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Dive into the research topics where Raija Tahvonen is active.

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Featured researches published by Raija Tahvonen.


Journal of Nutritional Biochemistry | 2002

Effects of an antioxidant-rich juice (sea buckthorn) on risk factors for coronary heart disease in humans.

Clair Eccleston; Yang Baoru; Raija Tahvonen; Heikki Kallio; Gerald Rimbach; Anne Marie Minihane

There is increasing evidence to support the hypothesis that free radical-mediated oxidative processes contribute to atherogenesis. More recently the ability of antioxidant nutrients to affect cell response and gene expression has been reported in vitro, providing a novel mechanistic perspective for the biological activity of antioxidants. Sea buckthorn (Hippophaë rhamnoides L.) is a rich source of antioxidants both aqueous and lipophilic, as well as polyunsaturated fatty acids. The objective of the study was to characterize the antioxidant profile of Sea buckthorn juice (SBJ) and to evaluate its effect on plasma lipids, LDL oxidation, platelet aggregation and plasma soluble cell adhesion protein concentration. Twenty healthy male volunteers were given either a placebo or SBJ for 8 weeks. Additional daily intakes of vitamin C, alpha-tocopherol, beta-carotene and flavonoids through SBJ supplementation were 462, 3.2, 1.0 and 355 mg respectively. There were no significant changes in plasma total cholesterol, LDL-C, platelet aggregation or plasma intercellular cell adhesion molecule 1 (ICAM-1) levels between treatment groups. Although not significant, a 20% and 17% increase in plasma HDL-C and triacylglycerol (TAG) concentrations were observed. SBJ supplementation also resulted in a moderate decrease in the susceptibility of LDL to oxidation.


Journal of Nutritional Biochemistry | 2000

Effect of dietary supplementation with sea buckthorn (Hippophaë rhamnoides) seed and pulp oils on the fatty acid composition of skin glycerophospholipids of patients with atopic dermatitis

Baoru Yang; K. Kalimo; Raija Tahvonen; Leena M Mattila; Jouko Katajisto; Heikki Kallio

Sea buckthorn (Hippophaë rhamnoides) seed and pulp oils have traditionally been used for treating skin diseases in China and Russia, but are not widely used in other countries. A placebo-controlled, parallel study was carried out to investigate the effects of these oils on the fatty acid composition of skin glycerophospholipids of patients with atopic dermatitis. Sixteen patients ate 5 g of sea buckthorn seed oil, pulp oil, or paraffin oil daily for 4 months. Skin fatty acids were analyzed with gas chromatography before and after treatment. The seed oil slightly increased the proportion of docosapentaenoic acid (22:5n-3) and decreased the proportion of palmitic acid (16:0) in skin glycerophospholipids (0.05 < P < 0.1). The levels of the other fatty acids remained stable. The results show that the fatty acid composition of skin glycerophospholipids is well buffered against short-term dietary modification.


Food Chemistry | 1996

Calculated vs analysed nutrient composition of weight reduction diets

Paula Hakala; Lars-Runar Knuts; Jorma Kumpulainen; Raija Tahvonen; Sirkka Plaami

Abstract The aim of the study was to compare calculated values with analysed values of some nutrients in weight reduction diets. Ten obese adults were instructed to follow a balanced low-energy diet (5.0 MJ/1200 kcal per day) for 6 months. They were asked to collect samples of all food and beverages they consumed on 3 consecutive days in two phases. During these days, the subjects filled in food records. In addition, samples of a low-energy model diet were collected. The following nutrients were analysed: protein, fat, fatty acids, dietary fibre, calcium, magnesium, iron, zinc, copper, selenium, manganese, molybdenum, sodium, potassium, cadmium and lead. The composition of the diets was calculated from food records by using the Nutrica computer program. Fifteen food samples were included in the final analysis. For most nutrients, calculated values were higher than the analysed ones. Results of our study suggest that the calculation method using food records and the current Finnish database can provide: (1) a reasonably good estimation for the intake of protein, fat, fatty acids, dietary fibre, calcium, magnesium, potassium and manganese; (2) a moderate or uncertain estimation for the intake of iron, sodium, zinc and selenium; and (3) a poor estimation for the intake of copper, molybdenum, cadmium and lead.


Journal of Agricultural and Food Chemistry | 2000

Effects of season and processing on oil content and fatty acids of Baltic herring (Clupea harengus membras).

Tarja Aro; Raija Tahvonen; Tomi Mattila; Johanna Nurmi; Terhi Sivonen; Heikki Kallio

Fatty acid composition, oil content, free fatty acid content, and peroxide value of Baltic herring (Clupea harengus membras) and two processed products (fried fillets and fish burgers) were investigated. The highest oil content of the fillets was found in autumn (10%), at the time when the free fatty acids had their minimum (1.4%). The main fatty acids were oleic (18-23%), palmitic (17%), palmitoleic (8-12%), and docosahexaeneoic (8-10%) acids. The proportion of saturated fatty acids was a constant 23% all year around, whereas mono- and polyunsaturated acids varied from 34 to 39% and 33 to 37%, respectively. During processing the oil content doubled and the fatty acid composition changed to the pattern of the rapeseed oil used for frying. Oleic acid was a major fatty acid in the products comprising over 40% of the total fatty acids. The proportion of n-3 acids decreased during processing but the total amount of polyunsaturated acids remained fairly constant.


