why people cant drink ocean water? Seawater contains salt. when humans drink seawater, their cells are thus taking in water and salt. while humans can safely ingest small amounts of salt, the salt content in seawater is much higher than what can be processed by the human body. when we consume salt as part of our daily diets, we also drink liquids, which help to dilute the salt and keep it at a healthy level. Living cells do depend on salt to maintain the body’s chemical balances and reactions; however, too much salt can be deadly.