Thursday, December 23, 2010

38 g of sardines or 2 fish oil softgels? Let us look at the numbers

The bar chart below shows the fat content of 1 sardine (38 g) canned in tomato sauce, and 2 fish oil softgels of the Nature Made brand. (The sardine is about 1/3 of the content of a typical can, and the data is from Nutritiondata.com. The two softgels are listed as the “serving size” on the Nature Made bottle.) Both the sardine and softgels have some vegetable oil added; presumably to increase their vitamin E content and form a more stable oil mix. This chart is a good reminder that looking at actual numbers can be quite instructive sometimes. Even though the chart focuses on fat content, it is worth noting that the 38 g sardine also contains 8 g of high quality protein.


If your goal with the fish oil is to “neutralize” the omega-6 fat content of your diet, which is most people’s main goal, you should consider this. A rough measure of the omega-6 neutralization “power” of a food portion is, by definition, its omega-3 minus omega-6 content. For the 1 canned sardine, this difference is 596 mg; for the 2 fish oil softgels, 440 mg. The reason is that the two softgels have more omega-6 than the sardine.

In case you are wondering, the canning process does not seem to have much of an effect on the nutrient composition of the sardine. There is some research suggesting that adding vegetable oil (e.g., soy) helps preserve the omega-3 content during the canning process. There is also research suggesting that not much is lost even without any vegetable oil being added.

Fish oil softgels, when taken in moderation (e.g., two of the type discussed in this post, per day), are probably okay as “neutralizers” of omega-6 fats in the diet, and sources of a minimum amount of omega-3 fats for those who do not like seafood. For those who can consume 1 canned sardine per day, which is only 1/3 of a typical can of sardines, the sardine is not only a more effective source of omega-3, but also a good source of protein and many other nutrients.

As far as balancing dietary omega-6 fats is concerned, you are much better off reducing your consumption of foods rich in omega-6 fats in the first place. Apparently nothing beats avoiding industrial seed oils in that respect. It is also advisable to eat certain types of nuts with high omega-6 content, like walnuts, in moderation.

Both omega-6 and omega-3 fats are essential; they must be part of one’s diet. The actual minimum required amounts are fairly small, probably much lower than the officially recommended amounts. Chances are they would be met by anyone on a balanced diet of whole foods. Too much of either type of fat in synthetic or industrialized form can cause problems. A couple of instructive posts on this topic are this post by Chris Masterjohn, and this one by Chris Kresser.

Even if you don’t like canned sardines, it is not much harder to gulp down 38 g of sardines than it is to gulp down 2 fish oil softgels. You can get the fish oil for $12 per bottle with 300 softgels; or 8 cents per serving. You can get a can of sardines for 50 cents; which gives 16.6 cents per serving. The sardine is twice as expensive, but carries a lot more nutritional value.

You can also buy wild caught sardines, like I do. I also eat canned sardines. Wild caught sardines cost about $2 per lb, and are among the least expensive fish variety. They are not difficult to prepare; see this post for a recipe.

I don’t know how many sardines go into the industrial process of making 2 fish oil softgels, but I suspect that it is more than one. So it is also probably more ecologically sound to eat the sardine.

29 comments:

Susan said...

Ned, thanks for the sardine rundown. Where do you find sardines for 50 cents per tin? At discount stores, I pay from $1.30 to $1.70, with the cheaper in soy oil and the more expensive in olive oil. I've wondered if it would behoove me to rinse the soy-oil-packed fishies before eating. Haven't tried the tomato-sauced ones, but maybe I should. Any thoughts?

Anonymous said...

i would be curious to see this chart with an overlay of krill oil

qualia said...

i'd also like to see a comparison with DHA only. at the end of the day, that's the molecule we are shooting for when taking fish oil. also, does the heating of the can (sterilisation)) alter or destroy the n-3s at all? i mean, there is a reason why delicate oils always are *cold processed*.. just curious

Angelo Coppola said...

Excellent article, Ned. I appreciate the footwork. I find that the wild caught sardines packed in water are the most palatable for me.

I'll take real food over supplements any day.

Daniel said...

Ned, thanks for the charts. The numbers are fascinating and interesting. I agree that we should reduce our omega 6 intake and try our best to neutralize the bad effects by eating fishes and seafood.

What is your opinion on the BPA used on the lining in the cans? Is eating canned sardines frequently safe?

Mark said...

Ned,

Have you read Ray Peat's articles on unsaturated fat? He believes that polyunsaturated fat is not essential at all. Do you have any thoughts?

http://raypeat.com/articles/articles/fishoil.shtml

Your blog is great - keep up the good work!

ben said...

wow, with this post and the post with the four charts regarding nuts from the other day you are on one heck of a roll. Terrific info here. Like others here I wonder your take/opinion on the canning process and its possible effects on the n3s, the BPA that is most likely involved in the canning process, and the heat from pasteurization. I continue to take my fermented cod liver oil daily and eat my one whole tin of oliveoil-packed sardines every week. Be well

Ned Kock said...

Hi Susan. Here in our local HEB (a Texas supermarket chain) it is often 3 tins for $1. I usually drain the added oil off.

Ned Kock said...

Hi qualia. The heat used in the canning process does not seem to have much of an effect on the omega-3 content. Omega-3s tend to become unstable when they are removed from their natural “package” and isolated.

Ned Kock said...

Hi Angelo, thanks.

Ned Kock said...

