In a recently published study, scientists found that removing the gonads from at least one species of fish caused decreased growth rates, suggesting that fish balls play a role similar to the pituitary gland.
Even when surgically transplanted to nonsense locations, fish nuts allowed for normal growth rates.
Further research is required to evaluate the growth promoting properties of multiple sets of fish testicles.As well as other possible side affects of increased naddage.
read more about the actual research here