For today’s edition of Dear Mark, I’m answering just one question from the comment section of last week’s omega-3 post.
It’s a short one, maybe one of the shortest reader questions ever, and it represents one of the few cut-and-dry stances in ancestral health. Humans are omnivores, seed oils are bad for you, no curls in the squat rack, and farmed salmon is toxic poison.
Right? Maybe not.
What’s with the pic of the farm raised salmon?
First of all, I’m not certain that salmon was actually farm-raised. Second, while I’m on the topic, allow me to make the case for farmed salmon. That may surprise you. For years, I’ve been a huge proponent of wild-caught salmon. It’s the only one I ever buy or consciously seek out at restaurants. I’ll eat farmed salmon if it’s the best option available, or if I’m a guest and that’s what’s for dinner—and do so happily, by the way—but I’ve always been a wild salmon guy.
However, not everyone has the means to buy fresh or frozen wild-caught salmon on a regular basis, and not everyone wants to eat canned salmon. Sometimes you just want a big slab of tender salmon with a swathe of crispy, salty skin. Sometimes all five members of your family want their own big slab of tender salmon with the crispy skin. Is farmed salmon a good, safe, effective option?
Let’s look at the evidence. First, what are the benefits of salmon, and how does farmed salmon compare?
The main reason people eat salmon is to get the long chained omega-3 fatty acids—the ones we use to quell inflammation, balance our omega-6 intake, and shift the membrane composition of our cells and structures.
Farmed salmon is a great source. A 6-ounce portion of farmed Atlantic salmon has 4.4 grams of omega-3 fatty acids, which is actually more than wild. A 6-ounce portion of wild sockeye salmon has 2 grams of omega-3s.
But what about the omega-6 fats? Isn’t farmed salmon “loaded” with them? Well, that same portion of farmed salmon has 3.3 grams of omega-6 fats to the wild salmon’s 0.3 grams. The ratio is “worse” than the wild salmon’s. But even then, it’s great. While the wild salmon’s omega-3:omega-6 ratio of 1:0.15 is about as perfect as you can get, the farmed salmon’s ratio of 1:0.75 is fantastic. Besides, it’s also the absolute amount of omega-6s that matter. Admittedly, 3.3 grams is nothing compared to what most people are getting from seed oils, junk food, or even random handfuls of almonds and pecans throughout the day.
There’s more to fish fats than the omega-3s. For instance, many fish fats have subfractional layers with specific health effects. Fats derived from organic Irish farmed salmon possess anti-thrombotic qualities—they reduce the formation of blood clots.
Astaxanthin is a carotenoid that gives salmon its pink hue and may provide neuroprotective effects, especially combined with omega-3s. Wild salmon obtain astaxanthin from the krill and other pink sea creatures they consume. Farmed salmon obtain it from the feed they eat, which has it added. Both farmed and wild salmon provide astaxanthin to those who eat it, but a recent study found that the astaxanthin in wild salmon has higher bioavailability.
What about the drawbacks of farmed salmon, like contaminants?
Even this issue isn’t so clear cut. For example, a 2017 study found higher levels of persistent organic pollutants, metals, and DHA in wild Atlantic salmon compared to farmed Atlantic salmon. Farmed salmon had more overall fat, mostly from saturated, monounsaturated, and omega-6 fats, but farmed was still loaded with omega-3s.
A recent study actually tracked the changes in blood markers of contaminants in response to a high intake of farmed salmon. Eating almost a pound of farmed salmon each week had no effect on blood levels of persistent organic pollutants or mercury.
Surprisingly, European farmed salmon seems to have the biggest contamination issue. Good news, though: a 13-year study of contaminant levels in Norwegian farmed salmon found that toxins are dropping as the years go on.
What about when the rubber hits the road, when actual living and breathing humans eat farmed salmon? Does it help or harm? Let’s see what’s out there:
In one 2016 study, overweight men and women who ate farmed salmon twice a week for 4 weeks had higher HDL, larger LDL particles, lower triglycerides, and an overall improved cardiovascular risk profile. Their large LDL particle number also increased, but I’m not sure what happened to their overall LDL particle number. Another study found farmed salmon reduced triglycerides and increased HDL compared to lean chicken.
Eating farmed salmon twice a week modified the plasma phospholipid composition in a favorable way, increasing DHA and EPA and decreasing omega-6 fats.
Chinese men with a high risk for heart disease improved cardiovascular biomarkers after adding farmed salmon to their diets.
This was an interesting one. A group of otherwise healthy overweight adults were told to eat add a large dose of either fatty fish or lean fish to their normal diets for 8 weeks. The fatty fish was farmed salmon. The lean fish was wild cod. What happened?
- Cod increased DHA in white blood cell membranes. Farmed salmon increased overall omega-3s and reduced omega-6s in white blood cell membranes.
- Farmed salmon improved postprandial blood glucose control. Cod did not.
- Farmed salmon resulted in a smaller increase in postprandial insulin than cod.
I’m not suggesting farmed salmon is better than wild, or even equivalent, but I want to impress upon everyone who reads this blog that you don’t have to drop $15 a pound for wild caught salmon if your budget doesn’t allow it. Those $6 a pound Atlantic salmon fillets might not be as vibrantly red, might have a couple more grams of omega-6, and might have more or less pollutants depending on where they were farmed, but they’ll still have way more omega-3 than omega-6, they’ll still have astaxanthin, and they can still be part of an overall healthy diet.
Thanks for reading, everyone. I’d love to get your thoughts on this down below.
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