Scientists say 'superfood' can tackle obesity and diabetes after breakthrough

Scientists say the study on olives could pave the way for the development of cheap and safe natural products for managing obesity and type 2 diabetes
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Olives could help beat obesity - and keep diabetes at bay, according to new research. The findings suggest that elenolic acid - a natural compound found in mature olives and extra virgin olive oil - can lower blood sugar levels and promote weight loss.

Scientists say the study involving mice could pave the way for the development of cheap and safe natural products for managing obesity and type 2 diabetes. The American research team found that after just one week, obese mice with diabetes that were given oral elenolic acid weighed "significantly" less and showed better blood sugar regulation than before treatment and compared to control obese mice who didn't receive elenolic acid.

They said the glucose-lowering effect was comparable with that of the injectable diabetic medication liraglutide and better than metformin, one of the most common oral medicines for type 2 diabetes.

Research team leader Professor Dongmin Liu, of Virginia Tech, said: “Lifestyle modifications and public health measures have had limited impact on the rising prevalence of obesity, one of the top risk factors for type 2 diabetes. “Available obesity drugs are ineffective in weight loss maintenance, expensive and/or carry potential long-term safety risks.

"Our goal was to develop safer, cheaper and more convenient multi-targeting agents that can prevent the occurrence of metabolic disorders and type 2 diabetes.” Prof Liu’s team focuses on discovering bioactive compounds from natural products for diabetes management.

They previously looked for specific molecular targets for natural compounds in parts of the body that actively help regulate metabolism - including the pancreas, muscle, fat tissues and liver. But as natural products usually have poor bioavailability, they decided to see if they could instead target metabolic hormone secretion in the gut to indirectly regulate metabolic function.

The team began the new study by identifying natural compounds that act on L-cells, which contain two metabolic hormones released during a meal. They explained that those hormones, called GLP-1 and PYY, work together to promote fullness and prevent overeating while also controlling blood sugar levels and metabolism.

The screening process revealed that elenolic acid can induce the release of those hormones in the gut. The researchers were able to make elenolic acid by breaking down its precursor oleuropein, which is less expensive than extracting it directly from olives.

Tests of the compound in obese mice with diabetes revealed that mice that received oral elenolic acid experienced "significant" improvements in their metabolic health compared to obese control mice. After four to five weeks of treatment, the mice showed a 10.7% reduction in obesity as well as blood sugar levels and insulin sensitivity that were comparable to those of healthy lean mice.

The researchers also found that elenolic acid significantly reduced food intake and promoted weight loss, which are associated with improved circulating levels of PYY and GLP-1 and the downregulation of agouti-related peptide in the hypothalamus.

Agouti-related peptide is known to increase eating and weight gain when overexpressed. Prof Liu said: “Overall, the study showed that elenolic acid from olives has promising effects on hormone release and metabolic health, particularly in obese and diabetic conditions."

He added: “The compound seems to mimic the physiological conditions of eating to directly promote gut metabolic hormone secretion, which helps regulate energy balance and metabolic health.”

The researchers said the concentration of elenolic acid in olive oil or olives is very low, so the benefits seen in the study would most likely not be gained from olive products alone. The team is now working to understand how this compound creates metabolic benefits by analysing its journey through the body. They said it will also reveal insights into its safety for future clinical trials.

Dr Hana Alkhalidy, a research scientist in Prof Liu’s lab, presented the findings at Nutrition 2024, the annual meeting of the American Society for Nutrition, in Chicago.