Submitted to: Acta Horticulturae
Publication Type: Review article
Publication Acceptance Date: 5/15/2009
Publication Date: 8/15/2009
Publication URL: http://www.actahort.org/books/841/841_6.htm
Citation: Prior, R.L. 2009. Antioxidant status in vivo: the case for regular consumption of antioxidant rich fruits and vegetables. Acta Horticulturae. (ISHS) 841:75-84. Interpretive Summary: Consumption of low quantities of antioxidants in the diet may lead to conditions of oxidative stress which over time can lead to numerous diseases of aging including cancer, cardiovascular disease, diabetes, etc. Fruits and vegetables are sources of dietary antioxidants but the quantities in different foods and availability of these antioxidants is not the same in all foods. We have studied the ability of some foods, particularly fruits and berries, to prevent oxidative stress following a meal. We found that consumption of meals containing no antioxidants was associated with oxidative stress as measured in the blood, but certain berries and fruits such as blueberries, mixed grapes, and kiwifruit, when consumed with a meal are able to increase the antioxidant status following a meal. Results from these findings indicate that individuals need to be selective in the foods eaten at each meal to insure that foods containing high levels of antioxidants are consumed with every meal and that during the day, more than 6 servings per day of fruits and vegetables that contain significant amounts of antioxidants are consumed.
Technical Abstract: Since metabolism of energy is a major source of reactive oxygen species, the quantity of dietary antioxidants needed may be related to energy consumption. Antioxidant status in vivo can be altered by diet, but the postprandial response is dependent upon factors such as 1) antioxidant capacity (AOC) of food, 2) amount consumed, 3) type of phytochemicals and their content in the foods, 4) absorption/metabolism of the dietary antioxidants in the body, and 5) the fructose content particularly of fruits and berries. The ability of different foods to prevent postprandial oxidative stress varies due to these and perhaps other factors. We have demonstrated that consumption of certain berries and fruits such as blueberries, mixed grape, and kiwifruit, was associated with increased plasma AOC in the postprandial state and consumption of an energy source of macronutrients containing no antioxidants was associated with a decline in plasma AOC. High antioxidant berries, which have high levels of anthocyanins, are not as effective in vivo as antioxidants as some other foods, apparently because of the poor stability and/or absorption of anthocyanins. In order to prevent periods of postprandial oxidative stress, increased consumption of high antioxidant foods is needed, and perhaps more important, antioxidant containing foods need to be consumed in conjunction with carbohydrate and other sources of energy in each meal.