Increased dietary intakes of specific antioxidant nutrients, like vitamin C, alpha-carotene, and proanthocyanidins were also individually associated with significant reductions in risks for the cancer, according to results published from the Iowa Women's Health Study in the International Journal of Cancer.
Non-Hodgkin lymphoma is a cancer that starts in the lymphatic system and ecompasses about 29 different forms of lymphoma. According to the American Cancer Society, over 50,000 new cases are diagnosed in the US every year.
A reduction in the risk was also recorded for dietary manganese, the first time such a link has been reported, “and thus this will require replication”, said the researchers.
“These results support a role for vegetables, and perhaps fruits and associated antioxidants from food sources, as protective factors against the development of non-Hodgkin lymphoma and follicular lymphoma in particular,” said the researchers.
Led by James Cerhan, from the Mayo Clinic College of Medicine, the researchers analysed dietary intakes for 35,159 Iowa women aged between 55 and 69. During the course of the study 415 cases of non-Hodgkin lymphoma were documented.
Dietary vitamin C intakes were associated with a 22 per cent reduction in lymphoma risk, while alpha-carotene, proanthocyanidins, and manganese were associated with 29, 30, and 38 per cent reductions in risk.
No associations with multivitamin use or supplements for the nutrients were observed.
Increased intakes of fruits and vegetables were associated with a 31 per cent reduction in risk, while yellow/orange and cruciferous vegetables were linked to a 28 and 18 per cent reduction.
“Most studies have not shown an association with supplemental intake of antioxidant nutrients, suggesting that any association is likely to be mediated through foods,” said the researchers.
“This has mechanistic implications (potential synergies between antioxidants; other anticarcinogenic compounds in these foods) and also suggests that prevention approaches will likely need to be targeted toward foods and food groups and not individual nutrients, particularly taken as supplements,” they concluded.
Source: International Journal of Cancer
Volume 126 Issue 4, Pages 992-1003
"Antioxidant intake from fruits, vegetables and other sources and risk of non-Hodgkin's lymphoma: the Iowa Women's Health Study"
Authors: C.A. Thompson, T.M. Habermann, A.H. Wang, R.A. Vierkant, A.R. Folsom, J.A. Ross, J.R. Cerhan