Drinking tomato juice daily for five weeks after a
vigorous workout or physical activity in untrained individuals can reduce
ROS-induced oxidative stress, according to a Swedish study published in the
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 cell
components 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 exercise
and diet rich in antioxidants, thus, protect against oxidative stress,
especially DNA based damage.
Oxidative stress induced DNA
damage is measured by the concentration of 8-Oxo-2'-deoxyguanosine (8-oxo-dG)
present within the cell.
So, to investigate whether tomato juice protects against
ROS induced by extensive physical exercise in untrained individuals, Swedish
researchers Mats Harms-Ringdahl and colleagues from Centre for Radiation
Protection Research (CRPR), Department of Genetics, Microbiology and
Toxicology, Stockholm University, Sweden, used 8-oxodG as 'sensitive marker' of oxidative stress.
They monitored serum
levels of 8-oxodG using a modified ELISA. Fifteen untrained healthy
subjects were given 150 ml tomato juice per day for two 5- week periods with a
5- week-without- tomato-juice period in between the two periods. Blood samples
were taken before and after each period. At the day of blood collection, the
subjects performed a 20-minute acute physical exercise using an ergometer
The results showed that -
Blood serum 8-oxodG increased significantly in all
subjects after an acute physical exercise. This suggests a positive correlation
between 8-oxodG in serum and ROS production.
Tomato juice intake (15 mg lycopene) of
150 ml per day significantly protected the nucleotide pool of the DNA from ROS
produced 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 and
stable in food processing. Therefore, the researchers believed that lycopene is
responsible for the antioxidant activity in tomato juice.
They concluded - 'Long term intake of tomato juice may
reduce oxidative stress levels in patients with enhanced level of oxidative
stress, for example, patients with diabetes, cardiovascular diseases or
Reference: Harms-Ringdahl M, Jenssen D, Haghdoost S. Tomato
juice intake suppressed serum concentration of 8-oxodG after extensive physical
activity. Nutr J. 2012 May 2;11(1):29.