Wednesday, 24 December 2008

Kinky DHA


Common in nature yet rare in your diet

Alpha-Linolenic acid (ALA) is found primarily in the green parts (chloroplasts) of plants where it is associated in photosynthesis – the process by which plants make sugars from light and the basis to all life on earth! Since ALA is found in plants, and the planet has more green vegetation than anything else, it is the most abundant fat there is. It accumulates into the tissues of animals that feed on this vegetation and is passed on to the subsequent predators. Unfortunately ALA has become rare in the average human diet, which is dense on seeds, the oil from seeds and meat from livestock fed on seeds. This rarity or deficiency is now being linked to a plethora of ills.

ALA the single parent

Alpha-Linolenic acid can be thought of as a single parent of the Omega 3 family of fats. ALA is a very weak acid with a similar strength to vinegar actually. That's not surprising since vinegar is Acetic acid which is another fatty acid.

In nature these fatty acids proceed to tag team up with a molecule of glycerol to become known as a triglyceride. They are more commonly known as FATS and are no longer acidic. It's helpful to know that all triglycerides have an identical glycerol backbone with three fatty acids of varying length. The equation is very simply summed up as follows:

1 glycerol + 3 fatty acids = 1 triglyceride (fat) + 3 molecules of water

Now whether these triglycerides take the shape of vegetable oil, butter or lard depends entirely on which fatty acids are involved. Some have straight saturated chains of atoms and produce solid fats. Others have kinky unsaturated chains and produce liquids.

ALA has a very kinky chain or tail and thus the fats in which it is abundant (linseed, canola) are liquids, even at low temperatures. However for humans and animals, which are both faster and more mobile than plants, it just isn't kinky enough. So before usage it has to be lengthened as I've described here.

DHA the wild child

Docosahexaenoic (DHA) is one of several offspring of ALA and the longest fatty acid in human and animal tissue. This is the fat that permits you to see and think. The highest concentrations of DHA are found in cell membranes of the brain and eyes. Here it has an amazing ability to quick-change between hundreds of shapes, billions of times per second.

The picture above illustrates DHA in one of its many shapes. Sometimes it curls up like a ball, other times it's perfectly straight. It just never sits still and is constantly on the move. Its concentrated presence in cell membranes (thin barrier surrounding cells) transforms them from 'orderly guards' to dancers at an all night rave party. Its diluted presence throughout the body is like oil added to an engine.

Examples of DHA use

DHA is called upon for life's speediest of tasks. It has a role in dynamic, fast acting cells in the heart. An organ which beats around seventy beats per minute or some two billion times in a lifetime. It is found in tissues of the brain and your eyes, which are hopefully focused on this blog. DHA can be found in lesser concentrations throughout your body, where amounts are subject to exercise, genetics and diet. Endurance athletes have more DHA in their skeletal muscle than couch potatoes. The Prima Indians of Arizona are a population with the highest reported incidence of type-2 diabetes. They have far less DHA in their skeletal muscle than anyone else – owing to genetic differences. In rattlesnakes, the rattle muscle has much more DHA than its stomach muscle. Reptiles in general tend to have lower levels of DHA in their tissues than mammals and birds.

Hummingbirds have flight muscles which beat an incredible fifty-two times per second and are incredibly rich in DHA. Their leg muscles however have little. Fish have high levels of DHA, which is perfectly understandable since they live in cold dimly light environments and they need greater flexibility and agility to cope. They also have ready access to algae and other omega 3 rich marine life.

Thursday, 18 December 2008

Omega 3 & Omega 6 ratios

In previous articles I've unpacked the basics of essential fatty acids so I thought I'd go ahead and root around further.

Just to recap, omega 3 and omega 6 are 'essential' fatty acids because your body cannot produce them. So they must be ingested as part of a diet regimen. Typical Western diets are incredibly rich in omega 6 owing to vegetable oil abuse and grain fed animals with omega 3 almost nonexistent. The British (and American) diet may have in excess of 20 parts omega 6 to 1 part omega 3 (>20:1).

