The previous discussion on Omega-3’s and comparisons between potential health benefits and costs between farmed and wild salmon from:
http://www.sportfishingbc.com/forum/topic.asp?TOPIC_ID=8847&whichpage=16
brings-up some important points.
In order to discuss this – we need to understand what an Omega-3 is, and more importantly - what is fat?
Fats and oils are a generic name for lipids - which consist of chains of fatty acids. A visual representation of different fatty acids below is from Wikkipedia:
A fatty acid has a carboxylic acid at one end and a methyl group at the other end. Don’t zone-out, yet – it’s not really that hard to follow – just continue reading for a few more seconds.
The carboxyl end is what allows these long fatty acid chains to bond, since carboxylic acids are polar, and form hydrogen bonds with each other. Think of it as the sticky end.
The other end - methyl group – doesn’t bond with water too well. It’s what causes the saying it mixes “like oil and water”. It’s the non-sticky end.
The Carbon atoms in a fatty acid are identified by Greek letters on the basis of their distance from the carboxylic acid group – or the sticky end. The carbon atom closest to the carboxylic acid is the alpha carbon, the next adjacent carbon is the beta carbon, etc. In a long-chain fatty acid the carbon atom in the methyl group is called the omega carbon because omega is the last letter of the Greek alphabet.
You can see where this is leading – when we talk about Omega-3’s. It’s just an accurate way of describing the exact chemical structure of the molecule. The molecule is described by where the double bonds are.
These carbon atoms may be joined together by single or double bonds.
In a saturated fat molecule, every carbon atom bonds with two hydrogen atoms. Foods with large amounts of saturated fats tend to raise cholesterol levels in humans, while foods with unsaturated fat tend to lower cholesterol levels. Saturated fatty acids raise total and low-density lipoprotein (LDL) cholesterol. The low density cholewsterol is thought to be bad as it sticks to the arterial walls. Foods that contain a high proportion of saturated fat are butter, ghee, suet, tallow, lard, coconut oil, cottonseed oil, and palm kernel oil, dairy products (especially cream and cheese), meat, chocolate, and some prepared foods.
In a monounsaturated fat molecule, one pair of hydrogen atoms is missing.
In a polyunsaturated fat molecule (PUFA), more than one pair of hydrogen atoms is missing. Corn and canola oils are polyunsaturated fats. Almost all naturally occurring PUFAs have a curly structure that is predominately in what is called a “cis” formation. This is in contrast to oils and fats that have been hydrogenated through chemical manipulation. Here a lot of the fat has been turned into a “trans” formation - a completely different curled structure. This is important because chemical shape is very important to how the body responds to it. These trans-fatty acids are harmful to the body and are much worse than saturated fats for heart disease.
Many oils have percentages of unsaturated, monosaturated, and polyunsaturated components.
Compounds with less than 8 carbon atoms are considered to be fatty acids, whereas fatty acids derived from natural fats and oils may be assumed to have at least 8 carbon atoms, and often have many more – up to 24. Most of the natural fatty acids have an even number of carbon atoms, because their biosynthesis involves acetyl-CoA, a coenzyme carrying a two-carbon-atom group.
Omega-3 fatty acids have a double bond three carbons away from the methyl carbon, whereas omega-6 fatty acids have a double bond six carbons away from the methyl carbon. Omega-9 oils are commonly found in avocados, olive and canola oil.
Okay – now we can talk about the differences between the oils and what our bodies need.
The human body can produce all but two of the fatty acids it needs. These two, linoleic acid (LA) and alpha-linolenic acid (ALA), are widely distributed in plant oils. In addition, fish oils contain the longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Other marine oils, such as from seal, also contain significant amounts of docosapentaenoic acid (DPA or 22:6-n3), which is also an omega-3 fatty acid. Although the body to some extent can convert LA and LNA into these longer-chain omega-3 fatty acids, the omega-3 fatty acids found in marine oils help fulfill the requirement of essential fatty acids (and have been shown to have wholesome properties of their own).