Hi Daniel. It seems like bisphenol A is not really a problem with canned seafood. Potentially bisphenol F could be, if it was allowed; my understanding is that it is not. See this article:
http://linkinghub.elsevier.com/retrieve/pii/S027869150800015X

I would have to look into it further, but it seems that plastic products such as water bottles are a bigger source of health concern regarding these compounds than anything else.

Ned Kock said...

Hi Mark. Yes, I did see that article by Ray Peat. The reality is that there are many studies that show health benefits from omega-3 supplementation, presumably because they counterbalance some of the negative effects of excessive omega-6. The problem is that when you isolate omega-3 fats they became less stable, and oxidize more easily. This is one of the key points in Peat’s article.

Ned Kock said...

Hi ben, thanks. I guess I answered your questions above, right?

Ned Kock said...

Oh, regarding krill oil. I think we’ll probably find the same problem with it that we find with fish oil – instability of the oil when it is isolated. In fact, this is a special case of a larger phenomenon, which is related to isolation of substances by industrial processes. Often the resulting product looks good on paper, but ends up being implicated, direct or indirectly, in one or more of the diseases of civilization.

Since evolution is “blind” to complexity, often there are many co-factors that are important in the proper use by the body of a food. Humans have to find a better way of dealing with this. Isolation of substances naturally found in foods should work in theory, but more often than not it doesn't.

Ned Kock said...
This comment has been removed by the author.
Ned Kock said...

I found this post by Byron Richards to be quite informative; it discusses krill oil and green-lipped mussel:

http://www.wellnessresources.com/health/articles/dha_krill_oil_green_lipped_mussel_which_is_best/

This is a topic that needs another post, but many types of seafood have reasonable amounts of omega-3; usually as a combination of EPA and DHA. And I am not talking about salmon and trout, which have larger than average amounts. Take shrimp for example. A 100 g portion will have 347 mg of omega-3 and 21 mg of omega-6 fats; plus 21 g of very high quality protein (with only 1 g of fat). And to think that many people have been avoiding seafood because of their “high cholesterol”.

Paleo Phil said...

Ned, thanks for the post on a topic I've been pondering myself. Where do you find wild caught sardines for $2/lb.? Are those at your supermarket as well? The wild sardines my local markets had today were small ones for $12.23/lb. Once in a while I see the bigger ones like in your photo, but they were gutted. I don't remember the price, but I know it was more than $2/lb.

Ned Kock said...

Hi Paleo Phil. Wow, that’s a lot! Sardines are actually $1.99/lb in our local HEB, throughout the year.

Jim said...

Hi Ned,

Thanks for another good one.

"Racial and geographic differences in fish consumption: The REGARDS Study" got some newspaper coverage both nationally and locally last week. I can't access the pdf, but the abstract is at http://goo.gl/y9QGd

Based on the canning process not harming/reducing n3 very much for sardines, the study's suspicion that n3 is damaged by frying seems off track to me.

I suspect the industrial seed oil oxidized by frying is the greater problem.

Oh, and the folks doing the study hope to keep it going basically forever... job security?

Ned Kock said...

Hi Jim , thanks. I agree with you. Frying with industrial vegetable oils is the problem, as it tends to increase the omega-6 content so much as to make the omega-3 content ineffective. The frying process itself has virtually no effect on the omega-3 content (see link below to a study by Sebedio et al.).
http://linkinghub.elsevier.com/retrieve/pii/096399699390049O

bee said...

great post. fish oil softgels have their use for people like my husband who won't eat meat or fish, but will eat softgels if they are enteric coated. i'll stick with sardines.

Nigel Kinbrum said...

Canned sardines in tomato puree also contain lycopene.

Razwell said...

Ned

I really respect your blog a lot.

You are so correct about whole foods. Remember the Inuits? They get their EPA and DHA from actually eating nutrient dense food like whale blubber, as well as numerous other vitamins and minerals all working in nature's synergy, that we have not begun to figure out yet. . They certainly are not taking industrialized processed fish oil pills. I am wary of supplements.


You also are spot on about the failure odf dieting. Really good points you bring up for thought. :)

Great blog you have.

Raz

Ned Kock said...

Hi Raz, thanks. Indeed, the Inuit (on their traditional diet) don’t seem to overload on O3. But it seems to be possible to have too much O3 from pills.

gwarm said...

Ned, what do you make of this BPA http://www.facebook.com/NutritionFacts.org/posts/191806344223680 (links to: http://1.usa.gov/p5Vh2K PDF)

Hakim Ferradj said...

Hello

This morning, after reading your post I ate one whole can of sardines (120g net).

However after I did it I realized that the sardines were in sunflower oil! As you know this oil is very rich in omega-6...

I used the wolframalpha search engine and found out that only 1 teaspoon of sunflower oil contains 1.6g of omega-6 :(

http://www.wolframalpha.com/input/?i=1+teaspoon+sunflower+oil+total+omega-6

So from the 2g of omega-3 I got from that can of sardines, I got almost the same (if not more) amount of omega-6...

Next time I will make sure to take some canned sardines with olive oil instead!

Thanks for the great article.

Praveen Pandey said...

Thanx for Sharing such a hugefull information and lots of benifits of Fish Oil. Fish Oil is the one of the best nutrician , it has been show to provide a number of health benifits, and recomended by many health autorities as a part of balanced diet.One of the health benefits linked to Fish Oil is a low risk of heart attack & very healpfull for blood circulations.

Jen said...


Sardines were central in Dr. Benjamin Frank's book The No Aging Diet, which he wrote back in the 70's. He said they were the food highest in anti-aging nucleic acids. Since then, foods like chlorella and bee pollen have been found to be even higher in nucleic acids, but of course sardines have other beneficial properties such
as you have described.

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