We’re often bombarded with messages about cutting down our fat intakes. Some people even avoid them wherever possible. However, some fats are ‘essential’ – we must include them in our diets because our bodies can’t make them. Research suggests increased needs for these fats in pregnancy, to support the developing baby’s growth and brain development. This article will explain the two types of ‘essential fatty acids’ (EFAs): omega-3 and omega-6 fatty acids, and how you can include them in the right balance.

EFAs are important for many reasons in general health and pregnancy

General health:

  • Supporting our cardiovascular, immune and nervous systems
  • Anti-inflammatory properties, promoting health benefits to diseases like heart disease and diabetes
  • Increasing ‘good cholesterol’ (HDL) levels and decreasing ‘bad cholesterol’ (LDL)


  • Prostaglandin production – these important compounds are involved in regulating fertility, conception and blood pressure, and in inducing labour
  • Development of baby’s brain and neural tube during pregnancy
  • May prevent premature labour and pre-eclampsia
  • Breastfeeding? Your baby obtains his/her EFAs through your breast milk

Omega-3 fatty acids

  • Alpha-linolenic acid (ALA) – found in plant-based sources, e.g. linseeds/flaxseeds and linseed/flaxseed oil, walnuts, brazil nuts, pumpkin and sesame seeds, avocados and green leafy vegetables
  • Eicosapentanoic acid (EPA) – found in oily fish, e.g. salmon, mackerel, sardines, pilchards, trout, fresh tuna
  • Docosahexanoic acid (DHA) – found in oily fish

Although the body can convert ALA into EPA and DHA, studies suggest that the omega-3 fatty acids in oily fish have greater benefits on reducing heart disease than ALA, found in plant-based sources. EPA and DHA are also absorbed better by the body. Breast milk and infant formula both contain DHA in addition to ALA, suggesting the importance of DHA.

Omega-6 fatty acids

Linoleic acid is the main omega-6 fatty acid your body requires. UK diets contain large amounts of omega-6 fatty acids, so there is no need to increase you intake of these fats.

Sources of linoleic acid include:

  • Vegetable oils, e.g. olive, sunflower, rapeseed, safflower, corn, sesame, evening primrose, linseed and canola oils
  • Linseeds & sunflower seeds
  • Pine nuts & pistacchios

Getting the balance right

Evidence suggests that the wrong balance between omega-3 and omega-6 fatty acids is a factor in various chronic illnesses. Western diets contain large amounts of omega-6 oils, and not enough omega-3. Only one teaspoon of corn oil will meet the daily omega-6 requirement, but most people eat 10-20 times this. To improve the balance, try these tips:

  • Reduce intake of saturated and non-essential fats, e.g. butter, lard, fatty meats, baked products
  • Use oils and spreads made from olive, sunflower, rapeseed or safflower oils, instead of butter/lard. Olive and canola oils are good choices, as they’re lower in saturated fats
  • Include oily fish once a week (but no more than twice a week)
  • Eat more plant-based sources of omega-3 (ALA), e.g. adding linseeds to soups, salads, cereals and yoghurt

What if I’m vegan / vegetarian?

Eating fish is the best way of obtaining EPA and DHA. If you’re vegan or vegetarian, your body can make EPA and DHA from ALA, but it’s not as efficient. Studies show that vegans/vegetarians have lower levels of EPA and DHA than meat eaters, and that without special diet planning, only meet 50% of their ALA requirements. Try to include sources of ALA so you can make the other essential fatty acids. You could also consider taking algae DHA supplements providing of 200g DHA/day in addition to other dietary sources.

As plant-based sources of omega-3 may not have the same benefits on heart health as oily fish, it’s important to look after your heart by eating 5 portions of fruit and vegetables every day, decreasing intake of saturated non-essential fats and watching your salt intake.


    Greenberg JA, Bell SJ and Ausdal WV (2008) Omega-3 fatty acid supplementation during pregnancy. Rev Obstet Gynecol. 1(4):162-169.

    Kris-Etherton PM, Grieger JA and Etherton TD (2009) Dietary reference intakes for DHA and EPA. Prostaglandins Leukot Essent Fatty Acids. 81(2-3):99-104.

    Kruger MC and Horrobin DF (2007) Calcium metabolism, osteoporosis and essential fatty acids: a review. Prog Lipid Res. 36(2-3):131-151.

    Simopoulos AP (2002) The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 56(8):365-379.