No need for fish oil supplements?
acids could improve people's health and also satisfy different
palates, according to US researchers who are testing additives of
conjugated linoleic acid, an omega-6 fatty acid believed to fight
cancers and diabetes.
Farm-raised fish eating specially formulated diets high in fatty acids could improve people's health and also satisfy different palates, according to US researchers who are concocting designer menus for aquatic creatures.
Fatty acid feed supplements for fish may help people get government-recommended amounts of health-enhancing macronutrients, said Paul Brown, a Purdue University forestry and natural resources professor. He is currently testing conjugated linoleic acid (CLA), an omega-6 fatty acid which researchers have found to fight cancers and diabetes.
"We found by adding CLA to fishes' diets we can get more of these fatty acids into the fishes' tissues than is found in any other animal," said Brown, a nutritional aquaculturalist. "Meat and milk from ruminant animals are good sources of CLA, but these fish retain even higher levels."
The US National Academy of Sciences Institute of Medicine recently recommended that people increase their consumption of food containing alpha-linoleic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). The institute set the daily requirements, or Dietary Reference Intakes, of these macronutrients necessary to maintain health, and noted that cold-water fish, such as swordfish, tuna and salmon, are prime sources of omega-3.
"Fish have always been the original and standard measure for good sources of omega-3," Brown said. "But now we find that we can introduce other fatty acids into fish. Next we must determine if there is an optimum ratio of omega-3 and omega-6 fatty acids that is healthy."
The American Heart Association recommends at least two servings each week of omega-3-rich fatty fish. In one study, senior citizens who ate one serving weekly had a 44 per cent lower risk of heart attack, according to the organisation.
Special fish diets using additives, such as CLA, and grains, such as soybeans, can be formulated to produce designer fish that are high in beneficial fatty acids, Brown said. The research team is studying different fish species to chronicle their development on specialised diets and determine how much of the nutrients they retain. Purdue scientists discovered that some fish stay lean while others become much fatter because they retain the lipids, or polyunsaturated fat, from the fatty acids. The ability to raise more nutritional fish of a variety of species should encourage growth of the aquaculture (fish farm) industry, according to Brown.
"The consumer doesn't know to ask the right questions about fish," he said. "They have the perception that farm-raised fish or shellfish are inferior products and don't have the healthy fatty acids people need. If they want more omega-3 in their fish, we can put it in. The public just needs to say what it wants."