Effects of Whole Grain, Fish and Bilberries on Serum Metabolic Profile and Lipid Transfer Protein Activities: A Randomized Trial (Sysdimet)

Maria Lankinen,Antti J Kangas,Helena Gylling,Laura Joukamo,Tiina Jääskeläinen,Hannu Mykkänen,Mika Ala-Korpela,Kaisa Poutanen,Marjukka Kolehmainen,Matti Jauhiainen,Ursula Schwab,Pasi Soininen,Matti Uusitupa,Matej Orešič,Jussi Paananen

doi:10.1371/journal.pone.0090352

Abstract

ObjectiveWe studied the combined effects of wholegrain, fish and bilberries on serum metabolic profile and lipid transfer protein activities in subjects with the metabolic syndrome.MethodsAltogether 131 subjects (40–70 y, BMI 26–39 kg/m2) with impaired glucose metabolism and features of the metabolic syndrome were randomized into three groups with 12-week periods according to a parallel study design. They consumed either: a) wholegrain and low postprandial insulin response grain products, fatty fish 3 times a week, and bilberries 3 portions per day (HealthyDiet), b) wholegrain and low postprandial insulin response grain products (WGED), or c) refined wheat breads as cereal products (Control). Altogether 106 subjects completed the study. Serum metabolic profile was studied using an NMR-based platform providing information on lipoprotein subclasses and lipids as well as low-molecular-weight metabolites.ResultsThere were no significant differences in clinical characteristics between the groups at baseline or at the end of the intervention. Mixed model analyses revealed significant changes in lipid metabolites in the HealthyDiet group during the intervention compared to the Control group. All changes reflected increased polyunsaturation in plasma fatty acids, especially in n-3 PUFAs, while n-6 and n-7 fatty acids decreased. According to tertiles of changes in fish intake, a greater increase of fish intake was associated with increased concentration of large HDL particles, larger average diameter of HDL particles, and increased concentrations of large HDL lipid components, even though total levels of HDL cholesterol remained stable.ConclusionsThe results suggest that consumption of diet rich in whole grain, bilberries and especially fatty fish causes changes in HDL particles shifting their subclass distribution toward larger particles. These changes may be related to known protective functions of HDL such as reverse cholesterol transport and could partly explain the known protective effects of fish consumption against atherosclerosis.Trial RegistrationThe study was registered at ClinicalTrials.gov NCT00573781.

Highlights

Wholegrain, fish, and polyphenol rich foods, such as berries, are known to have beneficial effects on human health [1,2,3]
According to tertiles of changes in fish intake, a greater increase of fish intake was associated with increased concentration of large HDL particles, larger average diameter of HDL particles, and increased concentrations of large HDL lipid components, even though total levels of HDL cholesterol remained stable
The results suggest that consumption of diet rich in whole grain, bilberries and especially fatty fish causes changes in HDL particles shifting their subclass distribution toward larger particles

Summary

Introduction

Wholegrain, fish, and polyphenol rich foods, such as berries, are known to have beneficial effects on human health [1,2,3]. These food items are part of the Nordic diet, which has recently raised a great interest. In intervention studies improvements in cardiovascular and diabetic risk markers, especially low-grade inflammation, in high risk individuals have been reported [5,6,7]. The Mediterranean diet is probably the best-known dietary pattern and has long been related to improved health and prevention of e.g. cardiovascular diseases (CVD) and type 2 diabetes [8,9,10]

Methods

Results

Conclusion