Dietary bodies and vocal internet groups seem to be at odds as to the correct ratio of omega 6 to omega 3. Some nutritionists state a 4:1 ratio whilst others are happy to push a 1:1 ratio. However a 2:1 ratio of omega 6 to omega 3 seems favourable here.

Why all the strife over ratios?

Omega 3 tends to keep Omega 6 in check otherwise omega 6 on its own causes mayhem, including the oxidisation of LDL cholesterol. Lower ratios have been associated with a decreased risk of diabetes and heart disease. In fact a 2:1 ratio of omega 3 to omega 6 was found to reduce inflammation associated with arthritis.

Recommended Daily Allowance

The World Health Organisation recommends 1-2 servings of fatty fish (e.g. salmon, sardines, pilchards, mackerel and herring) coupled with oils containing omega 3 per week. The British Heart Foundation says pretty much the same. There isn't a recommended daily allowance set in stone for those wishing to supplement with omega 3 oils but an approximated 2g of EPA and DHA seems good.

EPA, DHA and Linseeds (flax)

Linseeds are a great source of omega 3 but in the wrong form of it. They contribute an omega 3 called Alpha-Linolenic acid (ALA). This ALA is a 'short chain' fatty acid and must be converted to 'long chain' fatty acids known as Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). The process of converting ALA to EPA and DHA is inefficient. In women this conversion is about 36% and only 16% in men. Thus recommended dosages of Linseed oil for women would be approximately 10g for women and 20g for men daily. Those wishing to ingest blitzed powered seed would need to double those amounts.

How does ALA make EPA & DHA?

I'll try and keep this simple without too much technical jargon. When you take ALA the body has to convert it to EPA and DHA as mentioned earlier. This is done through several long winded rounds of elongating and desaturating. See the flowchart below for the steps involved:

In the top left corner, you have ALA. This is acted upon by delta-6 desaturase (an enzyme) to form Stearidonic acid. This is another 18-carbon omega 3 like ALA. This fatty acid is then elongated by the injection of an ethyl group to form Eicosatetraenoic acid. This is now a 20-carbon omega 3. It's then acted upon by delta-5 desaturase (another enzyme) and EPA is made.

EPA is still 2 carbon atoms short for DHA though. So it's elongated again by an ethyl group to form Docosapentaenoic acid (DPA). This is finally converted by delta-4 desaturase (yet another enzyme) to DHA.


Recommendation

The best sources of EPA and DHA are animal products. Fish, grass-fed meats and eggs (non-grain fed) are ideal sources. To hit your daily quota supplementation is required. If you do decide to pursue plant based omega 3 (e.g. Linseed, walnuts) please bear in mind the aforementioned conversion rates.

Wednesday, 17 December 2008

Vitamin D


It's that time of year again, Christmas is but round the corner and winter has settled in. You look outside and a cold cloaked earth looks back. The days grow shorter and darker, and you begin to murmur to yourself "Man I've got the blues".

So now would be a great opportunity to get acquainted with Vitamin D and reap the benefits it may provide. Health aficionado Nigel Kinbrum has written a most informative article on the subject here, I'd urge all to have a read.

Saturday, 13 December 2008

Saturated oils

I don't need to tell you that saturated fat is bad. Chances are that you've come across many vocal groups proclaiming polyunsaturated fats as 'good' and saturated fats as 'bad'. This is too simplistic. Any fat in excess is bad, especially polyunsaturated.

Saturated fat has been labelled a dietary monster causing {inset favourite disease here} and other untold health problems. Yet saturated fat has been a staple part of human diets for thousands of years but only recently had negative publicity – most probably profit motivated by those selling polyunsaturated products. Our ancestors lived on a diet rich in grease, lard and butter. It wasn't until the 20th century that vegetable oils (polyunsaturated) became widely available and with that has come a plague of degenerative diseases.


Polynesians and saturated fats

A study done on two populations of Polynesians, namely Pukapukans and Tokelauans on the effects of their dietary saturated fats showed some startling revelations. Pukapukans were getting 26-30% of their total calories from fats whereas Tokelauans were getting 47-49% of their total calories from fats.

