The effect of whole grain wheat sourdough bread consumption on serum lipids in healthy normoglycemic/normoinsulinemic and hyperglycemic/hyperinsulinemic adults depends on presence of the APOE E3/E3 genotype: a randomized controlled trial

Amy J Tucker,Terry E Graham,Alison M Duncan,Lindsay E Robinson,Kathryn A Mackay,Marica Bakovic

doi:10.1186/1743-7075-7-37

Amy J Tucker, Terry E Graham + Show 4 more

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https://doi.org/10.1186/1743-7075-7-37

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Journal: Nutrition & Metabolism	Publication Date: May 5, 2010
Citations: 86	License type: cc-by

Affiliation: University of Guelph

Abstract

BackgroundEpidemiological studies associate consumption of whole grain foods, including breads, with reduced cardiovascular disease (CVD) risk; however, few studies have compared wheat whole grains with wheat refined grains.MethodsThis study investigated effects of 6-week consumption of whole grain wheat sourdough bread in comparison to white bread on fasting serum lipids in normoglycemic/normoinsulinemic (NGI; n = 14) and hyperglycemic/hyperinsulinemic (HGI; n = 14) adults. The influence of single-nucleotide polymorphisms, 3 within the APOE gene (E2, E3, E4) and 2 within the hepatic lipase gene promoter (LIPC -514C>T, LIPC -250G>A) were considered.ResultsAt baseline, HGI participants had significantly higher body weight, waist circumference, body fat, and fasted glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), glucagon, triacylglycerols (TAG) and TAG:HDL-cholesterol, compared to NGI participants; however, none of these in addition to none of the other serum lipids, differed between bread treatments, within either participant group. For participants with the APOE E3/E3 genotype, LDL-cholesterol (P = 0.02) increased in the NGI group (n = 7), and TAG (P = 0.03) and TAG:HDL-cholesterol (P = 0.04) increased in the HGI group (n = 10), following consumption of whole grain wheat sourdough compared to white bread.ConclusionsIn summary, 6-week consumption of whole grain wheat sourdough bread did not significantly modulate serum lipids in NGI or HGI adults; however, it significantly increased LDL-cholesterol, TAG and TAG:HDL-cholesterol in participants with the APOE E3/E3 genotype. These data add to limited literature comparing wheat whole grains to wheat refined grains on CVD risk and highlight the need to consider genetic variation in relation to lipoprotein lipid content and CVD risk.

Highlights

Epidemiological studies associate consumption of whole grain foods, including breads, with reduced cardiovascular disease (CVD) risk; few studies have compared wheat whole grains with wheat refined grains
There were no significant differences in any baseline serum lipids between the genotypes for either the APOE or LIPC polymorphisms
Within the HGI participants, TAG and TAG:HDL-cholesterol significantly increased following consumption of whole grain wheat sourdough compared to white bread in participants with the APOE E3/E3 genotype (Table 5) but not in participants with the E2/E3 or E3/E4 genotypes

Summary

Introduction

Epidemiological studies associate consumption of whole grain foods, including breads, with reduced cardiovascular disease (CVD) risk; few studies have compared wheat whole grains with wheat refined grains. Other studies that have used less comprehensive interventions have demonstrated improved serum lipids following consumption of powdered wheat fibre [27]; high-protein, high-fibre wheat flakes [28]; and wheat whole grain and wheat bran cereal [29]. Potential mechanisms behind these effects include decreased glycemia, insulinemia and lipoprotein particles [30]. Studies that have focused on wheat breads have either not measured [31] or found no significant effect [32,33] on serum lipids, prompting the need for more whole grain wheat bread interventions

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