Strawberries Added to the Usual Diet Suppress Fasting Plasma Paraoxonase Activity and Have a Weak Transient Decreasing Effect on Cholesterol Levels in Healthy Nonobese Subjects

Phenolic Compounds from Cherries and Berries for Chronic Disease Management and Cardiovascular Risk Reduction

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide. Therefore, there is increasing interest in dietary interventions to reduce risk factors associated with these conditions. Cherries and berries are rich sources of bioactive compounds and have attracted attention for their potential cardiovascular benefits. This review summarises the current research on the effects of cherry and berry consumption on cardiovascular health, including in vivo studies and clinical trials. These red fruits are rich in phenolic compounds, such as anthocyanins and flavonoids, which have multiple bioactive properties. These properties include antioxidant, anti-inflammatory, and vasodilatory effects. Studies suggest that regular consumption of these fruits may reduce inflammation and oxidative stress, leading to lower blood pressure, improved lipid profiles, and enhanced endothelial function. However, interpreting findings and establishing optimal dosages is a challenge due to the variability in fruit composition, processing methods, and study design. Despite these limitations, the evidence highlights the potential of cherries and berries as components of preventive strategies against CVD. Further research is needed to maximise their health benefits and improve clinical practice.

Randomized Double-Blind Controlled Trial of Freeze-Dried Strawberry Powder Supplementation in Adults with Overweight or Obesity and Elevated Cholesterol

OBJECTIVE

Recommended dietary patterns improve cardiovascular disease (CVD) risk factors such as blood pressure and LDL-C, as well as emerging markers that confer residual risk. Strawberry consumption has been shown to improve CVD risk factors, but further research is needed to better understand these effects using a dose-response model that evaluates a standard serving and a higher (but still achievable) dose.

METHODS

A randomized, placebo-controlled, double-blinded crossover trial was conducted in middle-aged adults with overweight or obesity (n = 40; mean BMI = 29.4 ± 0.2 kg/m²; mean age = 50 ± 1.0 years) and moderately elevated LDL-C (mean LDL-C: 140 ± 3 mg/dL) to investigate the effect of two doses of strawberry supplementation on LDL-C and other CVD risk factors. Study interventions were: 0 g/d (control), 13 g/d (low-dose), and 40 g/d (high-dose) of freeze-dried strawberry powder (4-week supplementation periods separated by a 2-week compliance break).

RESULTS

There was a significant main effect of treatment for the primary outcome of LDL-C, with a 4.9% reduction following the low-dose strawberry supplement compared to the high-dose (P = 0.01), but not compared to the control. There was also a significant effect on total cholesterol (TC), with a 2.8% and 2.4% reduction following the low-dose compared to the control and high-dose, respectively (P ≤ 0.05 in post-hoc analyses). There was a near significant effect for direct LDL-C (P = 0.07). There were no significant treatment effects for other atherogenic lipoprotein characteristics, indices of vascular function, measures of inflammation, or HDL efflux.

CONCLUSION

Low-dose supplementation with freeze-dried strawberry powder, equivalent to ∼1 serving/day of fresh strawberries, improved cholesterol in adults with overweight or obesity, compared to both the high-dose (∼3 servings/day of fresh strawberries) and control, but did not alter other markers of CVD.

Supplemental data for this article is available online at.

Phytochemicals as Modulators of Paraoxonase-1 in Health and Diseases

Chronic diseases such as cardiovascular disease (CVD), atherosclerosis, chronic liver disease, and neurodegenerative diseases are major causes of mortality. These diseases have gained much attention due to their complications, and therefore novel approaches with fewer side effects are an important research topic. Free radicals and oxidative stress are involved in the molecular mechanisms of several diseases. Antioxidants can scavenge free radicals and mitigate their adverse effects. One of the most important antioxidant enzymes are paraoxonases (PONs). These enzymes perform a wide range of physiological activities ranging from drug metabolism to detoxification of neuroleptics. Paraoxonase-1 (PON1) is produced in the liver and then transferred to the bloodstream. It has been demonstrated that PON1 could have beneficial effects in numerous diseases such as atherosclerosis, CVD, diabetes mellitus, and neurodegenerative diseases by modulating relevant signalling pathways involved in inflammation and oxidative stress. These pathways include peroxisome proliferator-activated receptor gamma (PPAR-γ) and protein kinase B/nuclear factor kappa-light-chain-enhancer of activated B cells (AKT/NF-κB)-dependent signalling pathways. Increasing PON1 could potentially have protective effects and reduce the incidence of various diseases by modulating these signalling pathways. Several studies have reported that dietary factors are able to modulate PON1 expression and activity. This review aimed at summarizing the state of the art on the effects of dietary phytochemicals on PON1 enzyme activity and the relevant signalling pathways in different diseases.

