The effect of increased fruit and vegetable consumption on blood pressure and lipids: a pooled analysis of six randomised controlled fruit and vegetable intervention trials.

BACKGROUND: Increasing fruit and vegetable (FV) consumption is associated with reduced cardiovascular disease risk in observational studies but with little evidence from randomised controlled trials (RCTs). The impact of concurrent pharmacological therapy is unknown. OBJECTIVE: To pool data from six RCTs to examine the effect of increasing FV intake on blood pressure (BP) and lipid profile, also exploring whether effects differed by medication use. DESIGN: Across trials, dietary intake was assessed by diet diaries or histories, lipids by routine biochemical methods and BP by automated monitors. Linear regression provided an estimate of the change in lipid profile or BP associated with a one portion increase in self-reported daily FV intake, with interaction terms fitted for medication use. RESULTS: The pooled sample included a total of 554 participants (308 males and 246 females). Meta-analysis of regression coefficients revealed no significant change in either systolic or diastolic BP per portion FV increase, although there was significant heterogeneity across trials for systolic BP (I2 = 73%). Neither adjusting for change in body mass index, nor analysis according to use of anti-hypertensive medication altered the relationship. There was no significant change in lipid profile per portion FV increase, although there was a significant reduction in total cholesterol among those not on lipid-lowering therapy (P < 0.05 after Bonferroni correction). CONCLUSION: Pooled analysis of six individual FV trials showed no impact of increasing intake on BP or lipids, but there was a total cholesterol-lowering effect in those not on lipid-lowering therapy.

Computational modelling of atherosclerosis.

Atherosclerosis is one of the principle pathologies of cardiovascular disease with blood cholesterol a significant risk factor. The World Health Organization estimates that approximately 2.5 million deaths occur annually because of the risk from elevated cholesterol, with 39% of adults worldwide at future risk. Atherosclerosis emerges from the combination of many dynamical factors, including haemodynamics, endothelial damage, innate immunity and sterol biochemistry. Despite its significance to public health, the dynamics that drive atherosclerosis remain poorly understood. As a disease that depends on multiple factors operating on different length scales, the natural framework to apply to atherosclerosis is mathematical and computational modelling. A computational model provides an integrated description of the disease and serves as an in silico experimental system from which we can learn about the disease and develop therapeutic hypotheses. Although the work completed in this area to date has been limited, there are clear signs that interest is growing and that a nascent field is establishing itself. This article discusses the current state of modelling in this area, bringing together many recent results for the first time. We review the work that has been done, discuss its scope and highlight the gaps in our understanding that could yield future opportunities.

The effect of increased fruit and vegetable consumption on selected macronutrient and micronutrient intakes in four randomised-controlled trials.

Fruit and vegetable (FV) intake is associated with reduced risk of a number of non-communicable diseases. Research tends to focus on antioxidants, flavonoids and polyphenols contained in FV as the main beneficial components to health; however, increasing FV may also alter overall diet profile. Extra FV may be substituted for foods thought to be less healthy, therefore altering the overall macronutrient and/or micronutrient content in the diet. This analysis merged dietary data from four intervention studies in participants with varying health conditions and examined the effect of increased FV consumption on diet profile. Dietary intake was assessed by either diet diaries or diet histories used in four FV randomised intervention studies. All food and drink intake recorded was analysed using WISP version 3.0, and FV portions were manually counted using household measures. Regression analysis revealed significant increases in intakes of energy (172 kJ (+41 kcal)), carbohydrate (+3·9 g/4184 kJ (1000 kcal)), total sugars (+6·0 g/4184 kJ (1000 kcal)) and fibre (+0·8 g/4184 kJ (1000 kcal)) and significant decreases in intakes of total fat (-1·4 g/4184 kJ (1000 kcal)), SFA (-0·6 g/4184 kJ (1000 kcal)), MUFA (-0·6 g/4184 kJ (1000 kcal)), PUFA (-0·1 g/4184 kJ (1000 kcal)) and starch (-2·1 g/4184 kJ (1000 kcal)) per one portion increase in FV. Significant percentage increases were also observed in vitamin C (+24 %) and -carotene (+20 %) intake, per one portion increase in FV. In conclusion, pooled analysis of four FV intervention studies, that used similar approaches to achieving dietary change, in participants with varying health conditions, demonstrated an increase in energy, total carbohydrate, sugars and fibre intake, and a decrease in fat intake alongside an expected increase in micronutrient intake.

Effect of fruit and vegetable intake on oxidative stress and inflammation in COPD: a randomised controlled trial.

Epidemiological evidence supports a positive relationship between fruit and vegetable (FV) intake, lung function and chronic obstructive pulmonary disease (COPD). Increasing FV intake may attenuate the oxidative stress and inflammation associated with COPD. An exploratory randomised controlled trial to examine the effect of increased consumption of FV on oxidative stress and inflammation in moderate-to-severe COPD was conducted. 81 symptomatically stable patients with a habitually low FV intake (two or fewer portions of FV per day) were randomised to the intervention group (five or more portions of FV per day) or the control group (two or fewer portions of FV per day). Each participant received self-selected weekly home deliveries of FV for 12 weeks. 75 participants completed the intervention. There was a significant between-group change in self-reported FV intake and biomarkers of FV intake (zeaxanthin (p = 0.034) and ß-cryptoxanthin (p = 0.015)), indicating good compliance; post-intervention intakes in intervention and control groups were 6.1 and 1.9 portions of FV per day, respectively. There were no significant changes in biomarkers of airway inflammation (interleukin-8 and myeloperoxidase) and systemic inflammation (C-reactive protein) or airway and systemic oxidative stress (8-isoprostane). This exploratory study demonstrated that patients with moderate-to-severe COPD were able to comply with an intervention to increase FV intake; however, this had no significant effect on airway or systemic oxidative stress and inflammation.

