Assessing the dietary intake of polyphenols and their major food sources is the first step towards documenting the associations with health outcomes. Considering recent changes in dietary patterns of the Brazilian population, continuous monitoring of polyphenol intake is important. Thus, the present study was conducted to estimate the polyphenol intake and major food sources in the diet of the Brazilian population using data from the most recent National Dietary Survey (NDS, 2017–2018), to characterise the intake changes according to demographic characteristics and to compare the intake over the past decade in Brazil. Data from two cross-sectional population-based surveys were analyzed in the study. Trends in polyphenol intake and major food sources were estimated using food consumption data from NDS 2008–2009 (n 34 003) and 2017–2018 (n 46 164). The median (25–75th percentiles) of energy-adjusted polyphenol intake in 2017–2018 was 216·3 mg (125·3–495·2 mg) per 1000 kcal/d (4184 kJ/d), representing an increase of 12·3 mg/d from 2008–2009. However, unadjusted polyphenol intakes were similar between the surveys (medians: 364·3 mg/d in 2008–2009 and 366·9 mg/d in 2017–2018). The main food sources of total and polyphenol intake classes presented some variations between 2008–2009 and 2017–2018, with greater contribution of beans preparations, salads and tea to polyphenol intake, and decrease of orange contribution. Our study provided an updated information on polyphenol intake and its major food sources. The median intake remains lower than the reported by other populations. Furthermore, the results may contribute to future studies investigating temporal trends in polyphenol intake and disease risk.

Epidemiological studies have suggested an inverse association between polyphenol intake and the risk of chronic diseases. However, the lack of comprehensive data on population-level intakes, especially in Latin American countries, has limited research on this topic. We aimed to estimate total and individual polyphenol intakes and determine the major dietary contributors in a representative sample of the Brazilian population. Data were obtained from the Brazilian Household Budget Survey, a cross-sectional survey which included data on individual food intake of 34 003 subjects aged 10 years and over collected using two 24-h dietary records. Polyphenol content of foods was identified using the Phenol-Explorer database and Brazilian Food Composition Database. Total and individual polyphenol intake was calculated, as well as the intake distribution by socio-demographic factors. The median and 25–75th percentiles of polyphenol intake were 364·3 and 200·9–1008 mg/d, respectively. After energy adjustment, the median and 25–75th percentiles of polyphenol intake were 204 and 111·4–542·1 mg/1000 kcal/d (4184 kJ/d), respectively. Non-alcoholic beverages and fruits were the major polyphenol suppliers, and coffee and orange juice the main individual food contributors to polyphenol intake. The individual compounds most consumed were isomers of chlorogenic acid (5-caffeoylquinic acid, 4-caffeoylquinic acid, 3-caffeoylquinic acid), naringenin and hesperetin. The present study provides, for the first time, data on dietary intake of total and individual polyphenols by the Brazilian population and illustrates the low quality of their diet. These results will facilitate the study of associations between polyphenol class intake and health outcomes, and will also be useful for future dietary intake recommendations.

Whole-grain wheat, in particular coloured varieties, may have health benefits in adults with chronic metabolic disease risk factors. Twenty-nine overweight and obese adults with chronic inflammation (high-sensitivity C-reactive protein) > 1·0 mg/l) replaced four daily servings of refined grain food products with bran-enriched purple or regular whole-wheat convenience bars (approximately 41–45 g fibre, daily) for 8 weeks in a randomised, single-blind parallel-arm study where body weight was maintained. Anthropometrics, blood markers of inflammation, oxidative stress, and lipaemia and metabolites of anthocyanins and phenolic acids were compared at days 1, 29 and 57 using repeated-measures ANOVA within groups and ANCOVA between groups at day 57, with day 1 as a covariate. A significant reduction in IL-6 and increase in adiponectin were observed within the purple wheat (PW) group. TNF-α was lowered in both groups and ferulic acid concentration increased in the regular wheat (RW) group. Comparing between wheats, only plasma TNF-α and glucose differed significantly (P < 0·05), that is, TNF-α and glucose decreased with RW and PW, respectively. Consumption of PW or RW products showed potential to improve plasma markers of inflammation and oxidative stress in participants with evidence of chronic inflammation, with modest differences observed based on type of wheat.

