What are Essential Fatty Acids?

Essential fatty acids (EFA's) are a group of saturated fatty acids that your body needs for several important purposes, including cellular functions, mood and behaviour modulation, dealing with inflammation and certain DNA functions. They are called 'essential' because your body cannot make them from scratch and so you need to obtain them from your diet.

There are several two main groups of EFA's - omega-3 and omega-6.



OMEGA-3's:

The most important omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Plants only contain ALA but your body also needs EPA and DHA; while these other omega-3 fatty acids can be manufactured by your body from ALA, the process is quite inefficient and so you need quite a bit of ALA in your diet every day to ensure adequate amounts of these other omega-3's.

It is thought that fish consumption by our ancestors has led to a dependency on EPA and DHA as fish are high in these omega-3's. Interestingly though, these fatty acids are not produced by the fish themselves, but come from some of the algae they eat. This is why, instead of having to take a fish oil supplement to get enough EPA and DHA, you can now take vegan algae-based supplements instead, including Chlorella and Spirulina. These are actually a lot better for you as fish oil can contain unsafe levels of contaminants and is sometimes high in mercury and other environmental toxins that have no place in a healthy diet.



How efficiently does the body convert ALA to EPA and DHA?

The human body can convert ALA to EPA, and EPA to DHA, but the efficiency, and sufficiency for optimal health, of this conversion is controversial. Studies have found EPA and DHA levels in vegans to be about two thirds lower than in people who eat meat. The extent to which this poses a health risk is not yet known, but vegans have been advised to increase their intake of alpha-linolenic acid, and reduce their intake of omega-6 fatty acids and saturated fatty acids, which can limit the rate of conversion. Recently, some companies have begun to market vegan DHA supplements containing seaweed extracts. Whole seaweeds are not suitable for supplementation because their high iodine content limits the amount that may be safely consumed.

The most common estimate for ALA -> DHA conversion is that the body converts about 20% of ALA to DHA.



Where can I obtain ALA, EPA and DHA?

You can get ALA from flax, either in powdered (it is important to grind flax to make the ALA bio-available) or oil form. This is the best easily available source of ALA. You can also find ALA in hemp seeds, soy beans and canola oil.

EPA and DHA are available from Chlorella and Spirulina supplements, which you can find at most health stores these days.



OMEGA-6's:

Omega-6 fatty acids include linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA).

The biological effects of the omega-6 fatty acids are largely mediated by their interactions with omega-3 fatty acids (See the Essential fatty acid interactions article on Wikipedia for more information.)

Some medical research suggests that excessive levels of omega-6 fatty acids relative to omega-3 fatty acids may increase the probability of a number of diseases and depression. Modern non-vegan Western diets typically have ratios of omega-6 to omega-3 in excess of 10 to 1, some as high as 30 to 1. The optimal ratio is thought to be 4 to 1 or lower. In other words, most people get TOO MUCH omega-6 (relative to omega-3) in their diets.
This interferes with the health benefits of omega-3 fats and may aggravate or cause prothrombotic, proinflammatory and proconstrictive conditions. Chronic excessive production of omega-6 is associated with heart attacks, thrombotic stroke, arrhythmia, arthritis, osteoporosis, inflammation, mood disorders and cancer!



Where can I obtain LA, GLA, DGLA and AA?
Vegan sources of omega-6's include cereals, whole-grain breads, nuts, most vegetable oils, evening primrose oil (GLA specifically), borage oil, blackcurrant seed oil, linseed oil, soybean oil, cottonseed oil, sunflower seed oil, corn oil and safflower oil.

Many vegan supplements also contain omega 6 in a healthy ratio to omega-3 and omega-9.

As too much omega-6 relative to omega-3 is unhealthy, rather focus on ensuring adequate omega-3 intake - it'll be almost impossible for you not to get enough omega-6's in your diet!



What about omega-9's?

Unlike omega-3 and omega-6 fatty acids, omega-9 fatty acids are not classed as essential fatty acids. This is both because they can be created by the human body from unsaturated fat, and are therefore not essential in the diet.



Further reading:

For more information on EFA's, visit Vegan Outreach.

Calcium is a metal that combines with phosphate in our bodies to form hydroxylapatite, which is the mineral portion of human and animal bones and teeth.

It is a vital part of the diet (too little can cause osteoporosis in later life) and, fortunately, can be obtained from numerous sources: seaweeds such as kelp, wakame and hijiki, nuts and seeds (like almonds and sesame), blackstrap molasses, beans, oranges, figs, amaranth, collard greens, okra, rutabaga, broccoli, dandelion leaves, kale and fortified products such as orange juice and soy milk. If you're eating your leafy greens, some nuts and some fruit, you'll almost certainly be getting enough calcium.


Isn't milk the best source of calcium?

Dairy is actually a very poor source of calcium, for the following two major reasons:

1) Many people are lactose intolerant, including a significant percentage of people of Indo-European descent;

2) Dairy also contains lots of proteins that are thought to indirectly leech calcium back out of the bones. The counter-intuitive result of this is that drinking lots of milk might actually CAUSE osteoporosis, not prevent it!


For more information on the dangers of milk, visit NotMilk.com.

What is Vitamin B12?

