The Postprandial Effect of Anthocyanins on Cardiovascular Disease Risk Factors: a Systematic Literature Review of High-Fat Meal Challenge Studies

Effects of Single Low-Carbohydrate, High-Fat Meal Consumption on Postprandial Lipemia and Markers of Endothelial Dysfunction: A Systematic Review of Current Evidence

CONTEXT

Postprandial lipemia (PPL) is associated with increased risk of endothelial dysfunction (ED), a precursor of atherosclerotic cardiovascular disease (ASCVD). The effects of low-carbohydrate, high-fat (LCHF) diets on ASCVD risk are uncertain; therefore, gaining a greater understanding of LCHF meals on PPL may provide valuable insights.

OBJECTIVE

The current systematic review investigated the effects of single LCHF meal consumption on PPL and markers of ED.

DATA SOURCES

CINAHL Plus, PubMed, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for key terms related to endothelial function, cardiovascular disease, glycemia, lipemia, and the postprandial state with no restriction on date.

DATA EXTRACTION

Full-text articles were independently screened by 2 reviewers, of which 16 studies were eligible to be included in the current review. All trials reported a minimum analysis of postprandial triglycerides (PPTG) following consumption of an LCHF meal (<26% of energy as carbohydrate). Results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

DATA ANALYSIS

Single-meal macronutrient composition was found to play a key role in determining postprandial lipid and lipoprotein responses up to 8 hours post-meal. Consumption of LCHF meals increased PPTG and may contribute to ED via reduced flow-mediated dilation and increased oxidative stress; however, energy and macronutrient composition varied considerably between studies.

CONCLUSION

Consumption of an LCHF meal had a negative impact on PPL based on some, but not all, single-meal studies; therefore, the contribution of LCHF meals to cardiometabolic health outcomes remains unclear. Further research is needed on specific categories of LCHF diets to establish a causal relationship between postprandial modulation of lipids/lipoproteins and impaired vascular endothelial function.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD 42023398774.

Single anthocyanins effectiveness modulating inflammation markers in obesity: dosage and matrix composition analysis

Anthocyanins (ACNs) are phytochemicals with numerous bioactivities, e.g., antioxidant and anti-inflammatory. Health benefits from consuming ACN-rich foods, extracts, and supplements have been studied in clinical trials (CT). However, the individual effect of single ACNs and their correlation with doses and specific bioactivities or molecular targets have not been thoroughly analyzed. This review shows a recompilation of single anthocyanins composition and concentrations used in CT, conducted to investigate the effect of these anti-inflammatory derivatives in obese condition. Single anthocyanin doses with changes in the levels of frequently monitored markers were correlated. In addition, the analysis was complemented with reports of studies made in vitro with single ACNs. Anthocyanins' efficacy in diseases with high baseline obesity-related inflammation markers was evidenced. A poor correlation was found between most single anthocyanin doses and level changes of commonly monitored markers. Correlations between cyanidin, delphinidin, and pelargonidin derivatives and specific molecular targets were proposed. Our analysis showed that knowledge of specific compositions and anthocyanin concentrations determined in future studies would provide more information about mechanisms of action.

Acute effect of a beverage containing Brazil and cashew nuts on oxidative stress, lipemia, and blood pressure of women with cardiometabolic risk (Brazilian Nuts Study): a randomized clinical trial

Nuts are important sources of antioxidants that combat oxidative stress and improve lipid profile as well as vascular function. However, the intake of typical Brazilian nuts and its acute effect on cardiovascular health needs to be better understood. Thus, the present study aimed to evaluate the acute effect of a beverage containing cashew (Anacardium occidentale L.) and Brazil nuts (Bertholletia excelsa H.B.K.) on postprandial oxidative stress, lipemia, and blood pressure of adult women aged 20 to 55 years with cardiometabolic risk. This was an acute, randomized, parallel arm, controlled clinical trial. The participants received either a beverage containing nuts (30 g Brazil nuts + 15 g cashew nuts) or a beverage without nuts with similar macronutrient composition. Oxidative stress markers and lipid profiles were evaluated at fasting and 4 h after beverage consumption. Blood pressure was measured during fasting and after beverage intake (1, 2, 3, and 4 h). In the postprandial state, there was a greater reduction in malondialdehyde levels in the intervention group compared to the control group (-12.3 ± 0.59 vs. -10.7 ± 0.43 µmol/mL; p < 0.05), which was positively correlated with the concentrations of TG (r = 0.399; p < 0.05), VLDL (r = 0.399; p < 0.05), TG/HDL (r = 0.380; p < 0.05), and blood pressure (iAUC SBP r = 0.391; p < 0.05, iAUC DBP r = 0.409; p < 0.05). The remaining oxidative stress markers showed similar postprandial changes between groups. In women with cardiometabolic risk, a beverage containing Brazilian nuts promoted a significant acute reduction on postprandial malondialdehyde levels. The study was registered in the Brazilian Clinical Trials Registry-ReBEC (protocol: RBR-3ntxrm).

