Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials

Harnessing nutrients and natural products for sustainable drug development against aging

Developing treatments for age-related diseases requires cost-effective and efficient approaches. Nutrients and natural metabolites offer safer alternatives to synthetic drugs. Aging increases the need for solutions that protect health and repair cells. Recent studies show that nutrients and natural products reduce oxidative stress, regulate metabolism, and influence longevity-related genes. This review focuses on vitamins, minerals, antioxidants, and natural products that improve healthspan and combat aging. It also discusses challenges such as standardization, clinical validation, and regulatory approval. Finally, emerging trends, such as personalized nutrition and advanced delivery systems, highlight the potential of these metabolites for addressing aging.

Quantity and variety of food groups consumption and the risk of hypertension in adults: a prospective cohort study

The prospective association of dietary diversity and different food groups with the risk of hypertension in the general Chinese adults has not been evaluated. We aimed to evaluate the relationship of variety and quantity of 12 major food groups with new-onset hypertension in the Chinese adults. A total of 11,118 adults from the China Health and Nutrition Survey (CHNS) were included. The study outcome was new-onset hypertension, defined as systolic blood pressure (SBP) ≥ 140 mmHg or diastolic blood pressure (DBP) ≥ 90 mmHg or diagnosed hypertension by physician or under antihypertensive treatment during the follow-up. During a median follow-up period of 6.0 years, 3867 participants occurred new-onset hypertension. There was a L-shaped relationship of dietary variety score with new-onset hypertension (P for nonlinearity < 0.001). Compared with those in the quartile 1 of dietary variety score, participants in the quartile 2-4 were associated with a significantly lower risk of hypertension (HR, 0.64; 95% CI: 0.59, 0.69). In addition, there were U-shaped associations of dairy products, vegetables, aquatic products, nuts, red meat, whole grains, refined grains, processed meat, and poultry intake with new-onset hypertension, and L-shaped associations of fruits, legumes, and eggs intake with new-onset hypertension (all P for nonlinearity < 0.001). In conclusion, there was an inverse association of dietary variety score with new-onset hypertension in the Chinese adults. Furthermore, there was a negative association between different food group intake and new-onset hypertension when food group intake was relatively low; however, the risk of hypertension increased or plateaued when the intake exceeded a certain threshold.

Vitamin C: A Comprehensive Review of Its Role in Health, Disease Prevention, and Therapeutic Potential

Since Albert Szent-Györgyi discovered it and it became used in treating scurvy, vitamin C has attracted interest in many studies due to its unique properties. It is an important cofactor in the synthesis of collagen and hormones, and it is involved in immunity, iron absorption, and processes requiring antioxidants. Thus, this review aims to emphasize the importance and usefulness of vitamin C in improving quality of life and preventing various diseases (e.g., chronic diseases, cardiovascular diseases, cancer) but also for its use in treatments against infections, neurodegenerative diseases, and cancer. Although the studies presented provide essential information about the properties of VIC and its beneficial effect on health, some studies contradict these theories. In this respect, further studies on larger samples and over a longer period are needed to demonstrate the therapeutic potential of this nutrient. However, VIC remains a necessary vitamin that should be consumed daily to maintain optimal health and prevent deficiencies that can lead to scurvy and its associated complications.

Associations between oxidative balance scores and heart failure among americans: NHANES (2007-2018)

BACKGROUND

The relationship between oxidative balance score (OBS) and heart failure (HF) is controversial. The OBS was used to assess systemic oxidative stress status, with higher OBS scores implying exposure to more antioxidants. This study aimed to explore whether OBS is associated with heart failure in US adults.

METHODS

A cross-sectional investigation was carried out using information from the National Health and Nutrition Examination Survey 2007-2018. The linear link between OBS and HF in adults aged ≥ 45 years was investigated using multivariate linear regression models. Interaction tests and subgroup analysis were also conducted.

RESULTS

The prevalence of HF was 3.84%. There was a significant negative relationship between OBS (OR: 0.96 ,95%CI: 0.95-0.98, P < 0.0001) and HF. In the fully adjusted model, compared to the lowest quartile of OBS, subjects in the highest quartile had a 45% lower likelihood of developing HF (OR: 0.55, 95% CI: 0.41-0.74, p < 0.0001). In stratified analysis, OBS and HF showed no obvious negative correlation.

CONCLUSION

OBS was strongly negatively associated with heart failure. The findings underline the significance of adhering to an antioxidant diet and lifestyle, which helps prevent heart failure.

Effect of a Whole-Food Plant-Based Diet on Periodontal Parameters in Patients With Cardiovascular Risk Factors: A Secondary Sub-Analysis of a Randomized Clinical Trial

AIM

To investigate the effect of a 16-week whole-food plant-based diet (WPBD) on periodontal parameters in patients with increased cardiometabolic risk.

MATERIALS AND METHODS

A total of 36 participants from a randomized clinical trial received additional periodontal assessment. The intervention group (n = 17) followed a WPBD for 16 weeks, whereas the control group (CG) (n = 19) was instructed not to change their diet. Measurements were assessed at baseline (t1), week 8 (t2) and week 16 (t3). Periodontal examination included bleeding on probing (BOP), periodontal inflamed surface area (PISA) and plaque index (PI) on six index teeth, salivary pH and matrix-matalloproteinase-8 (MMP-8).

RESULTS

At t3, the mean PISA of the index teeth was reduced by 32 mm2 (53.8) in the WPBD group and increased by 22.6 mm2 (45.1) in the CG group (intra-group p = 0.255 and p = 0.977, respectively), BOP changes were similar (intra-group p = 0.89 and p = 0.839, respectively). MMP-8 values reduced in the WPBD group by 50.73 ng/mL (117) and in the CG by 5.40 ng/mL (96.6) (intra-group p = 0.066, p = 0.837, respectively). Difference in change (t3 - t1) between the groups was p = 0.001, p = 0.003 and p = 0.032, respectively. Saliva pH increased in the WPBD group only (intra-group p = 0.007).

CONCLUSION

A trend towards stabilization of the inflammatory parameters (BOP, PISA) was observed in the WPBD group. Because of the non-significant changes within the groups, this study highlights the imperative for future studies.

CLINICALTRIALS

GOV IDENTIFIER

NCT03901183.

Effect of vitamin C and hawthorn beverage formula on blood pressure and oxidative stress in heat-exposed workers: a cluster-randomized controlled trial

BACKGROUND AND OBJECTIVES

There is no evidence on antioxidant-rich diets in preventing hypertension in heat-exposed workers. We aimed to evaluate the effects of formula supplemented with vitamin C (Vit C) and hawthorn beverage on reducing blood pressure (BP) and oxidative stress levels in heat-exposed workers.

METHODS AND STUDY DESIGN

In the 40-day cluster-randomized controlled trial, four heat-exposed shift-teams were enrolled and randomly assigned to the intervention and control groups. The intervention group was given one Vit C tablet (130 mg) and a 500 mL hawthorn beverage containing 278.7 mg flavonoids daily whereas the control group was given 500 mL of slightly salted water daily; both groups were provided education on a healthy diet. BP and creatinine-corrected urinary 8-isoprostane-prostaglandin F2α (8-iso-PGF2α/Cr) concentrations were assessed at baseline, Day 17 (only BP) and Day 41, respectively.

RESULTS

Compared with the control group, the systolic BP (SBP), diastolic BP (DBP), and log10-transformed 8-iso-PGF2α/Cr in the inter-vention group decreased by 7.41 mmHg, 7.93 mmHg and 0.232, respectively, from baseline to day 41 (all p<0.05). When comparing BP levels at baseline, DBP in the intervention group was reduced by 5.46 mmHg when compared to control (p<0.05) among participants with lower baseline BP; SBP and DBP experienced reductions of 9.74 and 9.22 mmHg among participants with higher baseline BP (both p<0.05).

CONCLUSIONS

Supplementation of Vit C and flavonoids rich hawthorn beverage to heat-exposed workers prevented elevated BP caused by heat exposure which may be attributed to its oxidative stress inhibition effects.

