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Healthy Fat Reverses Diabetes

Researchers have been able to “reverse” type 2 diabetes by dampening the inflammatory response in fat tissue. A study published in Nature Immunology by Dr Ajith Vasanthakumar and Dr Axel Kallies of The Walter and Eliza Hall Institute found that regulatory T cells (Tregs) play a key role in controlling inflammation in fat tissue and maintaining insulin sensitivity.

People with type 2 diabetes have reduced sensitivity to insulin, a hormone that normally triggers glucose uptake by cells, and their cells no longer respond to insulin appropriately. This decrease in insulin sensitivity is thought to be a result of long-term, low-level inflammation of fat tissue in people who are obese.

Vasanthakumar said that Tregs prevent the immune response from getting out-of-hand and attacking the body’s own tissues. “When Treg numbers are reduced, inflammatory diseases such as diabetes and rheumatoid arthritis can occur,” he explained.

Fat tissue has a unique type of Treg that disappears during obesity. “The fat tissue of obese people has lower numbers of Tregs than the fat tissue of people in a healthy weight range,” Vasanthakumar said. “Without Tregs, inflammation-causing cell levels increase, and this rise in inflammation can lead to insulin resistance and high blood glucose levels – a classic hallmark of type 2 diabetes.”

The researchers discovered that a key hormone called interleukin-33 (IL-33) was able to boost Treg populations in fat tissue, effectively halting the development of type 2 diabetes or even reversing the disease in preclinical models.

“Treating fat tissues with IL-33 restored normal Treg cell levels, which reduced inflammation and decreased blood glucose levels,” Vasanthakumar said. “Treatments that mimic IL-33 could have the potential to reduce obesity-related inflammation and type 2 diabetes.”

Kallies said the research underscored the importance of “healthy” fat tissue. “We can no longer think of fat tissue simply as energy storage,” he said. “Fat tissue is increasingly being recognised as a crucial organ that releases hormones and regulates development. Keeping our fat tissue healthy is important for our general well-being.”