Evaluation of the perinatal, postnatal and teratogenic effects of cocoa powder and theobromine in Sprague-Dawley/CD rats.

Studies were conducted to evaluate the effects of cocoa powder (CP) and theobromine (TBR) on perinatal and postnatal parameters and to assess their potential teratogenicity in the rat. In the peri/postnatal study, CP was given at 0, 2.5, 5.0 or 7.5% in the diet throughout gestation and lactation (postnatal day 21). In the teratology study, rats were given diets containing 0, 2.5 or 5.0% CP or 0.0675 or 0.135% TBR on days 6-19 of gestation. The CP-treated dams in the peri/postnatal study consumed significantly more food than did the controls during gestation. Weight gain was increased only in the 5.0 and 7.5% CP groups during lactation. Litter size was reduced slightly at 7.5% CP and pup survival was slightly decreased at 5.0 and 7.5% CP but none of these reductions was statistically significant. However, small but statistically significant decreases in pup body weights were noted in all treatment groups throughout lactation. In the teratology studies, rats given 2.5 or 5.0% CP or 0.0675 or 0.135% TBR consumed significantly more food than did the controls and the CP-treated dams gained significantly more weight. The percentage of pregnant dams and the mean number of corpora lutea were not affected by either CP or TBR. Foetuses exposed to 0.135 TBR had a significantly higher incidence of incompletely ossified or absent sternebrae and pubic bones, indicating a delay in osteogenesis. On the basis of the survival of treated offspring in the peri/postnatal study, these effects were not considered to be deleterious to either growth or survival. The effects are similar to those that have been reported elsewhere and been considered to indicate potential maternal or foetal toxicity that is unrelated to a specific compound/treatment. We conclude that any variations observed in these studies may be attributed to this non-specific maternal toxicity and are not related to the ingestion of either CP or TBR. The major methylxanthine found in the serum after CP or TBR ingestion was unchanged TBR and it did not bioaccumulate during gestation. The levels of CP and TBR used in these studies were more than 50 times greater than the maximum level of consumption by humans as reported in marketing surveys and were equivalent to a consumption of 10 lb of milk chocolate per day. The results indicate that neither CP nor TBR pose any health hazard to the developing foetus.