This study aimed to test the association between dietary content of total and individual classes of polyphenols and incident cases of type 2 diabetes in Polish adults participating to the Health, Alcohol and Psychosocial factors In Eastern Europe study. At baseline, diet by 148-item FFQ and health information were collected from 5806 participants free of diabetes. Self-reported incident type 2 diabetes was ascertained at 2–4-year follow-up visit. OR and 95 % CI of type 2 diabetes comparing the various categories of polyphenol intake to the lowest one (reference category) and as 1 sd increase modelled as continuous variable were calculated by performing age-, energy-, and multivariate-adjusted logistic regression models. During the follow-up, 456 incident cases of type 2 diabetes occurred. When comparing extreme quartiles, intake of total polyphenol was inversely associated with the risk of type 2 diabetes (OR 0·43; 95 % CI 0·30, 0·61); 1 sd increase was associated with a reduced risk of diabetes (OR 0·68; 95 % CI 0·59, 0·79). Among the main classes of polyphenols, flavonoids, phenolic acids, and stilbenes were independent contributors to this association. Both subclasses of phenolic acids were associated with decreased risk of type 2 diabetes, whereas among subclasses of flavonoids, high intake of flavanols, flavanones, flavones and anthocyanins was significantly associated with decreased risk of type 2 diabetes. Total dietary polyphenols and some classes of dietary polyphenols were associated with lower risk of type 2 diabetes.

Salicylic acid, p-hydroxybenzoic acid, caffeine, hydroquinone, and umbelliferone were evaluated in the greenhouse for their effects on shoot dry-weight accumulation of several crop and weed species. With the exception of caffeine, all the chemicals reduced shoot growth in oats (Avena sativa L. ‘Goodfield’). Chemicals applied preplant incorporated, preemergence, or postemergence were effective, depending upon the rate of chemical. When applied preplant incorporated at rates as high as 56.0 kg/ha, most of the chemicals reduced growth of corn (Zea mays L. ‘B73 × Mo17′), soybean [Glycine max (L.) Merr. ‘Corsoy’], velvetleaf (Abutilon theophrasti Medic.), redroot pigweed (Amaranthus retroflexus L.), and wild proso millet (Panicum miliaceum L.). Exceptions were caffeine on corn and soybean and hydroquinone on soybean. At 11.2 kg/ha the chemicals inhibited the weed species more than the crop species. Postemergence applications of caffeine and hydroquinone inhibited growth of the weed species more than the crop species. Hydroquinone at 1.1 kg/ha inhibited redroot pigweed, but rates as high as 11.2 kg/ha did not inhibit soybean. These experiments show that growth of agronomically important crops and weeds can be inhibited differentially by allelopathic chemicals.

The effects of caffeic, vanillic, p-coumaric, chlorogenic, and ferulic acids, ragweed parthenium (Parthenium hysterophorus L. # PTNHY) residue and extracts on the growth, ion uptake, and chlorophyll content of 3-week-old tomatoes (Lycopersicon esculentum Mill. ‘Walter’) grown in the greenhouse were determined Vanillic, p-coumaric, chlorogenic, and ferulic acid at 10−3 M and parthenium extract at 0.5% (w/v) significantly reduced tomato root and shoot dry weight. Ragweed parthenium residue at 0.5% (w/w) and extract at 0.5% (w/v) significantly reduced tomato shoot and root dry weight. Leaf nitrogen content was reduced by phenolic acids (10−3 M) and ragweed parthenium extract (0.5%). Phosphorus content was reduced by all phenolic acids at 10−3 M and ragweed parthenium extract at 0.5% (w/v). In addition, p-coumaric and ferulic acids at 10−4 M reduced phosphorus content. No consistent relationship between chlorophyll content and tomato growth reduction was observed.

