Role of hazelnut consumption on DNA damage and lipid-related markers in children with primary dyslipidemia

Dyslipidemia is a risk factor for atherosclerosis and cardiovascular disease development; it is closely associated with an increase in oxidative stress and a decrease in antioxidant defense mechanisms (Tangvarasittichai 2015; Vaziri 2014). Nuts are a rich source of bioactives such as polyunsaturated fatty acids, vitamins, phytosterols and polyphenols (Chen & Blumberg 2008). These compounds could play an important role not only in the management of dyslipidemia, but also in the modulation of oxidative stress. The objective of the present study is to evaluate the effect of hazelnut consumption on markers of oxidative stress, fatty acid composition of erythrocytes and serum lipids, in children with primary dyslipidemia. Sixty children (11.5 ± 2.5 years) have participated in an 8-week controlled, parallel, dietary intervention study with hazelnuts (0.43 g/kg body weight per day). Subjects received dietary guidelines and were randomized in 3 groups: 1- hazelnuts with skin; 2- hazelnut without skin; 3- control (without hazelnuts). Before and after intervention, blood samples were collected and used to evaluate the levels of formamidopyrimidine-DNA glycosylase (FPG)-sensitive sites and H2O2-induced DNA damage in peripheral blood mononuclear cells (by comet assay), serum lipid profile (by automatic analyzer) and erythrocyte membrane phospholipids composition (by gas chromatography analysis). Preliminary results in a subgroup (5 subjects receiving hazelnut with skin and 5 controls) show a reduction in the FPG-sensitive sites (from 13.8 ± 3.16% to 7.88 ± 2.98%) and H2O2-induced DNA damage (from 44.4 ± 3.1% to 35.7 ± 7.6%) following 8-week hazelnut consumption, while no effect seems to occur in the control group. Hazelnut decreases serum LDL-C level (-11.2%; p= 0.01) and seems to affect erythrocyte membrane phospholipids composition compared to baseline, while no difference in triglycerides, total and HDL-C levels has been documented in the subgroup analyzed. These preliminary results show a tendency towards a decrease in the levels of FPG-sensitive sites, H2O2-induced DNA damage and serum LDL-C after an 8-week hazelnut intervention. Data elaboration on the complete group of subjects will help understanding the effect of hazelnut consumption on lipid profile and markers of oxidative stress in children affected by primary dyslipidemia.