Prickly pear juice consumption after fat intake affects postprandial heart rate variability but not traditional risk factors of cardiovascular disease in healthy men.

OBJECTIVE: Prickly Pear (PP) fruit is proposed to have anti-atherosclerotic and anti-hyperglycemic effects. The aim of this study was to examine the effects of a single consumption of PP juice on modifiable blood and physiological markers of cardiovascular disease risk in healthy men using a postprandial hyperlipidemia model. METHODS: This was a double-blind, randomized, placebo-controlled, crossover trial with 17 healthy men (body mass index 22.6 ± 2.04 kg/m2; 29.5 ± 7.19 y of age). Participants consumed PP juice (250 mL; 45 mg betalain content; reduced fiber) or a simple placebo drink (water-based), with a high-fat muffin (50 g fat) to determine potential effects on physiologic and biological responses, for up to 3 h post-consumption (hourly, 2 sessions, 7-d washout period). Blood pressure, heart rate variability (HRV), total cholesterol (TC), triacylglycerides (TGs), low-density and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively), and glucose were measured. RESULTS: Key findings included a lower HRV measure after PP consumption (main effect for group, P ≤0.001-0.020) but no differences for TC, TG, LDL-C, or HDL-C. CONCLUSION: Consumption of PP (with high-fat muffin), did not alter traditional cardiovascular disease risk responses but rather markers of HRV, beyond an expected increase in glucose attributed to the carbohydrate content of the trials foods. Additionally, macronutrient content is important when understanding HRV responses to meals.

The bioactive, antioxidant, antibacterial, and physicochemical properties of a range of commercially available Australian honeys.

Honey is a supersaturated sugar solution produced from plant nectar, with its composition influenced by geographic and floral origins, and with several properties contributing to its health-related abilities. This study aimed to determine the bioactive composition, antioxidant characteristics, antibacterial activity, and physicochemical properties of commercial Australian honeys. In total, 42 commercial Australian honeys were selected, and categorised according to front-label descriptions. Honeys were analysed: quality (Hydroxymethylfurfural); colour (colour intensity, L*,a*,b*); bioactive composition (phenolic, flavonoid, and carotenoid content); antioxidant characteristics (DPPH, CUPRAC, FRAP); antibacterial activity (MIC50); physicochemical properties (pH, TSS, viscosity, a w). Colour intensity correlated with each assessed bioactive compound and antioxidant characteristic (p ≤ 0.001). MIC50 (S. aureus) was associated with FRAP and a w, suggesting mechanisms of action for honey's antibacterial activity. Manuka-type honeys had higher colour intensity (1440 (98.5) mAU) than other categories (p ≤ 0.05), and consistently higher bioactive and antioxidant properties. This provides the potential to inform antioxidant-related health outcomes.

The effects of Prickly Pear fruit and cladode (Opuntia spp.) consumption on blood lipids: A systematic review.

BACKGROUND: The current dietary recommendations for cardiovascular disease (CVD) risk reduction include increased fruit and vegetable consumption. The Opuntia spp., Prickly Pear (PP) fruit is rich in dietary fiber and may have lipid-lowering effects but it is often confused with the PP stem/leaf (Cladode (CLD)), or not identified. The efficacy of the PP fruit and CLD in reducing CVD risk is a growing area of research. METHODS: This systematic review (PROSPERO: CRD42018110643), examined the effects of consuming the Opuntia spp. components (PP or CLD) on CVD risk factors, specifically total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG). The review, performed from February through September 2019, used resources available through Food Science and Technology Abstracts (EBSCO), Medline, Scopus, CINAHL, Web of Science and Cochrane databases. RESULTS AND DISCUSSION: Eleven articles met the inclusion criteria, which characterised Opuntia spp. products as either PP (n = 6), CLD (n = 4) or commercial products' (n=1). Effects were investigated in healthy and obese populations as well as those with metabolic illnesses, specifically type 2 diabetes and metabolic syndrome. PP consumption was associated with significant reductions in TC (p < 0.05) in all but one included study, whereas in the remaining studies (n=6), LDL-C levels decreased (p < 0.05). Separately, the effect of CLD consumption on lipids was small with one study reporting a significant increase in plasma HDL-C in a subgroup of participants (>45 years of age) following consumption of a patented CLD powder product. It is plausible, that differences in overall effect may be due to compositional distinctions between CLD and PP, such as fiber composition. Care must be taken in future studies to accurately report the identity of the selected components of Opuntia spp.

Effects of the Consumption of Prickly Pear Cacti (Opuntia spp.) and its Products on Blood Glucose Levels and Insulin: A Systematic Review.

Background and Objectives: There is confusion as to which component of the Opuntia spp. cacti has demonstrated anti-hyperglycemic effects or anti-diabetic properties. It is important to clarify these health benefits due to the increasing need for prevention and treatment of chronic diseases. The aim of this review is to identify the effects of Opuntia spp. cacti consumption on biomedical measures; glucose and insulin with consideration of its' components; fruit, leaf and combined or unidentified Opuntia spp. products. Materials and Methods: Prior to commencing the searches, this systematic review was registered with PROSPERO (CRD42018108765). Following the PRISMA 2009 guidelines, six electronic databases (Food Science and Technology Abstracts (EBSCO), Medline, Scopus, CINAHL, Web of Science and Cochrane) were searched for articles investigating the effect of Opuntia spp. consumption on glucose and insulin in humans. Results: Initially, 335 articles were sourced and filtered by exclusion criteria (human interventions, control trials and articles published in English) resulting in 20 relevant articles. The included studies were characterized by such plant components as fruit (n = 4), cladode (n = 12), and other Opuntia spp. products (n = 4), further separated by clinical populations ('healthy', hyperlipidemic, hypercholesterolemic, Type 2 Diabetes Mellitus). The findings of this review indicate variations in effects between cacti components and products. Cladode and select Opuntia spp. products predominately demonstrated significant reductions in serum glucose and insulin, indicating potential as a functional food candidate. Prickly Pear fruit was predominately reported to have no significant effects on glucose or insulin. The quality of evidence appeared to vary based on the type of Opuntia spp. product used. Studies that used specifically the fruit or cladode had high risk of bias, whereas studies which used combined Opuntia spp. products had a lower risk of bias. Numerous mechanisms of action were proposed where positive findings were reported, with emphasis on dualistic glucose-dependent and independent actions, however, mechanisms require further elucidation. Conclusion: Currently, there is a lack of evidence to support the recommendation of using Opuntia spp. fruit products as an alternative or complementary therapy in the reduction of risk or management of Type 2 Diabetes Mellitus. The Cladode does however show promise in potential glucose-lowering effects which warrant further investigation.