Purslane weed has long been used for animal feed in Thailand but has been underutilized, and no published data exist on the chemical and nutritional qualities of Thai wild purslane. In this study, we aimed to determine the microchemical components of purslane stem, leaf, and flower, including the phenolic acid, flavonoid, ascorbic acid, β-carotene, and fatty acid content. The water extract of the flower fraction contained the highest total phenolic acid content and had the highest O2-scavenging activities, whereas leaf contained the highest amount of total flavonoids and ascorbic acid. The β-carotene content was not significantly different in leaf and flower fractions but was significantly greater than that in stem (P < 0.05). The predominant phenolic acid was chlorogenic acid for all fractions. Rutin was the major flavonoid found in leaf, and myricetin was highest in flower and stem. Alpha linolenic acid (18:3n-3) content ranged from 16% (149 mg per 100-g sample) of total fatty acid in stem to 50% (523 mg per 100-g sample) in leaf. We suggest that Thai wild purslane could be considered a nutritional source for animal feed or an excellent vegetable in the human diet.

Introduction. The nutritional and functional qualities of wild and cultivated Mexican serviceberry have not yet been reported. This species could have similar potential for commercialization to that of Saskatoon berry (Amelanchier alnifolia Nutt.). Materials and methods. Wild and cultivated fruits at two maturity stages were assessed for CIE Lab color, fruit size, titratable acidity and total soluble solids. Also, chemical composition and mineral contents were determined. In addition, vitamin C and simple phenols were assessed. Total soluble phenols, condensed tannins and anthocyanins as well as Trolox antioxidant activity and oxygen radical antioxidant activity were determined. Results. Fruit size, titratable acidity, total soluble solids, iron and simple phenols were higher in fruits of cultivated plants than in those of wild plants. Total fiber, calcium, vitamin C, total soluble phenols and condensed tannins were higher in wild fruits. Wild and cultivated serviceberry showed higher Trolox antioxidant activity compared with oxygen radical antioxidant activity. Caffeic, chlorogenic, coumaric and syringic acids and rutin were the predominant simple phenolics; they comprised from 59.3% (cultivated overripe fruit) to 76.9% (wild ripe fruit) of the sum of simple phenolics. The antioxidant activity of wild and cultivated fruit (258.3–699.2 mmol·kg–1, fw) is up to 3.8 times higher compared with those of fruits commonly consumed. Conclusion. Contents of antioxidant compounds and the outstanding antioxidant activities of wild and cultivated Mexican serviceberry make this species a natural resource that could contribute to health.

Phenolic acids are secondary plant metabolites that may have protective effects against oxidative stress, inflammation and cancer in experimental studies. To date, limited data exist on the quantitative intake of phenolic acids. We estimated the intake of phenolic acids and their food sources and associated lifestyle factors in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Phenolic acid intakes were estimated for 36 037 subjects aged 35–74 years and recruited between 1992 and 2000 in ten European countries using a standardised 24 h recall software (EPIC-Soft), and their food sources were identified. Dietary data were linked to the Phenol-Explorer database, which contains data on forty-five aglycones of phenolic acids in 452 foods. The total phenolic acid intake was highest in Aarhus, Denmark (1265·5 and 980·7 mg/d in men and women, respectively), while the intake was lowest in Greece (213·2 and 158·6 mg/d in men and women, respectively). The hydroxycinnamic acid subclass was the main contributor to the total phenolic acid intake, accounting for 84·6–95·3 % of intake depending on the region. Hydroxybenzoic acids accounted for 4·6–14·4 %, hydroxyphenylacetic acids 0·1–0·8 % and hydroxyphenylpropanoic acids ≤ 0·1 % for all regions. An increasing south–north gradient of consumption was also found. Coffee was the main food source of phenolic acids and accounted for 55·3–80·7 % of the total phenolic acid intake, followed by fruits, vegetables and nuts. A high heterogeneity in phenolic acid intake was observed across the European countries in the EPIC cohort, which will allow further exploration of the associations with the risk of diseases.

Brewers’ spent grain (BSG) is a low-value co-product of the brewing industry produced in large quantities annually. This paper reviews the existing evidence regarding the phenolic component of BSG, focusing on composition, extraction and biofunctions such as antioxidant, anti-atherogenic, anti-inflammatory and anti-carcinogenic activities. Furthermore, the incorporation of BSG in foodstuffs will be discussed, including the use of BSG as an animal feed supplement and the potential of BSG to be incorporated into foods for human consumption. BSG contains hydroxycinnamic acids including ferulic acid, p-coumaric acid and caffeic acid; which have shown bioactivity in the pure form (antioxidant, anti-inflammatory, anti-atherogenic and anti-cancer). Phenolic extracts from BSG have also shown antioxidant potential, by protecting against oxidant-induced DNA damage, possibly by Fe chelation. Studies show that BSG has many benefits when used as a supplement in animal feed, such as increasing milk yield, milkfat content and in providing essential dietary amino acids. The incorporation of BSG in human foods such as cookies and ready-to-eat snacks has resulted in increased protein and fibre contents of the products, where the changes in organoleptic properties are controllable. It can be concluded that the phenolic component of BSG has potential bioactive effects, which are worth pursuing given that the inclusion of BSG into human foodstuffs is viable and beneficial.

