The latest hyperbolic (fear-mongering?) nutritional headlines have hit newsstands across the country (1), sparking debate, and causing many to question their own health and nutritional status.
These eye catching statements stem from a mouse study recently published in the British Journal of Nutrition, by researcher Sanjoy Ghosh (2). The study came to some very important conclusions. Namely that omega-3’s were unable to offset the deleterious effects of omega-6’s. This speaks volumes, as it shows that omega-3 oils cannot simply be taken as a band aid fix to the excessive ingestion of poor fats. We already knew that high consumption of omega-6 oils causes widespread inflammation in the body (3), so why should we be surprised to find increased inflammation when omega-3 fats are consumed in conjunction with a high omega-6 intake? Yet, the headlines (not the study!), seem to indicate that omega-3 oils are solely to blame.
Too Much of a Good Thing
Drank too much water? You’re going to have a bad time!
Ate too many carrots? You’re going to turn orange, and have a bad time!
Took too much fish oil? You guessed it, you’re going to have a bad time!
Too much of just about anything will invariably cause some sort of distress. Moderation is key, but so too is learning from what the evidence tells us. Too much fish oil in the short term can cause suffering in the way of intestinal distress. We now also know that too much fish oil in the long term can overburden the body and cause inflammation. We cannot in good faith advise people to consume fish oil in mega doses, with a failsafe of it being unable to cause any harm. But the opposite is also true. We cannot in good faith advise people to stop consuming omega-3 as part of a healthy nutritional intake, in fear of causing irreversible and catastrophic damage. It still holds true that omega-3 fats have a widely positive effect, when used correctly.
Brief Fat Biochemistry
In recent times, saturated (namely animal) fats have taken a backseat to the unsaturated fats, due to their supposed health benefits. Saturated fat is generally solid at room temperature as their chemical structure allows them to pack tightly, making them more impenetrable to heat. The building blocks of fat, fatty acids, are long straight chains, when saturated, due to the absence of any double bonds. A double bond in a fatty acid can be thought of as a ‘kink’ in the chain. The more kinks, the less tightly the molecules can pack together, allowing heat to disrupt the molecular structure easier, and making them liquid at room temperature. A fat containing a double bond is called an unsaturated fatty acid. A fat containing multiple double bonds is called a poly-unsaturated fatty acid (often abbreviated PUFA). Since saturated fats pack so tightly, they tend to accumulate in to cholesterol molecules with a propensity for clogging arteries (LDL). On the flip side, since unsaturated fats do not pack so tightly, they tend to accumulate in to healthier cholesterol (HDL).
The different types of PUFA’s are named numerically based on where the double bond resides on the fatty acid chain. The main players are omega 3 and 6, both of which are essential fatty acids, meaning we cannot manufacture them, and must obtain them from our diet. They also have antagonistic functions. Whereas omega-6 sparks inflammation and blood clotting to mediate immune reactions, omega-3 does the opposite, and is strongly anti-inflammatory. Omega-3’s from fish oil are composed of the two critical forms, EPA and DHA, whereas vegetarian sources contain ALA, which the body must convert to EPA/DHA to be used.
Too Much Omega-6, Not Enough Omega-3
Both omega 3 and 6 PUFA’s are necessary for life, but the actual amounts consumed tend to be way out of balance. Omega-6 is readily available in the modern diet, and in most cases, is consumed in major excess. It is found in healthy sources such as nuts and seeds, but also in unhealthy sources like refined vegetable oil (soy, corn, sunflower, etc.), fast food, sweets, and cookies. Conversely, omega-3 is grossly lacking in the modern diet, only found in high quantities in cold water fish, and a few vegetarian sources like walnuts and flaxseeds. Before processed foods existed, humans ate omega fats at a ratio close to 1:1. Today’s intake provides an astounding 10 omega-6’s to every 1 omega-3. This high ratio of 6 to 3 puts the body in to a chronic state of inflammation.
Balance Your Fats
Both saturated and unsaturated fats are necessary for proper health, but only in the right amounts. Ensuring a proper overall fat intake is necessary, as simply consuming more omega-3 fat will not correct the problem. Following an anti-inflammatory diet (or Mediterranean diet) will ensure your fat intake is more balanced. Avoid excessive saturated and omega-6 fat intake by steering clear of processed foods. Monounsaturated fats, found in olive oil, are an important part of a well balanced fat intake.
So, Do Fish Oils Damage Heart Health?
Thanks to grossly negligent reporting, many people who only read the headlines now believe that their fish oil is a culprit damaging their health. In reality, the study in question simply tells us that a pill will not correct our poor nutritional decisions. Replacing the omega-3’s from the study with any heart healthy variable would yield the same result. As long as the cause of the inflammation remains, so too does the outcome. Will the next headline proclaim “Exercise Worsens Heart Health”? Let’s hope not. And, just to be completely clear, omega-3 fatty acids in the presence of a healthy nutritional intake will not damage your heart health.
1. Shore, Randy. Excessive omega fatty acids may make inflammation and heart health worse, not better: B.C. researchers. National Post.
2. Diets rich in n-6 PUFA induce intestinal microbial dysbiosis in aged mice. Sanjoy Ghosha, Erin Molcana, Daniella DeCoffea, Chaunbin Daia and Deanna L. Gibsona. 2013, British Journal of Nutrition, pp. 1-9.
3. Health Implications of High Dietary Omega-6 Polyunsaturated Fatty Acids. E. Patterson, R. Wall, G. F. Fitzgerald, R. P. Ross, and C. Stanton. 2012, Journal of Nutrition and Metabolism.