Journal of Nutrition | 2010

Oral Sea Buckthorn Oil Attenuates Tear Film Osmolarity and Symptoms in Individuals with Dry Eye

Petra S. Larmo; Riikka Järvinen; Baoru Yang; Matti Viitanen; Janne Engblom; Raija Tahvonen; Heikki Kallio

Dry eye is a common condition that can severely impair the quality of life. We aimed to find out whether oral sea buckthorn (SB) oil, containing (n-3) and (n-6) fatty acids and antioxidants, affects dry eye. In this double-blind, randomized, parallel trial, 20- to 75-y-old women and men experiencing dry eye symptoms consumed 2 g of SB or placebo oil daily for 3 mo from fall to winter. One hundred participants were recruited and 86 completed the study. Clinical dry eye tests and symptom follow-ups were performed. Tear film hyperosmolarity is a focal factor in dry eye. There was a general increase in the osmolarity from baseline to the end of the intervention. Compared with the placebo group, the increase was significantly less in the SB group when all participants were included [intention to treat (ITT), P = 0.04] and when only participants consuming the study products for at least 80% of the intervention days were included [per protocol (PP), P = 0.02]. The maximum intensities of redness and burning tended to be lower in the SB group. In the ITT participants, the group difference was significant for redness (P = 0.04) but not for burning (P = 0.05). In the PP participants, the group difference was significant for burning (P = 0.04) but not for redness (P = 0.11). In conclusion, SB oil attenuated the increase in tear film osmolarity during the cold season and positively affected the dry eye symptoms.


Clinical & Experimental Allergy | 2010

Blackcurrant seed oil for prevention of atopic dermatitis in newborns: a randomized, double-blind, placebo-controlled trial.

P. Linnamaa; J. Savolainen; Leena Koulu; Saska Tuomasjukka; Heikki Kallio; Baoru Yang; T. Vahlberg; Raija Tahvonen

Background The present increased incidence of atopic diseases has been associated with an altered intake of essential fatty acids (EFAs). The composition of blackcurrant seed oil (BCSO) corresponds to the recommended dietary intake of EFAs, and as a dietary supplement could, in small doses, modify the imbalance of EFAs in an efficient way.


Microbiology and Immunology | 2003

In vivo safety assessment of two Bifidobacterium longum strains.

Henna Mäkeläinen; Raija Tahvonen; Seppo Salminen; Arthur C. Ouwehand

Bifidobacteria are important members of the intestinal microbiota and are considered to contribute to maintaining health. However, the level of bifidobacteria colonising the intestine of elderly subjects tends to be lower than in younger adults. Therefore, two Bifidobacterium longum strains, isolated from healthy elderly, were chosen for supplementation of the endogenous Bifidobacterium microbiota in the elderly. Bifidobacteria are generally regarded safe for human consumption. However, since the strains are intended for consumption by the elderly, whom may be more prone to disease, it is important to ascertain their safety. For this purpose, the strains were given to healthy adult volunteers. No side effects were reported and no undesirable changes observed in the immune parameters measured. Based on this study it appears that the two strains are well tolerated by human subjects and there are no reservations about their food use.


Journal of Food Composition and Analysis | 1992

Sugar and organic acid contents of vegetables consumed in Finland during 1988–1989

Katri Haila; Jorma Kumpulainen; Ulla Häkkinen; Raija Tahvonen

Abstract Vegetables of domestic and foreign origin were obtained from large wholesale outlets in Southern and Central Finland in 1988–1989 and then analyzed for sugars and major organic acids simultaneously by gas chromatography. The results showed great variation in the sugar and organic acid contents of the vegetable samples. The sugar and organic acid contents of tomato and Chinese cabbage differed significantly (P


Lipids | 2003

Chylomicron and VLDL TAG structures and postprandial lipid response induced by lard and modified lard.

Kaisa M. Yli-Jokipii; Ursula Schwab; Raija Tahvonen; Juha-Pekka Kurvinen; Hannu Mykkänen; Heikki Kallio

Alterations in chylomicron and VLDL TAG and the magnitude of postprandial lipemia were studied in healthy volunteers after two meals of equal FA composition but different TAG-FA positional distribution. Molecular level information of individual lipoprotein TAG regioisomers was obtained with a tandem MS method. The incremental area under the response curve of VLDL TAG was large (P=0.021) after modified lard than after lard. In plasma TAG, the difference did not quite reach statistical significance (P=0.086). In general, there were less TAG with palmitic acid in the sn-2 position and more TAG with oleic acid in the sn-2 position in chylomicrons than in fat ingested. From 1.5 to 8 h postprandially, the proportion of individual chylomicron TAG was constant or influenced by TAG M.W. VLDL TAG regioisomerism was similar regardless of the positional distribution of fat ingested. Significant alterations were seen in VLDL TAG FA, in M.W. fractions, and in individual regioisomers with respect to time. The TAG sn-14∶0-18∶1-18∶1+sn-18∶1-18∶1-14∶0, sn-16∶0-16∶1-18∶1+sn-18∶1-16∶1-16∶0, and sn-16∶1-18∶1-18∶1+sn-18∶1-18∶1-16∶1 decreased (P<0.05); and sn-16∶0-16∶0-18∶2+sn-18∶2-16∶0-16∶0, sn-16∶0-16∶0-18∶1+sn-18∶1-16∶0-16∶0, sn-16∶0-18∶1-16∶0, and sn-16∶0-18∶1-18∶2+sn-18∶2-18∶1-16∶0 increased (P<0.05) after both meals. In conclusion, positional distribution of TAG FA was found to affect postprandial lipid metabolism in healthy normolipidemic subjects.


Food Reviews International | 1996

Contents of lead and cadmium in foods and diets

Raija Tahvonen

Abstract Uptake of lead and cadmium by plants and animals, and factors affecting the contents of lead and cadmium in foods are discussed. Data on concentration of lead and cadmium in foods and diets presented in recent studies have been collected and evaluated. Trends of lead and cadmium contents in foods and diets are discussed.

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Ursula Schwab

University of Eastern Finland

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Hannu Mykkänen

University of Eastern Finland

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