Plant-based diets contain a plethora of secondary metabolites that may impact on health and disease prevention. Much attention has been focused on the potential bioactivity and nutritional relevance of several classes of phytochemicals such as flavonoids, carotenoids, phyto-oestrogens and glucosinolates. Less attention has been paid to simple phenolic acids that are widely found in fruit, vegetables, herbs, spices and beverages. Daily intakes may exceed 100 mg. In addition, bacteria in the gut can perform reactions that transform more complex plant phenolics such as anthocyanins, procyanidins, flavanones, flavonols, tannins and isoflavones into simple phenolic metabolites. The colon is thus a rich source of potentially active phenolic acids that may impact both locally and systemically on gut health. Both the small and large intestine (colon) contain absorption sites for phenolic acids but low post-prandial concentrations in plasma indicate minimal absorption early in the gastrointestinal tract and/or rapid hepatic metabolism and excretion. Therefore, any bioactivity that contributes to gut health may predominantly occur in the colon. Several phenolic acids affect the expression and activity of enzymes involved in the production of inflammatory mediators of pathways thought to be important in the development of gut disorders including colon cancer. However, at present, we remain largely ignorant as to which of these compounds are beneficial to gut health. Until we can elucidate which pro-inflammatory and potentially carcinogenetic changes in gene expression can be moderated by simple phenolic acids, it is not possible to recommend specific plant-based foods rich in particular phenolics to optimise gut health.

Coffee and green tea are two of the most widely consumed hot beverages in the world. Their respective bioavailability has been studied separately, but absorption of their respective bioactive phenolics has not been compared. In a randomised cross-over design, nine healthy subjects drank instant coffee and green tea. Blood samples were collected over 12 h and at 24 h to assess return to baseline. After green tea consumption, ( − )-epigallocatechin (EGC) was the major catechin, appearing rapidly in the plasma; ( − )-EGC gallate (EGCg) and ( − )-epicatechin (EC) were also present, but ( − )-EC gallate and C were not detected. Dihydroferulic acid and dihydrocaffeic acid were the major metabolites that appeared after coffee consumption with a long time needed to reach maximum plasma concentration, suggesting metabolism and absorption in the colon. Other phenolic acid equivalents (caffeic acid (CA), ferulic acid (FA) and isoferulic acid (iFA)) were detected earlier, and they peaked at lower concentrations. Summations of the plasma area under the curves (AUC) for the measured metabolites showed 1·7-fold more coffee-derived phenolic acids than green tea-derived catechins (P = 0·0014). Furthermore, we found a significant correlation between coffee metabolites based on AUC. Inter-individual differences were observed, but individuals with a high level of CA also showed a correspondingly high level of FA. However, no such correlation was observed between the tea catechins and coffee phenolic acids. Correlation between AUC and maximum plasma concentration was also significant for CA, FA and iFA and for EGCg. This implies that the mechanisms of absorption for these two classes of compounds are different, and that a high absorber of phenolic acids is not necessarily a high absorber of catechins.

