Antioxidants may prevent these degenerative processes by various mechanisms including scavenging of free radicals.
Mutagens and carcinogens may act through the generation of free radicals which initiate a series of degenerative processes related to cancer, heart disease, and aging ( 6). Adipositiy leads to oxidant stress because intracellular triglycerides cause increased superoxide formation ( 3) and stimulate adipocytes or preadiposites to produce inflammatory cytokines ( 4) which induce formation of various oxidative radicals ( 5). Oxidized LDL contributes to the formation of atherosclerotic lesions and poses an additional oxidant stress that injures smooth muscle and endothelial cells ( 2). Oxidative damage is involved in many chronic diseases including the major causes of death in Western societies such as cardiovascular disorders and cancer ( 1). We conclude from this pilot study that OJ is an excellent food source to enhance circulating concentrations of valuable hydrophilic as well as lipophilic phytochemicals. LDL-/HDL-cholesterol ratio decreased but cholesterol (HDL, LDL, total) and thiobarbituric acid reactive substance plasma concentrations did not change significantly.
8-Hydroxy deoxyguanosine (8OHdG) in white blood cells declined by 16% (p=0.38 n=11), and in individuals with high baseline concentrations by 29% (p=0.36 n=7), respectively.
After the 3-week intervention plasma concentrations of vitamins A and E did not change. Flavanones were excreted in urine 9 fold more at the end of the intervention (p=0.01) but returned to baseline two days after study completion. At the end of three weeks mean vitamin C, folate, carotenoid, and flavanone plasma concentrations increased significantly relative to baseline by 59% (p<0.001), 46% (p=0.018), and 22% (p<0.001), and 8 fold (p=0.045), respectively. Seven healthy females and six males consumed daily 256 mg vitamin C, 229 mg hesperidin (main flavonoid occurring as glycoside), 6 mg carotenoids (mainly luteins and cryptoxanthins), and 0.16 mg folate by incorporation of daily 236 mL of not-from-concentrate orange juice (OJ) into their habitual diet.