Omega-3 and the vegetarian diet
How to improve your intake of "good" fats without resorting to fish oils - and why you need to
By Mark Broughton
Fats are generally perceived as bad - regardless of your lifestyle or dietary choices. They are thought of as something to be avoided - not just by those trying to lose weight, but by anyone wanting a more healthy diet. And while it's true that people who eat animal products typically consume more fats, it's also true that not all fats are bad. Fats are more than just a source of energy which can migrate to your hips. Some fats are positively good for you. Indeed, without certain fats, we would fall ill and even die.
To understand the reasons, it helps to know that fats fall into three groups: saturated, monounsaturated and polyunsaturated. These terms describe the chemical structure of the fat.
Saturated fats - those with a high proportion of saturated fatty acids - are usually solid at room temperature. They generally come from animal sources. Typical examples are lard, suet and butter.
By contrast, the majority of plant fats are high in either polyunsaturated or monounsaturated fats. Two notable exceptions are palm and coconut fat, which do contain high saturated components.
Polyunsaturated fatty acids (PUFAs) are considered desirable fats - for a variety of reasons. As well as providing energy, they are reported to help with numerous metabolic processes. These include brain and eye development in the young, as well as joint and cardiovascular health in adults. However, many different PUFAs exist, and there's conflicting information about how well the body utilizes them.
It's widely accepted that two of the most important PUFAs are the Omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Hardly a week seems to go by without a report of these essential fatty acids being associated with one or more health benefits. More importantly, these reports are widely supported by clinical studies from reputable hospitals and research organisations around the world.
What they do
Photo © Stephen Cummings
Omega-3 PUFAs are important for maintaining the membranes of cells, for cardiovascular and joint health, and a host of general health benefits. Perhaps most important is the role of DHA as a major constituent of human eye and brain tissues. The reason that the vast majority of baby milk formulas are supplemented with DHA is to ensure the healthy development of babies. Both EPA and DHA have been associated with cognitive function as well as brain development and can help alleviate many disorders. These include Alzheimer's disease, attention-deficit hyperactivity disorder (ADHD) and poor memory.
Some key facts about DHA:
- DHA represents 10 to 15 percent of brain total fatty acids.
- DHA represents 97 percent of brain Omega-3 fatty acids.
The European Food Standards Agency (EFSA) Journal 2010, 8 (3) 1461, states:
- An AI (Adequate Intake) for prevention of cardiovascular disease (CVD) in adults is considered to be 250 mg per day of DHA + EPA (with the same dose for children of 2 -18 yrs).
- For children of 7 - 24 months, the AI for DHA is 100 mg per day for visual development.
- For women who are pregnant or lactating, an additional 100-200 mg per day of DHA is recommended.
Where do they come from?
The major dietary source of EPA and DHA is fish. Many strict vegetarians and vegans feel obliged to consume fish products such as Omega-3 food supplements to ensure they get enough of these elements in their diet.
What's interesting is that fish themselves do not produce EPA or DHA. They merely accumulate these fatty acids from the algae which they consume from their food.
Unfortunately, fish have also been shown to accumulate environmental contaminants such as heavy metals (mercury, lead, cadmium etc.), dioxins and PCBs, all of which are toxic to humans and must be avoided. Both the UK government's Food Standards Agency (FSA) and the USA Food and Drug Administration (FDA) have recommended that at-risk groups, such as pregnant and nursing mothers, should consume at most two portions of fish per week. This is because of concerns over the potential contaminants.
EPA and DHA do not occur in fruits and vegetables. But a number of vegan and vegetarian food supplements are available, these being derived from algae. Some of these offer DHA only, while a few provide a combination of EPA and DHA. Algae-derived Omega-3s are free from the contaminants associated with fish and most are certified by the Vegan and Vegetarian Societies in the UK.
It has also been documented that two dietary PUFAs (linoleic acid and alpha-linolenic acid) can be converted by the body to EPA and DHA, but it is widely accepted that this conversion is poor, and blood levels of either EPA or DHA arising from such dietary sources are low.
Many expert committees have recommended a reduced consumption of total fat by the general population. Only vegan diets generally comply with current guidelines that fat should not contribute more than 35 percent of the total energy intake of adults and older children.
Saturated fats contribute to high levels of cholesterol in the blood, a risk factor for cardiovascular disease, while PUFAs have the opposite effect.
Eicosapentaenoic acid and docosahexaenoic acid, the two non-essential Omega-3 PUFAs, do not generally occur in vegan diets. If you're a vegan or vegetarian seeking EPA and or DHA Omega-3, you should opt for an algae-derived source, certified by vegan and/or vegetarian societies, and approved for sale in your country or region.
Mark Broughton is a qualified analytical chemist with over 25 years experience in nutraceutical and pharmaceutical formulation development.
Vegetarian and vegan Omega-3 supplements (from non-fish sources) are available worldwide from Opti3.
Please note: Neither Veg World nor its contributors are qualified to give medical or nutritional advice. If in doubt, always consult a suitably-qualified professional.