Impact of thermal processing on polyphenols, carotenoids, glucosinolates, and ascorbic acid in fruit and vegetables and their cardiovascular benefits

Bioactive compounds in fruit and vegetables have a positive impact on human health by reducing oxidative stress, inflammation, and the risk of chronic diseases such as cancer, cardiovascular (CV) diseases, and metabolic disorders. However, some fruit and vegetables must be heated before consumption and thermal processes can modify the amount of nutraceuticals, that is, polyphenols, carotenoids, glucosinolates, and ascorbic acid, that can increase or decrease in relation to different factors such as type of processing, temperature, and time but also the plant part (e.g., flower, leaf, tuber, and root) utilized as food. Another important aspect is related to the bioaccessibility and bioavailability of nutraceuticals. Indeed, the key stage of nutraceutical bioefficiency is oral bioavailability, which involves the release of nutraceuticals from fruit and vegetables in gastrointestinal fluids, the solubilization of nutraceuticals and their interaction with other components of gastrointestinal fluids, the absorption of nutraceuticals by the epithelial layer, and the chemical and biochemical transformations into epithelial cells. Several studies have shown that thermal processing can enhance the absorption of nutraceuticals from fruit and vegetable. Once absorbed, they reach the blood vessels and promote multiple biological effects (e.g., antioxidant, anti-inflammatory, antihypertensive, vasoprotective, and cardioprotective). In this review, we described the impact of different thermal processes (such as boiling, steaming and superheated steaming, blanching, and microwaving) on the retention/degradation of bioactive compounds and their health-promoting effects after the intake. We then summarized the impact of heating on the absorption of nutraceuticals and the biological effects promoted by natural compounds in the CV system to provide a comprehensive overview of the potential impact of thermal processing on the CV benefits of fruit and vegetables.

The Role of Oxidative Stress in Hypertension: The Insight into Antihypertensive Properties of Vitamins A, C and E

Hypertension stands as a pervasive global health challenge, contributing significantly to mortality rates worldwide. Various factors, including lifestyle choices and dietary habits, contribute to the development of hypertension. In recent years, oxidative stress has garnered significant attention as a factor influencing hypertension risk, prompting a shift in research focus towards exploring it as a potential target for prevention and treatment. Antioxidants found in our diet, such as vitamins C, E and carotenoids exhibit the ability to neutralize reactive oxygen species, thereby mitigating oxidative stress. In addition, Vitamin A has an antioxidant effect despite not being an antioxidant itself. Consequently, supplementation or increased intake of these antioxidants has been hypothesized to potentially lower blood pressure levels and aid in the management of hypertension, thereby potentially prolonging life expectancy. Research findings regarding this effect have been diverse. This paper examines the existing literature demonstrating favorable outcomes associated with antioxidant supplementation.

Effects of dietary nitrate and vitamin C co-ingestion on blood pressure and hand-grip strength in young adults

Background: Co-administration of vitamin C and inorganic nitrate ([Formula: see text]) may reduce oxidative stress, boost the conversion of nitrite ([Formula: see text]) into NO and elicit positive vascular effects. Aims: We aimed to test the effects of oral inorganic [Formula: see text] and vitamin C co-supplementation on vascular function, muscular strength, and on concentrations of urinary [Formula: see text], vitamin C, 8-isoprostanes and salivary [Formula: see text] in healthy young adults. Methods: Ten young healthy participants were enrolled in a randomised, double-blind (only for the [Formula: see text] intervention) crossover clinical trial. Participants consumed in random order: 1) nitrate-rich beetroot juice and vitamin C (N+VC), 2) nitrate-rich beetroot juice alone (N) or 3) nitrate-depleted beetroot juice alone (ND). Resting blood pressure (BP) was measured at the research centre and at home. Non-invasive, continuous measurements of BP and cardiac function parameters were performed using a Finometer device. Free-living physical activity and hand-grip strength were assessed. Salivary [Formula: see text] and [Formula: see text] and urinary [Formula: see text], 8-isoprostanes and vitamin C concentrations were measured. Results: There were no significant differences for any of the vascular outcomes between the three interventions groups. However, analyses of within-intervention changes showed a significant lower daily systolic BP in the [Formula: see text]+vitamin C (N+VC) group only (P=0.04). Urinary [Formula: see text] (P=0.002) and salivary [Formula: see text] (P=0.001) were significantly higher in the N+VC group compared to the N and ND groups. Conclusion: These preliminary findings suggest that combining dietary [Formula: see text] with vitamin C could have protective effects on vascular function in young adults and could represent an effective strategy for the maintenance of healthy cardiovascular trajectories.

Preoperative and postoperative administration of vitamin C in cardiac surgery patients - settings, dosages, duration, and clinical outcomes: a narrative review

Vitamin C or ascorbic acid is a water-soluble vitamin capable of directly donating electrons to reactive oxygen species, attenuating electrical remodeling, and cardiac dysfunction in patients undergoing cardiac surgery (CS), considered one of the most effective defenses against free radicals in the blood, thus being one of the first antioxidants consumed during oxidative stress. The aim of this review is to assess the effects of perioperative administration of vitamin C in CS patients. A comprehensive literature search was conducted in order to identify prospective cohort studies and/or randomized controlled trials reporting on the perioperative effects of vitamin C among adult patients undergoing CS. Studies published between January 1980 to December 2022 were included in our search, resulting in a total of 31 articles that met all our inclusion criteria. There seems to be a beneficial effect of vitamin C supplementation in arrhythmias such as in postoperative atrial fibrillation, reduction of ICU length of stay, and hospital length of stay, reduction in postoperative ventilation time, in inotropic demand, and in postoperative fatigue. Vitamin C can act as a scavenger of free radicals to decrease the peroxidation of the lipids present in the cell membrane, and to protect the myocardium postoperatively from ischemia/reperfusion injury, thus attenuating oxidative stress and inflammation. It represents a readily available and cost-effective strategy that could improve the outcome of patients undergoing CS, by reducing the risk of serious cardiovascular adverse events, both perioperatively and postoperatively.

Association between homocysteine and blood pressure in the NHANES 2003-2006: the mediating role of Vitamin C

Background

The yearly escalation in hypertension prevalence signifies a noteworthy public health challenge. Adhering to a nutritious diet is crucial for enhancing the quality of life among individuals managing hypertension. However, the relationship between vitamin C and hypertension, as well as homocysteine, remains unclear.

Objective

The primary aim of this investigation was to scrutinize the potential mediating role of Vitamin C in the association between homocysteine levels and blood pressure, utilizing data extracted from the National Health and Nutrition Examination Survey (NHANES) database.

Methods

A total of 7,327 participants from the NHANES 2003-2006 were enrolled in this cross-sectional survey. The main information was obtained using homocysteine, Vitamin C, systolic blood pressure (SBP) and diastolic blood pressure (DBP). Correlation analysis was used to assess the correlation between homocysteine, SBP, DBP and vitamin C. Linear regression analysis was utilized to determine the β value (β) along with its 95% confidence intervals (CIs). Mediation analysis was performed to investigate whether the relationship between homocysteine and blood pressure was mediated by Vitamin C, and to quantify the extent to which Vitamin C contributed to this association.

Results

The results manifested that the homocysteine was positively associated with SBP (r = 0.24, p < 0.001) and DBP (r = 0.03, p < 0.05), while negatively correlated with Vitamin C (r = -0.008, p < 0.001). Vitamin C was found to be negatively associated with SBP (r = -0.03, p < 0.05) and DBP (r = 0.11, p < 0.001). Mediation effect analysis revealed that a partial mediation (indirect effect: 0.0247[0.0108-0.0455], p < 0.001) role accounting for 11.5% of total effect, among homocysteine and SBP. However, the mediating effect of Vitamin C between homocysteine and DBP was not statistically significant.

Conclusion

Hypertension patients should pay attention to homocysteine and Vitamin C level. What is more, hypertension patients ought to formulate interventions for Vitamin C supplementation as well as homocysteine reduce strategies to lower blood pressure.

