Antioxidant intakes

Flood, V., W. Smith et al. (2002). Dietary antioxidant intake and incidence of early age-related maculopathy The blue mountains eye study. Ophthalmology 109(12) 2272-2278. 

Snellen, E. L., A. L. Verbeek et al. (2002). Neovascular age-related macular degeneration and its relationship to antioxidant intake. Acta Ophthalmol. Scand. 80(4) 368-371. 

Regarding antioxidants, the parameter total dietary antioxidant capacity (TDAC) can be taken to reflect antioxidant intake it is defined as the antioxidant capacity of all plant foods and beverages (alcoholic and nonalcoholic) consumed daily in a diet and may represent the amount of antioxidant units (Trolox equivalents) present daily in the human gut (Saura-Calixto and Goni 2006). 

This ambivalence has generated criticism against antioxidants because they may interfere with this protection derived from the oxidative processes. Antioxidant intakes have been analyzed during clinical/epidemiological studies, which focused usually on vitamin C and E, beta-carotene, and flavonoids, respectively, The results were a mixture of positive and negative outcomes. 

Montonen J, Knekt R Jarvinen R, Reunanen A. Dietary antioxidant intake and risk of type II diabetes. Diabetes Care 2004 27 362-366. 

Kang JH, Pasquale LR, Willett W, et al. Antioxidant intake and primary open-angle glaucoma a prospective smdy. Am J Epidemiol 2003 158 337-346. 

Lykkesfeldt J, Christen S, Wallock LM, Chang HH, Jacob RA, Ames BN. Ascorbate is depleted by smoking and repleted by moderate supplementation a study in male smokers and nonsmokers with matched dietary antioxidant intakes. Am J Clin Nutr 2000 71 530-6. 

Some high-risk infants may benefit from modulation of maternal diet during lactation. A few studies indicate that the preventive effect of breast-feeding on the development of atopic eczema may be enhanced by maternal avoidance of potential food allergens (milk, egg and fish) during the lactation period, but other studies do not confirm this finding [99(NC), 107(IIIC), 111(11)]. The effects on the infant of other variations in the diet of a breast-feeding mother have not been studied, such as increased antioxidant intake. 

The effects on the infant of other variations in the diet of the pregnant mother have not been studied, such as increased antioxidant intake. 

Bodner C, Godden D, Brown K, et al Antioxidant intake and adult-onset wheeze A case-control study. Aberdeen WHEASE Study Group. Eur Respir J 1999 13 22-30. 

The influence of antioxidants (e.g. vitamin E or a-tocopherol, vitamin C or ascorbic acid, and carotenoids, including P-carotene and lycopene) on autoimmune diseases has not been extensively studied. There is some evidence that damage induced by reactive oxygen species contributes to the destruction of pancreatic beta cells, brain tissue, and joints seen in diabetes mellitus type 1, multiple sclerosis, and rheumatoid arthritis, respectively. However, there are few prospective studies of antioxidant intake and risk of autoimmune diseases. Although there is some evidence of a reduced risk of rheumatoid arthritis and lupus with higher intake or serum levels of antioxidants, there are inconsistent findings with respect to which antioxidants or foods are involved (Comstock et al., 1997 Knekt et al., 2000 Cerhan et al., 2003). Only one prospective study of antioxidants and risk of multiple sclerosis is available, and that study reported no association with intakes of vitamin C, vitamin E, or carotenoids (Zhang et al., 2001). 

If the prevention of oxidative DNA damage plays an important role in the cancer chemopreventive effects of dietary antioxidants, then one would expect to see an inverse relationship between antioxidant intake and biomarkers of oxidative DNA damage. Lymphocyte ascorbate concentrations were inversely associated with lymphocyte 8-oxodG concentrations in 105 men and women (r=-0.28)." However, plasma concentrations of a-tocopherol and carotenoids were positively correlated with lymphocyte concentrations of 8-oxodG in a study of 52 healthy women (r=0.29 to... 

In summary, trials of antioxidant supplementation of smokers and nonsmokers with vitamin C, a-tocopherol, or p-carotene did not generally find significant decreases in biomarkers of oxidative DNA damage, in contrast to observational studies, which suggest an inverse association between dietary antioxidant intake and oxidative DNA damage. 

Ekstrom, A.M., Serafmi, M., Nyren, O., Hansson, L.E., Ye, W., and WoUc, A., Dietary antioxidant intake and the risk of cardia cancer and noncardia cancer of the intestinal and diffuse types a population-based case-control study in Sweden, Int J. Cancer, 87, 133, 2000. 

The antioxidant theory is supported by results which show that some typical diseases of the elderly (Alzheimer s disease, cancer, diabetes, cardiovascular disorders) are often accompanied by the appearance of some markers of oxidative damage. However, the causal relationship is still unclear, so there is no way to tell cause from effect. The next paragraphs will surmnarize the main proven and assumed benefits of exogenous antioxidant intake. 

Van Gils CH, Bostick RM, Stem MC, Taylor JA (2002) Differences in base excision repair capacity may modulate the effect of dietary antioxidant intake on prostate cancer risk an example of polymorphisms in the XRCCl gene. Cancer Epidemiol Biomarkers Prev 11 1279-1284... 

The best sources of antioxidants are fruits and vegetables. Many nutritionists and doctors suggest that a balanced diet provides as much of these vitamins as you need. Others, however, recommend supplements that increase the amounts of antioxidants in the diet. Medical science has not given us a definitive answer about the use of supplements, but research continues to probe the correlation between antioxidant intake and disease. 

Com oil phenols have been studied with respect to their potential to scavenge the free radicals, the peroxyl radicals, the superoxide radicals, etc. The free radical scavenging activity of the phenolic acids using model free radicals such as l,7-diphenyl-2-picrylhydrazyl radical (DPPH ), or ABTS (2,2 -azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt cation radical) is often measured. TEAC (Trolox equivalent antioxidant capacity), FRAP (Ferric-reducing antioxidant capacity) and TRAP (total-radical-trapping antioxidant parameter) of the com oil are also used in order to obtain additional information, necessary to investigate the relation between the antioxidant intake and the oxidative stress related diseases (Stratil et al., 2008 Ceto et al., 2014 Apak et al., 2007). 

A high intake of antioxidants may slow or even prevent some of the deleterious age-related changes that lead to chronic disease, but antioxidants are unlikely to reverse established pathological changes Benefits of increased antioxidant intake may be seen only in those with marginal or depleted antioxidant status at baseline The effect of antioxidant supplementation may be seen only in subgroups of the study population, e.g., in those individuals with certain single-nucleotide polymorphisms... 

Vitamin C is concentrated in ocular tissues and fluids, particularly in the anterior aspect (cornea and lens). A case-control study in Spain reported a 64% reduction in the risk of cataract (p< 0.0001) in those with a plasma ascorbic-acid concentration of more than 49pmoll however, no significant association with the dietary intake of vitamin C was seen. In a case-control study in the Netherlands, the prevalence of age-related maculopathy was reported to be twice as high in those with low antioxidant intake (from fruits and vegetables) however the data on vitamin C intake or plasma levels and maculopathy are conflicting. Lipid-soluble antioxidants, especially zeaxanthin and lutein (dietary-derived carotenoids that are highly concentrated in the lipid-rich fovea), may be more relevant in this condition than water-soluble vitamin C. 

---