cancer By reducing the body’s readiness to form blood clots, it also lowers the incidence of stroke And it lowers the artery-damaging form of blood cholesterol In sum, it looks as though a moderate and regular consumption of fatty ocean fish is good for us in several ways Fish obtain their omega-3 fatty acids directly or indirectly from tiny oceanic plants called phytoplankton Farmed fish generally have lower levels of the omega-3s in their formulated feed, and so less in their meat Freshwater fish don’t have access to the oceanic plankton, and so provide negligible amounts of omega-3s However, all fish contain low amounts of cholesterolraising saturated fats, so to the extent that they replace meat in the diet, they lower artery-damaging blood cholesterol and reduce the risk of heart disease Health Hazards There are three general kinds of hazardous materials that contaminate fish and shellfish: industrial toxins, biological toxins, and disease-causing microbes and parasites Toxic Metals and Pollutants Because rain washes chemical pollution from the air to the ground, and rain and irrigation wash it from the ground, almost every kind of chemical produced on the planet ends up in the rivers and oceans, where they can be accumulated by fish and shellfish Of the potentially hazardous substances found in fish, the most significant are heavy metals and organic (carbon-containing) pollutants, preeminently dioxins and polychlorinated biphenyls, or PCBs The heavy metals, including mercury, lead, cadmium, and copper, interfere with oxygen absorption and the transmission of signals in the nervous system; they’re known to cause brain damage in humans Organic pollutants cause liver damage, cancer, and ... washes chemical pollution from the air to the ground, and rain and irrigation wash it from the ground, almost every kind of chemical produced on the planet ends up in the rivers and oceans, where they can be accumulated by... and oceans, where they can be accumulated by fish and shellfish Of the potentially hazardous substances found in fish, the most significant are heavy metals and organic (carbon-containing) pollutants, preeminently dioxins and polychlorinated... biphenyls, or PCBs The heavy metals, including mercury, lead, cadmium, and copper, interfere with oxygen absorption and the transmission of signals in the nervous system; they’re known to cause