Vitamin C variation in citrus in response to genotypes, storage temperatures, and storage times: A systematic review and meta-analysis

Numerous published studies have highlighted discrepancies in the duration and storage temperature used for preserving vitamin C content on various citrus genotypes worldwide. The present study aimed to analyze the variation in vitamin C content as influenced by citrus genotype, duration, and storage temperature using meta-analysis approaches. Data searching, selection, and tabulation resulted in a comprehensive database constructed from 1412 data points gathered from 54 individual studies, following PRISMA-P guidelines. The vitamin C content varied widely, ranging from 0 to 76.2 mg/100 mL in whole data of citrus fruit. Meta-analysis findings revealed that the duration of storage significantly impacted the vitamin C content in citrus fruits. Specifically, for grapefruit, mandarin, and orange, the length of storage significantly influenced their vitamin C levels (P < 0.01), with a consistent decrease observed over time. The correlation coefficients (R2) were 0.63 for grapefruit, 0.9 for mandarin, and 0.69 for orange. In contrast, no significant difference was found in terms of vitamin C levels between hybrid and lime citrus concerning the impact of storage time. However, other results indicated a significant influence of storage temperature on the variation in vitamin C levels for both citrus and hybrid varieties (P < 0.001). Depending on the genotype, tangerine had significantly lower vitamin C content compared to other varieties, at 16.9 mg/100 mL, with vitamin C ranging from 13.2 to 20.9 mg/100 mL (P < 0.001). The highest vitamin C content was found in lemon and hybrid varieties, around 65.5 (range 59.3-76.2) and 48.3 (range 29.6-75.5), respectively, all in mg/100 mL (P < 0.001). Furthermore, there was a tendency for decreasing vitamin C concentration due to temperature (P = 0.078), while citrus variety experienced a decrease, although not significant. The ideal temperature (15 °C) and duration of storage (56 days) to minimize vitamin C loss in citrus fruits are at their optimum point. In conclusion, the deterioration of vitamin C in citrus fruits is influenced by both temperature and storage duration, and its content is also impacted by the variety of citrus.

Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports

BACKGROUND

In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension.

METHODS

We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest.

RESULTS

We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH.

CONCLUSIONS

The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.

Riboflavin (vitamin B2) sensitized photooxidation of ascorbic acid (vitamin C): A kinetic study

Ascorbic acid (AH2) photoxidation sensitized by riboflavin (RF) has been studied between pH 2.0 and 12.0 in ambient air and anaerobic environment using UV and visible irradiation sources. The kinetics of AH2 degradation in aqueous medium along with RF is found to be first-order for its photodegradation. AH2 photolysis rate constants in aerobic and anaerobic conditions with RF (1.0-5.0 × 10-5 M) are 0.14-3.89 × 10-2 and 0.026-0.740 × 10-2 min-1, respectively. The rate constants (k2) of second-order kinetics for AH2 and RF photochemical interaction in aerobic and anaerobic conditions are in the range of 0.24-3.70 to 0.05-0.70 × 10-3 M-1 min-1, respectively, which manifests that increasing the RF concentration also increases the rate of photodegradation (photooxidation) of AH2. The k2 versus pH graph is bell-shaped which indicates that increasing the pH increases photolytic degradation rate of AH2 with RF. Increasing the pH results in the increased ionization of AH2 (ascorbyl anion, AH-) and redox potential which leads to the higher rates of photodegradation of AH2. Two-component spectrophotometric (243 and 266 nm, AH2 and RF, respectively) and high-performance liquid chromatography (HPLC) methods have been used to determine the concentration of AH2 and RF in pure and degraded solutions. The results obtained from these two methods are compared using a student t-test which showed no noteworthy difference between them.

Current understanding and future directions of cruciferous vegetables and their phytochemicals to combat neurological diseases

Neurological disorders incidences are increasing drastically due to complex pathophysiology, and the nonavailability of disease-modifying agents. Several attempts have been made to identify new potential chemicals to combat these neurological abnormalities. At present, complete abolishment of neurological diseases is not attainable except for symptomatic relief. However, dietary recommendations to help brain development or improvement have increased over the years. In recent times, cruciferous vegetables and their phytochemicals have been identified from preclinical and clinical investigations as potential neuroprotective agents. The present review highlights the beneficial effects and molecular mechanisms of phytochemicals such as indole-3-carbinol, diindolylmethane, sulforaphane, kaempferol, selenium, lutein, zeaxanthin, and vitamins of cruciferous vegetables against neurological diseases including Parkinson's disease, Alzheimer's disease, stroke, Huntington's disease, autism spectra disorders, anxiety, depression, and pain. Most of these cruciferous phytochemicals protect the brain by eliciting antioxidant, anti-inflammatory, and antiapoptotic properties. Regular dietary intake of cruciferous vegetables may benefit the prevention and treatment of neurological diseases. The present review suggests that there is a lacuna in identifying the clinical efficacy of these phytochemicals. Therefore, high-quality future studies should firmly establish the efficacy of the above-mentioned cruciferous phytochemicals in clinical settings.

Effect of vitamin B2, vitamin C, vitamin D, vitamin E and folic acid in adults with essential hypertension: a systematic review and network meta-analysis

OBJECTIVES

The objective of the current study is to compare the treatment effects of different vitamins on essential hypertension to provide an initial basis for developing evidence-based practices.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Five electronic databases (PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched from their inception to 25 September 2023.

OUTCOMES

The primary outcomes were the difference between the intervention group and the control group in changes in office systolic blood pressure (SBP) and office diastolic blood pressure (DBP) from baseline. The secondary outcomes were the difference between the intervention group and the control group in changes in 24-hour mean ambulatory systolic blood pressure (24 hours SBP), 24-hour mean ambulatory diastolic blood pressure (24 hours DBP) and heart rate (HR) from baseline.

RESULTS

A total of 23 studies comparing five vitamins (vitamin B2, vitamin C, vitamin D, vitamin E, folic acid) and involving 2218 participants were included. The included trials were all vitamin versus placebo, so the network was star-shaped. Among the five vitamins, only vitamin E was significantly more effective at reducing SBP (mean difference: -14.14 mm Hg, 95% credible intervals: -27.62 to -0.88) than placebo. In addition, no evidence was found that any of the five vitamins influenced DBP, 24 hours SBP, 24 hours DBP, or HR. The dose of vitamins, geographical region and percentage of males (only SBP) might be sources of heterogeneity. Sensitivity and subgroup analysis revealed that the effect of vitamin intervention on blood pressure varies according to different doses of vitamins.

CONCLUSIONS

According to the results, vitamin E might be an effective measure to reduce SBP, but more research is needed to validate this finding.

PROSPERO REGISTRATION NUMBER

CRD42022352332.

Fruits and vegetables intake improves birth outcomes of women with gestational diabetes mellitus and hypertensive disorders of pregnancy

BACKGROUND

Disorders of pregnancy such as hypertensive disorders of pregnancy (HDP) and gestational diabetes mellitus (GDM) have been associated with adverse birth outcomes. However, the ameliorating role of maternal nutrition in the relationship between disorders of pregnancy and adverse birth outcomes has received very little attention. We investigated the relationship between HDP and GDM, and adverse birth outcomes in a Ghanaian population and evaluated the effect modifying role of fruits and vegetables consumption in the relationship.

METHODS

We conducted a cross-sectional study among 799 mothers who had recently delivered singletons in the Cape Coast Metropolis, Ghana. Information on HDP, GDM and birth outcomes were retrieved from the maternal health book of the mothers. A food frequency questionnaire was used to assess fruits and vegetables intake during pregnancy. Modified Poisson regression was used to investigate the association between pregnancy disorders, and preterm birth (PTB) and low birth weight (LBW). Stratified analysis was used to assess the effect modifying role of fruits and vegetables consumption in the relationship.

RESULTS

The proportion of mothers with HDP and GDM was 11.3% and 7.5%, respectively. The proportion of the mothers with both conditions was 0.9%. The prevalence of PTB and LBW in the population was 27.9 and 7.3%, respectively. These disorders of pregnancy were associated with increased risk of PTB (Adjusted Prevalence Ration [APR] = 3.02; 95% CI: 2.42, 3.77) and LBW (APR = 5.32; 95% CI: 3.19, 8.88). In the stratified analysis, risk of PTB was higher among mothers classified in tertile I compared to mothers classified in tertiles II and III. For LBW, the risk increased with increasing fruits and vegetables consumption. The interaction p values were 0.0043 and 0.1604 for PTB and LBW, respectively.

