The reason why tuna is recommended for weight control and for the prevention of heart disease is because tuna contains high levels of Omega 3 fatty acids. Called "essential oils" because the body does not produce them on its own, but needs them for optimal health, Omega 3s are found primarily in cold water seafood such as tuna and salmon.
Some of the important benefits of Omega 3 fatty acids include:
- They aid in brain development in children and according to at least one study, Omega-3s may prevent dementia.
- Omega 3s contain healthy cholesterol (HDL) that fights unhealthy cholesterol (LDL) found in so many processed foods.
- Omega 3 fatty acids have anti-inflammatory properties.
- They help maintain joint health and can aid in reducing the symptoms of inflammatory joint diseases such as arthritis.
- They are good for teeth and bones.
The unique benefits of tuna and other cold water fish put them high on the list of "must have" foods recommended by nutritionists. If that is the case, why are many nutritionists and environmentalists raising the alarm about tuna?
Industrialised societies have taken their toll on the environment. Our polluted air has led to serious concerns about the greenhouse effect on our environment and industrial waste has resulted in high levels of lead, mercury and other dangerous heavy metals in our oceans. Many species of tuna, especially albacore, have been found to contain high levels of mercury. Mercury poisoning causes damage to the nervous system, brain, lungs and kidneys, as well as causing a number of serious diseases. Whilst mercury is also found in cattle, fish consumption is the primary way humans get mercury poisoning.
According to Greenpeace and other environmental organisations, since canned tuna was introduced in the 1950s, it has been in such high demand, many species of tuna are endangered and unless something is done soon, some may become extinct. In addition, the fishing practices of large fishing fleets are threatening many other species of marine life.
What Can We Do?
If tuna is so good and so bad at the same time, what are we to do? The U.S. Environmental Defense Fund (EDF) tackled this issue in an article, Mercury Alert: Is canned tuna safe to eat? This article points out that mercury levels are highest in the larger species of tuna; particularly albacore, which contains 3 times the amount of mercury on average as the smaller skipjack. While not ruling out albacore altogether, the EDF reporter made these recommendations:
- Children under six could safely eat albacore once a month; chilcren up to 12 twice a month; and adults (including pregnant women) 3 times per month.
- Skipjack (often labelled "canned light" in the U.S.) could be safely consumed 3 times a month by young children and once a week by older children and adults.
- Canned salmon, which is also high in Omega 3s, is also lower in mercury and other contaminants than tuna and should be considered a healthy alternative.
Good tuna, bad tuna? What's the answer? For now, at least, one answer seems to be to choose skipjack instead of albacore or substitute salmon for tuna. Another solution may be to take Omega 3 supplements. If you can't find them in your area, a supplier will be able to ship them to you. The important thing to remember is that Omega 3, not tuna, is essential to health.