Why Fish Should Be On Your Diet List?

Fish, like salmon, mackerel and albacore tuna, that high in omega-3 fatty acid is good for the heart because omega-3 fatty acid could reduce the risk of coronary heart disease. Perhaps this is why American Heart Association (AHA) advice people to eat at least 2 servings of fish a week.

Despite concerns on the impact of increased exposure to mercury in fish, Swedish researchers from Umea University in Sweden argued in their paper published in November 2010 in ‘American Journal of Clinical Nutrition’ that the benefits of consuming fish still outweigh the harmful effects of mercury. However, they also advised people to avoid eating fish high in mercury, which include perch, shark, swordfish and halibut.

More than 900 Swedish men and women took part in a study that required them to answer questionnaires about the amount of fish in their diet. Their mercury and selenium levels in red blood cells were analyzed.

While the mercury levels were generally low for Scandinavians, participants who had higher mercury level in their red blood did not have a higher risk of cardiac problems. It is possible that the protective nutrients in fish offset any harmful effect of mercury at these low levels of mercury, as explained by the researchers.

Meanwhile, the researchers admitted that relying on the participants’ memories on the amount of fish consumed could have drawbacks as this could have an impact on the results obtained. They also highlighted one finding from their study: participants who had elevated traces of selenium in their red blood cells appeared to have higher risk of sudden cardiac death.

Selenium is a trace mineral that is essential to good health but only small amounts are needed. It appears to act as an antioxidant that can reduce risk of cardiovascular disease and cancer.

Nevertheless, previous findings on effect of selenium on heart were mixed. Several studies suggested risk of heart disease and stroke might be reduced by about 40 percent by an added 100 mg per day of dietary selenium. On the other hand, a study by researchers from University of Warwick found that total cholesterol levels increased by 8 percent with an increase of 10 percent in LDL (so called bad cholesterol) in participants having more than 1.2 mol/L of selenium in their blood, leading to increase in risk of cardiovascular disease.

As such, the Swedish researchers felt that the health effect of selenium should further be probed.

Can Fish Oil Really Prevent Heart Disease?

Omega-3 fatty acid is healthy for all from growing children to heart disease patients. This is the message conveyed to people for years by many health professionals and doctors. In recent years, omega-3 has even been added to some foods such as margarine and eggs.

However, Dutch researchers found in their study of about 5,000 heart attack survivors that eating about 400 milligrams of fish fatty acids per day did not significantly decrease the risk of getting heart attack, stroke, heart failure and other cardiovascular events for those patients who were already getting good care. 400 milligrams of fish fatty acids is the equivalent of 2 fatty fish meals.

At the end of 3 and half years, there was no change in death, heart attack and other heart problems between those who consumed margarine with added omega-3 fatty acids and those who did not.

The findings were presented by researchers from Wageningen University in the Netherlands during the month of August 2010 at the European Society of Cardiology meeting in Stockholm, Sweden, and published online by the New England Journal Of Medicine.

Does the results mean that getting more of the fatty acid does not has any benefit? Of course NO!

As confirmed by several studies, omega-3 fish fatty acid (mostly from fish oil) help reduce heart disease. It would reduce the risk of abnormal heartbeats (arrhythmias) that can lead to sudden death, decrease triglyceride (harmful fats) levels, slow the growth of atherosclerotic plaque that could clog arteries, and lower blood pressure (slightly).

The reason that adding a low-dose of omega-3 fatty acid did not offer extra protection, as explained by the researchers, is that the participants were taken good care by their doctors: they were taking the best medicines to prevent future heart problem. Among the participants, about 98 percent were on anti-platelet treatments, 90 percent were taking blood pressure lowering agents and 85 percent were taking lipid-lowering agents.

As compared to those heart patients in earlier research who did benefit by taking fish oil pills, the participants in this study were also older (aged between 60 and 80) and took part in the study years after their heart attack.

Can Fish Oil Benefit Heart?

Omega-3 fatty acids can be found in such wild oily fish as salmon, tuna, mackerel, sardines and herring. It is believed that omega-3 fatty acids could benefit heart as it could raise HDL (high-density lipoprotein) or good cholesterol, lowers harmful fats known as triglycerides and slow the growth of plaque that tend to clog arteries.

According to the recommendation by the American Heart Association, adults should take fish at least twice a week, and people with heart disease should consume 1 gram of omega-3 fatty acid a day.

However, a recent large study conducted in Germany seemed to get a rather surprising finding. Researchers from the University of Heidelberg reported that fish oil capsules did not offer added benefit to heart attack patients who are already taking the right medications to prevent future problems. Their results were presented on March 30, 2009 at an American College of Cardiology conference.

In the study, more than 3,800 people who had suffered a heart attack in the previous 2 weeks were given 1-gram daily dose of a prescription version of highly purified omega-3 fatty acid or dummy capsules. About 90 percent of these people were already receiving all the necessary medications prescribed by their doctors to prevent a second attack, including aspirin, anti-clotting and cholesterol drugs.

The prescription version used in the study is a highly purified and standardized form, and is different from what many consumers buy off the shelf. They are sold as Omacor and Lovaza in the United States and as Zodin in Europe,

After a year, the researchers found no difference in both groups of patients, whether they took fish oil or dummy capsules. The researchers also found that 2 percent had suffered sudden cardiac death, 4 percent had another heart attack and fewer than 2 percent had suffered a stroke in both groups of patients.

The researchers argued that there is nothing much can be done to further reduce the risk for heart attack patients, who have already received good care from their doctors (given all necessary medications). Nevertheless, this does not mean that fish oil is of no value. In the first place, the study did not address whether fish oil could help prevent heart disease.