|Life Extension Update Exclusive |
Meta-analysis finds fish oil reduces heart rate
The results of a meta-analysis reported online on September 19, 2005 in the American Heart Association journal Circulation, “provide firm evidence that fish oil consumption directly or indirectly affects cardiac electrophysiology in humans,” via the finding that consuming the oil reduces heart rate. Higher heart rate is a major independent risk factor for death from cardiovascular disease, especially sudden death.
Researchers at Harvard Medical School in Boston and Wageningen University in the Netherlands analyzed data from 30 randomized double-blind trials of fish oil that included data on heart rate. The combined trials involved 1,678 individuals with a median age of 54 years.
In the overall pooled estimate, participants who received fish oil experienced a heart rate decrease of 1.6 beats per minute compared to the placebo groups. A reduction of this size has been estimated to correlate with an approximate 5 percent lower risk of sudden death. In studies in which participants had a greater average heart rate than 68 beats per minute or received fish oil for twelve weeks or longer, heart rate was reduced by 2.5 beats per minute compared to placebo. The dose of fish oil used in the studies did not appear to be correlated with the benefits observed.
Because fish oils are incorporated in to cardiac muscle cell membranes, they could exert their beneficial influence on heart rate by affecting ion channel function. Their ability to lower blood pressure may also contribute to heart rate reduction. Omega-3 fatty acids found in the oils may improve heart rate variability, which the authors note may have an effect on autonomic tone. In addition to improving heart rate, fish oil may affect other cardiovascular mechanisms that contribute to the reduction in sudden death risk observed in some trials. The authors conclude that a direct or indirect effect of fish oil on cardiac electrophysiology could account for some of fish oil’s ability to improve cardiovascular risk, particularly arrhythmias.
Heart rhythm is controlled by factors both intrinsic and extrinsic to the heart itself. The most common damage to the heart's "wiring" comes from damage caused by decreased blood flow from clogged coronary arteries, or from muscle death caused by a heart attack. Additionally, certain drugs and toxins can affect heart rhythm as well.
The development of potentially life-threatening dysrhythmias during the immediate period following an MI (myocardial infarction) is the reason that heart attack patients are monitored very closely in a CCU (coronary care unit). One therapy which can increase the risk of dysrhythmia is thrombolytic treatment of the clogged coronary artery. When this is successful, there is a sudden influx of blood into the blood-starved area. This often results in dysrhythmia, which can be fatal. The culprit is in part a free radical reaction. Therefore, any therapy directed at this free radical burden could be potentially helpful.
In fact, recent studies have shown that such treatment is important in this setting. A 1998 study looked at patients with a recent AMI (acute myocardial infarction). For 28 days one group received oral treatment with coenzyme Q10 (coQ10, 120 mg a day), and the other group received a placebo. After treatment, total arrhythmias were 9.5% in the coQ10 group, compared to 25.3% in the placebo group. When measuring angina pectoris, only 9.5% of coQ10-supplemented patients were symptomatic compared to 28.1% on placebo, while poor left ventricular function was observed in 8.2% of those patients taking coQ10 compared to 22.5% on placebo.
Total cardiac events, including cardiac deaths and nonfatal infarction, were also significantly reduced in the coQ10 group compared with the placebo group (15.0% vs. 30.9%). Other recent studies have demonstrated that giving patients who have recently suffered an AMI omega-3 fatty acids protects them from the development of dysrhythmias in the immediate post-AMI period. Omega-3 fatty acids may be found in flaxseed, perilla, and fish oils.
|Life Extension Magazine September 2005 |
How many Americans are magnesium deficient? by William Faloon
While the government officially refuses to recognize the effects of magnesium in preventing vascular disease, the National Institutes of Health does publish the following on its website:
“Magnesium is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis. There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes.”
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