What are the Nutritional Benefits of Omega-3?

what foods have omega 3

When it comes to fat intake, you (and your cells) are really what you eat. We can’t make long chain fatty acids like omega-3 or omega-6 in our bodies, so we need to get them from our diets. But what exactly is omega-3 and omega-6? Let's unpack this a little.


Essential fatty acids are like the vitamins of the fat world. We need to get them in our diets. There are two families of essential fatty acids: omega-3 (n−3) and omega-6 (n−6) fatty acids. Long-chain omega-3 fatty acids are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These are primarily found in oily fish. Algae often provides only DHA. Short-chain omega-3 fatty acids are ALA (alpha-linolenic acid). These are found in plants, such as flaxseed, chia seeds, walnuts and pumpkin seeds.

Though beneficial, ALA omega-3 fatty acids require extensive metabolism in the body to generate EPA and DHA which the body uses (the active components that can do the health promoting work). In addition, the conversion of ALA to DHA and EPA depend on factors like age, sex, genetics, micronutrient intake and deficiencies as well as alcohol intake. Food sources of omega-6 fatty acids include vegetable oils, such as soybean, safflower and corn oil, nuts, seeds. Think too of animal sources that are fed with soy or corn.


Omega-3’s supports cardiovascular function, nervous system function and brain development, all around immune health and a whole of other stuff. Particularly important stuff is linked to the production of signalling molecules called prostaglandins which are derived from omega-3 and omega-6 fats. Prostaglandins exert complex control over many bodily systems especially in inflammation, immunity and as messengers in the central nervous system. In general, omega-3 fats are anti-inflammatory and omega-6 are pro-inflammatory.

Poor dietary intake of these fats can lead to symptoms of deficiency and an increase in inflammatory conditions such as Alzheimer’s and cardiovascular diseases, diabetes, and cancer.

what are the benefits of omega 3


If you really want to determine the exact amount of omega-3 that you have in your cell membranes, you need to get your omega-3 index checked. The omega-3 index is the percent of EPA and DHA combined in the membranes of your red blood cells. Cell membranes in the human body have a fatty membrane (also known as the lipid bilayer). This membrane is semi-permeable which means it regulates what gets into the cell and what goes out of the cell. The fluidity of the cell membranes depends on the fatty acid composition of the diet.

A good balance of omega-3’s in the membrane means that the fluidity of the membrane is good, allowing molecules to pass back and forth and for neurotransmitters to be transmitted more easily. Not enough omega-3’s then these membranes become more rigid and stuff can’t get through. Too much fluidity however and the membranes become “leaky” allowing too much back and forth.

Both omega-3 and omega-6 compete with each other for space in the cell membranes and so the ratio of omega-6: omega-3 in the cell membranes is important. The omega-index measure gives an accurate picture of the fluidity of your cell membranes as well as your overall omega-6: omega-3 ratio. The ideal omega 6:3 ratio is 2/3:1. Within my clinical experience I have found that most people have an omega ratio that is closer to 1:20.

The simple reason for this is that we are not eating enough fish and algae (Omega-3) and we now have too much omega-6 in our diets as a result of the amounts of ready to eat foods and processed foods that we now consume.


By now you should know omega-3 fatty acids are very good for us. And, if you don’t. Stop. Now is the time to take note! So, the question is “if they are so good for us should you start eating bucket loads of salmon or popping handfuls of fish oil supplements?”. A definitive no is the answer to that question.

Apart from the fact that a large proportion of our fish supply is contaminated with heavy metals and other potential toxins (but that’s for another blog) when it comes to dietary fats, balance is absolutely essential. Currently, the government advice is to eat fish twice a week and to ensure that 1 portion of the fish is oily. Oily fish includes sardines, mackerel, trout, salmon, herring and anchovies to name but a few. Supplements can also be used to help you achieve a better omega index.

do omega 3 supplements work


Here are my top fish oil supplement rules:

  1. If you do decide to supplement, then make sure your fish oil is high quality. Quality matters, particularly when it comes to fish oil supplements.

  2. Get the dosage right. If you are taking an omega-3 supplement you have to get the dosing right. If you haven’t had your omega-3 index checked my clinical advice would be to stick to 1g of combined EPA and DHA per day. If you do know your numbers, then work with a dietitian or a nutritionist to determine what dosage of supplement you should be taking.

  3. Avoid cod liver oil supplements. They often are very low in EPA and DHA and come loaded with vitamin A (used a preservative), a fat-soluble vitamin that you should not take unless you have a known deficiency. This may also be helpful information to know if you are avoiding animal products and are in-search of vegan omega-3 supplements.

  4. Store well. When stored, store fish oil supplements in a cool, dark place to avoid oxidation. If they are stored in light, wrap your fish oil with aluminium foil to reduce exposure to light.


  1. Innes J. 2018. Omega-6 fatty acids and inflammation. Prostaglandin Leukot Essent Fatty Acids. 132:41-48
  2. Calder et al. 2017. Omega-3 fatty acids and inflammatory processes: from molecules to man. Biochem Soc Trans. 15; 45 (5):1105-1115
  3. Calder et al. 2015. Marine omega-3 fatty acids and inflammatory processes: Effects, mechanisms and clinical relevance. Biochem Biophys Acta. 1851 (4):469-84
  4. Watson et al. 2018. A randomised trial of the effect of omega-3 polyunsaturated fatty acid supplements on the human intestinal microbiota. Gut; 67 (11): 1974-1983
  5. Gao H et al. 2017. Fish oil supplementation and insulin sensitivity: a systematic review and meta-analysis. Lipids Health Dis. Jul; 3:16 (1) 132