High-monounsaturated fatty acid diets lower both plasma cholesterol and triacylglycerol concentrations

Am J Clin Nutr. 1999 Dec;70(6):1009-15. doi: 10.1093/ajcn/70.6.1009.


Background: Low-fat diets increase plasma triacylglycerol and decrease HDL-cholesterol concentrations, thereby potentially adversely affecting cardiovascular disease (CVD) risk. High-monounsaturated fatty acid (MUFA), cholesterol-lowering diets do not raise triacylglycerol or lower HDL cholesterol, but little is known about how peanut products, a rich source of MUFAs, affect CVD risk.

Objective: The present study compared the CVD risk profile of an Average American diet (AAD) with those of 4 cholesterol-lowering diets: an American Heart Association/National Cholesterol Education Program Step II diet and 3 high-MUFA diets [olive oil (OO), peanut oil (PO), and peanuts and peanut butter (PPB)].

Design: A randomized, double-blind, 5-period crossover study design (n = 22) was used to examine the effects of the diets on serum lipids and lipoproteins: AAD [34% fat; 16% saturated fatty acids (SFAs), 11% MUFAs], Step II (25% fat; 7% SFAs, 12% MUFAs), OO (34% fat; 7% SFAs, 21% MUFAs), PO (34% fat; 7% SFAs, 17% MUFAs), and PPB (36% fat; 8% SFAs, 18% MUFAs).

Results: The high-MUFA diets lowered total cholesterol by 10% and LDL cholesterol by 14%. This response was comparable with that observed for the Step II diet. Triacylglycerol concentrations were 13% lower in subjects consuming the high-MUFA diets and were 11% higher with the Step II diet than with the AAD. The high-MUFA diets did not lower HDL cholesterol whereas the Step II diet lowered it by 4% compared with the AAD. The OO, PO, and PPB diets decreased CVD risk by an estimated 25%, 16%, and 21%, respectively, whereas the Step II diet lowered CVD risk by 12%.

Conclusion: A high-MUFA, cholesterol-lowering diet may be preferable to a low-fat diet because of more favorable effects on the CVD risk profile.

Publication types

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

MeSH terms

  • Adult
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / prevention & control*
  • Cholesterol, HDL / blood*
  • Cholesterol, LDL / blood*
  • Cross-Over Studies
  • Dietary Fats, Unsaturated / administration & dosage*
  • Double-Blind Method
  • Fatty Acids, Monounsaturated / administration & dosage*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Peanut Oil
  • Plant Oils / administration & dosage*
  • Risk Factors
  • Triglycerides / blood*


  • Cholesterol, HDL
  • Cholesterol, LDL
  • Dietary Fats, Unsaturated
  • Fatty Acids, Monounsaturated
  • Peanut Oil
  • Plant Oils
  • Triglycerides