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ARS Home » Southeast Area » Little Rock, Arkansas » Arkansas Children's Nutrition Center » Research » Publications at this Location » Publication #195512
Title: ANTIOXIDANT STATUS IN VIVO: THE CASE FOR REGULAR CONSUMPTION OF ANTIOXIDANT RICH FOODS

Author
item Prior, Ronald
item WU, XIANLI - ACNC/UAMS

Submitted to: Food Science Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2006
Publication Date: 6/23/2006
Citation: Prior, R.L., Wu, X. 2006. Antioxidant status in vivo: the case for regular consumption of antioxidant rich foods. Institute of Food Technology Annual Meeting, June 24-28, 2006, Orlando, Florida. Paper No. 020H-12.

Interpretive Summary: Consumption of fruits and vegetables is beneficial in preventing cardiovascular disease and cancer. Antioxidants may protect against free radical damage; however, data is limited on the extent of absorption of nontraditional antioxidants in foods and their effect on oxidative stress in the body. The objective of the studies to be presented was to determine postprandial changes in blood antioxidants following a meal of selected berries/fruits and study effects of added macronutrients (carbohydrate, fat, protein) to the control meal on blood antioxidant levels. Blood antioxidant levels decreased when the control meal contained macronutrients without antioxidants. It was calculated that it would require about 2 servings of antioxidant-containing fruits and/or vegetables to overcome the negative effects of a meal without any antioxidants. Consumption of high doses of blueberries in 2 different studies and grapes in a third study increased the antioxidants in blood. The results indicate that it is possible to increase antioxidant levels in the body through dietary means. In order to prevent periods of apparent oxidative stress following a meal, antioxidant-containing foods need to be consumed in conjunction with energy sources in each meal.

Technical Abstract: Justification: Consumption of fruits and vegetables is beneficial in preventing cardiovascular disease and cancer. Antioxidant phytochemicals (AP) may protect against free radical damage; however, data is limited on the extent of absorption of AP and their effect on in vivo oxidative stress (OS). Objective: To determine postprandial changes in plasma antioxidant capacity (AOC) following a meal of selected berries/fruits and study effects of added macronutrients (carbohydrate, fat, protein) to the control meal on AOC. Methods: AOC of blood samples collected before and after a meal were analyzed (ORACFL assay). Changes in the area under the curve (AUC) of plasma AOC were used to estimate antioxidant status. Results: AOC decreased when the control meal contained macronutrients (~454 kcal) w/o antioxidants, with a net change in AUC of -1.0±0.4 unit ['mol Trolox Equivalents (TE)/L . h) per kcal of energy consumed] of AOC AUC. Postprandial AOC increased following blueberry, grape, cherry, strawberry and kiwi fruit consumption. An average increase in AUC AOC of 40 units per mmol TE of AOC consumed was observed (9 different foods) in human subjects. For a meal of 700 kcal, sufficient antioxidants would be needed to overcome a projected decline in AOC AUC of 693 units. Assuming foods provide on average, 40 units of AUC AOC of protection, 17.3 mmol TE of AOC would be needed to prevent a projected transient postprandial period of OS. However, if we assume that it is energy that is inefficiently utilized in the mitochondria (~25% of energy from carbohydrate) which accounts for most of the free radical production, 4.33 mmol TE of AOC or about 2 servings of antioxidant-containing fruits and/or vegetables would be required. Significance: In order to prevent periods of apparent postprandial OS, antioxidant-containing foods need to be consumed in conjunction with energy sources in each meal.