Linseed/Flaxseed & Flaxseed oil.

"Where flax is eaten...health abounds!" - Mahatma Gandhi.

These little seeds pack a quadruple-whammy of protein, omega-3 Essential Fatty Acids (EFAs), soluble fibre/fiber and vitamins, minerals & other anutrients.


What's in flaxseed and flaxseed oil?

Click http://www.nutritiondata.com/facts/nut-and-seed-products/3163/2 and set serving size: to 100g, to see what nutrients there are in flaxseeds.
Click http://www.nutritiondata.com/facts/fats-and-oils/7554/2 and set serving size: to 100g, to see what nutrients there are in flaxseed oil.


How do I eat flaxseed and flaxseed oil?

Flaxseed/Linseed have a fibrous coat which swells-up when wet and passes through our guts undigested. To get the benefit of the protein, omega-3 essential fatty acids, vitamins & minerals in flaxseeds, the seeds need to be powdered, crushed, cracked, chopped-up, sliced-up or ground-up using a coffee grinder, adjustable pepper grinder or most simply, a blender with a sharp blade.

The resulting powder can be mixed with liquids or sprinkled on foods, though extra fluid must be drunk, as the soluble fibre/fiber absorbs a lot of water.

Although whole flaxseed keeps fresh at room temperature, once powdered, it's advisable to keep the powder in a cool dark place to minimise oxidation of any exposed fat. Flaxseed oil must be kept refrigerated with the lid on the bottle at all times after opening and it must never be used for cooking.

The oil is O.K. drizzled over hot food, as long as the food is eaten shortly afterwards. Oxidised flaxseed oil tastes bitter and has lost its health benefits, so it should either be chucked, used to varnish something or soften hardened putty. Unoxidised flaxseed oil has a nutty flavour, or it may taste a bit like tea. Powdered flaxseed has virtually no flavour.

See Milled flaxseed stability information.


How much flaxseeds and flaxseed oil do I need to eat each day?

Men are much poorer converters of alpha-linolenic acid (the omega-3 fatty acid in flaxseed) into DHA than women.

See Eicosapentaenoic and docosapentaenoic acids are the principal products of α-linolenic acid metabolism in young men,

Conversion of α-linolenic acid to eicosapentaenoic, docosapentaenoic and docosahexaenoic acids in young women and

Extremely Limited Synthesis of Long Chain Polyunsaturates in Adults: Implications for Their Dietary Essentiality and Use as Supplements.

Therefore, men should eat ~50g/day of ground flaxseed and women should eat ~25g/day. The amount of flaxseed oil for men is ~20g/day and the amount for women is ~10g/day. Vegan men should also supplement with ~1000mg/day of vegan DHA.


Where can I buy flaxseeds and flaxseed oil?

Flaxseed/linseed come in different colours. The cheapest linseed are brown/bronze ones which are often sold as bird seed in pet shops, but they can also be found in small independent health food shops. There are also golden linseed, which is the type most often found in supermarkets. Linusit and Granovita are two well-known brands. Granovita organic flaxseed oil is a good brand and it comes in dark bottles to keep light out, as light causes photo-oxidation of omega-3 fats.

Fats: Spawn of Satan or Dogs' Doodads?

From http://ajcn.nutrition.org/content/65/5/1628S.full.pdf

Fats get a lot of bad press in the media. There are so many adverts with "X% fat-free" or "only 1g of fat per Jaffa Cake" as if that's going to stop you from getting fat when you "om nom nom" your way through a whole box of the things!

Saturated fats are usually described as "bad" and polyunsaturates are usually described as "good". This is simplistic. Everything is bad in excess, even polyunsaturates. The thing about fats is that there are four basic types (saturates, monounsaturates, ω-6 polyunsaturates and ω-3 polyunsaturates) and they need to be consumed in roughly the right proportions for optimum health. Suffice it to say, the majority of people in the West do not eat them in anywhere near the right proportions. So, what exactly are fats?


Fats

Fats are an ester of glycerol (CH₂OH-CHOH-CH₂OH) & 3 fatty acids, and are also known as triglycerides (TG's) or triacylglycerols (TAG's).

1 molecule of glycerol + 3 molecules of fatty acid = 1 molecule of triglyceride + 3 molecules of water.

It's the fatty acids that determine whether a fat is saturated, monounsaturated etc. The four different types of fatty acid have a CH₃ at one end and a COOH at the other. The difference is in the middle section.

Saturated fatty acids have a middle section consisting of CH₂'s. Here's a diagram for Stearic acid (the predominant fatty acid in beef):-

__H H H H H H H H H H H H H H H H H O
H-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-O-H
__H H H H H H H H H H H H H H H H H


Monounsaturated fatty acids have one C=C bond in the middle, which is usually (but not always) 9 from the left-hand end, resulting in monounsaturates often being referred to as ω-9's, as ω is the last letter of the Greek alphabet. Here's a diagram for Oleic acid (the predominant fatty acid in olive oil):-

__H H H H H H H H_____H H H H H H H O
H-C-C-C-C-C-C-C-C-C=C-C-C-C-C-C-C-C-C-O-H
__H H H H H H H H H H H H H H H H H


ω-6 polyunsaturated fatty acids have two or more C=C bonds in the middle, with the last one always being 6 from the left-hand end. Here's a diagram for Linoleic acid (the predominant fatty acid in sunflower oil):-

__H H H H H_____H_____H H H H H H H O
H-C-C-C-C-C-C=C-C-C=C-C-C-C-C-C-C-C-C-O-H
__H H H H H H H H H H H H H H H H H


ω-3 polyunsaturated fatty acids have three or more C=C bonds in the middle, with the last one always being 3 from the left-hand end. Here's a diagram for Alpha-linolenic acid (the predominant fatty acid in flax-seed oil):-