Strawberries contain many antioxidant phytochemicals such as vitamin C, carotenoids and phenolic compounds including anthocyanins (ACN). In the present study, antioxidant composition of fresh strawberries (FS) and stored strawberries (SS) and the bioavailability of the main strawberry bioactive compounds were determined in human subjects. Thirteen healthy volunteers consumed 300 g of FS and SS on two separate occasions. Blood, before and at different time points from meal consumption, as well as 24 h urine, was collected, and parent compounds and metabolites of the different compounds were determined by HPLC or LC/MS/MS. A reduction in α-carotene plasma concentrations v. baseline values was recorded after the consumption of FS, although the amount of this carotenoid was higher in the SS. On the contrary, a significant increase of plasma vitamin C after 2, 3 and 5 h (P < 0·05) of FS and SS consumption was recorded. No quercetin and ACN were found in plasma, while coumaric acid, 4-hydroxybenzoic acid (4HBA, 56 and 54 % of pelargonidin-3-glucoside (Pel-glc) ingested with FS and SS, respectively) and protocatechuic acid (59 and 34 % of cyanidin-3-glucoside ingested with FS and SS, respectively) over 8 h from strawberry consumption were retrieved in the plasma. Pelargonidin glucuronide, pelargonidin glucoside and pelargonidin aglycone peaked in urine within 2 h of strawberry consumption, and the 24 h amount excreted was always approximately 0·9 % of the Pel-glc dose ingested. The data indicated that the content of phytochemicals in strawberries may influence the bioavailability of individual compounds. Furthermore, in the present study, the metabolism of Pel-glc was elucidated, and, for the first time, 4HBA was suggested to be a major human metabolite of Pel-glc.

Oligomers and polymers of flavan-3-ols (proanthocyanidins) are very abundant in the Mediterranean diet, but are poorly absorbed. However, when these polyphenols reach the colon, they are metabolised by the intestinal microbiota into various phenolic acids, including phenylpropionic, phenylacetic and benzoic acid derivatives. Since the biological properties of these metabolites are not completely known, in the present study, we investigated the effect of the following microbial phenolic metabolites: 3,4-dihydroxyphenylpropionic acid (3,4-DHPPA), 3-hydroxyphenylpropionic acid, 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid and 4-hydroxyhippuric acid (4-HHA), on modulation of the production of the main pro-inflammatory cytokines (TNF-α, IL-1β and IL-6). The production of these cytokines by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) pre-treated with the phenolic metabolites was studied in six healthy volunteers. With the exception of 4-HHA for TNF-α secretion, only the dihydroxylated compounds, 3,4-DHPPA and 3,4-DHPAA, significantly inhibited the secretion of these pro-inflammatory cytokines in LPS-stimulated PBMC. Mean inhibition of the secretion of TNF-α by 3,4-DHPPA and 3,4-DHPAA was 84·9 and 86·4 %, respectively. The concentrations of IL-6 in the culture supernatant were reduced by 88·8 and 92·3 % with 3,4-DHPPA and 3,4-DHPAA pre-treatment, respectively. Finally, inhibition was slightly higher for IL-1β, 93·1 % by 3,4-DHPPA and 97·9 % by 3,4-DHPAA. These results indicate that dihydroxylated phenolic acids derived from microbial metabolism present marked anti-inflammatory properties, providing additional information about the health benefits of dietary polyphenols and their potential value as therapeutic agents.

Epidemiological studies indicate a J-shaped relationship linking coffee consumption and cardiovascular risk, suggesting that moderate coffee consumption can be beneficial. Platelet aggregation is of critical importance in thrombotic events, and platelets play a major role in the aetiology of several CVD. The aim of this study was to evaluate the effect of coffee drinking on platelet aggregation ex vivo, using caffeine as control. A crossover study was performed on ten healthy subjects. In two different sessions, subjects drank 200 ml coffee, containing 180 mg caffeine, or a capsule of caffeine (180 mg) with 200 ml water. Platelets were separated from plasma at baseline and 30 and 60 min after coffee drinking. Platelet aggregation was induced with three different agonists: collagen, arachidonic acid and ADP. Coffee drinking inhibited collagen (P < 0·05 from baseline at time 30 min) and arachidonic acid (P < 0·05 from baseline at time 60 min) induced platelet aggregation. Caffeine intake did not affect platelet aggregation induced by the three agonists. Coffee consumption induced a significant increase of platelet phenolic acids (likely present as glucuronate and sulphate derivatives), caffeic acid, the principal phenolic acid in coffee, raising from 0·3 (sem 0·1) to 2·4 (sem 0·6) ng/mg (P < 0·01). Caffeine was not detectable in platelets. Coffee drinking decreases platelet aggregation, and induces a significant increase in phenolic acid platelet concentration. The antiplatelet effect of coffee is independent from caffeine and could be a result of the interaction of coffee phenolic acids with the intracellular signalling network leading to platelet aggregation.

