Drinking tomato juice daily for five weeks after avigorous workout or physical activity in untrained individuals can reduce ROS-induced oxidative stress, according to a Swedish study published in the Nutrition Journal. 

Reactive oxygen species (ROS) that include oxygen ions, hydroxyl ions and peroxides play an important role in the development of cancer and aging process. They react with cellcomponents such as proteins, lipids, and DNA and bring about chemical modifications in the cells, causing what is known as oxidative stress. 

 Under normal conditions,anti-oxidants present in the cell fight ROS and bring down their levels thereby minimizing damage to the cells. Regular physical activity or exerciseand diet rich in antioxidants, thus, protect against oxidative stress,especially DNA based damage. 

 Oxidative stress induced DNAdamage is measured by the concentration of 8-Oxo-2'-deoxyguanosine (8-oxo-dG)present within the cell. 

 So, to investigate whether tomato juice protects againstROS induced by extensive physical exercise in untrained individuals, Swedishresearchers Mats Harms-Ringdahl and colleagues from Centre for RadiationProtection Research (CRPR), Department of Genetics, Microbiology andToxicology, Stockholm University, Sweden, used 8-oxodG as 'sensitive marker' of oxidative stress.

 They monitored serumlevels of 8-oxodG using a modified ELISA. Fifteen untrained healthysubjects were given 150 ml tomato juice per day for two 5- week periods with a5- week-without- tomato-juice period in between the two periods. Blood sampleswere taken before and after each period. At the day of blood collection, thesubjects performed a 20-minute acute physical exercise using an ergometerbicycle. 

 The results showed that - 

. Blood serum 8-oxodG increased significantly in allsubjects after an acute physical exercise. This suggests a positive correlationbetween 8-oxodG in serum and ROS production.

. Tomato juice intake (15 mg lycopene) of150 ml per day significantly protected the nucleotide pool of the DNA from ROSproduced in response to extensive physical activity.

 Besides lycopene, tomatoes also contain vitamin C,tocopherols and polyphenols but lycopene is found to be the most abundant andstable in food processing. Therefore, the researchers believed that lycopene isresponsible for the antioxidant activity in tomato juice. 

 They concluded - 'Long term intake of tomato juice mayreduce oxidative stress levels in patients with enhanced level of oxidativestress, for example, patients with diabetes, cardiovascular diseases orinflammation'.

Reference: Harms-Ringdahl M, Jenssen D, Haghdoost S. Tomatojuice intake suppressed serum concentration of 8-oxodG after extensive physicalactivity. Nutr J. 2012 May 2;11(1):29. http:www.nutritionj.com/content/pdf/1475-2891-11-29.pdf