New technologies are promising for the use of short-term instruments for dietary data collection; however, innovative tools should be validated against objective biomarkers. The aim of the present study was to investigate the validity of a Web-based, self-administered dietary record (DR) tool using protein, K and Na intakes against 24 h urinary biomarkers (24 h U). Of the total participants, 199 adult volunteers (104 men and 95 women, mean age 50·5 (23 -83 years)) of the NutriNet-Santé Study were included in the protocol. They completed three non-consecutive-day DR and two 24 h U on the first and third DR days. Relative differences between reported (DR) and measured (24 h U) intakes were calculated from the log ratio (DR/24 h U) for protein, K and Na intakes: 2 14·4, þ 2·6 and 2 2·1 % for men; and 2 13·9, 2 3·7 and 28·3 % for women, respectively. The correlations between reported and true intakes were 0·61, 0·78 and 0·47 for men and 0·64, 0·42 and 0·37 for women for protein, K and Na, respectively. Attenuation factors, that represent attenuation of the true diet-disease relationship due to measurement error (a value closer to 1 indicating lower attenuation), ranged from 0·23 (Na, women) to 0·60 (K, men). We showed that the Web-based DR tool used in the NutriNet-Santé cohort study performs well in estimating protein and K intakes and fairly well in estimating Na intake. Furthermore, three non-consecutive-day DR appear to be valid for estimating usual intakes of protein and K, although caution is advised regarding the generalisability of these findings to other nutrients and general population.

Plasma selenium (Se), zinc (Zn) and copper (Cu) levels and antioxidant metalloenzymes, glutathione peroxidase (GPX) and superoxide dismutase (SOD), were studied in 17 patients on maintenance hemodialysis (HD) (group I), 14 uremic patients (group II) and 14 healthy subjects (group III). Plasma Se levels and erythrocyte GPX were significantly lower in the HD group (for Se: 0.69 ± 0.12 vs. 1.05 ± 0.13 μmol/l in controls; for erythrocyte GPX: 34.4 ± 6.4 vs. 49.2 ± 9 lU/g hemoglobin in controls) and a significant correlation was found between the two parameters (r = 0.66, p < 0.005). There was also a correlation between decreased plasma Zn and erythrocyte SOD activity (r = 0.58, p < 0.02) and between decreased plasma Cu and erythrocyte SOD (r = 0.60, p < 0.02). Plasma malondialdehyde levels were augmented in HD patients (5.08 ± 0.26 vs. 2.55 ± 0.15 μmol/l in controls and 2.79 ± 0.40 μmol/l in the uremic group). The catalase activity was increased in HD patients (202 ± 24 vs. 140 ± 40 IU/mg hemoglobin in group III). A defective antioxidant activity may thus contribute to increased peroxidative damage to cells in the course of dialysis.

Phytoprostanes (PP) are autoxidation products of alpha-linolenate that are present in all plant tissues. Several classes of PP with a prostaglandin (PG) F1-, E1-, A1- and B1-like structure were identified and quantified by gas chromatography-mass spectrometry in vegetable oils and parenteral nutrition (intralipid). High levels of PP (0.09 up to 99 mg/l) were found even in apparently fresh vegetable oils. After oral consumption of olive or soybean oil, PPF1 were absorbed, found to circulate in plasma in conjugated form and excreted in free form into urine. Evidence is emerging that certain PP, such as the PPE1, may modulate the function of immune cells in a PG-like fashion. Here, we show that PPA1- and deoxy-PPJ1 display potent anti-inflammatory and apoptosis inducing activities similar to PGA1 and deoxy-PGJ2. Results of this study indicate that PP are novel, biologically active lipids in plant nutrition.