Written by Greg Arnold, DC, CSCS. Research has shown that oleic acid reduces insulin resistance risk by 20% for every 1% increase. 

The Mediterranean Diet is perhaps the best-studied dietary pattern in the world. With olive oil, fish, nuts and fruits and vegetables, the Mediterranean Diet may help decrease mortality by 23 percent (1) by increasing antioxidant levels (2), improve mental health (3), peripheral vascular health (4), blood sugar health (5), lung health (6) and heart health (7).

Olive oil’s health benefits include helping to maintain cell health (8), digestive health (9), bone health (10) and cholesterol health (11). Its health benefits result from high levels of antioxidants called polyphenols (12, 13), which produce “a protective effect” against cardiovascular disease risk factors (14).  Now a new study (15) suggests that olive oil, a rich source of oleic acid, may help with blood sugar health by maintaining healthy levels of insulin, the hormone that brings sugar into cells (16).

In the study, 361 men and women with an average age of 45 with no clinical diagnosis of type 2 diabetes were divided into two groups: those with insulin resistance (92 patients) and those without insulin resistance (269 patients).  Insulin resistance was diagnosed from blood samples before the study began using previous research (17) of Body Mass Index (BMI) and a model of blood sugar control called the Homeostatic Model Assessment (HOMA) (18).

The researchers then took the blood samples and analyzed the structure of a fat in the blood called phosphatidylcholine (PC). This is a component of every cell membrane and is involved in numerous reactions in the body, including fat digestion and absorption as well as being a source of choline, an essential nutrient (19). The researchers found a direct relationship between the risk of insulin resistance and the amount of oleic acid, a component of olive oil, found in PC.

The average amount of oleic acid making up the PC molecule was 11.7% for all of the patients. For each 1% increase in oleic acid content of PC, the risk of insulin resistance decreased by 25%. When they looked at linoleic acid, an omega-6 fatty acid known to have a beneficial effect on body composition (20), every 1% increase resulted in a 16% reduced risk of insulin resistance.  But when the researchers used a different method of classifying insulin resistance also used in previous research (21), only oleic acid remained significant, reducing insulin resistance risk by 20% for every 1% increase.

For the researchers, “[high oleic acid intake] relates to less insulin resistance, suggesting an added benefit of increasing olive oil intake within the Mediterranean diet.”

Source: Sala-Vila, A., et al. “Inverse association between serum phospholipid oleic acid and insulin resistance in subjects with primary dyslipidaemia.” Clinical Nutrition 30.5 (2011): 590-592.

© 2011 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism

Posted March 6, 2012.

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