Journal of the American Heart Association
ORIGINAL RESEARCH
Effect of Fructose on Established Lipid Targets: A Systematic Review and Meta‐Analysis of Controlled Feeding Trials
Journal of the American Heart Association. 2015;4:e001700
Originally published September 10, 2015
https://doi.org/10.1161/JAHA.114.001700http://jaha.ahajournals.org/content/4/9/e001700Abstract
Background
Debate over the role of fructose in mediating cardiovascular risk remains active. To update the evidence on the effect of fructose on established therapeutic lipid targets for cardiovascular disease (low‐density lipoprotein cholesterol [LDL]‐C, apolipoprotein B, non‐high‐density lipoprotein cholesterol [HDL‐C]), and metabolic syndrome (triglycerides and HDL‐C), we conducted a systematic review and meta‐analysis of controlled feeding trials.
Methods and Results
MEDLINE, EMBASE, CINHAL, and the Cochrane Library were searched through July 7, 2015 for controlled feeding trials with follow‐up ≥7 days, which investigated the effect of oral fructose compared to a control carbohydrate on lipids (LDL‐C, apolipoprotein B, non‐HDL‐C, triglycerides, and HDL‐C) in participants of all health backgrounds. Two independent reviewers extracted relevant data. Data were pooled using random effects models and expressed as mean difference with 95% CI. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Eligibility criteria were met by 51 isocaloric trials (n=943), in which fructose was provided in isocaloric exchange for other carbohydrates, and 8 hypercaloric trials (n=125), in which fructose supplemented control diets with excess calories compared to the control diets alone without the excess calories.
Fructose had no effect on LDL‐C, non‐HDL‐C, apolipoprotein B, triglycerides, or HDL‐C in isocaloric trials. However, in hypercaloric trials, fructose increased apolipoprotein B (n=2 trials; mean difference = 0.18 mmol/L; 95% CI: 0.05, 0.30; P=0.005) and triglycerides (n=8 trials; mean difference = 0.26 mmol/L; 95% CI: 0.11, 0.41; P<0.001). The study is limited by small sample sizes, limited follow‐up, and low quality scores of the included trials.
Conclusions
Pooled analyses showed that fructose only had an adverse effect on established lipid targets when added to existing diets so as to provide excess calories (+21% to 35% energy). When isocalorically exchanged for other carbohydrates, fructose had no adverse effects on blood lipids. More trials that are larger, longer, and higher quality are required.
Relation of total sugars, fructose and sucrose with incident type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies.
CMAJ. 2017 May 23;189(20):E711-E720. doi: 10.1503/cmaj.160706.
Abstract
BACKGROUND:
Sugar-sweetened beverages are associated with type 2 diabetes. To assess whether this association holds for the fructose-containing sugars they contain, we conducted a systematic review and meta-analysis of prospective cohort studies.
METHODS:
We searched MEDLINE, Embase, CINAHL and the Cochrane Library (through June 2016). We included prospective cohort studies that assessed the relation of fructose-containing sugars with incident type 2 diabetes. Two independent reviewers extracted relevant data and assessed risk of bias. We pooled risk ratios (RRs) using random effects meta-analyses. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.
RESULTS:
Fiffeen prospective cohort studies (251 261 unique participants, 16 416 cases) met the eligibility criteria, comparing the highest intake (median 137, 35.2 and 78 g/d) with the lowest intake (median 65, 9.7 and 25.8 g/d) of total sugars, fructose and sucrose, respectively. Although there was no association of total sugars (RR 0.91, 95% confidence interval [CI] 0.76-1.09) or fructose (RR 1.04, 95% CI 0.84-1.29) with type 2 diabetes, sucrose was associated with a decreased risk of type 2 diabetes (RR 0.89, 95% CI 0.80-0.98). Our confidence in the estimates was limited by evidence of serious inconsistency between studies for total sugars and fructose, and serious imprecision in the pooled estimates for all 3 sugar categories.
INTERPRETATION:
Current evidence does not allow us to conclude that fructose-containing sugars independent of food form are associated with increased risk of type 2 diabetes. Further research is likely to affect our estimates.