Carbohydrates and Fibre

Find the most important recent research around carbohydrates and fibre and cardiovascular health.

Low Carbohydrate Diets

Review of current evidence and clinical recommendations on the effects of low-carbohydrate and very-low-carbohydrate (including ketogenic) diets for the management of body weight and other cardiometabolic risk factors: A scientific statement from the National Lipid Association Nutrition and Lifestyle Task Force. J Clinical Lipidology (2019)

This scientific statement provides a comprehensive review of the current evidence base available from recent systematic reviews and meta-analyses on the effects of low-CHO and very-low-CHO diets on body weight, lipoprotein lipids, glycemic control, and other cardiometabolic risk factors. In addition, evidence on emerging risk factors and potential safety concerns of low-CHO and very-low-CHO diets, especially for high-risk individuals, such as those with genetic lipid disorders, was reviewed. 

Retterstøl, Kjetil et al. (2018) Effect of low carbohydrate high fat diet on LDL cholesterol and gene expression in normal-weight, young adults: A randomized controlled study. Atherosclerosis, Volume 279, 52 - 61

A low carbohydrate high fat diet (LCHF) for three weeks increased LDL-C by 44% compared to controls. The individual response on LCHF varied profoundly.


Sara B Seidelmann, Brian Claggett, et al. (2018) A low carbohydrate high fat diet (LCHF) for three weeks increased LDL-C by 44% compared to controls. The individual response on LCHF varied profoundly. The Lancet Public Health; 3; (9): 419-428

Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis


Joshi S, Ostfeld RJ, et al (2019) The Ketogenic Diet for Obesity and Diabetes—Enthusiasm Outpaces Evidence. JAMA Intern Med.179(9):1163–1164.

Although the ketogenic diet has garnered much attention for the dietary treatment of chronic diseases such as obesity and type 2 diabetes, the evidence supporting its use is currently limited and the diet’s potential risks are real. Physicians and patients should continue to judiciously appraise the benefits and risks of the ketogenic diet in accordance with the evidence, not the hype.

Fibre

Andrew Reynolds, Jim Mann, et al (2019) Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet; 393: 10170; 434-445

Findings from prospective studies and clinical trials associated with relatively high intakes of dietary fibre and whole grains were complementary, and striking dose-response evidence indicates that the relationships to several non-communicable diseases could be causal. Observational data suggest a 15–30% decrease in all-cause and cardiovascular related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers. Clinical trials show significantly lower body weight, systolic blood pressure, and total cholesterol when comparing higher with lower intakes of dietary fibre. Risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g.

Dietary fibre for the primary prevention of cardiovascular disease - A Cochrane Systematic Review 2016

The primary objective of this systematic review was to determine the effectiveness of dietary fibre for the primary prevention of CVD. Included studies were short term and therefore did not report on primary outcomes, CVD clinical events. The pooled analyses for CVD risk factors suggest reductions in total cholesterol and LDL cholesterol with increased fibre intake, and reductions in diastolic blood pressure. 

Sugar

Lukas Schwingshackl, Manuela Neuenschwander, Georg Hoffmann, et al (2020) Dietary sugars and cardiometabolic risk factors: a network meta-analysis on isocaloric substitution interventions. The American Journal of Clinical Nutrition, Volume 111, Issue 1, Pages 187–196, https://doi.org/10.1093/ajcn/nqz273 

The aim of this network meta-analysis (NMA) of randomized controlled trials was to assess how isocaloric substitutions of dietary sugar with other carbohydrates affect cardiometabolic risk factors, comparing different intervention studies. Findings indicate that substitution of sucrose and fructose with starch yielded lower LDL cholesterol. However, these findings were limited by the very low to moderate certainty of evidence.