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Ritva Järvinen

Bio: Ritva Järvinen is an academic researcher from University of Eastern Finland. The author has contributed to research in topics: Cancer & Risk factor. The author has an hindex of 33, co-authored 47 publications receiving 8968 citations.

Papers
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Journal ArticleDOI
TL;DR: The risk of some chronic diseases may be lower at higher dietary flavonoid intakes, and a trend toward a reduction in risk of type 2 diabetes was associated with higher quercetin intakes.

1,690 citations

Journal ArticleDOI
24 Feb 1996-BMJ
TL;DR: Flavonoids offer an explanation for the suggested beneficial effect of fruits and vegetables in coronary heart disease and people with very low intakes of flavonoids have higher risks of coronary disease.
Abstract: Objective: To study the association between dietary intake of flavonoids and subsequent coronary mortality. Design: A cohort study based on data collected at the Finnish mobile clinic health examination survey from 1967-72 and followed up until 1992. Settings: 30 communities from different parts of Finland. Subjects: 5133 Finnish men and women aged 30-69 years and free from heart disease at baseline. Main outcome measure: Dietary intake of flavonoids, total mortality, and coronary mortality. Results: In women a significant inverse gradient was observed between dietary intake of flavonoids and total and coronary mortality. The relative risks between highest and lowest quarters of flavonoid intake adjusted for age, smoking, serum cholesterol concentration, blood pressure, and body mass index were 0.69 (95% confidence interval 0.53 to 0.90) and 0.54 (0.33 to 0.87) for total and coronary mortality, respectively. The corresponding values for men were 0.76 (0.63 to 0.93) and 0.78 (0.56 to 1.08), respectively. Adjustment for intake of antioxidant vitamins and fatty acids weakened the associations for women; the relative risks for coronary heart disease were 0.73 (0.41 to 1.32) and 0.67 (0.44 to 1.00) in women and men, respectively. Intakes of onions and apples, the main dietary sources of flavonoids, presented similar associations. The relative risks for coronary mortality between highest and lowest quarters of apple intake were 0.57 (0.36 to 0.91) and 0.81 (0.61 to 1.09) for women and men, respectively. The corresponding values for onions were 0.50 (0.30 to 0.82) and 0.74 (0.53 to 1.02), respectively. Conclusion: The results suggest that people with very low intakes of flavonoids have higher risks of coronary disease. Key messages Key messages The protective effect of flavonoids was associated with a diet high in intake of apples and onions The effect may be mediated through prevention of oxidation of low density lipoproteins but other mechanisms could be involved Flavonoids offer an explanation for the suggested beneficial effect of fruits and vegetables in coronary heart disease Further studies should concentrate on the effects of various flavonoid compounds and on populations with different intakes

1,314 citations

Journal ArticleDOI
TL;DR: The association between flavonoid intake and lung cancer incidence was not due to the intake of antioxidant vitamins or other potential confounding factors, as adjustment for factors such as smoking and intakes of energy, vitamin E, vitamin C, and beta-carotene did not materially alter the results.
Abstract: Flavonoids are effective antioxidants and, in theory, may provide protection against cancer, although direct human evidence of this is scarce. The relation between the intake of antioxidant flavonoids and subsequent risk of cancer was studied among 9,959 Finnish men and women aged 15-99 years and initially cancer free. Food consumption was estimated by the dietary history method, covering the total habitual diet during the previous year. During a follow-up in 1967-1991, 997 cancer cases and 151 lung cancer cases were diagnosed. An inverse association was observed between the intake of flavonoids and incidence of all sites of cancer combined. The sex- and age-adjusted relative risk of all sites of cancer combined between the highest and lowest quartiles of flavonoid intake was 0.80 (95% confidence interval 0.67-0.96). This association was mainly a result of lung cancer, which presented a corresponding relative risk of 0.54 (95% confidence interval 0.34-0.87). The association between flavonoid intake and lung cancer incidence was not due to the intake of antioxidant vitamins or other potential confounding factors, as adjustment for factors such as smoking and intakes of energy, vitamin E, vitamin C, and beta-carotene did not materially alter the results. The association was strongest in persons under 50 years of age and in nonsmokers with relative risks of 0.33 (95% confidence interval 0.15-0.77) and 0.13 (95% confidence interval 0.03-0.58), respectively. Of the major dietary flavonoid sources, the consumption of apples showed an inverse association with lung cancer incidence, with a relative risk of 0.42 (95% confidence interval 0.23-0.76) after adjustment for the intake of other fruits and vegetables. The results are in line with the hypothesis that flavonoid intake in some circumstances may be involved in the cancer process, resulting in lowered risks.