CONCLUSIONS

We found mothers who were diagnosed with GDM and HDP to have increased risk of delivering a PTB and LBW baby. We also found fruits and vegetables consumption to modify the observed relationship. Mothers diagnosed with GDM and HDP should be advised during antenatal care visits to increase intake of fruits and vegetable consumption to help safeguard their health and that of the developing foetus.

Evidence on the use of alternative substances and therapies in hypertension

OBJECTIVE

Review of some of the best-known biological and non-biological complementary/alternative therapies/medicines (CAM) and their relationship with blood pressure (BP) and hypertension (HT).

SEARCH STRATEGY

Narrative review assessing a recent series of systematic reviews, meta-analyses, and clinical trials published in recent years, focusing on the effects of CAM on BP and HT.

SELECTION OF STUDIES

We searched EMBASE, MEDLINE, Cochrane Library and Google Scholar, obtaining a total of 4336 articles, finally limiting the search to 181 after applying filters.

SYNTHESIS OF RESULTS

Some studies on biological therapies show some usefulness in BP reduction with an adequate benefit-risk balance, although there is a scarcity of high-quality trials that support these results. Some mind-body therapies have shown hypothetical benefit; in contrast, others lack robust evidence.

CONCLUSIONS

Although some therapies present a reasonable risk-benefit ratio, they should in no case replace pharmacological treatment when indicated.

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

Lifestyle management of hypertension: International Society of Hypertension position paper endorsed by the World Hypertension League and European Society of Hypertension

Hypertension, defined as persistently elevated systolic blood pressure (SBP) >140 mmHg and/or diastolic blood pressure (DBP) at least 90 mmHg (International Society of Hypertension guidelines), affects over 1.5 billion people worldwide. Hypertension is associated with increased risk of cardiovascular disease (CVD) events (e.g. coronary heart disease, heart failure and stroke) and death. An international panel of experts convened by the International Society of Hypertension College of Experts compiled lifestyle management recommendations as first-line strategy to prevent and control hypertension in adulthood. We also recommend that lifestyle changes be continued even when blood pressure-lowering medications are prescribed. Specific recommendations based on literature evidence are summarized with advice to start these measures early in life, including maintaining a healthy body weight, increased levels of different types of physical activity, healthy eating and drinking, avoidance and cessation of smoking and alcohol use, management of stress and sleep levels. We also discuss the relevance of specific approaches including consumption of sodium, potassium, sugar, fibre, coffee, tea, intermittent fasting as well as integrated strategies to implement these recommendations using, for example, behaviour change-related technologies and digital tools.

Vitamin C - a scoping review for Nordic Nutrition Recommendations 2023

Vitamin C has multiple metabolic functions in the body, but the available information on the exact relationship between these functions and the intake necessary to maintain them is very limited. However, most attempts to objectively measure adequacy of vitamin C status, including, for example, replacement of metabolic turnover, chronic disease prevention, urinary excretion, and saturation of immune cells and body compartment, currently point toward 50 µmol/L as a reasonable target plasma concentration. As a strong correlation between body weight and vitamin C status exists, recommended intakes (RIs) for other age groups may be extrapolated from the adult RI based on weight. However, as body weights above 70 kg are becoming increasingly common - also in the Nordic region - an RI of 140 mg/day for individuals weighing 100 kg or more should be considered to compensate for the larger volume of distribution. Finally, smoking continues to be a common contributor to poor vitamin C status; therefore, it is proposed that people who smoke increase their daily vitamin C intake by 40 mg/day to compensate for the increased metabolic turnover induced by smoking.

Vitamin C supplementation showed greater effects on systolic blood pressure in hypertensive and diabetic patients: an updated systematic review and meta-analysis of randomised clinical trials

Results from randomised controlled trials (RCTs) testing the effect of vitamin C supplementation on blood pressure (BP) have been inconsistent. This systematic review evaluated the effects of vitamin C supplementation on BP and included RCTs testing the effects of vitamin C supplementation alone, on systolic and diastolic BP in adult participants (≥18 years). Random-effect models were conducted to estimate the pooled effects of vitamin C supplementation on BP. A total of 20 studies with 890 participants were included. The median dose of vitamin C was 757.5 mg/d, the median duration was 6 weeks. Vitamin C supplementation was found to reduce systolic BP by -3.0 mmHg (95%CI: -4.7, -1.3 mmHg; p = 0.001). Subgroup analysis showed a more pronounced effect on systolic BP in patients with hypertension (-3.2 mmHg, 95%CI -5.2, -1.2 mmHg, p = 0.002) and diabetes (-4.6 mmHg, 95%CI -8.9, -0.3 mmHg, p = 0.03). Further research needs to evaluate the long-term effect of vitamin C on BP in populations with impaired cardio-metabolic health.

An Exploration of Dietary Strategies for Hypertension Management: A Narrative Review

This review aims to clarify the influence of various nutritional approaches in the management of hypertension. An extensive search of databases, namely, PubMed, Cochrane Library, Scopus, and Web of Science, was performed, covering the period from January 2012 to October 2023. We used keywords, such as "hypertension," "nutrition," "nutritional management," "nutrient intake," "dietary strategies," "DASH diet," "Mediterranean diet," and related terms. Hypertension, a grave global health concern, affects more than one billion people worldwide. Lifestyle modifications, including nutritional strategies, are important in non-pharmacological interventions. Dietary patterns, such as the DASH (Dietary Approaches to Stop Hypertension) and Mediterranean diets, which emphasize fruit and vegetable consumption, have demonstrated efficacy in reducing blood pressure. Certain nutrients, such as potassium, calcium, and magnesium, have significant effects on blood pressure. The mechanisms underlying these dietary strategies include vasodilation, improvement in endothelial function, regulation of sodium balance, and mitigation of oxidative stress. However, successful implementation of these strategies can be hindered by various factors, such as adherence challenges, socioeconomic disparities, and cultural preferences. In conclusion, robust evidence supports the effectiveness of nutritional strategies in the management of hypertension. DASH and Mediterranean diets, along with an increased intake of specific nutrients, contribute to blood pressure reduction. Hence, comprehensive lifestyle modifications, with a focus on nutritional changes, are recommended as primary or complementary treatments for hypertension. Addressing the identified barriers could enhance the efficacy and use of these dietary approaches in clinical practice.

Therapeutic potential role of vitamin C in prevention and control of heart transplant rejection and cardiac allograft vasculopathy. A need for consideration

The burden of cardiovascular diseases is rising rapidly globally. Heart transplant is one of the most last resort medical option for patients with heart failure. Unfortunately, this surgical intervention is associated with several serious complications including heart transplant rejection (HTR) and Cardiac Allograft Vasculopathy (CAV) which can manifest just within few years' posttransplant. These complications affect significantly the prognosis and quality of life among postheart transplant patients. Several medications including immunosuppressant, antibiotics, antihypertensive, and statins have been used during posttransplant care so as to address such complications. Unfortunately, most of those drugs are expensive and pose a number of serious side effects to the patients enough to compromise patients' quality of life too. Several studies on Vitamin C are therapeutically suggestive that it can be used during postheart transplant care with more cost-effective benefits with less and minimized side effects compared to the current drugs in place. It should be considered pharmacologically that Vitamin C has a great potential role clinically in prevention and control of HTR and CAV development. On the light of such findings as described above, we recommend more studies especially clinical trials and molecular studies to determine whether Vitamin C can be repositioned to replace or to be used along the current drug regimens used in postheart transplant care for prevention and control of HTR and CAV.

