Background – Carotenoids are fat soluble pigments, which may play an anti-inflammatory role. Their circulating levels are low in the asthma, a disease that is defined as chronic inflammation of the airways. It has been shown that lycopene supplementation can reduce exercise-induced oxidative stress in stable asthma.
Objectives – The aim of this study was to determine the effect of the lycopene supplementation (as tomato juice and lycopene capsules) on the plasma levels of selected cytokines in stable asthma.
Design – Thirty-two asthma patients visited the clinic on 7 occasions over the 51-day period. They received 3 different treatments ie tomato juice, lycopene capsules, and placebo for 7 days each, in random order with a 10 day washout period between each treatment. During the study period, patients were advised to consume a low antioxidant diet. Blood samples were collected and interleukin-6, interleukin-8, high sensitivity CRP, and TNF-α levels in plasma were measured by ELISA. The difference between the levels of different cytokines after each treatment was analyzed by Friedman test, and the change during the initial washout period was analyzed by Wilcoxon test.
Outcomes – Seventeen subjects completed the study. There was no significant difference between the levels of each cytokine after each treatment, and the levels of the cytokines were not statistically different following the initial washout period. There was a trend toward decreased CRP after tomato juice and lycopene capsules, but because of small sample size and high variability of the data, these changes were not statistically significant.
Conclusion – Treatment of asthmatic subjects with lycopene supplements has not led to changes in systemic inflammation.