Now since the Tokelauans were obtaining around seven times more calories from saturated fats than the 7% current 'healthy' guidelines recommend, one would have expected them to perish from strokes and coronary heart disease. However, contradictory to this the investigation found that vascular disease was uncommon in both populations. No evidence of high saturated fat intake having a harmful effect was found in these populations. Interestingly the rest of the Tokelauans' diet consisted of no refined sugars, no cereals and certainly no Mc Donald's – they were not eating junk!

Reference: Nigel Kinbrum's eBook and a whole host of links to great articles can be found here

Should you wish to read up on the study it can be found here



Health benefits of saturated oils

Saturated fat is needed for proper digestive function, growth, and is an essential component of every single cell in your body. Nature has infused this fat into almost all of the foods we eat, both plant and animal. Even polyunsaturated vegetable oils contain at least some saturated fats.

Lauric acid, the main fatty acid found in coconut oil has many viral and bacterial properties. It's also great for the skin when rubbed in.

Short and medium chain fatty acids may promote weight loss. They are metabolised rapidly without passing through the liver to provide a quick source of energy.


Health dangers of saturated oils

The most recognised danger of saturated fats is that it elevates your LDL (bad) cholesterol. It does also elevate your HDL (good) cholesterol but the net effect of the two is still negative. This cholesterol will block arteries, making it harder for blood to flow ultimately causing heart attacks (simplified extremely). Cholesterol is not the only thing that makes saturated fat less healthy. It has a bad effect on blood glucose levels and may cause diabetes. It also causes inflammation, which as Dr. Art Ayers blogs about causes many diseases.


Recommendation

In moderation and coupled with anti-oxidants I see no reason discourage the use of saturated fats. My personal favourite is extra virgin coconut oil which is not refined, bleached or deodorised.

Thursday, 11 December 2008

Monounsaturated oils

Foreword: Newbies please check out the introduction to cooking oils here before divulging into this topic.

The most prominent mono-unsaturated oil in this category is olive oil. Another oil that is getting more and more coverage is a high-oleic sunflower/safflower oil. Normal sunflower and safflower oils are very high in polyunsaturated fatty acids but the high-oleic varieties are made with a particular seed that is about as high in monounsaturated fats as olives. Below is a table with the fatty acid ratios for comparison:


Health benefits of monounsaturated oils

Monounsaturated oils are much easier to understand than their polyunsaturated counterparts. There are no different types or kinds that you need to worry about. Try to think of monounsaturated oils as a hybrid between very unstable polyunsaturated oils and very stable saturated oils. They do not get rancid as easily as polyunsaturated oils and do not have the artery clogging effects of saturated fats. Monounsaturated oils have an anti-inflammatory effect: they are good for people with arthritis and asthma. They tend to lower LDL (bad) cholesterol and increase HDL (good) cholesterol - whether this actually reduces disease is up for debate though.

Heath dangers of monounsaturated oils

Though more stable than polyunsaturated oils, they do still oxidise readily. Even though olive oil is rich in monounsaturated fatty acids, it still contains 11% of unstable polyunsaturated fat. Oxidised oils are toxic to your health. They oxidise cholesterol – think of rusting arteries!

Monounsaturated fats have a plethora of health benefits, that is agreed but as extracted oils they are still mostly empty calories. That means they contain very few vitamins and no minerals. You can get the same health promoting fats in a far healthier way by simply eating avocados and almonds.

Recommendation

Buy cold pressed extra virgin oil over standard. This is the best quality olive oil that is pressed without heat thus preserving at least some antioxidants (like Vitamin E) that were originally present in the olive itself. Look for olive oil that is stored in dark bottles and still has a long use by date. Always store the oil sealed in a dark cool place. I have mine in the fridge where it slowly solidifies and is removed a few hours prior to usage in its liquid form. Moderation is the key and two tablespoons of oil as a salad dressing is more than sufficient.

Saturday, 6 December 2008

Polyunsaturated oils

Many health organisations recommend using oils consisting primarily of polyunsaturated fatty acids (PUFA's for short). The most widespread of which is sunflower oil. We're told these oils are good for the heart so I decided to have a look into the facts.

