Consuming clams as a primary source of protein markedly reduces levels of cholesterol in both the blood and the liver - at least in mice. In a recent study, when male mice on high cholesterol diets were given little-neck clams, their serum and hepatic (liver) cholesterol levels dropped significantly - a reduction not seen in control animals given casein (a protein found in dairy products) instead.
Earlier studies on humans have produced similar results. In one study, eighteen men with normal cholesterol levels were given diets in which shellfish, one of which was clams, were used to replace animal foods normally in their diet. When the men ate clams or oysters prepared with less than half the amount of fat found in the animal foods they normally ate, their total cholesterol, VLDL (very bad) cholesterol, and LDL cholesterol dropped, while diets using squid and shrimp did not produce these beneficial effects on blood lipids.