Since they cannot be made in the body from other substrates and must be supplied in food, they are called essential fatty acids. Mammals lack the ability to introduce double bonds in fatty acids beyond carbons 9 and 10. Hence linoleic acid (AA acid) and alpha-linolenic acid (ALA) are essential fatty acids for humans.
The ‘industrialized’ Western diet is very high in omega-6 PUFAs (Linoleic acid or 18:3n-6) and very low in omega-3 PUFAs. Cultures that have a high dietary fish intake (Japanese, Inuits) have very low rates of these ‘Industrialized’ associated diseases noted above because their diet is very high in LC omega-3 PUFAs. Fish and fish oil serves as the only meaningful source of LC omega-3 PUFAs. Flaxseed contains only short-chain omega-3 (ALA), which is not the biological equivalent of the long-chain omega-3 molecules found in fish (DHA and EPA).
The typical American diet has an arachidonic acid or AA/EPA (omega-6 to omega-3) ratio > 20:1. For anti-inflammatory purposes, the ideal or desired ratio is 2:1. This can only realistically be achieved through omega-3 fish oil supplementation. The LC omega-3 FA’s EPA and DHA are a much better source of omega-3 than the SC ALA, typically found in flax seed oil. Although ALA can be converted in the body to EPA & DHA, it’s a very poor and inefficient conversion, and there are many factors that further inhibit this conversion including excess alcohol, caffeine, smoking, aging, high cholesterol and saturated fats, high sugar diets and vitamin and mineral deficiency (such as zinc, chromium and B6).
Okay – finished the chemistry talk. Lets summarize:
1/ Polyunsaturated fats better than saturated ones,
2/ linoleic acid (ALA acid) and alpha-linolenic acid (ALA) are essential fatty acids for humans. The Canadian FDA recommends about 1.5 grams/day of omega-3.
3/ the (AA or Linoleic acid) omega-6 to omega-3 (EPA and DHA) should be something more like 2:1, rather than 20:1.
4/ High levels of omega-6 can actually block omega-3 usage, since omega-6 competes for the same elongase enzymes that the body uses in utilizing the omega-3 oil. Similarly, conversion of ALA is inhibited by n-6 and n-3 PUFAs
Enough already you say. Lets look at the oils and nutrition differences between farmed and wild salmon…
The fish highest in omega-3 fatty acids are salmon, sardines, herring, trout, mackerel and both albacore and blue fin tuna. Cold water fish get a lot of omega 3 fats from the fish they eat, which get it in turn ultimately from cold water plankton. It may also be that cold itself stimulates fish to make more omega-3's.
I put together a list to compare oils between fish species below:
From this picture – it can be seen that while cod and salmon have the highest Omega-3 levels; tuna, flounder and rockfish have better (lower) Omega-6 to Omega-3 levels. However, all the fish (exception lemon sole) have low Omega-6 to Omega-3 ratios.
There are conflicting reports about whether wild or farmed salmon have more Omega-3s. I'd guess that each study had differently fed fish, and that needs to be explained before any meaningful comparisons can be made.
Also, returning wild salmon stop eating, and use-up oils as an energy source once the enter fresh water. So location and nutritional health of the fish examined are also keys to comparing.
For the most part - all fish and fish oils are ultimately good for you (you can do without the contaminants, though).
Having said all of this; farmed salmon is much higher in saturated fats than wild salmon. This can contribute to health problems. According to the U.S. Department of Agriculture, farmed Atlantic salmon contain 70 percent more fat than wild Atlantic salmon and 200 percent more fat than wild Pacific salmon.
There are also changes in the fatty acid composition of farmed salmon; as salmon farmers are switching from fish-based oils in the feed, to other plant-based oils and from fishmeal-based filler to corn meal filler.
