Observational studies of fruit and vegetable intake

A number of studies of people who eat a diet rich in fruit and vegetables, and therefore rich in antioxidant nutrients, have tried to test the hypothesis that fruit and vegetables lower the risk of CHD (Phillips et al., 1980 Chang-Claude et al., 1992 Thorogood et al., 1994 Key et al., 1996). In general, observational studies of vegetarians and those with diets rich in fruits and vegetables support the hypothesis that such diets might lower the risk of CHD. Vegetarians generally have high...

Closed trials

This section summarizes five large-scale, randomized trials for which accrual has been either completed or closed and results reported long-term follow-up is continuing for these trials to determine safety as well as efficacy (Omenn et al., 1996a). The Linxian Trials, conducted by the NCI in collaboration with the Cancer Institute of the Chinese Academy of Medical Sciences, were two randomized, double-blind chemoprevention trials designed to determine whether daily ingestion of vitamin mineral...

Vitamin C

Vitamin C is probably the most effective, least toxic water-soluble antioxidant identified in mammalian systems (Levine, 1986 Frei et al., 1988). Lens concentrations of vitamin C (mmol l-1) are many times higher than in plasma or other tissues and are related to dietary intake in humans (Taylor et al., 1991, 1997). The concentration of vitamin C in the lens is increased with dietary supplements beyond levels achieved in persons who already consume more than two times the recommended daily...

Future Directions

We have provided a brief overview of studies that demonstrate the presence of membrane deficits and oxidative stress in schizophrenia, and have suggested that membrane deficits are a consequence of oxidative stress. The obvious implication of these findings is the possibility of therapeutic interventions. However, any rational approach to using adjunctive EFA supplementation and antioxidants will require a series of studies to establish the parameters within which treatment recommendations can...

Isoprostanes as Oxidative Markers in Degenerative Diseases

Free radical-mediated tissue damage has been implicated in a wide variety of degenerative diseases. The exposed double bonds of the PUFA of cell membrane phospholipids are particularly susceptible to attack by free radicals. Increased isoprostane levels have been reported in a wide variety of disorders, from scleroderma (Stein et al., 1996) to cystic fibrosis (Collins et al., unpublished observations) and hepatorenal syndrome (Morrow et al., 1993). High levels of free radicals found at a site...

References

Bierenbaum, M.L., Noonan, F.J., Machlin, L.J., Machlin, S., Stier, A., Watson, P.B., Naso, A.M. and Fleischman, A.I. (1985) The effect of supplemental vitamin E on serum parameters in diabetics, postcoronary and normal subjects. Nutrition Reports International 31, 1171-1180. Ceriello, A., Giugliano, D., Quatraro, A., Donzella, C., Dipalo, G. and Lefebvre, P.J. (1991) Vitamin E reduction of protein glycosylation in diabetes. Diabetes Care 14, 68-72. Cushing, S.D., Berliner, J.A., Valente, A.J....

Cigarette Smokers

This experimental model related to cigarette smokers compared with non-smokers (Hulea et al., 1995). Smokers generally had a higher plasma lipid peroxide concentration (TBAR) but a lower total antioxidant capacity (Table 14.5). This was significant at ages 46-80 (groups C and D). These subjects had smoked at least 12 cigarettes per day for more than 2 years. It was shown in an in vitro study (Mahfouz et al., 1995) that smoking increased the concentration of lipid peroxides. We used the...

Antioxidants from herbs and spices

The consumption of herbs and spices, which is a feature of many dietary practices world-wide, makes a significant contribution to the intake of phytochemicals with biological action (Huang et al., 1994 Plumb et al., 1995). Numerous spices have been shown to exert biological effects by modulating arachidonic acid metabolism and platelet aggregation (Table Table 15.2. Isoflavone content (mg 100 g 1) in traditional and commercial soy items. Adapted from Samman et al. (1996). Table 15.2. Isoflavone...

Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an obstructive airway disorder characterized by a gradually progressive and irreversible decrease in forced expiratory volume (FEVj) (Siafakas et al., 1995). The condition usually arises due to chronic bronchitis or emphysema and the airflow obstruction may be accompanied by airway hyperreactivity. Asthma is generally differentiated from COPD, although distinguishing the two in a patient who smokes and has allergies can be difficult. This decrease...