australia Research Trust, and the Royal Australasian College of Physicians.
Source: Meredith Ross, Garvan Institute of Medical Research.
Original research: The findings are reported in the journal Cell Metabolism in the article “Brown Adipose Tissue Exhibits a Glucose‑Responsive Thermogenic Biorhythm in Humans” by Paul Lee et al., published online March 10, 2016. DOI: 10.1016/j.cmet.2016.02.007.
Abstract summary
High amounts of brown adipose tissue (BAT) are associated with lower blood glucose in humans, suggesting a protective role against diabetes. This study characterised glucose excursions and BAT thermogenic responses using human brown adipocytes, BAT explants, and continuous supraclavicular temperature profiling in healthy adults. The results reveal a circadian coupling between BAT thermogenesis and glucose regulation, implicating molecular players such as UCP1 and glucose transport pathways. Together, the data indicate potential cross‑talk between BAT and systemic glucose control across cellular, tissue, individual, and population levels, motivating further research to harness BAT for therapeutic purposes.