Dispelling nutrition myths, ranting, and occasionally, raving


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Omega-3-6-9

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Based on some things I’ve seen lately, I thought it was time for a little omega refresher.

Omega-9 fatty acids: These are non-essential fatty acids as our bodies are capable of synthesizing them. This means that a dietary source is unnecessary. Don’t be fooled into buying a 3-6-9 supplement.

Omega-6 fatty acids: These are essential fatty acids; our bodies are not capable of synthesizing them so we must obtain them from dietary sources. Omega-6 FAs are plentiful in most of our diets and, therefore, don’t require supplementation. We get Omega-6 from plant oils, nuts, and seeds. In fact, we get so much Omega-6 that it may be having negative effects, such as increasing inflammation. We should be consuming a ratio of 2:1 to 4:1, Omega-6 to Omega-3. However, many of us are consuming in excess of 14-25 times more Omega-6 than Omega-3 (1)!

Omega-3 fatty acids: These are also essential fatty acids. In order to obtain enough Omega-3 we only need 2-4 teaspoons of plant oils a day. This is where it gets tricky. You’ll see a lot of foods marketed as being good sources of Omega-3, more than salmon for example, but they neglect to mention that we also need to consume EPA and DHA, two forms of Omega-3 which are not available from plant-based sources. Plants can provide us with plenty of ALA, which was can modestly convert to EPA and DHA. However, the conversion rate is pretty minimal. Under optimal conditions (such as when we’re not also consuming excessive quantities of Omega-6) conversion can reach up to about 4%. Not great when it’s advisable to consume 0.3-0.5 grams of EPA and 0.8-1.1 grams of DHA per day (2). It’s best to obtain these by eating fatty fish (e.g. salmon, tuna, sardines, herring, mackerel, or trout) twice a week. If you don’t consume fish regularly, it may be worthwhile considering taking an Omega-3 supplement that contains both EPA and DHA as it’s pretty much impossible to get as much as you need by converting plant sources.

 


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Krill oil vs fish oil

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I get a lot of questions about omega-3 supplements. Generally these are from fish oil. However, there’s been more interest in the less common krill oil expressed recently.

Krill are tiny little crustaceans. Fish obtain their omega-3s from eating plankton, as do krill. I’d heard that krill oil may be a superior source of omega-3s in comparison to traditional fish oil.

Krill oil actually contains less EPA and DHA (the essential omega-3 fatty acids we aim to obtain from supplements) than fish oils. 1, 000 mg of krill oil generally contains 230-300 mg of omega-3s; 140-160 mg EPA, and 80-90 mg DHA. Compare that to a 1, 000 mg fish oil supplement: 500 mg EPA and 333 mg DHA. However, amounts tend to vary widely between brands and varieties and it’s important to ensure you’re looking at the dose you’ll be taking (many will advise you to take multiple capsules each day which is unnecessary). Advocates for krill oil will tell you that the omega-3s in it are better absorbed than the omega-3s in fish oil. However, there’s not yet any evidence to support this (1).

There may be other benefits to krill oil, such as antioxidant properties. However, as with the previous claim, there is insufficient research to make any claims at this time (2).

One benefit of krill oil that is likely true is that it won’t give you the “fishy burps” that other omega-3 supplements may. If this is a concern to you it’s still avoidable when taking fish oil supplements. Look for supplements that have “enteric coating”. This means that they’ll survive your stomach acid intact and dissolve in your intestine so that they won’t be able to come back to haunt you. You should also take your supplement before your meal, or on an empty stomach, to decrease the transit time.

I had thought that fish oil supplements might be at greater risk of mercury contamination as the fish are considerably larger than the krill. A study showed that fish oil supplements range from no contamination to negligible contamination, rendering that an useless theory.

Other differences between krill oil and fish oil supplements: krill oil tends to be pricier. Also, as krill are crustaceans, krill oil supplements are not safe for sufferers of shellfish allergies.

