More Americans die from heart disease than from any other cause. You may be familiar with the common symptoms--chest pain, pain in one or both arms, shortness of breath--but about half of all heart-related deaths result from sudden cardiac death (SCD), with little or no warning. In other words, there are no warning chest pains. You just drop dead and die.

You may be at risk for SCD even if your cholesterol is normal and you feel healthy. Half of all SCD events in the United States, about 125,000 per year, occur in people with no history of heart disease. So what is the cause? In some cases SCD can be triggered by a massive heart attack, but the underlying cause is a disruption in the heart’s electrical system that interrupts the heart’s normal rhythm, also known as a cardiac arrhythmia.

Along with sudden death, there are other, lesser known, symptoms of heart problems such as:

• Unexplained dizziness or fainting spells, or light-headedness
• Nausea, vomiting or lasting discomfort after meals, similar to heartburn symptoms
• Toothache
• Pain in the armpits
• A sudden, severe headache
• Fatigue with no known cause
• Heart palpitations
• A sudden change in vision, particularly if in only one eye
• Swelling of the feet, ankles, legs or abdomen
• Persistent coughing
• Breaking out into a cold sweat
• Pressure/discomfort in the chest
• Numbness or weakness in the legs, arms or face, especially if on only one side
• Back, neck, abdomen or jaw pain
• A sudden change in your ability to speak or understand speech
• No symptoms at all--up to 25 percent of heart attacks produce no symptoms

If you notice any of these symptoms, even if they appear to be slight, you should seek medical attention. But, your best bet is to prevent heart disease from ever occurring, and one of the best ways to do that is by optimizing your intake of omega-3 fats in fish oil. This is one simple, natural solution that even the traditional medical community cannot dispute.

Study after study, like these two published in JAMA and NEJM in 2002, shows that supplementing the diet with omega-3 reduces the risk of sudden death, heart attack and stroke. According to an article on Dr. Jay Cohen’s Web site, "we began learning about fish oils in the late 1970s, when studies showed that Eskimos, despite fat-laden diets, had substantially fewer heart attacks than westerners." Dr. Cohen is the author of "Over Dose: The Case Against the Drug Companies", and I interviewed him last year regarding his book. He makes some good arguments in his article that the media is intentionally overlooking fish oil as a solution in favor of the statin drugs, which don't help to prevent sudden death at all.

All fish oils are not the same, however, so it is important that you use a high-quality brand in order to get the greatest health benefit. In my research--and in my clinical experience with my patients--I have found that:

• The liquid form is superior to capsules
• Certain brands definitely seem inferior to others
• The Carlson's brand of fish oil/cod liver oil is of an exceptional quality and purity
• It is likely not the only brand in the world of such high quality, but up to this point it is the only one of such quality that I can recommend, so I now offer the Carlson's fish oil and cod liver oil on Mercola.com; you can also check your local health food store to see if they carry it.

Now is the time of year when people living in cooler climates will want to switch from fish oil to cod liver oil. The main difference between cod liver oil and fish oil is that cod liver oil is high in vitamin D. In warm weather months, the more intense sunshine allows your body to produce high and usually sufficient levels of vitamin D without any supplementation necessary. However, in cool weather when intense sun exposure is limited, your body will need more vitamin D, and so I recommend cod liver oil versus fish oil in cool weather months or climates.

I generally recommend that you take cod liver oil from autumn to early spring, and fish oil from late spring through the end of summer. However, those who live in more tropical environments with regular exposure to more intense sun will most likely be fine taking fish oil year round, as your vitamin D intake from the sun will be sufficient. If you aren't sure of what you should take, please have your vitamin D levels tested, as it is possible to overdose on vitamin D.

Also be sure to check out my other heart healthy recommendations in the links below.

Protect Yourself From Heart Disease With Simple Lifestyle Changes

Garlic Lowers Heart Disease Risk

Soy Can Increase Heart Disease Risk

Aspirin Not Recommended for Heart Disease Anymore

Another Reason Why Eggs Actually Lower the Risk of Heart Disease

Bacteria and Viral Exposure Linked to Heart Disease