Replacement of Dietary Saturated Fat by PUFA-Rich Pumpkin Seed Oil Attenuates Non-Alcoholic Fatty Liver Disease and Atherosclerosis Development, with Additional Health Effects of Virgin over Refined Oil

PLoS One. 2015 Sep 25;10(9):e0139196. doi: 10.1371/journal.pone.0139196. eCollection 2015.

Abstract

Background and aims: As dietary saturated fatty acids are associated with metabolic and cardiovascular disease, a potentially interesting strategy to reduce disease risk is modification of the quality of fat consumed. Vegetable oils represent an attractive target for intervention, as they largely determine the intake of dietary fats. Furthermore, besides potential health effects conferred by the type of fatty acids in a vegetable oil, other minor components (e.g. phytochemicals) may also have health benefits. Here, we investigated the potential long-term health effects of isocaloric substitution of dietary fat (i.e. partial replacement of saturated by unsaturated fats), as well as putative additional effects of phytochemicals present in unrefined (virgin) oil on development of non-alcoholic fatty liver disease (NAFLD) and associated atherosclerosis. For this, we used pumpkin seed oil, because it is high in unsaturated fatty acids and a rich source of phytochemicals.

Methods: ApoE*3Leiden mice were fed a Western-type diet (CON) containing cocoa butter (15% w/w) and cholesterol (1% w/w) for 20 weeks to induce risk factors and disease endpoints. In separate groups, cocoa butter was replaced by refined (REF) or virgin (VIR) pumpkin seed oil (comparable in fatty acid composition, but different in phytochemical content).

Results: Both oils improved dyslipidaemia, with decreased (V)LDL-cholesterol and triglyceride levels in comparison with CON, and additional cholesterol-lowering effects of VIR over REF. While REF did not affect plasma inflammatory markers, VIR reduced circulating serum amyloid A and soluble vascular adhesion molecule-1. NAFLD and atherosclerosis development was modestly reduced in REF, and VIR strongly decreased liver steatosis and inflammation as well as atherosclerotic lesion area and severity.

Conclusions: Overall, we show that an isocaloric switch from a diet rich in saturated fat to a diet rich in unsaturated fat can attenuate NAFLD and atherosclerosis development. Phytochemical-rich virgin pumpkin seed oil exerts additional anti-inflammatory effects resulting in more pronounced health effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Atherosclerosis / blood
  • Atherosclerosis / complications
  • Atherosclerosis / drug therapy*
  • Atherosclerosis / genetics
  • Biomarkers / blood
  • Blood Vessels / pathology
  • Cholesterol
  • Cucurbita / chemistry*
  • Dietary Fats
  • Dietary Fats, Unsaturated / therapeutic use*
  • Dyslipidemias / blood
  • Dyslipidemias / complications
  • Dyslipidemias / drug therapy
  • Dyslipidemias / genetics
  • Fatty Acids / adverse effects*
  • Gene Expression Regulation / drug effects
  • Humans
  • Inflammation / blood
  • Inflammation / pathology
  • Lipid Metabolism / drug effects
  • Lipid Metabolism / genetics
  • Lipids / blood
  • Mice
  • Non-alcoholic Fatty Liver Disease / blood
  • Non-alcoholic Fatty Liver Disease / complications
  • Non-alcoholic Fatty Liver Disease / drug therapy*
  • Non-alcoholic Fatty Liver Disease / genetics
  • Phytochemicals / analysis
  • Plant Oils / pharmacology
  • Plant Oils / therapeutic use*

Substances

  • Biomarkers
  • Dietary Fats
  • Dietary Fats, Unsaturated
  • Fatty Acids
  • Lipids
  • Phytochemicals
  • Plant Oils
  • cocoa butter
  • Cholesterol

Grant support

The study was funded partly by the Netherlands Organisation for Applied Scientific Research (TNO) research program Healthy Nutrition and partly by Bunge Ltd. MCM received funding from TNO and Top Institute Food and Nutrition (TIFN), a public-private partnership on pre-competitive research in food and nutrition. Co-author P. Mark Stavro is employed by Bunge Ltd. Bunge Ltd provided support in the form of salary for author PMS and had a role in data collection (analyses of fatty acid composition of the oils). Bunge Ltd had no role in the data analysis, decision to publish, or preparation of the manuscript. The specific roles of PMS are articulated in the ‘author contributions’ section.