__H H_____H_____H_____H H H H H H H O
H-C-C-C=C-C-C=C-C-C=C-C-C-C-C-C-C-C-C-O-H
__H H H H H H H H H H H H H H H H H


These diagrams are slightly misleading. Where there is a C=C bond, there are two H's on the "underside" only of the molecule. This asymmetry causes the H's to repel each other and bend the molecule into a V-shape at each C=C bond. C=C bonds with H's on the same side are known as "cis" bonds. The above molecule is really cis, cis, cis (c,c,c) Alpha-linolenic acid. The other type of C=C bond is known as "trans" and looks like the following diagram:-

__H H H___H H___H H___H H H H H H H O
H-C-C-C=C-C-C=C-C-C=C-C-C-C-C-C-C-C-C-O-H
__H H___H H___H H___H H H H H H H H


This is a diagram of trans, trans, trans (t,t,t) Alpha-linolenic acid. As the H's are on opposite sides of the molecule, they do not repel each other and the molecule is straight, as shown above. Note that saturated fatty acid molecules are naturally straight. Therein lies the problem with trans-fatty acids. They're straight, like saturated fatty acids, but they have unsaturated bonds, which are prone to peroxidation. See http://www.cyberlipid.org/perox/oxid0002.htm WARNING! Heavy-duty organic chemistry!

Our bodies take trans-fatty acids and incorporate them into cell membranes as if they were saturated fatty acids. This results in atherogenicity (artery-clogging), damage to the immune system and other health problems. Trans-fatty acids are found in partially-hydrogenated vegetable oils, so any cooking/spreading fats which have the word "hydrogenated" high-up in the ingredients list should be avoided. These are bad fats.

There are naturally-occurring trans-fatty acids made by bacteria in the stomachs of ruminant animals, like Conjugated Linoleic Acid (CLA). This looks a bit like the diagram below:-

__H H H H H_____H___H H H H H H H H O
H-C-C-C-C-C-C=C-C=C-C-C-C-C-C-C-C-C-C-O-H
__H H H H H H H___H H H H H H H H H


This has one of the C=C bonds shifted to the left and also has one cis bond and one trans bond, so the molecule is always bent. CLA has possibly beneficial properties, but human trials show mixed results. It's certainly not artery-clogging, so don't let anyone put you off eating butter from grass-fed cows (e.g. Anchor or Kerrygold butter) by saying that it has trans-fats in it. CLA is a harmless trans-fat.


Saturated fat consumption should be about 10% of total calories. This is because, even though saturated fats are not essential (our bodies can synthesise them), this guarantees adequate synthesis of sex hormones. Total polyunsaturate consumption should be about 5% of total calories, with a ω-6:ω-3 ratio of between 1:2 and 4:1. As ω-3's are found in greater quantities than ω-6's only in flax-seeds (a.k.a. linseeds) and oily fish, and many people eat way too little or no oily fish (and who, other than body-builders and some vegetarians/vegans, eats flax-seeds?), the ω-6:ω-3 ratio in the West is ~20:1. This is due to the widespread consumption of meats, eggs & milk from grain-fed animals, grains, nuts and seeds. There are high rates of heart disease and other inflammatory diseases in the West, as ω-6's end up in series 1 & 2 prostaglandins, and series 2 prostaglandins are pro-inflammatory. ω-3's end up in series 3 prostaglandins, which are anti-inflammatory.

So eat up yer oily fish if you're not vegetarian or vegan. Otherwise, eat up yer ground-up flax-seeds!

Monounsaturates can make up about 15% to 35% of total calories, depending on activity levels. From the histogram in Everyone is Different, sedentary people, on average, burn twice as much energy from fats as from carbohydrates.

So, if 25% of energy comes from protein say, 25% of energy can come from carbohydrates, and 50% can come from fats, i.e. a 2:1 ratio of fats:carbs. The cyclists at the left-hand end of the histogram in Chapter 1 would do best on 25% protein, 15% carbohydrate, 60% fat, when sedentary, whereas the cyclist at the right-hand end of the histogram would do best on 25% protein, 60% carbohydrate, 15% fat, when sedentary. When active, more carbs are needed by everyone.

Which fats contain which fatty acids? See https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQcYggz8ORx7mdTT7_ngR-jKOG-2FB4sm5HZWFyJF7xFYlNn-XCkbs4tSIuFFaJFVUdFTw13Q5M2-Adu_jeVnu3O37NhPlK_XWrxIACJ_QT1KmVElpl1YoLO4nfBBoqJNI5FQlhSDh/s640/comparison-of-fats.gif for a Comparison of Dietary Fats.

For high-temperature cooking, saturates are the least likely to oxidise (when they're on fire, they're oxidising!), followed by monounsaturates, then ω-6's, with ω-3's being the most likely to oxidise. An oil doesn't have to be smoking, to be oxidising. Alpha-linolenic acid oxidises to varnish at room temperature without smoking, which is why linseed oil is used to varnish cricket bats and dilute putty. The best non-animal fat for high-temperature cooking is Coconut Oil, followed by Palm Oil and then Olive Oil.

Extra-Virgin Olive Oil (EVOO) has a lower smoke point than refined Olive Oil (due to higher levels of free fatty acids), but has higher levels of polyphenol antioxidants, which makes it heart-healthy.

Oils high in polyunsaturates shouldn't be heated to temperatures greater than 100°C, as polyunsaturates can change from the cis configuration to the trans configuration at 102°C. See http://www.harricksci.com/sites/default/files/pdf/application_notes/FatIR_App-Notes_ATR_Oil-Analysis.pdf