Two Faces of Vitamin C in Hemodialysis Patients: Relation to Oxidative Stress and Inflammation

Hemodialysis (HD) is the most common method of renal replacement therapy. Besides toxins, it eliminates nutrients from the circulation, such as ascorbic acid (AA). HD-patients present AA deficiency more often than representatives of the general population, also due to dietary restrictions. This condition aggravates oxidative stress and inflammation related to uremia and extracorporeal circulation and increases cardiovascular risk followed by mortality. Supplementation of AA seems to be a promising approach in the treatment of hemodialysis patients. Many successful interventions restored plasma AA concentration in HD patients by enteral or intravenous supplementation, concomitantly inhibiting oxidative stress and inflammation. A significant number of studies reported opposite, serious pro-oxidant effects of AA. In this narrative review, we present studies, commenting on their limitations; on AA plasma or serum concentration and the influence of its supplementation on protein and lipid peroxidation, DNA damage, reactive oxygen species generation, paraoxonase activity, advanced glycation endproducts, and C-reactive protein (CRP) concentration. Moreover, in terms of safety, the possible development of oxalosis in HD patients regarding the intravenous or enteral route of AA administration is discussed. Unequivocal clinical results of recent studies on hemodialysis patients are displayed.

Effects of strawberry supplementation on cardiovascular risk factors: a comprehensive systematic review and meta-analysis of randomized controlled trials

Based on our findings, strawberry supplements that contained 10–454 g day⁻¹ freeze-dried/fresh strawberries and taken for 3–12 weeks can improve DBP, CRP, MDA and LDL.

Anthocyanin-rich plum juice reduces ambulatory blood pressure but not acute cognitive function in younger and older adults: a pilot crossover dose-timing study

Consumption of anthocyanins from fruit sources may exert protection against hypertension and improve cognition. However, the effect of dose timing in studies is rarely considered. We hypothesized that timed-dose consumption of juice from an anthocyanin-rich Japanese plum variety (Queen Garnet plum, QGP) will have acute and dose-timing effects on cardiovascular responses, cognition, and urinary anthocyanin excretion profiles. Our study objective was to investigate the impact of plum juice on these health parameters. Twelve older (65+ years) and 12 younger (18-45 years) adults participated in an acute crossover study. Participants received, randomly, either 1 × 300 mL or 3 × 100 mL plum juice over 3 hours on 2 different occasions with a 2-week washout period. A battery of cognitive tasks was administered at 0 and 6 hours on each study day. Blood pressure (BP) and urinary anthocyanin/metabolite excretion profiles were measured over 24 hours. Area under the curve for BP was calculated (0-6 hours). A significant reduction in BP and cardiovascular responses was observed in both age groups which was more obvious in the older age group on the single dose for systolic BP, diastolic BP, mean arterial pressure, and heart rate (P values = .035, .028, .017, and .006, respectively). No significant difference was observed between dose-timing regimens for either age group. There was no observed effect on cognition. Native QGP anthocyanins, as well as methylated/glucuronidated metabolites, were detected in urine with no significant differences between age groups or dose timing. High-anthocyanin plum juice significantly reduced BP, but dose timing did not appear to be a significant factor in the potential acute BP-lowering effect of QGP juice.

Addition of strawberries to the usual diet increases postprandial but not fasting non-urate plasma antioxidant activity in healthy subjects

Strawberries can augment plasma antioxidant activity, but this may be confounded by selection of methods, time of blood sampling and concomitant dietary restrictions. We examined the effect of strawberry consumption on ferric reducing ability (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (DPPH-test) of native and non-urate plasma in healthy subjects on their usual diet. Eleven subjects consumed strawberries (500 g daily) for 9 days. Fasting and 3-h postprandial plasma and 24-h urine collection were obtained before, during and after strawberry course for FRAP, DPPH-test and polyphenols determination. Fifteen subjects served as a control in respect to plasma antioxidant activity changes and effect of 300 mg of oral ascorbate. First, 5th and 9th strawberry dose increased 3-h postprandial DPPH-test by 17.4, 17.6 and 12.6%, and FRAP by 15.5, 25.6 and 21.4% in comparison to fasting values in non-urate plasma (p<0.05). In native plasma only a trend was observed to higher postprandial values for both tests. Strawberries increased urinary urolithin A and 4-hydroxyhippuric acid whereas plasma polyphenols were stable. No changes of FRAP and DPPH-test were noted in controls and after ascorbate intake. Strawberries transiently increased non-urate plasma antioxidant activity but this cannot be attributed to direct antioxidant effect of polyphenols and ascorbate.