Estimation of dietary intake of polyphenols is difficult, due to limited availability of food composition data and bias inherent to dietary assessment methods. The aim of the present study was to evaluate the associations between the intake of polyphenol-rich foods and the urinary excretion of several phenolic compounds and therefore explore whether these phenolic compounds could be used as a biomarker of intake. Fifty-three participants of the SU.VI.MAX study (a randomised primary-prevention trial evaluating the effect of daily antioxidant supplementation on chronic diseases) collected a 24h urine and a spot urine sample and filled a dietary record during a 2d period. Thirteen polyphenols and metabolites, chlorogenic acid, caffeic acid, m-coumaric acid, gallic acid, 4-o-methylgallic acid, quercetin, isorhamnetin, kaempferol, hesperetin, naringenin, phloretin, enterolactone and enterodiol, were measured using HPLC–electrospray ionisation–MS–MS. In spot samples apple consumption was positively correlated to phloretin, grapefruit consumption to naringenin, orange to hesperetin, citrus fruit consumption to both naringenin and hesperetin, with r coefficients ranging from 0·31 to 0·57 (p<0·05). The combination of fruits and/or fruit juices was positively correlated to gallic acid and 4-o-methylgallic acid, isorhamnetin, kaempferol, hesperetin, naringenin and phloretin (r 0·24–0·44, p<0·05). Coffee consumption was positively correlated to caffeic and chlorogenic acids (r 0·29 and 0·63, p<0·05 respectively). Black tea and wine consumption were positively correlated with gallic and 4-o-methylgallic acids (r 0·37–0·54, p<0·001). The present results suggest that several polyphenols measured in a spot urine sample can be used as biomarkers of polyphenol-rich food intake.

Dietary polyphenols are suggested to participate in the prevention of CVD and cancer. It is essential for epidemiological studies to be able to compare intake of the main dietary polyphenols in populations. The present paper describes a fast method suitable for the analysis of polyphenols in urine, selected as potential biomarkers of intake. This method is applied to the estimation of polyphenol recovery after ingestion of six different polyphenol-rich beverages. Fifteen polyphenols including mammalian lignans (enterodiol and enterolactone), several phenolic acids (chlorogenic, caffeic, m-coumaric, gallic, and 4-O-methylgallic acids), phloretin and various flavonoids (catechin, epicatechin, quercetin, isorhamnetin, kaempferol, hesperetin, and naringenin) were simultaneously quantified in human urine by HPLC coupled with electrospray ionisation mass-MS (HPLC-electrospray-tandem mass spectrometry) with a run time of 6 min per sample. The method has been validated with regard to linearity, precision, and accuracy in intra- and inter-day assays. It was applied to urine samples collected from nine volunteers in the 24 h following consumption of either green tea, a grape-skin extract, cocoa beverage, coffee, grapefruit juice or orange juice. Levels of urinary excretion suggest that chlorogenic acid, gallic acid, epicatechin, naringenin or hesperetin could be used as specific biomarkers to evaluate the consumption of coffee, wine, tea or cocoa, and citrus juices respectively.

Tea and coffee are rich in polyphenols with a variety of biological activities. Many of the demonstrated activities are consistent with favourable effects on the risk of chronic diseases. 4-O-methylgallic acid (4OMGA) and isoferulic acid are potential biomarkers of exposure to polyphenols derived from tea and coffee respectively. 4OMGA is derived from gallic acid in tea, and isoferulic acid is derived from chlorogenic acid in coffee. Our major objective was to explore the relationships of tea and coffee intake with 24 h urinary excretion of 4OMGA and isoferulic acid in human subjects. The relationships of long-term usual (111 participants) and contemporaneously recorded current (344 participants) tea and coffee intake with 24 h urinary excretion of 4OMGA and isoferulic acid were assessed in two populations. 4OMGA was related to usual (r 0·50, P<0·001) and current (r 0·57, P<0·001) tea intake, and isoferulic acid was related to usual (r 0·26, P=0·008) and current (r 0·18, P<0·001) coffee intake. Overall, our present results are consistent with the proposal that 4OMGA is a good biomarker for black tea-derived polyphenol exposure, but isoferulic acid may be of limited usefulness as a biomarker for coffee-derived polyphenol exposure.