Bottom line: krill oil may be equally beneficial to fish oil as an omega-3 supplement. It may even have additional benefits. However, the research is not there to support any additional claims. You may want to try krill oil if you’re willing to take a gamble on those additional benefits and if you’re not budget conscious. If you’d rather save your pennies, stick with a high-quality fish oil supplement. And, as always, check with your doctor or pharmacist before taking any supplements, especially if you’re taking any other kind of medication.


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Grocery store lessons: Savi Seeds

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I’ve been curious about these savi seeds (traditionally known as sacha inchi seeds) for a little while now. They claim to be “the richest source of omega-3 on the planet” with 7000 mg of omega-3 per serving. In contrast, a 75 g serving of Atlantic salmon contains just under 2000 mg of omega-3.

I came across a sample of the plain variety the other day and decided to give them a try. One was enough. As I’ve heard from other people, they taste a touch fishy, and the consistency is a little odd. They crunch and then kind of crumble in your mouth. Personal opinion aside, I wondered about their nutrition claims.

An internet search showed me that Dr Oz endorsed them as the top snack food of 2010. Not generally a good sign. The thing I wondered about most though, was the omega-3 content. It turns out that I was right to be suspicious. The form of omega-3 present in savi seeds is ALA, the same form present in other plant sources of omega-3 (such as flax). The forms of omega-3 that we need most are EPA and DHA. These are the forms present in fish and fish oils. You’ve probably heard that our bodies can convert ALA into both EPA and DHA. While true, this statement is also highly misleading. Research indicates that our bodies can convert approximately 6% of ALA into EPA and only 0-4% to DHA. These conversion rates are based on diets in which other fats are primarily saturated. When most fats are polyunsaturated (as many of ours are with use of olive oil, canola oil, and other plant oils and margarines quite common in North America and fear of butter rife) the conversion rates become even lower. This means, at most, that you’ll obtain 420 mg of EPA and 280 mg of DHA from a serving of savi seeds.

I’m not saying that savi seeds are bad for you. They are certainly a healthy snack (although coating them in sugary flavours tends to make them less so). One ounce contains about 190 calories, 8 grams of protein, 5 g of fibre, and small amounts of both iron and calcium. However, the emphasis on their omega-3 content is extremely misleading to consumers who may not be aware of the different varieties of omega-3 and the limited conversion rates in our bodies.


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Getting to the heart of hemp seeds

I recently received a request to write a post on hemp seed nutrition. Not knowing much about hemp seeds myself I’ve had to do a little bit of research. Hemp seeds, or hemp hearts, contain about 170 calories per 3 tablespoons. That same serving contains 13 grams of fat (1.5 g saturated, 8 g omega-6, and 2.5 g omega-3, 1.5 monounsaturated), 3 g fibre, 10 g of protein, and 30% of your daily iron requirement.

As we tend to consume plenty of omega-6 fatty acids in our Western diets but not enough omega-3s, I’m not entirely convinced that hemp seeds are the way to go if you’re looking for a vegan source of omega-3s. It seems that hemp seeds contain more SDA (an omega-3 fatty acid) but less ALA (an omega-3 fatty acid that we convert a percentage of into the essential omega-3 fatty acids: EPA and DHA). I tried to find  a good study to support (or refute) the ingestion of SDAs. However, the only studies I could find were very small and were supported by Monsanto thus rendering them unworthy of mention here. I found a few comparisons of hemp seeds, flax seeds, and chia seeds but they were all posted by a producer of one of those products. Again, rendering them unworthy of mention here.

With very little decent research on hemp seeds and nutrition I think that the best we can go by is the nutrition facts panel in combination with our personal preferences and budgets. There is certainly nothing in the nutrient panel that would suggest not consuming hemp seeds. Indeed, the protein, fibre, and iron content are all pretty good even if we’re not sure of their provision of omega-3s. However, at $8.99 for a 227 gram bag they’re not exactly cheap. Also, it’s my understanding that they’re not to everyone’s taste. While there’s nothing wrong with consuming hemp seeds, there’s also not enough evidence to support my advising anyone to consume them.