Vitamin B12, also known as cobalamin(e) because it contains cobalt, is a very important essential nutrient: among other things we use it to synthesise red blood cells and maintain the health of our nervous systems and deficiencies can cause all sorts of neurological damage. Vitamin B12 is unique in that it is manufactured solely by micro-organisms that are commonly found in the soil around the root networks of plants. Animals that eat these plants also ingest some of these micro-organisms that then continue to produce a B12 supply from within their gut.

Our evolutionary relationship to dietary B12 can thus be seen to have developed either from eating animals or from eating unwashed plants. In either instance though, it's not the animal or the plant that is supplying us with our B12, it's the micro-organism that lives in or around the plant or animal.

Many non-vegans oversimplify the B12 issue, stating bluntly that are just no non-animal sources of B12, which is worrying as B12 deficiency can result in blindness, brain-damage, infertility, miscarriage and children with impaired cognitive ability and major skin and muscle wasting.

This is worrying, but do vegans have to be specifically concerned about B12 deficiency?

Causes of deficiency

There are several causes of B12 deficiency in both vegans and the general population. While lack of dietary intake is prominent amongst these, a significant percentage of people (including up to 30% of the elderly[1]) cannot absorb naturally occurring B12 due to conditions like intrinsic factor deficiency or celiac disease.


Decificency and diet

While vegans are at greater risk of B12 deficiency if they do not supplement, it is interesting to note that almost 40% of the US population show very low levels of B12, and that these levels (below 258 picomoles per liter [2]) have been correlated with symptoms of deficiency. An equally worrying percentage of people in developing countries also show serious deficiency, possibly due to pathogen-related malabsorption, poor sanitation or similar issues.

For now, however, let's accept that vegans are at specific risk of developing B12 deficiency if they do not supplement or consume fortified foods.

Sources

The daily requirement for B12 is between 1-3 micrograms (1-3 millionths of a gram). Some professionals suggest taking this amount daily, and most daily multivitamins thus contain several micrograms of cobalamine (up to several hundred micrograms in some cases). Others suggest a much larger weekly dose, leading to the provision of weekly dedicated B12 supplements that contain 100mcg or more (it should be noted that your body stores B12 for a reasonably long time - you only lose around 0.1% of your reserves per day. It will, however, eventually run out if you're not taking enough in).

These supplements are the best way to obtain dietary B12 and should be taken by anyone who is not certain of their B12 status, vegan or not.

Historically, people have promoted countless other 'natural' sources of B12: micro-algaes like spirulina and chlorella, fermented soy products like tempeh and miso, and seaweed and sea vegetables like nori, arame and wakame, etc. However, apart from the fact that the levels of naturally occurring B12 in these foods can vary greatly, they usually contain only the inactive analogue of the vitamin, which not metabolized by humans even though it does show up in tests. In fact, these analogues may actually interfere with the metabolism of active B12.

One of the reasons for the continued promotion of non-supplementary sources of B12 is that there are prominent examples thereof: rural Chinese people for example, some of whom are, for all intents and purposes vegan, don't display the symptoms we would usually attribute to B12 deficiency.

Indonesians who consume tempeh regularly also don't seem to suffer from deficiency; it is thought that this is due to B12 producing bacteria that grow on certain kinds of mold that grow on the tempeh. [3][4]

In both cases though, industrial production and processing of food in developed countries dramatically decreases the amount of bacteria, molds, etc. that grow on our foodstuffs, and so we cannot rely on these same sources.

Some people also think that the human gut (or even mouth) contains sufficient concentrations of the necessary micro-organisms to produce ample B12; this is far from proven though, and is likely not to be the case.

Vegans who do not want to use supplements (even though supplementary B12 almost always comes from the same place you would obtain it if you ate unwashed vegetables, moldy tempeh or animal liver: micro-organisms) can still choose to consume fortified breakfast cereals, fortified soy milks (almost all of them tend to be these days), or fortified meat substitutes.

Even energy drinks like Red Bull contain Vitamin B12, although it should be noted that this is often included as a replacement for vitamins that the caffeine stops your body from absorbing.

In conclusion

In short, B12 is not a real concern for vegans if they are willing to supplement (which is an exceedingly small price to pay for the arguable ethical, health and environmental advantages the vegan diet confers) or simply make sure their soy milk and breakfast cereal contain sufficient amounts of B12/cobalamin(e). While the rather dramatic list of symptoms of deficiency does represent the realistic worst case scenarios of severe lack of dietary B12, these are entirely avoidable at all ages of life (via breastfeeding at birth right through to increased supplementation in old age) through simple supplementation and fortification.

[1] US Institute of Medicine – www.iom.edu
[2] Katherine Tucker and Jean Mayer - USDA Human Nutrition Research http://www.ars.usda.gov/is/pr/2000/000802.htm
[3] Areekul S, Churdchu K, Pungpapong V. Serum folate, vitamin B12 and vitamin B12 binding protein in vegetarians. J Med Assoc Thai 1988 May;71(5):253-7.
[4]. Areekul S, Pattanamatum S, Cheeramakara C, Churdchue K, Nitayapabskoon S, Chongsanguan M. The source and content of vitamin B12 in the tempehs. J Med Assoc Thai 1990 Mar;73(3):152-