Then there are other contaminants in the feed, as well. I’ll save that conversation for later…
http://www.sportfishingbc.com/forum/topic.asp?TOPIC_ID=8847&whichpage=16
brings-up some important points.
In order to discuss this – we need to understand what an Omega-3 is, and more importantly - what is fat?
Fats and oils are a generic name for lipids - which consist of chains of fatty acids. A visual representation of different fatty acids below is from Wikkipedia:
A fatty acid has a carboxylic acid at one end and a methyl group at the other end. Don’t zone-out, yet – it’s not really that hard to follow – just continue reading for a few more seconds.
The carboxyl end is what allows these long fatty acid chains to bond, since carboxylic acids are polar, and form hydrogen bonds with each other. Think of it as the sticky end.
The other end - methyl group – doesn’t bond with water too well. It’s what causes the saying it mixes “like oil and water”. It’s the non-sticky end.
The Carbon atoms in a fatty acid are identified by Greek letters on the basis of their distance from the carboxylic acid group – or the sticky end. The carbon atom closest to the carboxylic acid is the alpha carbon, the next adjacent carbon is the beta carbon, etc. In a long-chain fatty acid the carbon atom in the methyl group is called the omega carbon because omega is the last letter of the Greek alphabet.
You can see where this is leading – when we talk about Omega-3’s. It’s just an accurate way of describing the exact chemical structure of the molecule. The molecule is described by where the double bonds are.
These carbon atoms may be joined together by single or double bonds.
In a saturated fat molecule, every carbon atom bonds with two hydrogen atoms. Foods with large amounts of saturated fats tend to raise cholesterol levels in humans, while foods with unsaturated fat tend to lower cholesterol levels. Saturated fatty acids raise total and low-density lipoprotein (LDL) cholesterol. The low density cholewsterol is thought to be bad as it sticks to the arterial walls. Foods that contain a high proportion of saturated fat are butter, ghee, suet, tallow, lard, coconut oil, cottonseed oil, and palm kernel oil, dairy products (especially cream and cheese), meat, chocolate, and some prepared foods.
In a monounsaturated fat molecule, one pair of hydrogen atoms is missing.
In a polyunsaturated fat molecule (PUFA), more than one pair of hydrogen atoms is missing. Corn and canola oils are polyunsaturated fats. Almost all naturally occurring PUFAs have a curly structure that is predominately in what is called a “cis” formation. This is in contrast to oils and fats that have been hydrogenated through chemical manipulation. Here a lot of the fat has been turned into a “trans” formation - a completely different curled structure. This is important because chemical shape is very important to how the body responds to it. These trans-fatty acids are harmful to the body and are much worse than saturated fats for heart disease.
Many oils have percentages of unsaturated, monosaturated, and polyunsaturated components.
Compounds with less than 8 carbon atoms are considered to be fatty acids, whereas fatty acids derived from natural fats and oils may be assumed to have at least 8 carbon atoms, and often have many more – up to 24. Most of the natural fatty acids have an even number of carbon atoms, because their biosynthesis involves acetyl-CoA, a coenzyme carrying a two-carbon-atom group.
Omega-3 fatty acids have a double bond three carbons away from the methyl carbon, whereas omega-6 fatty acids have a double bond six carbons away from the methyl carbon. Omega-9 oils are commonly found in avocados, olive and canola oil.
Okay – now we can talk about the differences between the oils and what our bodies need.
The human body can produce all but two of the fatty acids it needs. These two, linoleic acid (LA) and alpha-linolenic acid (ALA), are widely distributed in plant oils. In addition, fish oils contain the longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Other marine oils, such as from seal, also contain significant amounts of docosapentaenoic acid (DPA or 22:6-n3), which is also an omega-3 fatty acid. Although the body to some extent can convert LA and LNA into these longer-chain omega-3 fatty acids, the omega-3 fatty acids found in marine oils help fulfill the requirement of essential fatty acids (and have been shown to have wholesome properties of their own).
