Despite all those talks about some fish containing high levels of toxins (mercury, for instance), medical researchers still love fish, touted to be the last wild meal in the human diet.
The biggest reason: It combats top health threats, according to an article published in Reader’s Digest.
“If you eat a modest amount of fish, you dramatically decrease your risk of dying from a heart attack,” Dr. Dariush Mozaffarian, a researcher of the Harvard School of Public Health, was quoted as saying by the magazine. Findings from 30 large studies conducted around the world show that people who consume just one or two servings of fish per week lower their risk of a fatal heart attack by an average of 36 percent, according to Mozaffarian.
That’s good news since the Department of Health ranks heart disease as the number-one killer in the Philippines. “The death toll from cardiovascular diseases in the country is about one every seven minutes,” says Dr. Philip S. Chua, one of the country’s top cardiologists. Cardiovascular diseases don’t affect the heart itself but also the blood vessel system, especially the veins and arteries leading to and from the heart.
If you have already a heart attack, shifting to a high-fish diet can cut your chances of future deadly attacks by one third. You see, fish contains oil that is nature’s richest source of omega-3 fatty acids called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Omega-3 fatty acid is a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids because they are important for good health. The body cannot make these fatty acids on its own so omega-3s must be obtained from food.
An article, which appeared in the Journal of the American Society for Clinical Nutrition said omega-3 fatty acids in fish oil prevent heart disease by exerting an anti-arrhythmic effect on the heart, by inhabiting the developing of narrowing arteries, by reducing the levels of undesirable lipoproteins in the blood, and by reducing blood clots within intact blood vessels.
“If your heart’s high blood pressure is caused by hardening of the arteries, heart disease, or high cholesterol, fish oil may be just what the doctor ordered,” wrote the editors of Super Life, Super Health. “The higher your cholesterol levels and the worse your heart disease, the better fish oil works to lower your blood pressure.”
The American Heart Association suggests that people should eat at least two servings of oily fish each week to help keep their hearts healthy. Best sources of omega-3s are bass (striped), herring, mackerel, oysters, sablefish, salmon, trout (freshwater), and tuna.
But hearts are not the only human part that benefit from fish. Older folks considered fish as “brain food” and now scientists have evidence to back the claim. A 2007 study of nearly 12,000 pregnant women found that children born to mothers who ate more than 340 grams of seafood per week during pregnancy scored six points higher on tests of verbal IQ than kids born to mothers who had other foods on the menu.
What about adults? A study done in Sweden found that young men who ate fish more than once a week scored nearly 11 percent higher on IQ tests than males who rarely ate seafood. And in later years, fish eaters appear to be less likely to develop dementia.
But you ain’t heard anything yet. A study published in Biological Psychiatry has shown that omega-3 fatty acids may help prevent depression. Dr. Joseph Hibbeln, who studies the health benefits of fish at the US National Institutes of Health, discovered omega-3 fatty acids can raise the levels of serotonin and dopamine, two brain chemicals that are thought to play a role in depression.
Fish oil appears to have anti-inflammatory properties, and has been researched as a treatment for many conditions including inflammatory bowel disease and rheumatoid arthritis. It also has some preventive effect for Parkinson’s disease.
So when is fish not so good for your health? Almost all fish is contaminated with trace amounts of mercury. While most healthy adults have no problem eliminating the mercury from their bodies, children and women who are pregnant or breast-feeding should avoid some types of fish and shellfish to reduce their risk of mercury exposure.
Fish that contain the low level of mercury are anchovies, catfish, clam, crab, haddock, hake, herring, salmon, sardines, shrimp, trout (freshwater), tuna, and whitefish. The following have higher content of mercury: swordfish, shark, king mackerel, and tilefish. “Avoid eating them, as possible,” warn experts.
If you are concerned about mercury, or if you just don’t want to eat fish, you need to get omega-3 fatty acids from other sources. There are many plant sources of omega-3 fatty acids, such as canola oil, flax seeds, walnuts and pumpkin seeds. The type of omega-3 fatty acids found in plants, called alpha linolenic acid (ALA), is not exactly the same as the fats found in fish, but experts say your body has the capability to transform ALA to both EPA and DHA.
Our very own tilapia has very low levels of mercury because it is a fast-growing and short-lived fish that mostly eats a vegetarian diet. However, a study done in the US has shown that eating tilapia is not good for those with heart problems.
“Cardiologists are telling their patients to go home and eat fish, and if the patients are poor, they’re eating tilapia. And that could translate into a dangerous situation,” said the researchers from the Wake Forest University School of Medicine.
“For individuals who are eating fish as a method to control inflammatory diseases such as heart disease, it is clear from these numbers that tilapia is not a good choice,” said an article which appeared in the Journal of the American Dietetic Association. “All other nutritional content aside, the inflammatory potential of hamburger and pork bacon is lower than the average serving of farmed tilapia.”
The American study found farm-raised tilapia has very low levels of beneficial omega-3 fatty acid and, perhaps worse, very high levels of omega-6 fatty acids. “In a fish-farming situation, the fish that you get depends on what they are fed,” explained Dr. Floyd Chilton, a professor of physiology and pharmacology and the director of the Wake Forest Center for Botanical Lipids.
“Now if these fish are fed, as in the wild, omega-3 fatty acids and algae, then they’re going to have long-chain omega-3 fatty acids, which are going to be incredibly beneficial. However, if these fish are fed short-chain omega-6 products that comes from corn products which is happening so often now then what one sees is the long-chain detrimental omega-6 fatty acids. So really the fish really are what they eat and we really are what we eat as well,” said Chilton, who headed the study.
That may be true of the tilapia raised in the US, pointed out Dr. Rafael Guerrero III, former executive director of the Laguna-based Philippine Council for Aquaculture and Marine Research and Development “It is true that farmed tilapia has lower omega-3 fatty acids than marine fish that feed on natural food [algae] in the ocean compared to tilapia fed in ponds and cages using feeds containing corn,” he explains. “But this applies more in the US. In the Philippines, we feed our tilapia with rice bran and soybean meal that contain less omega-6 fatty acids.”
On the controversy, which tilapia has created a stir among health buffs, Guerrero said, “There is still a controversy or disagreement among nutritionists with regard to the right balance of omega-6 and omega-3 which, we both need in our diet. More studies are needed.”
However, he believes that eating tilapia raised in the Philippines “is healthier than eating bacon and red meat because of its other attributes other than fatty acids such as proteins, minerals, and vitamins, among others.”