Biomarkers of fruit and vegetable intake in human intervention studies: a systematic review.

Observational evidence consistently shows that consumption of a diet rich in fruit and vegetables may offer protection against diseases such as cardiovascular disease and cancer. Assessment of dietary intake is complex and prone to many sources of error. More objective biomarkers of fruit and vegetable intake are therefore of interest. The aim of this review is to examine the usefulness of the main biomarkers of fruit and vegetable intake to act as objective indicators of compliance in dietary intervention studies. A comprehensive search of the literature was conducted using six databases. Suitable papers were selected and relevant data extracted. The papers were categorized into 3 sub-groups: whole diet interventions; mixed fruit and vegetable interventions; and studies involving individual varieties of fruits or vegetables. Ninety-six studies were included in the review. Overall, the most commonly measured, and most consistently responsive, biomarkers were the carotenoids and vitamin C. Based on the results of this systematic review, it remains prudent to measure a panel of biomarkers in fruit and vegetable intervention studies. The only possible exception to this is "fruit only" intervention studies where assessment of vitamin C alone may suffice.

Vitamin D status is associated with muscle strength and quality of life in patients with COPD: a seasonal prospective observation study.

Background: Owing to hospitalization, reduced functional capacity and consequently, less sunlight exposure, suboptimal vitamin D status (25-hydroxyvitamin D [25(OH)D]⩽50 nmol/L) is prevalent among COPD patients. Objective: This study aimed to investigate seasonal changes in vitamin D status and any associated changes in fat-free mass (FFM), muscle strength and quality of life (QoL) in COPD patients. Patients and methods: COPD patients living in Northern Ireland (n=51) completed study visits at the end of winter (March/April) and at the end of summer (September/October), corresponding to the nadir and peak of vitamin D status, respectively. At both time points, serum concentration of 25(OH)D was quantified by liquid chromatography-tandem mass spectrometry, FFM (kg) was measured using bioelectrical impedance and muscle strength (kg) was measured using handgrip dynamometry. QoL was assessed using the validated St George's Respiratory Questionnaire. Results: Mean±SD 25(OH)D concentration was significantly higher at the end of summer compared to the end of winter (52.5±30.5 nmol/L vs 33.7±28.4 nmol/L, P<0.001); and house- bound patients had significantly lower 25(OH)D concentration compared to nonhousebound patients at the end of summer (42.9±4.2 vs 57.2±9.9 nmol/L; P⩽0.001). Muscle strength (at both time points) and QoL (end of summer only) were positively predicted by 25(OH)D concentration, independent of age, sex and smoking status. Conclusion: This study highlights the need for health policies to include a recommendation for year-round vitamin D supplementation in housebound COPD patients, and wintertime supplementation in nonhousebound patients, to maintain optimal 25(OH)D concentrations to protect musculoskeletal health. Furthermore, an optimal vitamin D status may have potential benefits for QoL in these patients.

Impact of a (poly)phenol-rich extract from the brown algae Ascophyllum nodosum on DNA damage and antioxidant activity in an overweight or obese population: a randomized controlled trial.

Background: Epidemiologic evidence suggests that a diet rich in (poly)phenols has beneficial effects on many chronic diseases. Brown seaweed is a rich source of (poly)phenols. Objective: The aim of this study was to investigate the bioavailability and effect of a brown seaweed (Ascophyllum nodosum) (poly)phenol extract on DNA damage, oxidative stress, and inflammation in vivo. Design: A randomized, double-blind, placebo-controlled crossover trial was conducted in 80 participants aged 30-65 y with a body mass index (in kg/m2) ≥25. The participants consumed either a 400-mg capsule containing 100 mg seaweed (poly)phenol and 300 mg maltodextrin or a 400-mg maltodextrin placebo control capsule daily for an 8-wk period. Bioactivity was assessed with a panel of blood-based markers including lymphocyte DNA damage, plasma oxidant capacity, C-reactive protein (CRP), and inflammatory cytokines. To explore the bioavailability of seaweed phenolics, an untargeted metabolomics analysis of urine and plasma samples after seaweed consumption was determined by ultra-high-performance liquid chromatography-high-resolution mass spectrometry. Results: Consumption of the seaweed (poly)phenols resulted in a modest decrease in DNA damage but only in a subset of the total population who were obese. There were no significant changes in CRP, antioxidant status, or inflammatory cytokines. We identified phlorotannin metabolites that are considered potential biomarkers of seaweed consumption including pyrogallol/phloroglucinol-sulfate, hydroxytrifurahol A-glucuronide, dioxinodehydroeckol-glucuronide, diphlorethol sulfates, C-O-C dimer of phloroglucinol sulfate, and C-O-C dimer of phloroglucinol. Conclusions: To the best of our knowledge, this work represents the first comprehensive study investigating the bioactivity and bioavailability of seaweed (poly)phenolics in human participants. We identified several potential biomarkers of seaweed consumption. Intriguingly, the modest improvements in DNA damage were observed only in the obese subset of the total population. The subgroup analysis should be considered exploratory because it was not preplanned; therefore, it was not powered adequately. Elucidation of the biology underpinning this observation will require participant stratification according to weight in future studies. This trial was registered at clinicaltrials.gov as NCT02295878.