A Randomised Placebo-Controlled Study of Purified Anthocyanins on Cognition in Individuals at Increased Risk for Dementia

IMPORTANCE

Identifying nutritional compounds which can reduce cognitive decline in older people is a hugely important topic.

OBJECTIVE

To study the safety and effect of anthocyanins in maintaining cognitive functioning in people at increased risk for dementia.

DESIGN, SETTING, AND PARTICIPANTS

Participants (206 individuals, aged 60-80 years) diagnosed with either mild cognitive impairment (MCI) or two or more cardiometabolic disorders (i.e., diabetes, hypertension, obesity) were enrolled at three different centres in Norway.

INTERVENTION

Participants were randomly assigned to four capsules with a total of 320 mg/d of naturally purified anthocyanins or placebo 1:1 for 24 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome was the Quality of Episodic Memory composite measure (0-100) from an online cognitive test battery CogTrack, which was administered at baseline and monthly for the next 24 weeks. Secondary outcomes included other cognitive scores from the CogTrack battery. We applied mixed effects models with a baseline test score, group, time and their interaction as fixed effects, as well as other predefined baseline covariates. The primary comparison was the group difference at week 24 based on a modified intention-to-treat principle.

RESULTS

The primary analysis did not show a significant group difference at 24 weeks (78.2 versus 76.8; adjusted mean difference 1.4 (95% confidence interval -0.9-3.7); effect size 0.15; p = 0.23). However, there was a significant difference in slopes during weeks 8-24 (p = 0.007); the anthocyanin group improved while the placebo group worsened. No differences were found for the secondary cognitive outcomes. Anthocyanin capsules were well-tolerated and safe to use.

CONCLUSION

Anthocyanin supplementation for 24 weeks was safe and well tolerated in people with MCI or cardiometabolic disorders. We found no significant group difference in episodic memory at the end of the study but statistically significant differences in slopes. Further studies are warranted to explore whether anthocyanins supplementation can reduce cognitive decline in people at increased risk of dementia.

TRIAL REGISTRATION

ClinicalTrials.gov, (Identifier NCT03419039). http://www.

CLINICALTRIALS

gov/, NCT03419039.

Anthocyanins attenuate vascular and inflammatory responses to a high fat high energy meal challenge in overweight older adults: A cross-over, randomized, double-blind clinical trial

BACKGROUND & AIMS

Postprandial metabolic imbalances are important indicators of later developing cardiovascular disease (CVD). This study investigated the effects of food anthocyanins on vascular and microvascular function, and CVD associated biomarkers following a high fat high energy (HFHE) meal challenge in overweight older adults.

METHODS

Sixteen subjects (13 female, 3 male, mean age 65.9 SD 6.0 and body mass index 30.6 kg/m² SD 3.9) participated in a crossover, randomized, controlled, double-blind clinical trial (registered under Australian New Zealand Clinical Trials Registry, identifier no. ACTRN12620000437965). Participants consumed a HFHE meal with a 250 mL dose of either intervention (anthocyanins-rich Queen Garnet Plum) or control (apricot) juice. Blood samples and blood pressure measures were collected at baseline, 2 h and 4 h following the HFHE meal. Vascular and microvascular function were evaluated at baseline and 2 h after the HFHE meal.

RESULTS

Participants had a higher 2 h postprandial flow-mediated dilatation (+1.14%) and a higher microvascular post-occlusive reactive hyperaemia (+0.10 perfusion units per mmHg) when allocated to the anthocyanin compared to the control arm (P = 0.019 and P = 0.049, respectively). C-reactive protein was lower 4 h postprandially in the anthocyanins (1.80 mg/L, IQR 0.90) vs control arm (2.30 mg/L, IQR 1.95) (P = 0.026), accompanied by a trend for lower concentrations of interleukin-6 (P = 0.075). No significant postprandial differences were observed between treatments for blood pressure, triacylglycerol, total cholesterol, serum derivatives of reactive oxidative metabolites, tumor necrosis factor alpha, interleukin-1 beta, or maximum microvascular perfusion following iontophoresis of acetylcholine.

CONCLUSION

Fruit-based anthocyanins attenuated the potential postprandial detrimental effects of a HFHE challenge on parameters of vascular and microvascular function, and inflammatory biomarkers in overweight older adults. Anthocyanins may reduce cardiovascular risk associated with endothelial dysfunction and inflammatory responses to a typical high fat 'Western' meal. Further studies are required to better elucidate the clinical implications of postprandial biomarkers of CVD.