Can hemp oil replace fish oil in the human diet?

By Dionne Payn
Source: HempLifestyleMagazine.com

You've probably heard about how good omega-3 and 6 fatty acids are
for human health. The common advice is that to get a good supply in
your diet you need to eat oily fish on a regular basis. 

Not many people know that hemp is a fantastic source of omega-3 and
6 fatty acids. But can hemp replace fish oil in the diet? Before we
get into that, let me start by giving you the lowdown on why these
fatty acids are important for good health.

What are essential fatty acids anyway?

Alpha-linoleic acid (ALA) is an omega-3 fatty acid and is known as
an 'essential' fatty acid. Our bodies can't make it so we need to
consume it through the food we eat. Our bodies convert ALA to the
longer chain fatty acids, eicosapentaenoic acid (EPA) and
docosahexaenoic acid (DHA).

EPA and DHA are very important for good health. They are powerful
anti-inflammatory compounds, which is beneficial as inflammation is
the cause of many degenerative diseases. EPA & DHA also lower blood
pressure and blood triglycerides which can reduce the risk of
strokes and heart disease. 

Linoleic acid (LA) is an essential omega-6 fatty acid and is the
precursor to gamma-linolenic acid (GLA). We get plenty of omega-6
fatty acids in our diet from sources such as cooking oils (soybean,
sunflower, and canola oil), poultry and eggs. 

The problem is that our intake of omega-3 fatty acids is too low,
yet our intake of omega-6 fatty acids is too high. The typical
Western diet has an omega-6 to omega-3 ratio of 15:1 but the
recommended ratio is 3:1. In a number of clinical studies, patients
with diseases such as rheumatoid arthritis and asthma have reduced
their symptoms just by eating the correct balance of omega-6 to
omega-3.

The general advice is to consume more oily fish such as mackerel,
salmon & sardines, or take supplements that contain concentrated
amounts EPA & DHA. But what if you don't want to eat fish or take
fish oil supplements?

The problem with fish and fish oils

There are a few issues to consider when deciding to consume fish or
fish oils. Firstly, there is the human health aspect. Our oceans
are polluted with methylmercury, polychlorinated biphenyls (PCB's)
and dioxins, and these contaminants are found in fish. Fish that
are predatory (eat other fish) are large and at the top of the food
chain, and so tend to contain more toxins. 

Governments around the world are advising pregnant and
breastfeeding women to limit the amount of fish they eat as mercury
can cause harm to unborn babies or young children. 
 
For the general population, the medical consensus is that the
benefits of eating fish far outweigh the risk to human health from
these toxins. However to be on the safe side, many people choose to
avoid fish and fish oil supplements altogether.

Then there is the environmental issue. In 2010, Time Magazine
published an article which asked the question, "Is the fatty-acid
craze threatening our ecosystem?" They made the point that the
market for omega-3 supplements doubled to $1 billion US dollars
between 2006 - 2010. 

Environmentalists feared that menhaden, a small filter feeding
species of fish, were being overfished to produce fish oil
supplements. This led to 13 out of 15 Atlantic States banning the
fish oil company that caught 90% of the fish from their waters. 

Fish oil companies strenuously deny that they are having an effect
on declining fish stocks arguing that only 1% of fish catch is used
for making supplements. However, a Canadian research group argued
that the recommended dose of 100 mg of fish oils per day was not
sustainable and would lead to fish stocks collapsing by the middle
of the 21st century. 

Then there is the question of whether it is ethical to kill fish
for food or fish oil. The Vegetarian Society's website states that: 

"Fish have a nervous system and pain receptors like all other
animals" and "an estimated 23% of that total catch is killed and
discarded as a result of 'incidental capture".

So if you choose not to eat fish or use fish oils, where do you get
your beneficial omega-3 fatty acids?

Plant sources of omega-3 fatty acids
 
Because eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
are only found in oily fish, a lot of research has focused on how
much alpha linoleic acid (ALA) can be found in plants. 

By far, the best source of ALA is flax seed (over 50%), followed by
hemp (15-20%), walnut (14%), canola (11%) and soy (7%). While ALA
can be converted to EPA & DHA in the body, the conversion between
ALA to EPA is not very efficient; even in healthy people it is only
2-5%.

The reason for this is that ALA has to be converted to a fatty acid
called stearidonic acid (SDA) before it can be converted to EPA. 
The enzyme responsible for this conversion is very inefficient and
this effect is worse in the elderly, people suffering from diabetes
or obesity, and people that have a high omega-6 intake.

The good news is that if you take SDA directly, the conversion to
EPA is much easier, which hasn't gone unnoticed by big
Agri-companies. Monsanto have cottoned onto this (excuse the pun)
and have genetically modified the soya bean to produce SDA, while
BASF is working on genetically modifying canola to do the same. 

Thankfully for us, hemp is a natural source of SDA and we don't
have to resort to GM foods to get a plant based source of our
omega-3's. 

Hemp is one of the few sources of a rare omega-6 fatty acid,
gamma-linolenic acid (GLA). GLA has a similar chemistry to EPA and
has many of the health benefits of EPA. 
Ideal dosages

According to the Good Oil Website, a daily dose of 1 tablespoons of
hemp oil will gove you 94% of your recommended daily allowance of
omega-3 and 94% of your recommended daily allowance of omega-6
fatty acids.

A comparison of flax and hemp oil

As I mentioned before, flax contains more ALA than hemp, but does
not contain SDA. Many people that try flax oil find it has a strong
aftertaste which can be a bit off-putting. Flax oil also has a
short shelf life, needs to be used as quickly as possible after
pressing and should be kept in the freezer, otherwise it turns
rancid. 

In comparison, hemp contains linoleic acid (omega-6) and alpha
linoleic acid (omega-3) in the optimum 3:1 ratio for human health
and it has a pleasant nutty taste. It does need to be kept
refrigerated to preserve the quality of the oil, but is more robust
and doesn't go off as quickly as flax oil.

Summary

Omega-3 & 6 fatty acids are important for our health and longevity,
and it is great to know that we aren't restricted to consuming fish
or fish oils to get our recommended dose. If you want to avoid fish
for ethical reasons, hemp is a fantastic alternative.

Reading

http://en.wikipedia.org/wiki/Essential_fatty_acid
http://heart-disease.emedtv.com/fish-oil/fish-oil.html
http://www.professional-counselling.com/omega-3-side-effects.html
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/mercury_in_fish?open
http://www.foodstandards.gov.au/consumerinformation/mercuryinfish.cfm
http://www.time.com/time/magazine/article/0,9171,1953700,00.html
http://www.vegsoc.org/page.aspx?pid=723#
http://ontheshelf.com/attached-file/hempandflax.pdf
http://manitobaharvest.com/articles_studies/3810/Hemp-Seed-Oil---Your-source-for-essential-fat.html
http://www.thefishsite.com/articles/654/are-dietary-recommendations-for-fish-oils-sustainable
http://www.echiumoil.eu/health-benefits.php
http://goodwebsite.wordpress.com/2009/07/