Flavonols and flavones in foods and their relation with cancer and coronary heart disease risk

Flavonoids are polyphenolic antioxidants occurring ubiquitously in vegetable foods. Flavonols and flavones inhibit chemically induced tumors in rodents. The flavonol quercetin also inhibits LDL oxidation and platelet aggregation in vitro . We therefore decided to investigate the relation between flavonoid intake and cancer and coronary heart disease risk in humans. The three flavonols quercetin, kaempferol, myricetin, and the two flavones luteolin and apigenin were selected because of their anticarcinogenic and antioxidant activities and because of their ubiquitous occurrence in foods. We first developed and validated a HPLC method for the quantitative determination of these flavonoids in foods. We then determined the flavonol and flavone content of 28 types of vegetables, 12 types of fruits and 9 types of beverages commonly consumed in The Netherlands. Quercetin was the main flavonoid and occurred in most fruits, beverages and in some vegetables. Mean intake of flavonols and flavones combined among Dutch adults was 23 mg/day, and main dietary sources of these flavonoids were tea (48 %), onions (38%), and apples (8 %). Mean flavonol and flavone intake of 805 men aged 65-84 years participating in the Zutphen Elderly Study 1985 was 26 mg/day. During five year followup period 75 men had a first diagnosis of cancer, of which 28 men had lung cancer. Thirty-four men died from all-cause cancer. Intake of flavonols and flavones in 1985 was not related to subsequent (lung) cancer morbidity ( P trend 0.54) and mortality ( P trend 0.51). Between 1985 and 1990 43 men died from coronary heart disease and 38 men had a first myocardial infarction. Intake of flavonols and flavones, expressed as tertiles of intake, was, independently from known risk- and confounding factors, inversely associated with mortality from coronary heart disease ( P trend 0.015) and incidence of a first myocardial infarction ( P trend 0.08). Average intake of flavonols and flavones in 16 cohorts participating in the Seven Countries Study around 1960 was also inversely related to mortality from coronary heart disease after 25 years of follow-up, but it was not related to cancer mortality. In multivariate regression analysis including saturated fat intake, flavonoid intake, and percentage of smokers as independent variables about 90 % of the total variance in coronary heart mortality was explained. Flavonol and flavone intake contributed about 9 % to the explained variance.We conclude that intake of flavonols and flavones may protect against coronary heart disease in humans, but that it does not seem to be an important determinant of cancer risk. However, more experimental, clinical, and epidemiological evidence is needed before firm conclusions on the health effects of these flavonoids can be drawn

Non-nutritive anticarcinogens in foods : state of the art and future developments : a report of the international workshop held on March 26 - 27 1990 in Wageningen, The Netherlands

On March 26-27 1990 an international workshop on non-nutritive anticarcinogens in foods was organised in Wageningen, The Netherlands. Aim of the workshop was to review progress in the research on natural occurring non-nutritive anticarcinogens and to set priorities for future analytica! and epidemiological research. About fifteen experts from different countries were invited to hold lectures on experimental, analytical and epidemiological research on non-nutritive anticarcinogens. The total range of natural ocurring non-nutritive anticarcinogens was thus covered. In the final discussion it was concluded that polyphenols were the most promising group of anticarcinogens for future analytical and epidemiological research

Effects of Aronia melanocarpa fruit juice on exploratory behaviour and locomotor activity in rats

The main bioactive substances in Aronia melanocarpa fruit juice (AMFJ) are polyphenols (flavonoids, procyanidins, and phenolic acids). A great number of polyphenols are able to traverse the blood-brain barrier. In recent years more attention is drawn to the ability of these substances to influence central nervous system functions. The aim of the present study was to investigate the effects of AMFJ on exploratory behaviour and locomotor activity in male Wistar rats. AMFJ was administered orally for 7, 14, 21, and 30 days at three increasing doses (2.5, 5, and 10 ml kg−1). The changes in exploratory behaviour and locomotor activity were recorded in an Opto Varimex apparatus. It was found that the low doses of AMFJ (2.5 and 5 ml kg−1) for all treatment periods did not significantly affect exploratory behaviour and locomotor activity of rats compared to the saline-treated controls. AMFJ at the highest dose of 10 ml kg−1 had no significant effect on exploration and locomotion for the treatment periods of 7 and 14 days, while for the periods of 21 and 30 days it significantly decreased the number of horizontal and vertical movements, which might be the result of a sedative effect. At all the doses and testing periods, AMFJ did not disturb the progressive decrease in motor behaviour, suggesting habituation

Analyseresultaten Zevenlanden-studie

In het kader van de Zevenlandenstudie, een epidemiologische studie naar de relatie tussen voeding en kanker, heeft het RIKILT de gemiddelde voedingspakketten van 16 cohorten onderzocht op het gehalte aan vitamines, spoorelementen en non-nutritieve stoffen als glucosinolaten en flavonoïden. In dit verslag worden de analytisch-chemische aspecten van dit onderzoek nader toegelicht, waarbij aandacht wordt besteed aan de gebruikte analysemethoden, de monstervoorbehandeling, de monsterbewaring en de kwaliteitsbewaking van de analyses