A Pilot Study on the Effects of Almond Consumption on DNA Damage and Oxidative Stress in Smokers

Abstract

The effects of almond consumption on DNA damage and oxidative stress among cigarette smokers were studied. Thirty healthy adult male regular smokers were randomly divided into three groups, 10 subjects per group. Group A (control group) did not receive any almonds. Subjects in Groups B and C received 3 oz and 6 oz (84 g and 168 g) of almonds each day respectively for 4 wk. Two known biomarkers for DNA damage, urinary 8-hydroxy-2'-deoxyguanosine (8-OH-dG) and single strand DNA breaks of peripheral blood lymphocytes, were measured by enzyme-linked immunosorbent assay and comet assay, respectively. In addition, plasma malondialdehyde (MDA) level, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were measured as biomarkers for oxidative stress. The results showed lower levels of urinary 8-OH-dG and single strand DNA breaks in the two almond-treated groups as compared with the control group. Furthermore, MDA levels in the almond-treated groups were lower than the controls. However, no significant effects of almonds on SOD and GSH-Px activities were found. In conclusion, results from this pilot study indicate that almond consumption has preventive effects on oxidative stress and DNA damage caused by smoking. A larger, randomized, placebo-controlled clinical trial on almonds will be initiated in the near future.

Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts

“…Lopez-Uriarte et al (160) found a significant reduction in DNA damage, measured as urinary 8-oxo-7,8-dihydro-2 0 -deoxyguanosine, a biomarker of oxidatively modified nucleic acids, after 12 weeks with 30 g mixed nuts (15 g walnuts, 7·5 g almonds, 7·5 g hazelnuts) when compared with a nut-free diet in a study of fifty metabolic syndrome patients. Jia et al (161) and Li et al (162) both reported significant reductions in oxidative DNA damage among smokers following 4 weeks of almond consumption at 84 g/d. Li et al (162) evaluated the effects of almonds v. pork (120 g/d) in a cohort of sixty male smokers serving in the Chinese army, and compared these effects with thirty non-smokers who consumed the control (pork) diet.…”

Lipophilic antioxidant content of almonds (Prunus dulcis): A regional and varietal study

“…For example, in pre-clinical trials almond oil provided therapeutic prevention against rat liver damage, demonstrated by increased levels of hepatic superoxide dismutase, catalase and glutathione (Jia et al, 2011). Almond consumption is also thought to ameliorate oxidative stress in the DNA of smokers (Jia et al, 2006). All of these health benefits have been largely attributed to high proportions of the unsaturated fatty acids (USFA), oleic acid and linoleic acid, as well as vitamin E.…”

Nut Consumption and Lung Cancer Risk: Results from Two Large Observational Studies

“…For example, tree nut extracts were found to be protective against oxidative damage [28], although results from animal studies and human clinical trials have shown mixed results [29, 30]. Studies on healthy male smokers consuming a diet enriched with powdered almonds showed a significant decrease in oxidative DNA damage and lipid peroxidation [31, 32]. This suggests nut consumption may decrease oxidative stress mediated by tobacco smoking [31].…”