Omega 3 fats

download this information sheet as a pdf - omega 3 fats

• Essential Fatty Acids
• How does this affect vegetarians?
• So where do I find good vegetarian sources of omega 3?
• How much omega 3 should I be taking in per day?
• Still worried about your DHA levels?

So how does current government advice that “we” should try to eat at least two servings of fish a week, including one serving of oily fish, as part of a healthy balanced diet translate into dietary advice for vegetarians?
And what should you do if your GP suggests fish oils for creaking joints or to thin your blood? Well, the first thing to remember is that the vegetarian diet is widely recognised as being protective against heart disease, the main ailment that the advice is aimed at, so vegetarians have a head start already, and of course the general population doesn’t exactly eat much oily fish, or indeed offal, the other “good” source of omega 3 fats.

An adequate intake of both may prevent and control a number of inflammatory conditions such as heart disease, arthritis, PMS, macular degeneration, immune dysfunction (e.g. asthma, eczema). However, because these fatty acids utilise the same enzymes for their metabolic pathway, it is important that there is an appropriate balance between their intakes. The ideal ratio of LA to ALA is 3:1; however the Western diet which is heavily dependant on fried and processed foods tends to have a ratio closer to 15:1. Additionally the activity of these enzymes can be affected by excessive intake of other elements common in the Western diet such as saturated fats, alcohol, caffeine and sugar as well as deficiencies in zinc, magnesium and vitamins B and C. Under these circumstances omega 6 fatty acids can not only inhibit the conversion pathway of omega 3 fatty acids but also where omega 3 deficiency occurs – its metabolic pathway creates hormone-like substances which encourage platelet stickiness, inflammation and water retention leading to high blood pressure.

These are some examples of foods naturally found in a vegetarian diet.

Note:

» Although flaxseed oil may appear to deliver greater amounts of omega 3 fatty acids, flaxseeds contain fibre and important compounds such as lignans which can have additional health benefits. Flaxseeds must always be crushed in order to ensure nutrient availability.

» Hemp seeds again should be de-hulled for nutrient absorbency. These have an ideal O6:O3 balance and contain significant amounts of GLA (gamma-linolenic acid) and stearidonic acid already, which curtails the need for the first stage in both fatty acid metabolic pathways.

» Although rapeseed oil is a good source of omega 3 fatty acids, it should not be heated and preferably only used as cold-pressed. Both essential fatty acids can easily generate free radicals once they are subjected to heat, light and oxygen. For cooking it is better to use oils high in mono-unsaturated fats such as olive or groundnut. For the same reasons flaxseed oil is best purchased in dark bottles and stored away from heat or light.

» Other foods can also add to your ALA intake. Most of the little fat in leafy green vegetables is ALA, for example broccoli has 0.13g per 100g and cabbage 0.11g per 100g. Occasionally you will also find eggs, where the hens have been fed on flaxseeds or algae, but the levels of ALA or DHA provided will be small.

» Although organic milk has been heralded as having 60-70% higher levels of ALA than ordinary milk it must be remembered that even though it has a good omega 6:3 ratio, its overall level of polyunsaturated fats is low.

There is no RDA for essential fatty acid intake and most of the guidelines are based on an intake of fatty fish. The European Food Safety Authority guidelines for daily intake, which were revised in 2009, recommend 2-3g ALA or 250mg EPA/DHA and 10g LA to support cardiovascular health and neurodevelopment. The American Heart Association is currently looking at levels of EPA/DHA daily intake closer to 500mg, which using a 10% ratio figure would imply a requirement of 5g ALA. Clearly a tablespoon of flaxseed oil per day would fulfil this.

References - We would like to thank Sarah Kearns (Nutritional Therapist) for donating her time and knowledge in the production of this information sheet.

Further Information - Any questions regarding this information sheet please contact Gilly Prime - Information and Research Officer gilly@vegsoc.org

Back to the Info Index

food facts index : health index