| 1. |
- Cashman, Kevin D., et al.
(författare)
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Individual participant data (IPD)-level meta-analysis of randomised controlled trials with vitamin D-fortified foods to estimate Dietary Reference Values for vitamin D
- 2021
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Ingår i: European Journal of Nutrition. - : Springer Berlin/Heidelberg. - 1436-6207 .- 1436-6215. ; 60:2, s. 939-959
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Tidskriftsartikel (refereegranskat)abstract
- Context and purpose: Individual participant data-level meta-regression (IPD) analysis is superior to meta-regression based on aggregate data in determining Dietary Reference Values (DRV) for vitamin D. Using data from randomized controlled trials (RCTs) with vitamin D3-fortified foods, we undertook an IPD analysis of the response of winter serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among children and adults and derived DRV for vitamin D.Methods: IPD analysis using data from 1429 participants (ages 2–89 years) in 11 RCTs with vitamin D-fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D DRV estimates across a range of serum 25(OH)D thresholds using unadjusted and adjusted models.Results: Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25 and ≥ 30 nmol/L are 6 and 12 µg/day, respectively (unadjusted model). The intake estimates to maintain 90%, 95% and 97.5% of concentrations ≥ 50 nmol/L are 33.4, 57.5 and 92.3 µg/day, respectively (unadjusted) and 17.0, 28.1 and 43.6 µg/day, respectively (adjusted for mean values for baseline serum 25(OH)D, age and BMI).Conclusions: IPD-derived vitamin D intakes required to maintain 90%, 95% and 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L are much higher than those derived from standard meta-regression based on aggregate data, due to the inability of the latter to capture between person-variability. Our IPD provides further evidence that using food-based approaches to achieve an intake of 12 µg/day could prevent vitamin D deficiency (i.e., serum 25(OH)D < 30 nmol/L) in the general population.
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| 2. |
- Dawczynski, Christine, et al.
(författare)
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Long-term moderate intervention with n-3 long-chain PUFA-supplemented dairy products : effects on pathophysiological biomarkers in patients with rheumatoid arthritis
- 2009
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Ingår i: British Journal of Nutrition. - 0007-1145 .- 1475-2662. ; 101:10, s. 1517-1526
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Tidskriftsartikel (refereegranskat)abstract
- n-3 long-chain PUFA (n-3 LC-PUFA) may improve cardiovascular and inflammatory diseases. The effects of n-3 LC-PUFA-supplemented dairy products on inflammation and immunological parameters, biomarkers of oxidative stress, serum lipids, and on disease activity were determined in patients with rheumatoid arthritis (RA). Forty-five subjects (forty-three females and two males) were randomly divided into two groups in a double-blind, placebo-controlled cross-over study. Both groups received placebo or verum products consecutively for 3 months with a 2-month washout phase between the two periods. Blood samples were taken at the beginning and at the end of each period. The dairy products generally improved serum lipids by increasing HDL and lowering lipoprotein it. The n-3 LC-PUFA supplements act to lower TAG. Additionally, a decreased lipopolysaccharide-stimulated cylo-oxygenase-2 expression was found in patients who had consumed the enriched dairy products. The majority of the CD analysed were not influenced, although n-3 LC-PUFA did suppress the immune response as lymphocytes and monocytes were found to be significantly decreased. The n-3 LC-PUFA did not increase the biomarkers of oxidative stress such as 8-iso-PGF(2 alpha), and 15-keto-dihydro PGF(2 alpha), and DNA damage like 7,8-dihydro-8-oxo-2'-deoxyguanosine. The long-term consumption of dairy products (2 x 12 weeks) diminished the excretion of hydroxypyridinium crosslinks, and favoured the diastolic blood pressure. The consumption of moderate doses of n-3 LC-PUFA in combination with dairy products did not improve the disease activity. However, there is evidence of cardioprotective effects. Furthermore, the long-term consumption of dairy products acts against the cartilage and bone destruction in RA.
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| 3. |
- Helbig, Dorit, et al.
