Radiation is often used to treat prostate cancer, but it can lead to damage in surrounding non-cancerous tissues resulting in bowel and sexual dysfunction in some men. Approaches that reduce the risk of prostate cancer and/or its progression include dietary interventions containing tomato carotenoids. These antioxidants are capable of quenching the singlet oxygen produced by radiation therapy and by doing so may reduce apoptosis induction in normal tissues. However, the extent to which the inclusion of tomatoes or their carotenoids in the diet may mitigate the non-targeted effects of radiation therapy is not known. Rowles and colleagues conducted a study to evaluate the impact of dietary tomatos on apoptosis in neoplastic and non-neoplastic tissues. Results from this work are published in the November 2021 issue of The Journal of Nutrition.
The TRAMP model of prostate cancer was used to study the effect of including 10% of a freeze-dried tomato paste in the diet of mice starting at 4 weeks of age. The tomato and control diets were balanced for all macronutrients. The caudal half of the mice were exposed to 7.5 Gy or 0 Gy of 60Co at 24 weeks of age and mice were euthanized 24 hours after irradiation.
Serum concentrations of lycopene, phytoene, and a-tocopherol were lower in the tomato-fed mice exposed to radiation when compared with those consuming the tomato diet but receiving the sham treatment. Radiation led to increased apoptosis in tumors and this effect was not altered by the tomato diet. Apoptosis in the cranial and caudal duodenum was lower in the irradiated mice consuming the tomato diet relative to those consuming the control diet. Apoptosis in the dorsolateral prostate also tended to be lower in the irradiated mice consuming the tomato diet. These observations led the authors to conclude that long term tomato consumption selectively reduced apoptosis in non-neoplastic tissues without decreasing apoptosis in the tumors. However, they recommend more work to determine if consuming tomatoes at the time of cancer detection could be used as a therapeutic approach.
Joe L Rowles, III, Matthew A Wallig, Kimberly A Selting, Timothy M Fan, Rita J Miller, William D O’Brien, Jr, John W Erdman, Jr, A 10% Tomato Diet Selectively Reduces Radiation-Induced Damage in TRAMP Mice, The Journal of Nutrition, Volume 151, Issue 11, November 2021, Pages 3421–3430, https://doi.org/10.1093/jn/nxab257.
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