Comparison of the effects of dietary beef tallow and corn oil on pancreatic carcinogenesis in the hamster model

Abstract

We previously reported an enhancement of pancreatic carcinogenesis induced by N-nitrosobis(2-oxopropyl)amine (BOP) in hamsters fed diets containing high levels of corn oil. The research presented here compared diets high in corn oil with those high in beef tallow in the enhancement of pancreatic carcinogenesis. Pancreatic cancer was induced with 20 mg BOP/kg body wt, s.c. administered at 8 weeks of age. One week later, hamsters were assigned to one of five diet treatments: (i) 4.3% corn oil (control); (ii) 20.5% corn oil (high corn oil); (iii) 0.5% corn oil + 3.8% beef tallow (low beef tallow); (iv) 0.6% corn oil + 19.9% beef tallow (high beef tallow); and (v) 5.1% corn oil + 15.4% beef tallow (high fat mixture). These diets were fed until the study ended 84 weeks after BOP treatment. Hamsters were trained through pair feeding to consume the same calorie allotment as the control corn oil group. By the end of the experiment, BOP-treated hamsters that were fed diets containing beef tallow were consistently heavier than those fed corn oil. Survival was longer in hamsters fed the high-beef tallow and high-fat mixture compared with the other diet groups. Tumor data were age adjusted to correct for survival differences. Pancreatic adenoma incidence and multiplicity (no./effective animal) were higher in hamsters fed beef tallow than those fed corn oil diets. Carcinoma in situ multiplicity was elevated in hamsters fed high-fat diets irrespective of the nature of fat fed. Pancreatic adenocarcinoma multiplicity was elevated in hamsters fed the low- or high-beef tallow diets compared with the low- or high-corn oil diets. The mixture of fat resulted in an intermediate yield.

A Prospective Analysis of Intake of Red and Processed Meat in Relation to Pancreatic Cancer among African American Women

“…Decreased b-cell mass and function can lead to type 2 diabetes (55), which is an established risk factor for pancreatic cancer. High levels of dietary fat can also cause pancreatic hypertrophy or hyperplasia, which may increase the vulnerability of the pancreas to other carcinogenic insults (56,57). Bile acids are also hypothesized to promote pancreatic cancer, as bile acids stimulate the tumor promoter cyclooxygenase-2 in cell lines (4,(58)(59)(60)(61).…”

Dietary Fatty Acids and Cancer

“…Appel et al [188], however, found that increasing the linoleic acid content of the diet did not increase pancreatic carcinogenesis in either rats or hamsters. Birt et al [185] found that feeding a saturated fat [beef tallow] enhanced pancreatic carcinogenesis in hamsters greater than a polyunsaturated fat [corn oil]. In transgenic models, increasing dietary corn oil led to a higher incidence and size of pancreatic ductal neoplasia in elastase-Kras mice [189] and in PDX-1-Cre;LSL-KRAS G12D mice [190].…”

Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

“…It has been shown that a high-corn oil diet increased pancreatic ductal adenocarcinoma development in BOP-treated hamsters as compared with a low-corn oil diet [69]. Furthermore, a diet containing beef tallow has been shown to increase pancreatic cancer development compared with a diet containing corn oil [70]. Type and composition of fat are considered to be important.…”