779 citations

Journal ArticleDOI
TL;DR: The hypothesis that antioxidant vitamins protect against coronary heart disease is supported, but it cannot be excluded that foods rich in these micronutrients also contain other constituents that provide the protection.
Abstract: Oxidation of lipoproteins is hypothesized to promote atherosclerosis and, thus, a high intake of antioxidant nutrients may protect against coronary heart disease. The relation between the intakes of dietary carotene, vitamin C, and vitamin E and the subsequent coronary mortality was studied in a cohort of 5,133 Finnish men and women aged 30-69 years and initially free from heart disease. Food consumption was estimated by the dietary history method covering the total habitual diet during the previous year. Altogether, 244 new fatal coronary heart disease cases occurred during a mean follow-up of 14 years beginning in 1966-1972. An inverse association was observed between dietary vitamin E intake and coronary mortality in both men and women with relative risks of 0.68 (p for trend = 0.01) and 0.35 (p for trend < 0.01), respectively, between the highest and lowest tertiles of the intake. Similar associations were observed for the dietary intake of vitamin C and carotenoids among women and for the intake of important food sources of these micronutrients, i.e., of vegetables and fruits, among both men and women. The associations were not attributable to confounding by major nondietary risk factors of coronary heart disease, i.e., age, smoking, serum cholesterol, hypertension, or relative weight. The results support the hypothesis that antioxidant vitamins protect against coronary heart disease, but it cannot be excluded that foods rich in these micronutrients also contain other constituents that provide the protection.

636 citations

Journal ArticleDOI
TL;DR: An inverse association between whole-grain intake and the risk of type 2 diabetes was found and the similar result for cereal fiber intake suggests that the whole- grain association is due to cereal fiber or another factor related to cereal Fiber intake.

599 citations


Cited by
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Journal ArticleDOI
TL;DR: This review examines the evidence for involvement of the oxidative stress in the carcinogenesis process and the role of enzymatic and non-enzymatic antioxidants in the process of carcinogenesis as well as the antioxidant interactions with various regulatory factors.

5,937 citations

Journal Article
TL;DR: Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional, and suggestions are made where such possibilities may be worth pursuing.
Abstract: Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

4,663 citations

Journal ArticleDOI
TL;DR: This review presents the current knowledge on structural aspects and in vitro antioxidant capacity of most common flavonoids as well as in vivo antioxidant activity and effects on endogenous antioxidants.
Abstract: Flavonoids are phenolic substances isolated from a wide range of vascular plants, with over 8000 individual compounds known. They act in plants as antioxidants, antimicrobials, photoreceptors, visual attractors, feeding repellants, and for light screening. Many studies have suggested that flavonoids exhibit biological activities, including antiallergenic, antiviral, antiinflammatory, and vasodilating actions. However, most interest has been devoted to the antioxidant activity of flavonoids, which is due to their ability to reduce free radical formation and to scavenge free radicals. The capacity of flavonoids to act as antioxidants in vitro has been the subject of several studies in the past years, and important structure-activity relationships of the antioxidant activity have been established. The antioxidant efficacy of flavonoids in vivo is less documented, presumably because of the limited knowledge on their uptake in humans. Most ingested flavonoids are extensively degraded to various phenolic acids, some of which still possess a radical-scavenging ability. Both the absorbed flavonoids and their metabolites may display an in vivo antioxidant activity, which is evidenced experimentally by the increase of the plasma antioxidant status, the sparing effect on vitamin E of erythrocyte membranes and low-density lipoproteins, and the preservation of erythrocyte membrane polyunsaturated fatty acids. This review presents the current knowledge on structural aspects and in vitro antioxidant capacity of most common flavonoids as well as in vivo antioxidant activity and effects on endogenous antioxidants.

4,211 citations

Journal ArticleDOI
TL;DR: It is now possible to establish the antioxidant activities of plant-derived flavonoids in the aqueous and lipophilic phases, and to assess the extent to which the total antioxidant potentials of wine and tea can be accounted for by the activities of individual polyphenols.

4,076 citations

Journal ArticleDOI
TL;DR: High activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet and potato peel and beetroot peel extracts showed strong antioxidant effects.
Abstract: The antioxidative activity of a total of 92 phenolic extracts from edible and nonedible plant materials (berries, fruits, vegetables, herbs, cereals, tree materials, plant sprouts, and seeds) was examined by autoxidation of methyl linoleate. The content of total phenolics in the extracts was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Among edible plant materials, remarkable high antioxidant activity and high total phenolic content (GAE > 20 mg/g) were found in berries, especially aronia and crowberry. Apple extracts (two varieties) showed also strong antioxidant activity even though the total phenolic contents were low (GAE < 12.1 mg/g). Among nonedible plant materials, high activities were found in tree materials, especially in willow bark, spruce needles, pine bark and cork, and birch phloem, and in some medicinal plants including heather, bog-rosemary, willow herb, and meadowsweet. In addition, potato peel and beetroot peel extracts showed strong antioxidant effects. To utilize these significant sources of natural antioxidants, further characterization of the phenolic composition is needed.

3,612 citations