The research published in Nutrition Journal suggests that olive oil and its phenolic compounds, oleuropein and cafeic acid may have myocardial antioxidant activity in non-obese lab rats, whilst boosting the heart’s metabolism and fat oxidation in obese rats.
“To the best of our knowledge this is the first study that evaluated the relative potency of olive oil and its phenolic constituents, oleuropein and cafeic acid, on …markers of metabolic pathways in cardiac tissue of obese rats,” stated the researchers, led by Dr. Geovana Ebaid from São Paulo State University, Brazil.
“It was evident that the beneficial effects of olive oil and its minor constituents enhancing fat oxidation were reflected in cardiac tissue of obese rats,” they added.
Olive oil compounds
Dietary olive oil supplementation, and more recently phenols derived from olive oil have been marketed as therapeutic interventions in preventive medicine. But the question of what benefits olive oil and its minor phenolic compounds have on obesity-induced changes to the hearts metabolism is yet to be addressed.
Olive oil phenolic compounds, such as oleuropein and cafeic acid have attracted attention because of their potential anti-diabetic, anti-atherosclerotic and anti-inflammatory properties. Such compounds have been also associated with the antioxidant activity of olive oil.
The aim of the new study was to investigate the effects of olive oil and its minor phenolic constituents, oleuropein and cafeic acid, on calorimetric parameters, myocardial oxidative stress and energy metabolism in cardiac tissue of control and obese rats.
Phenolic benefits
After 42 days, researchers found energy expenditure, oxygen consumption, and fat-oxidation were lower in obese rates group than in the non-obese control group.
Obese rats supplemented with olive oil, oleuropein, and cafeic acid had higher oxygen consumption, increased fat-oxidation, and lower carbon dioxide production than non supplemented obese rats, according to the researchers.
Dr. Ebaid and colleagues noted that antioxidant enzymes were unaffected by olive oil and its compounds in obesity condition, but increased in non-obese olive oil and oleuropein supplemented rats.
In non-obese, standard feeding conditions, dietary supplementation with olive oil phenolic compounds induced changes in the substrate used for energy generation in cardiac tissue, said the researchers.
New insights
“The present study demonstrated for the first time that olive-oil, oleuropein and cafeic-acid enhanced fat-oxidation and optimized cardiac energy metabolism in obesity conditions,” concluded the authors.
They added that the study has “brought new insights” for the actions of olive oil on obesity related cardiac metabolism, noting that olive oil and its phenolic compounds, oleuropein and cafeic acid also had myocardial antioxidant activity in standard-fed conditions.
Further studies testing for similar benefits in humans are needed to confirm their findings, and to “show the importance of these changes on cardiac function”, said the researchers.
Source: Nutrition Journal
Published online ahead of print, doi: 10.1186/1475-2891-9-46
“Effects of olive oil and its minor phenolic constituents on obesity-induced cardiac metabolic changes”
Authors: G.M.X. Ebaid, F.R.F. Seiva, K.K.H.R. Rocha, G.A. Souza, E.L.B. Novelli