(författare)
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Blackcurrant seed press residue increases tocopherol concentrations in serum and stool whilst biomarkers in stool and urine indicate increased oxidative stress in human subjects
- 2009
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Ingår i: British Journal of Nutrition. - 0007-1145 .- 1475-2662. ; 102:4, s. 554-562
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Tidskriftsartikel (refereegranskat)abstract
- Berry seeds are a tocopherol-rich by-product of fruit processing without specific commercial value. In a human intervention study, the physiological impact of blackcurrant seed press residue (PR) was tested. Thirty-six women (aged 24 +/- 3 years; twenty non-smokers, sixteen smokers) consumed 250 g bread/d containing 8% PR for a period of 4 weeks (period 3). Comparatively, a control bread without PR (250 g/d) was tested (period 2) and baseline data were obtained (period 1). Blood, stool and 24 h urine were collected during a 5 d standardised diet within each period. Tocopherol and Fe intakes were calculated from food intake. In serum, tocopherol concentration and Fe parameters were determined. In urine, oxidative stress markers 8-oxo-2'-deoxyguanosine, 8-iso-PGF2alpha and inflammatory response marker 15-keto-dihydro-PGF2alpha were analysed. Stool tocopherol concentration, genotoxicity of faecal water (comet assay) and antioxidant capacity of stool (aromatic hydroxylation of salicylic acid) were determined. Fe and total tocopherol intake, total tocopherol concentrations in serum and stool, and genotoxicity of faecal water increased with PR bread consumption (P < 0.05). The antioxidant capacity of stool decreased between baseline and intervention, expressed by increased formation of 2,3- and 2,5-dihydroxybenzoic acid in vitro (P < 0.05). In smokers, 8-oxo-2'-deoxyguanosine increased with PR consumption (P < 0.05). Prostane concentrations were unaffected by PR bread consumption. In summary, the intake of bread containing blackcurrant PR for 4 weeks increased serum and stool total tocopherol concentrations. However, various biomarkers indicated increased oxidative stress, suggesting that consumption of ground berry seed may not be of advantage.
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| 4. |
- Kuhnt, Katrin, et al.
(författare)
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Dietary supplementation with 11trans- and 12trans-18:1 and oxidative stress in humans
- 2006
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Ingår i: American Journal of Clinical Nutrition. - 0002-9165 .- 1938-3207. ; 84:5, s. 981-988
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Tidskriftsartikel (refereegranskat)abstract
- Background: High consumption of trans fat has been associated with high oxidative stress in humans, which could increase the risk of the development or acceleration of several diseases, such as atherosclerosis, cancer, and type 2 diabetes. Objective: Several urinary and blood biomarkers of oxidative stress [8-iso-prostaglandin-F2(alpha) (PGF(2 alpha)), 15-keto-dihydro-PGF(2 alpha), and 7,8-dihydro-8-oxo-2'-deoxy-guanosine in urine and alpha-, beta, gamma-, delta-tocopherol, and retinol in plasma] were monitored to evaluate the oxidative stress induced by dietary supplementation of 11trans- and 12trans-18:1 isomers in humans during a 6-wk intervention. Design: After a 14-d adaptation period free of trans fatty acid supplementation (baseline), the test group (n = 12) received 3.0 g 11trans-18:1/d and 3.0 g 12trans-18:1/d (Sigma 6.0 g/d), and the control group (n = 12) consumed a control oil free of trans fatty acids and conjugated linoleic acids for 6 wk. Results: The postintervention concentration of urinary 8-iso-PGF(2 alpha) (free radical-induced lipid peroxidation) in the test group was significantly higher than baseline and significantly higher than that observed in the control group. The concentrations of 15-ketodihydro-PGF(2 alpha) (cyclooxygenase-mediated inflammatory response indicator) and 7,8-dihydro-8-oxo-2'-deoxy-guanosine (oxidative DNA damage) were not affected by the 11trans- and 12trans-18:1 supplementation. Conclusions: Although an increase in urinary 8-iso-PGF(2 alpha) was observed and the effects of prolonged high (ie, > 5.0 g/d) consumption of trans fat could be relevant to the development of disease, the mean intakes of 11trans- and 12trans-18:1 in Europeans are estimated to be significantly below the amounts administered in this study (ie, 6.0 g/d); such low intakes could minimize the possible risk of detrimental effects on human health.
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