Cardiovascular disease (CVD) continues to be one of the leading causes of death in North America, despite being largely preventable through simple lifestyle changes (healthy diet, exercising, quitting smoking) and controllable with therapeutics (statins, beta-blockers).

Scientists have been very interested in which lifestyle factors lead to a decreased risk of getting CVD. To get some hints, they started looking at the lifestyles of people that have CVD versus those that do not. One major difference was the amount of omega 3 fatty acids in their diets. People who ate higher levels of omega 3 fatty acids were less likely to develop CVD.

Since then, they’ve been able to figure out what exactly omega 3s are doing to help keep the heart and the arteries healthy:

(1) Anti-Inflammatory: Inflammation is the body’s way of signalling the presence of an unwanted invader or damage somewhere in the body – either a virus or damage to a blood vessel.

Under normal circumstances, this is a good thing because it leads to repair and healing. However, when there’s too much of it around, the inflammation actually causes additional damage to your cells and prevents them from repairing themselves. Your body has the capability of making both good and bad inflammatory signals. The good ones don’t cause additional damage to your cells and gives them time to heal.

The bad ones, which are high in CVD, cause additional damage to your heart and arteries. Omega 3 fatty acids are the building blocks of the good kind of inflammatory signals. In addition, they prevent your body from accessing the instructions for making the bad inflammatory signals.

Therefore, by getting adequate amounts of omega 3 fatty acids in your diet, you ensure that your body makes the good inflammatory signals, and not the bad ones.

(2) Cell Walls: Omega 3 fatty acids are an important component of our cell walls. Because of their flexibility, they can easily expand and contract to allow your cells to communicate with one another. One of the ways that cells communicate is via ions such as calcium, sodium and potassium.

Special channels within our cell walls open and close to let ions into (or out of) our cells. If your cell walls are made up of omega 3 fatty acids, they can easily accommodate these changes in size by contracting (when the channels are open) or expanding (when the channels are closed). By ensuring that your channels can function normally, omega 3 fatty acids ensure that you have a strong and regular heartbeat. When you don’t have enough omega 3 fatty acids in your diet, your cell walls begin to incorporate saturated or trans fats. These fats are very rigid and can’t adapt as easily to channels opening and closing. This makes communication between cells difficult and can result in arrhythmias such as an irregular heartbeat.

(3) Blood Vessels (Arteries and Veins): Omega 3 fatty acids play an important role in two functions associated with your blood vessels. First, omega 3 fatty acids tell your blood vessels to dilate. They relax your vascular smooth muscles, which are responsible for constricting and dilating your blood vessels. A great analogy is untying your belt after Thanksgiving dinner.

When you loosen it up, it feels like you have so much more room to move around. Conversely, when your spouse tells you to look presentable and do up your pants, suddenly, there’s not so much mobility. The same thing happens in your arteries and veins. When the smooth muscles contract, the vessels constrict and the blood cannot flow as freely.

Therefore, oxygen and glucose cannot reach your hungry cells. In CVD, the blood vessels are often already filled with plaques that prevent the flow of blood (atherosclerosis). When you couple that with blood vessel constriction, it’s amazing that our cells are able to survive at all! Second, omega 3 fatty acids prevent excessive blood clotting.

Excessive blood clotting is a serious concern for people with CVD, or for people who are at high risk of developing CVD. If the clots get big enough, they can obstruct an artery and lead to a heart attack. Or, if the clots travel to your brain and block a blood vessel there, you could have a stroke. Therefore, by minimizing excessive clotting, omega 3 fatty acids can reduce the risk for heart attacks and strokes.

(4) Triglycerides: Omega 3 fatty acids lower your triglyceride levels. High levels of triglycerides in your blood lead to atherosclerosis. Omega 3 Fatty Acid Food Sources Incorporating omega-3 fatty acids into your diet is a great way to decrease your risk for developing CVD. There are three omega-3 fatty acids that we can incorporate in our diet to achieve this effect: docosahexaenoic acid (DHA), ecosapentaenoic acid (EPA) and alpha-linolenic acid (ALA). Of these, DHA and EPA are found predominantly in fish oils such as salmon, whereas ALA is found in plants such as flax.

The American Heart Association recommends 1g of EPA and DHA per day to prevent CVD in people who are at risk for developing CVD. If you are trying to lower your triglycerides (i.e., you were diagnosed with hypertriglyceridemia), they recommend between 2 – 4g of EPA and DHA every day. Finally, if you’re a healthy adult who is not at risk for CVD, then you can get away with eating one serving of oily fish twice per week (which works out to about 0.5g of EPA and DHA per day). Currently, North Americans consume only 1.6g of omega 3 fatty acids, with only 0.1 – 0.2g coming from DHA and EPA. The remainder is obtained from ALA. Although ALA may have some of the same health benefits, it’s currently unclear if ALA is as good for your heart as EPA and DHA. The best sources for DHA and EPA are oily fish.

These include salmon, tuna, sardines, anchovies, mackerel and herring. If you’re a vegetarian, don’t despair – these fish don’t make the omega 3 fatty acids themselves; they actually get it by eating algae. This means that anyone can get their daily recommended intake through supplements. So whatever your dietary preferences, there’s no excuse for missing out. Eat your omega 3 fatty acids and your heart will thank you!