Since they cannot be made in the body from other substrates and must be supplied in food, they are called essential fatty acids. Mammals lack the ability to introduce double bonds in fatty acids beyond carbons 9 and 10. Hence linoleic acid (AA acid) and alpha-linolenic acid (ALA) are essential fatty acids for humans.
The ‘industrialized’ Western diet is very high in omega-6 PUFAs (Linoleic acid or 18:3n-6) and very low in omega-3 PUFAs. Cultures that have a high dietary fish intake (Japanese, Inuits) have very low rates of these ‘Industrialized’ associated diseases noted above because their diet is very high in LC omega-3 PUFAs. Fish and fish oil serves as the only meaningful source of LC omega-3 PUFAs. Flaxseed contains only short-chain omega-3 (ALA), which is not the biological equivalent of the long-chain omega-3 molecules found in fish (DHA and EPA).
The typical American diet has an arachidonic acid or AA/EPA (omega-6 to omega-3) ratio > 20:1. For anti-inflammatory purposes, the ideal or desired ratio is 2:1. This can only realistically be achieved through omega-3 fish oil supplementation. The LC omega-3 FA’s EPA and DHA are a much better source of omega-3 than the SC ALA, typically found in flax seed oil. Although ALA can be converted in the body to EPA & DHA, it’s a very poor and inefficient conversion, and there are many factors that further inhibit this conversion including excess alcohol, caffeine, smoking, aging, high cholesterol and saturated fats, high sugar diets and vitamin and mineral deficiency (such as zinc, chromium and B6).
Okay – finished the chemistry talk. Lets summarize:
1/ Polyunsaturated fats better than saturated ones,
2/ linoleic acid (ALA acid) and alpha-linolenic acid (ALA) are essential fatty acids for humans. The Canadian FDA recommends about 1.5 grams/day of omega-3.
3/ the (AA or Linoleic acid) omega-6 to omega-3 (EPA and DHA) should be something more like 2:1, rather than 20:1.
4/ High levels of omega-6 can actually block omega-3 usage, since omega-6 competes for the same elongase enzymes that the body uses in utilizing the omega-3 oil. Similarly, conversion of ALA is inhibited by n-6 and n-3 PUFAs
Enough already you say. Lets look at the oils and nutrition differences between farmed and wild salmon…
The fish highest in omega-3 fatty acids are salmon, sardines, herring, trout, mackerel and both albacore and blue fin tuna. Cold water fish get a lot of omega 3 fats from the fish they eat, which get it in turn ultimately from cold water plankton. It may also be that cold itself stimulates fish to make more omega-3's.
I put together a list to compare oils between fish species below:
From this picture – it can be seen that while cod and salmon have the highest Omega-3 levels; tuna, flounder and rockfish have better (lower) Omega-6 to Omega-3 levels. However, all the fish (exception lemon sole) have low Omega-6 to Omega-3 ratios.
There are conflicting reports about whether wild or farmed salmon have more Omega-3s. I'd guess that each study had differently fed fish, and that needs to be explained before any meaningful comparisons can be made.
Also, returning wild salmon stop eating, and use-up oils as an energy source once the enter fresh water. So location and nutritional health of the fish examined are also keys to comparing.
For the most part - all fish and fish oils are ultimately good for you (you can do without the contaminants, though).
Having said all of this; farmed salmon is much higher in saturated fats than wild salmon. This can contribute to health problems. According to the U.S. Department of Agriculture, farmed Atlantic salmon contain 70 percent more fat than wild Atlantic salmon and 200 percent more fat than wild Pacific salmon.
There are also changes in the fatty acid composition of farmed salmon; as salmon farmers are switching from fish-based oils in the feed, to other plant-based oils and from fishmeal-based filler to corn meal filler.
Then there are other contaminants in the feed, as well. I’ll save that conversation for later…
I'll definitely have to go over those posts 3-4 times for it to sink in. Thanks for the information.
