Corn Oil Lowers Plasma Cholesterol Compared with Coconut Oil in Adults with Above-Desirable Levels of Cholesterol in a Randomized Crossover Trial

J Nutr. 2018 Oct 1;148(10):1556-1563. doi: 10.1093/jn/nxy156.

Abstract

Background: Few trials have examined the effects of coconut oil consumption in comparison with polyunsaturated fatty acid-rich oils such as corn oil.

Objective: This trial assessed the effects of consuming foods made with corn oil compared with coconut oil on lipids, glucose homeostasis, and inflammation.

Methods: This was a preliminary randomized crossover study of men (n = 12) and women (n = 13) with a mean age of 45.2 y, mean body mass index (in kg/m2) of 27.7, fasting LDL cholesterol ≥115 mg/dL and <190 mg/dL, and triglycerides (TGs) ≤375 mg/dL. Subjects consumed muffins and rolls providing 4 tablespoons (∼54 g) per day of corn oil or coconut oil as part of their habitual diets for 4 wk, with a 3-wk washout between conditions. Fasting plasma lipids and high-sensitivity C-reactive protein (hs-CRP) and glucose metabolism were assessed via an intravenous glucose tolerance test at baseline and 15 and 29 d of treatment. Responses were compared between treatments by ANCOVA.

Results: Median baseline concentrations of LDL cholesterol, non-HDL cholesterol, total cholesterol (total-C), HDL cholesterol, total-C:HDL cholesterol, and TGs were 123, 144, 188, 46.0, 4.21, and 92.5 mg/dL, respectively. Changes from baseline for corn oil and coconut oil conditions, respectively, were: LDL cholesterol (primary outcome; -2.7% compared with +4.6%), non-HDL cholesterol (-3.0% compared with +5.8%), total-C (-0.5% compared with +7.1%), HDL cholesterol (+5.4% compared with +6.5%), total-C:HDL cholesterol (-4.3% compared with -3.3%), and TGs (-2.1% compared with +6.0%). Non-HDL cholesterol responses were significantly different between corn and coconut oil conditions (P = 0.034); differences between conditions in total-C and LDL cholesterol approached significance (both P = 0.06). Responses for hs-CRP and carbohydrate homeostasis parameters did not differ significantly between diet conditions.

Conclusions: When incorporated into the habitual diet, consumption of foods providing ∼54 g of corn oil/d produced a more favorable plasma lipid profile than did coconut oil in adults with elevated cholesterol. This trial was registered at clinicaltrials.gov as NCT03202654.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Analysis of Variance
  • Bread / analysis
  • C-Reactive Protein / metabolism
  • Cholesterol / blood*
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Coconut Oil / pharmacology*
  • Coconut Oil / therapeutic use
  • Cocos / chemistry
  • Corn Oil / pharmacology
  • Corn Oil / therapeutic use*
  • Cross-Over Studies
  • Diet
  • Dietary Fats / pharmacology
  • Dietary Fats / therapeutic use*
  • Feeding Behavior*
  • Female
  • Humans
  • Hypercholesterolemia / blood
  • Hypercholesterolemia / diet therapy*
  • Male
  • Middle Aged
  • Triglycerides / blood*
  • Young Adult
  • Zea mays / chemistry

Substances

  • Cholesterol, HDL
  • Cholesterol, LDL
  • Dietary Fats
  • Triglycerides
  • Corn Oil
  • C-Reactive Protein
  • Cholesterol
  • Coconut Oil

Associated data

  • ClinicalTrials.gov/NCT03202654