Natural Compound in Olives May Help Fight Obesity And Type 2 Diabetes
A naturally occurring compound in olives, elenolic acid, has shown promise as a potential treatment for obesity and type 2 diabetes.
In mouse models of the health conditions, researchers from Virginia Tech in the US discovered that after one week of treatment, elenolic acid reduced blood sugar levels as well as, or even better than, two leading medications.
"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," says Dongmin Liu, a nutrition scientist from Virginia Tech.
"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."
Chemical signals play major roles in orchestrating messages from our gut. In a previous study on mice from Liu's lab, the team found that elenolic acid prompts the release of two metabolic hormones that help us sense when to stop eating, by signaling fullness to the brain.
One of those hormones is glucagon-like peptide-1 (GLP-1), which Ozempic and similar drugs mimic in order to regulate blood sugars and satiety. The other is the less well-known peptide YY (PYY), which is released by cells in the gut to reign in your appetite at the end of a meal.
Even a single dose of concentrated elenolic acid stimulated GLP-1 and PPY secretion, the team's past research found. And obese mice on a high-fat diet who were given doses of 50 mg/kg/day for two weeks attained glucose tolerance and fasting blood glucose levels equivalent to their peers on a standard diet.
The new research, which hasn't been peer-reviewed, was presented by clinical nutritionist Hana Alkhalidy from Virginia Tech at NUTRITION 2024 in Chicago on June 29.
Liu, Alkhalidy, and colleagues outline in their presentation abstract that mice with type 2 diabetes and diet-induced obesity were given elenolic acid orally. The dose, concentration, frequency, and duration of the treatment are, so far, undisclosed, as is the number of mice included in the experiments.
The researchers report that after just one week of treatment, the mice weighed significantly less and had better-regulated blood sugar levels than they did prior to treatment, and when compared to mice with the two conditions that were not given elenolic acid.
Unlike GLP-1 receptor agonists such as Ozempic – which, disguised as GLP-1, can activate the receptor in lieu of the real thing – elenolic acid offers an indirect approach that triggers the body to release more of its own metabolic hormones.
Its effect on blood glucose, Liu's team reports, was on par with GLP-1 receptor agonist liraglutide, and better than anti-hyperglycemic agent metformin, which is a first-line glucose-lowering drug for type 2 diabetes.
"Overall, the study showed that elenolic acid from olives has promising effects on hormone release and metabolic health, particularly in obese and diabetic conditions," says Liu.
"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."
Elenolic acid is found in extra virgin olive oil and mature olives (Olea europaea), but it can be created more cheaply by breaking down its precursor oleuropein, which is present not only in olive skin and flesh, but in the plant's leaves and seeds too.
The researchers say you likely couldn't eat enough olives – or chug enough extra virgin – to get the beneficial effects they observed in their experiments. And oleuropein has been deliberately removed from most of the olive products you might eat, because of its bitter taste.
And as with any experiments on mice, we won't truly know what the effects of concentrated elenolic acid are on humans until further trials are conducted.
The team is now investigating how elenolic acid affects metabolism by tracking its path through the body, which will also provide information about its safety for clinical trials in the future.
The preliminary findings are not yet peer-reviewed, though studies are evaluated and selected for presentation by a committee of experts.
This research was presented at the annual meeting of the American Society for Nutrition, NUTRITION 2024.
