Extra virgin olive oil lowers bad cholesterol, inflammatory marker in people with central obesity – 12-week RCT

The effects of extra virgin olive oil were compared with two other “healthier oils” such as extra virgin coconut oil and red palm olein oil in research financed by Malaysian Palm Oil Board (MPOB).

Writing in the European Journal of Nutrition, ​the researchers reported that the three types of oils have produced similar cardiometabolic effects, but there were differences in their impact on low-density lipoprotein cholesterol or the “bad” cholesterol, the inflammatory marker high-sensitivity C-reactive protein (hs-CRP), as well as alpha- and beta-carotene levels.

A total of 149 individuals with central obesity or large waistline – 90cm and above for men and 80cm and above for women – took part in this study.

However, they did not have medical history of cardiovascular diseases, diabetes, dyslipidaemia or were diagnosed with chronic diseases.

Females made up 83.1 per cent of the subjects. Most of the participants were Malay and there were only two Chinese and one Indian participant.

During the study, they were randomised to consume three isocaloric meals cooked with either red palm olein, or extra virgin coconut oil, or extra virgin olive oil for five days a week for 12 weeks.

Blood and urine samples were collected to measure the effects of the intervention on their cardiometabolic health. They also underwent bi-weekly weight monitoring as well as oil and snack consumption recording.

Findings found that all three groups reported a significant decrease in LDL-cholesterol levels.

However, those taking extra virgin olive oil reported a greater decrease. For example, their LDL-cholesterol decreased from 3.17 ± 0.11 mmol/L to 2.6 mmol/L, which was a reduction of 0.57 mmol/L.

The group taking extra virgin coconut oil reported the second largest decrease in their LDL-cholesterol levels, which decreased from 3.37 ± 0.09 mmol/L to 3.00 mmol/L, while that of the red palm olein oil group dropped from 3.25 ± 0.11 mmol/L to 2.91 mmol/L.   

The three groups also reported a decrease in their good cholesterol levels, the high-density lipoprotein or HDL-cholesterol, although the reduction was not significant. 

In addition, the groups taking extra virgin coconut oil and extra virgin olive oil reported a significant decrease in the inflammation marker hs-CRP, but the amount of hs-CRP had increased in the group taking red palm olein oil.

For example, hs-CRP levels had dropped from 4.64 ± 0.78 mg/L to 4.45mg/L for the group taking extra virgin coconut oil and from 5.36 ± 1.11 mg/L to 4.63mg/L for the group taking extra virgin olive oil.

The reduction also corresponds to previous findings, including a systematic review by Schwingshackl et al​​ which reported that the daily intake of olive oil, ranging from one to 50mg per day, had resulted in a pronounced reduction of CRP levels when compared to the control group.

The group taking red palm olein oil, however, reported an increase in hs-CRP which increased from 5.05 ± 1.11 mg/L to 5.48mg/L.

C-reactive protein is made by the liver and increases when there is inflammation in the body.

Red palm olein led to greatest increase in antioxidant levels​

On the other hand, the group taking red palm olein oil reported a significantly greater increase in their blood plasma antioxidant levels as compared to the other two groups, which the researchers said was a finding that corresponded to the rich carotenoid content in the oil.

The antioxidants measured were alpha- and beta-carotenes.

The blood plasma levels of alpha-carotenes had increased from 0.21 ± 0.02g/mL to 1.55g/mL in the group taking red palm olein oil, while that of the group taking extra virgin coconut oil only increased from 0.18 ± 0.01g/mL to 0.32g/mL, and from 0.19 ± 0.02g/mL to 0.27g/mL in the group taking extra virgin olive oil.

A similar trend was also seen in beta-carotenes, where it increased from 0.76 ± 0.05 g/mL to 1.75g/mL for the group taking red palm olein oil, but only slightly increased from 0.66 ± 0.04g/mL to 0.9g/mL for the extra virgin coconut oil group and from 0.68 ± 0.05g/mL to 0.8g/mL for the extra virgin olive oil group.

“The three oils, each of which has unique phytonutrient and fatty acid compositions, manifested statistically similar cardiometabolic effects in individuals with central obesity at risk of developing cardiovascular diseases with distinct circulating antioxidant properties.​

“This research indicates that red palm oil demonstrates a comparable lipid and cardiometabolic profile when compared to well-accepted premium oils like EVOO and EVCO. Therefore, we suggest promoting the use of red palm oil for purposes such as salad dressing, cooking oil or as part of blended oils,” ​the researchers concluded.

Source: European Journal of Nutrition ​

Diverse impacts of red palm olein, extra virgin coconut oil and extra virgin olive oil on cardiometabolic risk markers in individuals with central obesity: a randomised trial​

DOI: 10.1007/s00394-024-03338-6.

Authors: Teng KT, Loganathan R, Chew BH, Khang TF