Antihypertensive and Vasorelaxant Effects of Citric Acid and Lemon Juice in Spontaneously Hypertensive Rats: In Vivo and Ex Vivo Studies

Hypertension is a key risk factor for heart, brain, and kidney disease development. Fruit consumption has been associated with a decrease in blood pressure. Lemon juice, which contains antihypertensive compounds, may exert antihypertensive effects. However, no research has verified the antihypertensive effects of citric acid, the most abundant ingredient in lemon juice. In the present study, we demonstrated the antihypertensive effects of citric acid and lemon juice by performing single oral administration tests and the aortic ring assay using spontaneously hypertensive rats (SHRs). Single oral doses of both agents markedly reduced the systolic and diastolic blood pressures in the SHRs. In addition, both these agents relaxed the thoracic aorta from the SHRs; however, these effects were notably attenuated by the removal of the aortic endothelium. Orally administered citric acid was rapidly absorbed and metabolized in vivo. Among the functional compounds in lemon juice, citric acid was identified as the primary antihypertensive component. Although more detailed studies are required to validate our findings, the novel functional attributes of citric acid can achieve the normalization of blood pressure when it is consumed via diet.

Dietary factors and hypertension risk in West Africa: a systematic review and meta-analysis of observational studies

BACKGROUND

Contrary to North America and Europe, the prevalence of hypertension is rising in West Africa. Although diet is implicated as a contributor to this trend, nutritional guidelines in West Africa are not tailored to address this concern. This study aimed to address this limitation by investigating dietary factors common to West Africa and evaluating their association with hypertension.

METHODS

PubMed, Scopus, Web of Science, and Medline were searched to identify studies that investigated diet and hypertension in West African adults. All meta-analyses used a generic inverse-variance random effects model, with subgroup analyses by age, BMI, and study location, and were performed in R.

RESULTS

Three thousand, two hundred ninety-eight studies were identified, of which 31 ( n  = 48 809 participants) satisfied inclusion criteria - all cross-sectional. Meta-analyses of the association between dietary factors and hypertension included dietary fat [odds ratio (OR) = 1.76; 95% confidence interval (95% CI) 1.44-2.14; P  < 0.0001], red meat (OR = 1.51; 95% CI: 1.04-2.18; P  = 0.03), junk-food (OR = 1.41; 95% CI: 1.19-1.67; P  < 0.0001), dietary salt (OR = 1.25; 95% CI: 1.12-1.40; P  < 0.0001), alcohol (OR = 1.17; 95% CI: 1.03-1.32; P  = 0.013), and 'fruits and vegetables' (OR = 0.80; 95% CI: 0.24-1.17; P  < 0.0001). Subgroup analyses suggested that 'fruit and vegetable' consumption is less protective in the elderly.

CONCLUSION

High consumption of dietary salt, red meat, dietary fat, junk food, and alcohol are associated with increased odds of hypertension, whereas high fruit and vegetable appear protective. This region-specific evidence will support the development of nutritional assessment tools for clinicians, patients, and researchers aiming to reduce hypertension in West Africa.

Sugar, salt, immunity and the cause of primary hypertension

Despite its discovery more than 150 years ago, the cause of primary hypertension remains unknown. Most studies suggest that hypertension involves genetic, congenital or acquired risk factors that result in a relative inability of the kidney to excrete salt (sodium chloride) in the kidneys. Here we review recent studies that suggest there may be two phases, with an initial phase driven by renal vasoconstriction that causes low-grade ischemia to the kidney, followed by the infiltration of immune cells that leads to a local autoimmune reaction that maintains the renal vasoconstriction. Evidence suggests that multiple mechanisms could trigger the initial renal vasoconstriction, but one way may involve fructose that is provided in the diet (such as from table sugar or high fructose corn syrup) or produced endogenously. The fructose metabolism increases intracellular uric acid, which recruits NADPH oxidase to the mitochondria while inhibiting AMP-activated protein kinase. A drop in intracellular ATP level occurs, triggering a survival response. Leptin levels rise, triggering activation of the sympathetic central nervous system, while vasopressin levels rise, causing vasoconstriction in its own right and stimulating aldosterone production via the vasopressin 1b receptor. Low-grade renal injury and autoimmune-mediated inflammation occur. High-salt diets can amplify this process by raising osmolality and triggering more fructose production. Thus, primary hypertension may result from the overactivation of a survival response triggered by fructose metabolism. Restricting salt and sugar and hydrating with ample water may be helpful in the prevention of primary hypertension.

How Do Minerals, Vitamins, and Intestinal Microbiota Affect the Development and Progression of Heart Disease in Adult and Pediatric Patients?

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, far ahead of cancer. Epidemiological data emphasize the participation of many risk factors that increase the incidence of CVDs, including genetic factors, age, and sex, but also lifestyle, mainly nutritional irregularities and, connected with them, overweight and obesity, as well as metabolic diseases. Despite the importance of cardiovascular problems in the whole society, the principles of prevention of CVDs are not widely disseminated, especially among the youngest. As a result, nutritional neglect, growing from childhood and adolescence, translates into the occurrence of numerous disease entities, including CVDs, in adult life. This review aimed to draw attention to the role of selected minerals and vitamins in health and the development and progression of CVDs in adults and children. Particular attention was paid to the effects of deficiency and toxicity of the analyzed compounds in the context of the cardiovascular system and to the role of intestinal microorganisms, which by interacting with nutrients, may contribute to the development of cardiovascular disorders. We hope this article will draw the attention of society and the medical community to emphasize promoting healthy eating and proper eating habits in children and adults, translating into increased awareness and a reduced risk of CVD.

Dietary Antioxidant Quality Score (DAQS), serum lipids, markers of glucose homeostasis, blood pressure and anthropometric features among apparently metabolically healthy obese adults in two metropolises of Iran (Tabriz and Tehran): a cross-sectional study

BACKGROUND

Oxidative stress (OS) is associated with a variety of non-communicable diseases, including MetS, diabetes mellitus, metabolic syndrome, and cardiovascular disease through increased production of reactive oxygen species (ROS) and impairment of antioxidant defense mechanisms. Antioxidants can protect cells against free radical damage, so it seems important to determine the relationship between the quality of dietary antioxidants intake and chronic diseases. The Dietary Antioxidant Quality Score (DAQS) is obtained by adding the daily intake of known dietary vitamins and minerals, including selenium, zinc, vitamin A, vitamin C, and vitamin E, compared to the recommended daily intake (RDI). Therefore, this study aims to determine the relationship between DAQS, serum lipids, markers of glucose homeostasis, blood pressure and anthropometric features among obese adults.

METHODS

In the present cross-sectional study, 338 individuals who were obese (BMI ≥ 30 kg/m²) aged 20-50 years were recruited from Tabriz and Tehran, Iran. A validated semi-quantitative Food Frequency Questionnaire (FFQ) with 168 food items was used to quantify dietary consumption; accordingly, DAQS was computed. Blood biomarkers were measured using enzyme-linked immunosorbent assay (ELISA) kits. A standard mercury sphygmomanometer was used to assess blood pressure, and bioelectrical impedance analysis (BIA) was performed to determine body composition. The association between the DAQS tertiles and biochemical variables was investigated using multinomial logistic regression.

RESULTS

Participants in the highest tertile of DAQS have a lower diastolic blood pressure (DBP) values in all of the adjusted models [odds ratio (OR) = 0.920; confidence interval (CI)= 0.852-0.993, P-value = 0.03] in the analysis of co-variance (ANCOVA) model. Similarly, subjects at the second tertile of DAQS had lower DBP compared with the first tertile in age and sex-adjusted model [OR= 0.937; CI= 0.882-0.997]. There was no statistically significant difference for other metabolic parameters in different DAQS tertiles.

CONCLUSION

According to our findings, higher DAQS was associated with lower DBP among obese adults with obesity in two major cities of Iran (Tehran and Tabriz). Other studies with interventional design are needed to better elucidate these associations and underlying mechanisms.

Fruit and vegetable consumption and the risk of hypertension: a systematic review and meta-analysis of prospective studies

PURPOSE

A high fruit and vegetable intake has been associated with reduced risk of hypertension; however, results have been inconsistent and it is unclear whether specific types of fruits and vegetables are particularly beneficial. This systematic review and meta-analysis aimed to summarize the published prospective studies on fruit and vegetable consumption and risk of hypertension.

METHODS

Embase and PubMed databases were searched for relevant prospective studies up to 15th May 2022. Random effects models were used to calculate summary relative risks (RRs) and 95% confidence intervals (CIs) for the association between fruit and vegetable intake and risk of hypertension. Strength of evidence was assessed using World Cancer Research Fund (WCRF) criteria.