Understand that there are two separate issues important here:

  1. The health aspects of polyunsaturated fatty acids
  2. The health aspects of extracted oil made from those fatty acids

Different kinds of polyunsaturated fatty acids

PUFA's can be divided into two groups: Omega 3 and Omega 6. For years and years the experts thought the two were identical in their health benefits but lately omega 3 seems to have got the limelight. Science has now shown that too much Omega 6 PUFA's are actually unhealthy.

Omega 3 fatty acids

Three important Omega 3 fatty acids are Alpha-Linolenic acid (ALA), Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). Your body CANNOT make the ALA so you have no choice but to get it from your diet. Linseeds and walnuts are naturally rich in ALA – and thus are both highly recommended by me so go out and buy them now.

ALA by itself has a plethora of health benefits, but as I previously blogged the Omega 3 fatty acids that are good for your brain are DHA and EPA. Your body CAN covert ALA into EPA and EPA into DHA as long as your diet is a healthy one. Natural sources of EPA and DHA are fish and algae (Vegetarians may purchase it from the following: www.water4.net ).

Omega 6 fatty acids

Three important Omega 6 fatty acids are Linoleic acid (LA), Gamma-Linolenic acid (GLA) and Arachidonic acid (AA). Your body CANNOT make LA, so again you have no choice but to obtain it from your diet. Then once ingested the body can convert LA into the other Omega 6 fatty acids. Now here is where it all goes pear shaped...

Those ever so many health organisations that push sunflower oils and other LA rich products as the saviour for your heart fail to mention an important fact. And that is that our diets are way too rich in LA already, we certainly don't need more LA. Sunflower oil for example may or may not be healthy but since we already have a surplus of LA it is simply a non requirement.

Health benefits of PUFA's

PUFA's do lower cholesterol. We all know the drill here right? High levels are associated with higher rates of heart disease and lower rates are vice versa. But it is important to note though, that PUFA's lower both LDL (the bad type) and HDL (the good type) cholesterol and those populations that have low levels of heart disease do not consume much PUFA's at all.

Health dangers of PUFA's

PUFA's are prone to rancidity and oxidation. These affect both the taste and the health properties of the fats. If you take whole nuts and seeds as an example, then their original packaging by nature protects the fragile oils with many anti-oxidants. When the oils are extracted, the packaging that nature intended to protect with is disregarded. Thus these extracted fats are far more likely to go bad than properly stored nuts and seeds.

If you do not want your arteries to rust up then always store your PUFA rich products in sealed containers in a refrigerator. Never ever overheat them.

Also an overload of Omega 6 fatty acids, particularly LA and AA compared to Omega 3 ALA will lead to inflammatory diseases like asthma and arthritis.

Recommendation

Nuts and seeds are very high in polyunsaturated fatty acids. These fats are very unstable, so it makes sense to eat them in their original packaging (i.e. as whole nuts themselves) and not use extracted polyunsaturated oils.

There are exceptions to this rule as sesame oil still contains many anti-oxidants and a large amount of more stable fats. These are called mono-unsaturated fatty acids and I will discuss them at a later date.

Tuesday, 2 December 2008

Cooking Oils

Oil is a refined food. And if its refined, chances are it isn't healthy per say. The processing of oil to prevent it going rancid robs it from most of its original nutrients. It isn't something that is good for you and should be used in limited amounts. It's perfectly possible to cook without oil, and instead get all your Essential Fatty Acids from nuts, avocados etc. But would your food taste as good without the oil content? Of course not. Food just tastes so much better with the addition of oil. That said, oil in small amounts is not harmful if you are not overweight or suffering from disease.

Different kinds of oils

There are three kids of oils: saturated, mono-unsaturated and poly-unsaturated. Saturated oils are solid at room temperature. Mono-unsaturated oils are fluid at room temperature but solid in the refrigerator. Poly-unsaturated oils are fluid at room temperature and in the refrigerator.

However, all oils contain a mixture of the above three kinds of oils. Below I've highlighted some common oils and their fatty acid contents: