Selenium and sulphur derivatives of hydroxytyrosol: inhibition of lipid peroxidation in liver microsomes of vitamin E-deficient rats.

Purpose: The objective of this study was to evaluate the capacity of modified phenols synthesized from hydroxytyrosol, a natural olive oil phenol, specifically those containing a selenium or sulphur group, to inhibit lipid peroxidation.

Methods: The compounds' abilities to inhibit lipid peroxidation in liver microsomes obtained from vitamin E-deficient rats were compared to hydroxytyrosol.

Results: All synthetic compounds had a significant higher ability to inhibit lipid peroxidation than hydroxytyrosol.

Bioavailable Concentrations of Delphinidin and Its Metabolite, Gallic Acid, Induce Antioxidant Protection Associated with Increased Intracellular Glutathione in Cultured Endothelial Cells.

Despite limited bioavailability and rapid degradation, dietary anthocyanins are antioxidants with cardiovascular benefits. This study tested the hypothesis that the antioxidant protection conferred by the anthocyanin, delphinidin, is mediated by modulation of endogenous antioxidant defences, driven by its degradation product, gallic acid. Delphinidin was found to degrade rapidly (t1/2 ~ 30 min), generating gallic acid as a major degradation product.

An application of partial least squares for identifying dietary patterns in bone health.

Unlabelled: In a large cohort of older women, a mechanism-driven statistical technique for assessing dietary patterns that considers a potential nutrient pathway found two dietary patterns associated with lumbar spine and femoral neck bone mineral density. A "healthy" dietary pattern was observed to be beneficial for bone mineral density.

Introduction: Dietary patterns represent a broader, more realistic representation of how foods are consumed, compared to individual food or nutrient analyses.

Acute Consumption of Flavan-3-ol-Enriched Dark Chocolate Affects Human Endogenous Metabolism.

Flavan-3-ols and methylxanthines have potential beneficial effects on human health including reducing cardiovascular risk. We performed a randomized controlled crossover intervention trial to assess the acute effects of consumption of flavan-3-ol-enriched dark chocolate, compared with standard dark chocolate and white chocolate, on the human metabolome. We assessed the metabolome in urine and blood plasma samples collected before and at 2 and 6 h after consumption of chocolates in 42 healthy volunteers using a nontargeted metabolomics approach.

Effect of increasing fruit and vegetable intake by dietary intervention on nutritional biomarkers and attitudes to dietary change: a randomised trial.

Purpose: Low fruit and vegetable consumption is linked with an increased risk of death from vascular disease and cancer. The benefit of eating fruits and vegetables is attributed in part to antioxidants, vitamins and phytochemicals. Whether increasing intake impacts on markers of disease remains to be established.

Longitudinal study of weight, energy intake and physical activity change across two decades in older Scottish women.

Background: The perimenopausal and postmenopausal periods are times of pronounced physiological change in body mass index (BMI), physical activity and energy intake. Understanding these changes in middle age could contribute to formation of potential public health targets.

Method: A longitudinal cohort of 5119 perimenopausal women from the Aberdeen Prospective Osteoporosis Screening Study (APOSS) recruited between 1990 and 1994, with follow-up visits at 1997-1999 and 2009-2011.

Bioactive polyphenols and cardiovascular disease: chemical antagonists, pharmacological agents or xenobiotics that drive an adaptive response?

Unlabelled: Polyphenols are widely regarded to have a wide range of health-promoting qualities, including beneficial effects on cardiovascular disease. Historically, the benefits have been linked to their well-recognized powerful antioxidant activity. However, the concept that the beneficial effects are attributable to direct antioxidant activity in vivo does not pay sufficient heed to the fact that polyphenols degrade rapidly, are poorly absorbed and rapidly metabolized, resulting in very low bioavailability.

Availability and dose response of phytophenols from a wheat bran rich cereal product in healthy human volunteers.

Scope: Phytophenols present in cereals are metabolised to compounds that could be partly responsible for the reduced risk of chronic diseases and all-cause mortality associated with fibre-rich diets. The bioavailability, form and in vivo concentrations of these metabolites require to be established.

Materials And Methods: Eight healthy volunteers consumed a test meal containing a recommended dose (40 g) and high dose (120 g) of ready-to-eat wheat bran cereal and the systemic and colonic metabolites determined quantitatively by LC-MS.

Antioxidants in Cardiovascular Therapy: Panacea or False Hope?

Oxidative stress is a key feature of the atherothrombotic process involved in the etiology of heart attacks, ischemic strokes, and peripheral arterial disease. It stands to reason that antioxidants represent a credible therapeutic option to prevent disease progression and thereby improve outcome, but despite positive findings from in vitro studies, clinical trials have failed to consistently show benefit. The aim of this review is to re-appraise the concept of antioxidants in the prevention and management of cardiovascular disease.

Role of dietary pro-oxidants in the maintenance of health and resilience to oxidative stress.

The average length of human life is increasing, but so does the incidence of age- and lifestyle-related diseases. Improving diet and lifestyle is a key strategy for lifelong health and underlying mechanisms may well include increasing resilience pathways. The purpose of this review is to highlight and evaluate novel mechanisms by which dietary pro-oxidants, including bioactive phytochemicals and fatty acids, increase reactive oxygen species (ROS) concentrations just enough to activate transcription factor activation of nuclear factor erythroid 2 related factor 2 (Nrf-2) and heat shock factor (HSF), leading to an increase in levels of antioxidant enzymes and heat shock proteins that protect against the damaging effects of ROS.

Postprandial cell defense system responses to meal formulations: stratification through gene expression profiling.

Scope: Cell defenses regulating homeostatic control of postprandial stress are influenced by interindividual variation, food composition and health status. This study investigates effects of food composition on individual postprandial responses and associations with health.

Methods And Results: Volunteers (n = 16) consumed four food formulations (50% unsaturated/saturated fat, with/without beetroot extract 10 g/100 g) on separate occasions.

Deleterious consequences of antioxidant supplementation on lifespan in a wild-derived mammal.

While oxidative damage owing to reactive oxygen species (ROS) often increases with advancing age and is associated with many age-related diseases, its causative role in ageing is controversial. In particular, studies that have attempted to modulate ROS-induced damage, either upwards or downwards, using antioxidant or genetic approaches, generally do not show a predictable effect on lifespan. Here, we investigated whether dietary supplementation with either vitamin E (α-tocopherol) or vitamin C (ascorbic acid) affected oxidative damage and lifespan in short-tailed field voles, Microtus agrestis.

Flavan-3-ol-enriched dark chocolate and white chocolate improve acute measures of platelet function in a gender-specific way--a randomized-controlled human intervention trial.

Scope: We examined whether flavan-3-ol-enriched dark chocolate, compared with standard dark and white chocolate, beneficially affects platelet function in healthy subjects, and whether this relates to flavan-3-ol bioavailability.

Methods And Results: A total of 42 healthy subjects received an acute dose of flavan-3-ol-enriched dark, standard dark or white chocolate, in random order. Blood and urine samples were obtained just before and 2 and 6 h after consumption for measurements of platelet function, and bioavailability and excretion of flavan-3-ols.

Alperujo extract, hydroxytyrosol, and 3,4-dihydroxyphenylglycol are bioavailable and have antioxidant properties in vitamin E-deficient rats--a proteomics and network analysis approach.

Scope: Olive products are rich in phenolic compounds, which are natural antioxidants in vitro. We tested the in vivo effects of alperujo, an olive production by-product, as well as hydroxytyrosol and 3,4-dihydroxyphenylglycol (DHPG) isolated from alperujo, on indices and pathways of oxidative and metabolic stress in a vitamin E-deficient rat model.

Methods And Results: Rats were fed a vitamin E-deficient diet for 10 weeks, followed by this diet supplemented with either 100 mg/kg diet dα-tocopherol, alperujo extract, hydroxytyrosol, or 10 mg/kg diet DHPG, for a further 2 weeks.

In vitro anti-platelet effects of simple plant-derived phenolic compounds are only found at high, non-physiological concentrations.

Scope: Bioactive polyphenols from fruits, vegetables, and beverages have anti-platelet effects and may thus affect the development of cardiovascular disease. We screened the effects of 26 low molecular weight phenolic compounds on two in vitro measures of human platelet function.

Methods And Results: After platelets had been incubated with one of 26 low molecular weight phenolic compounds in vitro, collagen-induced human platelet aggregation and in vitro TRAP-induced P-selectin expression (as marker of platelet activation) were assessed.

Natural salicylates: foods, functions and disease prevention.

Salicylic acid and related compounds are produced by plants as part of their defence systems against pathogen attack and environmental stress. First identified in myrtle and willow, the medical use of salicylate-rich preparations as anti-inflammatory and antipyretic treatments may date back to the third millennium BC. It is now known that salicylates are widely distributed throughout the plant kingdom, and they are therefore present in plant products of dietary relevance.

Determination of 3,4-dihydroxyphenylglycol, hydroxytyrosol and tyrosol purified from olive oil by-products with HPLC in animal plasma and tissues.

A simple, fast and reliable method to quantify, simultaneously, 3,4-dihydroxyphenylglycol (DHPG), hydroxytyrosol (HT) and tyrosol (Ty) extracted and purified successfully from olive oil by-product, called alperujo, in animal plasma and tissues samples has been developed using a high-performance liquid chromatographic (HPLC) method with UV-Vis detection. Extraction of compounds is based on solid-phase extraction for plasma and homogenisation with zirconia beads and centrifugation for tissues. Calibration curves were linear for all three phenols at a relatively low concentration range (0.

Effects of a high-protein, low-carbohydrate v. high-protein, moderate-carbohydrate weight-loss diet on antioxidant status, endothelial markers and plasma indices of the cardiometabolic profile.

There are concerns that weight-loss (WL) diets based on very low carbohydrate (LC) intake have a negative impact on antioxidant status and biomarkers of cardiovascular and metabolic health. Obese men (n 16) participated in a randomised, cross-over design diet trial, with food provided daily, at approximately 8.3 MJ/d (approximately 70 % of energy maintenance requirements).

High-protein, reduced-carbohydrate weight-loss diets promote metabolite profiles likely to be detrimental to colonic health.

Background: Diets that are high in protein but reduced in carbohydrate contents provide a common approach for achieving weight loss in obese humans. However, the effect of such diets on microbiota-derived metabolites that influence colonic health has not been established.

Objective: We designed this study to assess the effect of diets with reduced carbohydrate and increased protein contents on metabolites considered to influence long-term colonic health, in particular the risk of colorectal disease.

Anti-platelet effects of olive oil extract: in vitro functional and proteomic studies.

Purpose: Platelets play a key role in haemostasis and wound healing, contributing to formation of vascular plugs. They are also involved in formation of atherosclerosic plaques. Some traditional diets, like the Mediterranean diet, are associated with a lower risk of cardiovascular disease.

Impact of dietary polyphenols on human platelet function--a critical review of controlled dietary intervention studies.

Cardiovascular disease is a chronic disease influenced by many factors, with activated blood platelets being one of them. Platelets play a central role in the formation of plaques within blood vessels, contributing to early inflammatory events. Consumption of diets rich in plant-based products protects against the development of cardiovascular disease.

Dietary flavonoid intake and colorectal cancer: a case-control study.

Diets rich in flavonoids may reduce the risk of developing colorectal cancer. Flavonoids are widely distributed in foods of plant origin, though in the UK tea is the main dietary source. Our objective was to evaluate any independent associations of total dietary and non-tea intake of four flavonoid subclasses and the risk of developing colorectal cancer in a tea-drinking population with a high colorectal cancer incidence.

Changes in vitamin biomarkers during a 2-year intervention trial involving increased fruit and vegetable consumption by free-living volunteers.

Trials in free-living populations involving increased consumption of fruit and vegetables are difficult to monitor. We evaluated biomarkers for assessing fruit and vegetable intake and compliance in a 2-year trial. Postmenopausal women were randomised to 300 g additional fruit and vegetables per d (n 66), placebo (n 70) or potassium citrate (n 140).

Aspirin, salicylates, and cancer.

Evidence from a wide range of sources suggests that individuals taking aspirin and related non-steroidal anti-inflammatory drugs have reduced risk of large bowel cancer. Work in animals supports cancer reduction with aspirin, but no long-term randomised clinical trials exist in human beings, and randomisation would be ethically unacceptable because vascular protection would have to be denied to a proportion of the participants. However, opportunistic trials of aspirin, designed to test vascular protection, provide some evidence of a reduction in cancer, but only after at least 10 years.