RESULTS

Eighteen prospective studies (451 291 participants, 145 492 cases) were included. The summary RR (95% CI) of hypertension per 200 g/day was 0.97 (0.95-0.99, I² = 68%, n = 8) for fruits and vegetables, 0.93 (0.89-0.98, I² = 77%, n = 10) for fruits, and 1.00 (0.98-1.02, I² = 38%, n = 10) for vegetables. Reductions in risk were observed up to 800 g/day for fruits and vegetables, and 550 g/day for fruits, and these two associations were considered probably causal using WCRF criteria. Inverse associations were observed for apples or pears, blueberries, raisins or grapes, avocado, broccoli, carrots and lettuce, while positive associations were observed for cantaloupe, Brussels sprouts, cruciferous vegetables, and total and fried potatoes (n = 2-5).

CONCLUSION

A high intake of fruit and vegetables combined, and total fruit was associated with reduced risk of hypertension, while results for fruit and vegetable subtypes were mixed and need further study.

Subclinical Vitamin C Plasma Levels Associated with Increased Risk of CAD Diagnosis via Inflammation: Results from the NHANES 2003-2006 Surveys

Vitamin C remains an important, yet frequently unassessed, component of a healthy immune system though it may prove useful in alleviating the chronic inflammatory processes underlying chronic diseases such as coronary artery disease (CAD). Recent research identified a sizeable proportion of the United States population with insufficient vitamin C plasma levels and significant associations to both acute and chronic inflammation. This cross-sectional study used the 2003-2006 NHANES surveys data to extrapolate associations between plasma vitamin C levels (deficiency, hypovitaminosis, inadequate, adequate, and saturating) and CAD through inflammation (C-reactive protein and red cell distribution width). Increased reports of CAD diagnosis were identified in participants with vitamin C deficiency (OR: 2.31, CI: 1.49-3.58) and inadequate plasma levels (OR: 1.39, CI: 1.03-1.87). No significant correlation was identified between any other plasma vitamin C quintiles and CAD. When inflammation was controlled, previous associations in the deficient level of plasma vitamin C were no longer significant in association with CAD and participants with inadequate plasma vitamin C showed a reduced association to CAD diagnoses (OR: 0.33, CI: 0.13-0.86). Most chronic inflammation and vitamin C plasma statuses do not demonstrate specific signs or symptoms until the deficient level of vitamin C and/or disease. Thus, increased surveillance of both, and healthy nutritional habits remain crucial modifiable risk factors for disease prevention.

Vitamin C supplementation for diabetes management: A comprehensive narrative review

Growing evidence suggests that vitamin C supplementation may be an effective adjunct therapy in the management of people with diabetes. This paper critically reviews the current evidence on effects of vitamin C supplementation and its potential mechanisms in diabetes management. Evidence from meta-analyses of randomized controlled trials (RCTs) show favourable effects of vitamin C on glycaemic control and blood pressure that may be clinically meaningful, and mixed effects on blood lipids and endothelial function. However, evidence is mostly of low evidence certainty. Emerging evidence is promising for effects of vitamin C supplementation on some diabetes complications, particularly diabetic foot ulcers. However, there is a notable lack of robust and well-designed studies exploring effects of vitamin C as a single compound supplement on diabetes prevention and patient-important outcomes (i.e. prevention and amelioration of diabetes complications). RCTs are also required to investigate potential preventative or ameliorative effects of vitamin C on gestational diabetes outcomes. Oral vitamin C doses of 500-1000 mg per day are potentially effective, safe, and affordable for many individuals with diabetes. However, personalisation of supplementation regimens that consider factors such as vitamin C status, disease status, current glycaemic control, vitamin C intake, redox status, and genotype is important to optimize vitamin C's therapeutic effects safely. Finally, given a high prevalence of vitamin C deficiency in patients with complications, it is recommended that plasma vitamin C concentration be measured and monitored in the clinic setting.

Ascorbic acid as antioxidant

Ascorbic acid, as one of the basic exogenous vitamins, is known for its tremendous antioxidant properties. This review has been prepared to show not only the importance of ascorbic acid as a free radical scavenger, but also to summarize its antioxidant action based on other mechanisms, including activation of intracellular antioxidant systems. Ascorbic acid interacts with small molecule antioxidants, including tocopherol, glutathione and thioredoxin, but also can stimulate the biosynthesis and activation of antioxidant enzymes, such as superoxide dismutase, catalase or glutathione peroxidase. Moreover, ascorbic acid promotes the activity of several transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this connection, both DNA, protein and lipids are protected against oxidation. Although ascorbic acid has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in prevention of DNA mutation and cellular apoptosis, especially in relation to cancer cells is controversial.

Adherence to lifelines diet score and risk factors of metabolic syndrome among overweight and obese adults: A cross-sectional study

Background

Metabolic syndrome (MetS) is one of the most significant public health issues worldwide, and diet quality is an important controllable environmental factor influencing the incidence of MetS. Numerous dietary scores have been established to assess compliance with dietary recommendations or eating patterns, many of which are not entirely food-based. Hence, Lifelines Diet Score (LLDS) was developed in response to the shortcomings of existing tools. This study aimed to assess any possible links between total food quality and cardiometabolic risk factors among overweight and obese adults.

Methods

This cross-sectional study included 338 overweight and obese individuals [body mass index (BMI) > 25 kg/m2] aged 20-50 years in Tabriz, Iran. To collect dietary data, we used a validated semi-quantitative Food Frequency Questionnaire (FFQ) for Iranian population. Enzymatic-colorimetric methods were used to assess serum glucose and lipids, and enzyme-linked immunosorbent assay (ELISA) kits were used to measure insulin levels. In addition, the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Quantitative Insulin Sensitivity Check Index (QUICKI) were calculated.

Results

BMI and hip circumference (HC) were significantly different (P < 0.05) amongst LLDS tertiles. Adherence to the highest tertile of LLDS was associated with lower SBP, and the subjects in higher LLDS tertiles significantly had lower systolic blood pressure (SBP) (P = 0.04). Triglyceride (TG) levels were also lower in the third tertile of LLDS with a near-significant P-value (P = 0.05).

Conclusion

According to our results, a higher diet quality score, determined by LLDS, can be associated with a lower risk of MetS. Further experimental and longitudinal studies are needed to better understand this relationship.

Vitamin C Deficiency Exacerbates Dysfunction of Atherosclerotic Coronary Arteries in Guinea Pigs Fed a High-Fat Diet

Vitamin C (vitC) deficiency has been associated with an increased risk of cardiovascular disease; while several putative mechanistic links have been proposed, functional evidence supporting a causal relationship is scarce. In this study, we investigated how vitC deficiency affects coronary artery vasomotor function and the development of coronary atherosclerotic plaques in guinea pigs subjected to chronic dyslipidemia by a high-fat diet regime. Female Hartley guinea pigs were fed either a control (low-fat diet and sufficient vitC) (N = 8) or a high-fat diet with either sufficient (N = 8) or deficient (N = 10) vitC for 32 weeks. Guinea pigs subjected to the high-fat diet developed significant atherosclerotic plaques in their coronary arteries, with no quantitative effect of vitC deficiency. In isolated coronary arteries, vasomotor responses to potassium, carbachol, nitric oxide, or bradykinin were studied in a wire myograph. Carbachol, bradykinin, and nitric oxide mediated relaxation in the coronary arteries of the control group. While vasorelaxation to carbachol and nitric oxide was preserved in the two high-fat diet groups, bradykinin-induced vasorelaxation was abolished. Interestingly, bradykinin induced a significant contraction in coronary arteries from vitC-deficient guinea pigs (p < 0.05). The bradykinin-induced contraction was unaffected by L-NAME but significantly inhibited by both indomethacin and vitC, suggesting that, during vitC deficiency, increased release of arachidonic acid metabolites and vascular oxidative stress are involved in the constrictor effects mediated by bradykinin. In conclusion, the present study shows supporting evidence that poor vitC status negatively affects coronary artery function.

Current Evidence and Future Perspectives of the Best Supplements for Cardioprotection: Have We Reached the Final Chapter for Vitamins?

