Blackcurrant seed press residue increases tocopherol concentrations in serum and stool whilst biomarkers in stool and urine indicate increased oxidative stress in human subjects

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 0 -deoxyguanosine, 8-iso-PGF 2a and inflammatory response marker 15-keto-dihydro-PGF 2a 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 0 -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.

Toxicity potentials of the nutraceutical Moringa oleifera at supra-supplementation levels

“…Blackcurrant seeds, for example, are a tocopherol-rich by-product of fruit processing, without any specific commercial value. In a human intervention study, the physiological impact of blackcurrant seed press residue was examined after its incorporation into food and found to demonstrate genotoxicity through an oxidative stress/damage mechanism (Helbig et al, 2009). Similarly, selenium at nutritional levels has been shown to have numerous anti-carcinogenic or preventative effects.…”

The health benefits of blackcurrants

“…States of increased oxidative stress can be seen in disease, smoking activity and physical exercise in unconditioned individuals. 51 Multiple accounts show empirical support regarding the antioxidant ability of blackcurrants. 38,52 Data from additional studies demonstrates the neutralization of hydrogen peroxide (H 2 O 2 ) and NO, as well as impeding the propagation of lipid and protein peroxidation.…”

“…Blackcurrant seeds contain high levels of PUFAs as well as polyphenolic and tocopherol content, which help inhibit the oxidative damage to DNA, lipids and proteins seen in coronary heart disease, particularly concerning the generation of atherosclerotic plaques. 51 Additional studies have demonstrated that administration of a blackcurrant soft oil capsule increases serum HDL-C protein while lowering triglyceride levels and total cholesterol in hyperlipidemic patients with a low body mass index, thus increasing a favorable lipid profile. 100 Consumption of blackcurrant juice by healthy human subjects was shown to have no significant effect on total plasma nitrate, nitrite, intracellular adhesion molecules (ICAM) or vascular cell adhesion molecules (VCAM).…”

Recent Perspectives on the Relations between Fecal Mutagenicity, Genotoxicity, and Diet

“…This led to the conclusion that smokers and non-smokers benefited differently from the intervention with probiotic bread ± antioxidants. A subsequent study from the same group (Helbig et al, 2009) examined the effect of 250 g/day of bread supplemented with tocopherol-rich blackcurrant seed press residue on stool tocopherol, antioxidant capacity, and fecal water genotoxicity ( n  = 36 women, 4 weeks intervention). Tocopherol in plasma and stool were increased and genotoxicity of fecal water was also increased after consumption of supplemented bread compared to control bread.…”