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WILD VS FARMED SALMON

問題和答案

Is Salmon still healthy?

Salmon has long been touted for its health benefits, but what many people don’t realize is that not all salmon is the same. These days, it’s important to be careful about what you eat, which means doing some research to find out about the origins of your food. For instance, was the salmon in your grocery store caught in the wild or bred on a fish farm? This might seem like a semantic difference to some of you, but in fact, it can severely affect the nutritional quality of your meat.

The fact is, much of the salmon available today is bred on a farm instead of being caught in the wild. Estimates are that more than half of the salmon available worldwide is bred on fish farms instead of coming from its natural environment. In the past two decades, the amount of salmon produced on farms has increased from roughly 27,000 metric tons annually to over 1 million. So, why is that important?

Simple: farmed salmon is raised on an entirely different diet than wild salmon. Ever hear the phrase, “you are what you eat”? This is one of those situations where it applies in the literal sense. Wild salmon grows on a diet of other organisms typically found in nature, whereas salmon from fish farms eat a heavily processed diet. This diet is generally high in fat, which means that when you eat farmed salmon, you’ll be eating more fat, too.“But wait,” you might be saying to yourselves, “aren’t some fats supposed to be healthy?” Yes, but that’s not necessarily a good reason to stop worrying about all the fat you eat—and it doesn’t apply to farmed salmon. While it’s true that farmed salmon have slightly higher levels of Omega-3 fats (often referred to as “healthy” fats) than their cousins from the wild, it’s also true that farmed salmon is much higher in Omega-6 and saturated fat content—two kinds of fat that are far less beneficial to humans.

Omega-3s and Omega-6s are both necessary parts of the human diet that prevent us from falling ill. However, although both fats are classified as EFAs (or Essential Fatty Acids), most people are currently eating much larger portions of Omega-6 than necessary, and throwing off the body’s natural balance. Many scientists theorize that this imbalance can contribute to many serious health conditions, including heart disease.

Wild salmon, on the other hand, has a much lower ratio of Omega-6 to Omega-3 fats (only about a third of farmed salmon, in fact). It also tends to be much higher in minerals, including potassium, zinc, and iron. Compare this to farmed salmon, which has extra vitamin C in many cases—but only because of it being artificially added to the feed, whereas the vitamins and minerals found in wild salmon are almost always a product of its natural diet. So, what does this mean regarding concrete nutrition information?

Here’s a statistic you’ll want to remember: farmed salmon typically has 46% more calories than wild salmon. What’s more, most of these calories are from fat.

Contaminants are another area where wild and farmed salmon differ significantly. You might assume that farmed salmon would have lower contaminant levels than salmon found in the wild because farms are easier environments to control. In truth, though, the levels of contaminants in farmed salmon are quite a bit higher than salmon found in the wild. These can include polychlorinated biphenyls (PBCs), dioxins, and a variety of chlorinated pesticides.

PCBs are the main culprits frequently associated with many health risks including cancer. A recent study looking at over 700 different varieties of salmon from around the world found that the PCB concentrations in farmed salmon were up to eight times higher than in salmon from the wild. While the FDA has deemed this to be safe, the EPA disagrees. Research suggests that if EPA guidelines applied to salmon from the study, farmed salmon would only be safe to eat about once per month.

That’s not to say you should stop eating salmon entirely. In fact, it is widely agreed upon that the Omega-3 health benefits from any salmon still outweigh the potential risks of eating salmon from fish farms. Still, if you’re looking to reduce risk as much as possible, wild salmon is a highly preferable alternative.

Further research suggests that farmed salmon has higher levels of arsenic too—although trace metals are found in all salmon, and for the most part they exist in such small concentrations that it doesn’t present a reasonable health concern. Nevertheless, there is overwhelming evidence to suggest that wild salmon is a healthier dietary choice.