Cardiovascular disease (CVD), a broad-spectrum term comprising coronary artery disease, stroke, hypertension, and heart failure, presents as one of the most significant strains on global healthcare systems. Coronary artery disease, caused by atherosclerosis, has various modifiable risk factors such as dietary changes and exercise. Since these risk factors are found to be linked to oxidative stress and inflammations, the dietary supplementation with vitamins' role in treating and preventing the diseases has been of much debate. With various vitamins having anti-inflammatory and antioxidative properties, studies have explored their correlation with cardiovascular health. Therefore, this narrative review explores and evaluates the benefits and risks of all vitamin supplementations in patients with CVD and provides future recommendations.

Antioxidative and Anti-Inflammatory Activity of Ascorbic Acid

Ascorbic acid, as a one of the basic exogenous vitamins, occurs in the body in the form of ascorbate, known for its strong antioxidant and anti-inflammatory properties. The presented review shows not only the importance of ascorbate as a free radical scavenger but also summarizes its antioxidant action based on other mechanisms, including the activation of intracellular antioxidant systems and its effect on the NFκB/TNFα pathway and apoptosis. Ascorbate interacts with small-molecule antioxidants, including tocopherol, glutathione, and thioredoxin; it can also stimulate biosynthesis and the activation of antioxidant enzymes, such as superoxide dismutase, catalase, or glutathione peroxidase. Moreover, ascorbate promotes the activity of transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this regard, both DNA, proteins, and lipids are protected against oxidation, leading to an inflammatory reaction and even cell death. Although ascorbate has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in the prevention of DNA mutation, inflammation, and cell apoptosis, especially in relation to cancer cells, is controversial.

Diet-related knowledge, attitudes, and behaviors among young and middle-aged individuals with high-normal blood pressure: A cross-sectional study in China

Background

Dietary modifications play an important role in the prevention and management of high-normal blood pressure (BP). The aim of this study was to investigate diet-related knowledge, attitudes, and behaviors, and the socio-demographic determinants of these, among young and middle-aged Chinese individuals with high-normal BP.

Methods

Data from the 2015 China Health and Nutrition Survey (CHNS) were analyzed in this study. A total of 1,756 subjects with high-normal BP were included. A chi-square test and binary logistic regression analysis were conducted to identify the risk factors toward diet-related knowledge, attitudes, and behaviors.

Results

A total of 37.4% of the participants knew about the Chinese Food Pagoda (CFP) or the Dietary Guidelines for Chinese Residents (DGCR). Overall, 39.8% of the subjects were classified as having adequate diet-related knowledge literacy, 27.8% reported positive diet-related attitudes to healthy eating, and 35.3% reportedly looked for nutrition knowledge. Of note, 72.4% and 80.1% of the participants reported liking to eat fruits and vegetables, respectively. Individuals with a middle school education [odds ratio (OR) = 1.784, 95% CI = 1.236-2.576], high school/vocational education (OR = 1.944, 95% CI = 1.305-2.896), and college degree or above (OR = 2.089, 95% CI = 1.341-3.322), who were living in a rural area (OR = 1.311, 95% CI = 1.048-1.639), proactively looking for nutrition knowledge (OR = 1.529, 95% CI = 1.227-1.906), and reported liking to eat vegetables (OR = 1.939, 95% CI = 1.409-2.688), were more likely to have sufficient dietary knowledge literacy. Managers (OR = 1.655, 95% CI = 1.039-2.635) were more likely to have positive dietary attitudes. Female gender (OR = 1.396, 95% CI = 1.089-1.790), high school/vocational school education (OR = 2.071, 95% CI = 1.269-3.379), college degree and above (OR = 2.207, 95% CI = 1.262-3.862), knowledge about the CFP or DGCR (OR = 8.138, 95% CI = 6.326-10.468), and sufficient dietary knowledge literacy (OR = 1.338, 95% CI = 1.050-1.705) were associated with an increased likelihood of looking for nutrition knowledge.

Conclusion

Individuals with high-normal BP, predominantly males, living in rural area, with lower education, farmers, workers, service workers, and workers in the non-government employment unit may have poor diet-related knowledge, attitudes, and behaviors.

Vascular benefits of vitamin C supplementation against fine particulate air pollution in healthy adults: A double-blind randomised crossover trial

Evidence on the health benefits of vitamin C supplementation in highly polluted areas has not been evaluated. We aimed to evaluate whether dietary vitamin C supplementation can improve vascular health linked to particulate matter (PM) exposure. A randomised double-blind crossover trial involving 58 health young adults was performed in Shijiazhuang, China in 2018. All subjects were randomly assigned to the vitamin C supplementation group (2000 mg/d) or placebo group for a week alternating with a 2 week washout period. Fifteen circulating biomarkers were measured. Linear mixed-effect model was applied to evaluate the effect of vitamin C supplementation on health outcomes. The average concentrations of PM_2.5 and PM₁₀ were 164.91 and 327.05 μg/m³, respectively. Vitamin C supplementation was significantly associated with a 19.47% decrease in interleukin-6 (IL-6), 17.30% decrease in tumour necrosis factor-a (TNF-α), 34.01% decrease in C-reactive protein (CRP), 3.37% decrease in systolic blood pressure (SBP) and 6.03% decrease in pulse pressure (PP). Furthermore, glutathione peroxidase (GSH-Px) was significantly increased by 7.15%. Sex-subgroup analysis showed that vitamin C significantly reduced TNF-α by 27.85% in male participants and significantly increased APOB by 6.28% and GSH-Px by 14.47% only in female participants. This study indicated that vitamin C supplementation may protect vascular vessels against PM exposure among healthy young adults in China.

Dietary Patterns Derived from Reduced Rank Regression Are Associated with the 5-Year Occurrence of Metabolic Syndrome: Aichi Workers' Cohort Study

The aim of the present study was to derive dietary patterns to explain variation in a set of nutrient intakes or in the measurements of waist circumference (WC) and fasting blood glucose (FBG) using reduced rank regression (RRR) and to prospectively investigate these patterns in relation to the risk of developing metabolic syndrome (MetS) and its components during the follow-up. The study participants were comprised of 2944 government employees aged 30−59 years without MetS. RRR was applied with 38 food groups as predictors and with two sets of response variables. The first set included intake of putatively beneficial nutrients, and the first factor retained was named the Healthy Dietary Pattern (HDP). The second one included baseline WC and FBG, and the first factor was named the Unhealthy Dietary Pattern (UHDP). Multivariable Cox proportional hazard model was used to estimate hazard ratio and 95% confidence intervals with adjustments for age, sex, total energy consumption and other potential confounders. During the 5-year median follow-up, we ascertained 374 cases of MetS. The HDP score was inversely associated with the incidence of MetS (p-trend = 0.009) and hypertension (p-trend = 0.002) and marginally significantly associated with elevated triglyceride and decreased high-density lipoprotein cholesterol (p-trend = 0.08). The UHDP score was linearly positively associated with the incidence of MetS and all its components (all p-trend < 0.05). Both the HDP and UHDP predicted the development of MetS and its components.

Vitamin C Lowers Blood Pressure in Spontaneously Hypertensive Rats by Targeting Angiotensin-Converting Enzyme I Production in a Frequency-Dependent Manner

The lowering blood pressure effect of vitamin C (VC) has been evaluated in various models. As VC has a fast degradation rate in the body after consumption, a study of the frequency-dependent manner of VC is essential for the sustained antihypertension effect of VC. In this study, we investigated the frequency and dose dependency of vitamin C (VC) on blood pressure reduction in spontaneously hypertensive rats (SHRs). Wistar–Kyoto rats (WKYs) and SHRs were orally administered tap water or VC (250, 500, 1000, and 2000 mg/60 kg/day). Blood pressures were measured using the tail-cuff method, and thoracic aortas, liver, and blood were harvested from sacrificed rats after 8 weeks to measure angiotensinogen, angiotensin-converting enzyme (ACE) I, endothelial nitric oxide synthase (eNOS), and total nitric oxide (NOx) concentration. VC decreased blood pressure from the fourth week with no significant differences between doses. The twice-a-day administration of VC decreased blood pressure from the second week, and the blood pressure in these groups was close to that of the WKY group in the eighth week. Treatment with once a day VC decreased ACE I production which was further significantly reduced in twice a day groups. Angiotensinogen and eNOS production were increased upon VC treatment but were not significant among groups. The NOx content was decreased by VC treatment. These results suggest that VC lowers blood pressure in SHRs by directly targeting ACE I production in a frequency-dependent manner and may improve endothelial function depending on the frequency of administration.

