Randomised trial of coconut oil, olive oil or butter on blood lipids and other cardiovascular risk factors in healthy men and women

Randomised parallel-group clinical trial conducted in the general community in Cambridgeshire, UK (June–July 2017). Participants were adults aged 50–75 years without cancer, cardiovascular disease or diabetes and not on lipid-lowering medication; 96 randomised, 94 baseline assessments, 91 completed follow-up; two withdrawals; two-thirds women; 98% European Caucasian.

Consume 50 g daily for 4 weeks of one of: extra virgin coconut oil, unsalted butter, or extra virgin olive oil; may be substituted for other fats or taken as a supplement within usual diet.

Butter increased LDL-C more than coconut oil and olive oil over 4 weeks (approx +0.38–0.42 mmol/L); coconut oil did not differ from olive oil for LDL-C and slightly lowered LDL-C vs baseline. Coconut oil significantly increased HDL-C compared with butter or olive oil. Butter increased TC/HDL-C ratio and non-HDL-C versus coconut oil. No significant differences between groups for weight, BMI, central adiposity, fasting glucose or blood pressure; coconut oil reduced C-reactive protein vs olive oil. In practical terms, olive oil remains favorable for LDL-C; coconut oil behaves more like olive oil for LDL-C and raises HDL-C more than butter, suggesting effects depend on fatty acid profiles and food matrix; findings do not modify general guidance to reduce saturated fat but highlight nuanced relationships and the need for further study.

Short 4-week duration; not blinded to the intervention; pragmatic design with no control of total energy intake; no objective biomarker of fat adherence (no blood fatty acid profiling); highly selected BBC-recruited volunteers which may limit generalisability; results address intermediate lipid markers rather than clinical outcomes.