|
|
| Omega 3s (or Fatty Fish) |
|
|
| By Aileen Marshall | ||
| March 2011 | ||
|
Do you remember scenes from The Little Rascals where they were forced to ingest a spoonful of cod liver oil? Or perhaps you’ve heard stories from older family members of how they had to undergo the same ritual. As unpleasant as it tasted (I’ve heard), it seems the old wives really did know what was good for you. In recent years, Omega-3 fatty acids have become popular as an important part of a healthy diet, preventing anything from a heart attack to depression. While there is some scientific evidence for the benefit of this polyunsaturated fat ideally obtained from fish, not all claims are well proven at this point. What are Omega-3 fatty acids? Chemically speaking, they are long chains of poly unsaturated fatty acids that have a carbon double bond at the third bond from the methyl end. These should not be confused with Omega-6 fatty acids, that are chemically similar. However, Omega-6s compete with Omega-3s for conversion in the body, and will reduce the benefit of Omega-3s. Americans tend to consume fourteen to twenty-five times more Omega-6s than Omega-3s. There are three main kinds of Omega-3s: α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is mostly found in plant sources like flaxseed, walnuts, pecans, hazelnuts and soybeans. DHA and EPA are mostly found in cold water fatty fish such as salmon, pollock, halibut, and tuna. There appears to be more effect of DHA and EPA than ALA. Studies have found that people who eat fatty fish twice a week have a lower chance of dying from cardiovascular disease. Several studies have shown DHA to produce a small decrease in blood pressure. The Inuits have a diet high in fatty fish and high-density lipoproteins (HDLs, or good cholesterol) and low blood triglycerides. People who have had a heart attack were given fish oil supplements, and it was found that they had a greatly reduced rate of death from a heart attack and a lower total mortality rate than those who did not consume the fish oil. Epidemiologic studies have shown that people who eat fish regularly have a much lower chance of dying from heart disease than those who do not. There have been many studies looking at the effects of Omega-3s on transplant rejection, rheumatoid arthritis, asthma, cancers, cystic fibrosis, lupus, psoriasis, diabetes, bipolar disorder, depression, schizophrenia, and dementia. For every one of these studies that has indicated a beneficial effect, there is another study that did not show any effect. However, there is evidence that Omega-3s are significant during neurological development in utero and during early childhood. High doses of Omega-3s can cause increased bleeding, bruising, and an increased risk of hemorrhagic stroke. The American Heart Association (AHA) recommends eating fish twice a week. For those who have coronary heart disease, the AHA recommends one gram of DHA and EPA per day, and two to four grams a day for those with high cholesterol. Next time you are at your favorite sushi bar, remember you may be doing something good for your heart. References: |
||