The Role of Berry Consumption on Blood Pressure Regulation and Hypertension: An Overview of the Clinical Evidence

The existence of a relationship between the consumption of dietary berries and blood pressure reduction in humans has been repeatedly hypothesized and documented by an increasing body of epidemiological and clinical evidence that has accumulated in recent years. However, results are mixed and complicated by a number of potentially confounding factors. The objective of this article is to review and summarize the available clinical evidence examining the effects of berry consumption on blood pressure regulation as well as the prevention or treatment of hypertension in humans, providing an overview of the potential contribution of distinctive berry polyphenols (anthocyanins, condensed tannins and ellagic acid), and results of dietary interventions with blueberries, bilberries, cranberries, raspberries, strawberries, chokeberries, cherries, blackcurrants and açai berries. We conclude that, while there is insufficient evidence supporting the existence of a direct blood pressure lowering effect, there is stronger evidence for specific types of berries acting indirectly to normalize blood pressure in subjects that are already hypertensive.

Metabolic and Blood Pressure Effects of Consuming Two Kiwifruit Daily for 7 Weeks: A Randomised Controlled Trial

Background: Eating two kiwifruit before breakfast by equi-carbohydrate partial exchange of cereal has been associated with lower postprandial glucose and insulin, but it increases the intake of fruit sugar. We assessed the effects of kiwifruit ingestion at breakfast over 7 weeks on metabolic and physiologic factors. Method: Forty-three healthy Asian participants were randomised to ingest 500 mL of carbonated water (control) or 500 mL of carbonated water plus two kiwifruit (intervention), before breakfast. Three-day weighed diet records were taken before and at week 4 during the intervention. Overnight fasting blood samples were taken at baseline and week 7. Forty-two participants completed the study (n = 22 control, n = 20 intervention). Results: The kiwifruit group consumed more fructose, vitamin C, vitamin E, and carbohydrates as a percentage of energy compared with the control group (p < 0.01). There was no evidence of between-group changes in metabolic outcomes at the end of the intervention, with the following mean (95% confidence interval) differences in fasting blood samples: glucose 0.09 (−0.06, 0.24) mmol/L; insulin −1.6 (−3.5, 0.3) μU/mL; uric acid −13 (−30, 4) μmol/L; triglycerides −0.10 (−0.22, 0.03) mmol/L; and total cholesterol −0.05 (−0.24, 0.14) mmol/L. There was a −2.7 (−5.5, 0.0) mmHg difference in systolic blood pressure for the intervention group compared with the control group. Conclusion: Eating two kiwifruit as part of breakfast increased fruit consumption and intake of antioxidant nutrients without a change in fasting insulin. There was a difference in systolic blood pressure and no adverse fructose-associated increases in uric acid, triglycerides, or total cholesterol. This simple intervention may provide health benefits to other demographic groups.

The Impact of Chronic Kidney Disease on Nutritional Status and Its Possible Relation with Oral Diseases

Several studies have demonstrated a strong relation between periodontal diseases and chronic kidney disease (CKD). The main mechanisms at the base of this link are malnutrition, vitamin dysregulation, especially of B-group vitamins and of C and D vitamins, oxidative stress, metabolic acidosis and low-grade inflammation. In particular, in hemodialysis (HD) adult patients, an impairment of nutritional status has been observed, induced not only by the HD procedures themselves, but also due to numerous CKD-related comorbidities. The alteration of nutritional assessment induces systemic manifestations that have repercussions on oral health, like oral microbiota dysbiosis, slow healing of wounds related to hypovitaminosis C, and an alteration of the supporting bone structures of the oral cavity related to metabolic acidosis and vitamin D deficiency. Low-grade inflammation has been observed to characterize periodontal diseases locally and, in a systemic manner, CKD contributes to the amplification of the pathological process, bidirectionally. Therefore, CKD and oral disease patients should be managed by a multidisciplinary professional team that can evaluate the possible co-presence of these two pathological conditions, that negatively influence each other, and set up therapeutic strategies to treat them. Once these patients have been identified, they should be included in a follow-up program, characterized by periodic checks in order to manage these pathological conditions.

Associations between fruit consumption and home blood pressure in a randomly selected sample of the general Swedish population

Frequent fruit consumption has been associated with lower office blood pressure. Less is known about associations between fruit consumption and home blood pressure. Our aim was to study the correlation between consumption of specific fruits and home blood pressure in a large randomly selected study population. The main outcome was systolic home blood pressure. Home blood pressure measurements were performed with calibrated oscillometric meters during seven consecutive days. Means for all available measurements were used. Validated food frequency questionnaires were used for estimating frequency of fruit consumption. The specified fruits were bananas, apples/pears and oranges/citrus fruit. Complete case analysis regarding fruit consumption, office‐ and home blood pressure measurements and other relevant variables was performed in 2283 study participants out of 2603 available. Multivariable linear regression analysis was performed. There were statistically significant associations between consumption of all fruit types and lower systolic home blood pressure unadjusted (p for trend; bananas, apples/pears and oranges/citrus fruit p < .001). The numerical differences between most and least frequent consumption of fruit were for bananas ‐2.7 mm Hg, apples/pears ‐3.9 mm Hg and for oranges/citrus fruit ‐3.4 mm Hg. When adjusted for covariates, both consumption of apples/pears and oranges/citrus fruit had an independent statistically significant association with lower blood pressure (p = .048 resp. p = .009). Future controlled interventional studies are needed to evaluate the effect of specific fruit on home blood pressure.

Vitamin C May Improve Left Ventricular Ejection Fraction: A Meta-Analysis

Background

Vitamin C deprivation can lead to fatigue, dyspnea, oedema and chest pain, which are also symptoms of heart failure (HF). In animal studies vitamin C has improved contractility and mechanical efficiency of the heart. Compared with healthy people, patients with HF have lower vitamin C levels, which are not explained by differences in dietary intake levels, and more severe HF seems to be associated with lower plasma vitamin C levels. This meta-analysis looks at the effect of vitamin C on left ventricular ejection fraction (LVEF).

Methods

We searched for trials reporting the effects of vitamin C on LVEF. We assessed the quality of the trials, and pooled selected trials using the inverse variance, fixed effect options. We used meta-regression to examine the association between the effect of vitamin C on LVEF level and the baseline LVEF level.

Results

We identified 15 trials, three of which were excluded from our meta-analysis. In six cardiac trials with 246 patients, vitamin C increased LVEF on average by 12.0% (95% CI 8.1–15.9%; P < 0.001). In six non-cardiac trials including 177 participants, vitamin C increased LVEF on average by 5.3% (95% CI 2.0–8.5%; P = 0.001). In meta-regression analysis we found that the effect of vitamin C was larger in trials with the lowest baseline LVEF levels with P = 0.001 for the test of slope. The meta-regression line crossed the null effect level at a baseline LVEF level close to 70%, with progressively greater benefit from vitamin C with lower LVEF levels. Some of the included trials had methodological limitations. In a sensitivity analysis including only the four most methodologically sound cardiac trials, the effect of vitamin C was not substantially changed.

Conclusions

In this meta-analysis, vitamin C increased LVEF in both cardiac and non-cardiac patients, with a strong negative association between the size of the vitamin C effect and the baseline LVEF. Further research on vitamin C and HF should be carried out, particularly in patients who have low LVEF together with low vitamin C intake or low plasma levels. Different dosages and different routes of administration should be compared.

Does chronic consumption of orange juice improve cardiovascular risk factors in overweight and obese adults? A systematic review and meta-analysis of randomized controlled trials

This is the first meta-analysis that investigates the effects of chronic consumption of orange juice on cardiovascular risk factors in overweight and obese adults, demonstrating beneficial effects on blood pressure and HDL-C.