The beneficial fat many of us need more of.

Last week I attended a full day workshop on a special group of fats called the omega-3s. You probably know them as fish oils and perhaps take supplements – they are some of the most commonly sold supplements.

Yet despite this the latest data presented shows that the vast majority of people in Western countries including Australia, New Zealand, USA and the UK have blood levels that are low in omega-3s.

This matters because low blood levels – measured as the omega-3 content of red blood cells, which have been shown to reflect the levels in other body tissues and indicative of intake over the previous few months – have been shown to be significantly associated with an increased risk of several diseases and conditions including cardiovascular disease, depression and anxiety, arthritis, macular degeneration, cognitive decline and the chronic inflammation that is at the root of many of these conditions.

It does seem extraordinary that a small group of fats could have such dramatic impact on the health of the human body, but the evidence is compelling and real. So much so that I don’t think it will be long before this is properly recognised and the long chain omega-3s are named as essential nutrients alongside vitamins and minerals.

What are omega-3s and where do we find them?

Omega-3 fats are specific types of polyunsaturated fats and the principal ones that are critical to the body are EPA and DHA. These are the long chain omega-3s and they are found in largest amounts in oily fish from deep, cold waters.

Our highest dietary sources are therefore fish such as salmon, trout, sardines, barramundi and mackerel.

Providing a little less, but still excellent levels are other fish including canned tuna and white fish, and other seafood such as oysters, mussels, scallops, prawns and octopus. Omega-3 enriched eggs are another great source.

You also find tiny but still significant amounts in grass fed red and game meats.

You will find omega-3s in some plant foods but it’s important to realise these are not the long chain omega-3s EPA and DHA. Plant foods sources, such as chia, flaxseed, hemp seeds and walnuts, contain ALA, a shorter chain omega-3. This is still beneficial as we can elongate this in the body to come extent to make the longer chain fats, but there is much variation between people in their ability to do this and none of us are particular efficient at it.

To me this is interesting as it provides pretty compelling evidence that seafood has played a major role in the human diet, although it is also true that the wild meats our paleo ancestors ate were richer in omega-3s than today’s domesticated breeds.

What do they do in the body?

Long chain omega-3s are found in pretty much every cell in the body. They are essential to the correct functioning of cells, especially in the brain where they are concentrated and in the heart. We know that they play vital roles in both of these organs – get enough omega-3s and your risk of heart disease is staggeringly lower and your brain will function better and age better so you can ward off dementia.

You’re more likely to be able to keep depression and anxiety at bay when your brain has optimal levels of omega-3s. Your eyes require long chain omega-3s, otherwise your risk of macular degeneration is greater.

The other major effect is that they are anti-inflammatory. High doses of omega-3s have even been shown to be successful in treating inflammatory conditions such as arthritis and inflammatory bowel diseases. But since inflammation is also involved in atherosclerosis, in the development of many cancers, in dementia and other brain disorders, and even in the development of type 2 diabetes, you start to understand how these fast might be helpful in avoiding and managing all of these conditions.

How much is enough?

Most health authorities around the world give a rather conservative recommendation of 500mg a day of EPA and DHA. In Australia the Suggested Dietary Target is 610mg/day for men and 430mg/day for women.

The National Heart Foundation further recommends that those with cardiovascular disease should take 1g of long chain omega-3s a day and for those with high blood triglycerides (a risk factor for heart disease that is lowered by taking EPA and DHA) up to 4g a day.

Note that these levels are for total EPA and DHA and not total omega-3s. That's an important differentiation as fish oil supplements give total omeag-3s and you need to read the nutrition label to find out how much of the total is actually EPA and DHA.

Should I take a supplement?

One of the major steps forward is that there is now a simple finger prick blood test analysis that will give you your omega 3 index. This is just being launched in Australia and is already available in the US. You will be able to have this test done at pharmacies, at doctor’s surgeries and from dietitians or other health professionals.

This will give you a clear indication of whether you are deficient or your levels are adequate. But until that time this is one supplement I strongly recommend, unless you are the most ardent fish eater! The recommendation is to consume at least two meals of oily fish a week plus take a daily supplement of at least 1g of EPA and DHA.

Take higher levels if you have cardiovascular disease, arthritis, high cholesterol or triglycerides, depression or anxiety, or as recommended by your doctor, dietitian or other health professional.

Unlike drugs there really are no side effects, although those taking blood thinning medications should speak with their doctors as these fats will also have a blood thinning effect (usually a good thing!).

These really are important nutrients and critical for good health and happiness. They are worthy of our attention and finally just remember you need to up your intake for several months for body cell levels to increase, so stick with the plan.

This post originally appeared on Dr Joanna, and has been republished with full permission. You can follow Joanna on Facebook here or Instagram here. Speak to your doctor before making any big decisions with your health.