MONDAY, Oct. 26 (HealthDay News) -- Among Jewish survivors of World War II, those who were potentially exposed to the Holocaust have an increased risk of cancer, likely due to physical and mental stress, an Israeli study has found.


University of Haifa researchers compared cancer rates in more than 300,000 Israeli Jews who were born in Europe and immigrated to Israel either before World War II (non-exposed) or after the war (potentially exposed).


Compared to the non-exposed group, those in the potentially exposed group had a statistically significantly increased risk for cancer, especially breast and colorectal cancer, the researchers found. The younger a person was when they were exposed to the Holocaust, the greater their risk of cancer.


"These observations may have direct impact on the health of World War II Jewish survivors and thus the care required from their caregivers in Israel and elsewhere," wrote Dr. Lital Keinan-Boker, of the University of Haifa School of Public Health, and colleagues. "These findings warrant further epidemiological studies [such as case-control studies] of past and present risk factors that use individual data."


The study is published in the Oct. 26 online edition of the Journal of the National Cancer Institute.


The findings add to a growing body of knowledge about the links between cancer risk and severely restricted calorie intake and severe psychosocial and physical suffering, explained the authors of an accompanying editorial.


"Taken together, data from animal and human studies suggest that while [calorie reduction] typically decreases cancer risk, the anticancer effects of [calorie reduction] may be neutralized or overwhelmed in the presence of extreme stressors," wrote the editorialists, Stephen D. Hursting, of the nutritional sciences department at the University of Texas, Austin and Michele R. Forman, of the epidemiology department at the University of Texas M.D. Anderson Cancer Center in Houston.


"From this unique cohort we can learn lessons about adaptation to extreme hardships in early life, resilience during life, and cancer susceptibility later in life," they added.