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The influence of Omega-3 on postnatal depression – by Melanie McGrice, AvdAPD

Dietetics, Psychology, The Health Industry

My Health Career is pleased to publish an article by dietitian Melanie McGrice where she discusses omega-3 fatty acids, their role in post-natal depression and what you can do to make sure you and your patients are getting enough.

“For most women, having a baby is the most significant life changing event they will ever experience. It is usually a happy time, however with all the changes that new mums have to adjust to in combination with a hurricane of hormonal fluctuations and less sleep than studying for a medical exam, it is common to experience changes in your emotions and mood. When emotional distress is persistent and disabling it can reach the level of clinical depression otherwise known as post-natal depression, PND.

Many new mothers experience the “baby blues” generally 3-10 days after delivery. Symptoms of the baby blues include mood swings, insomnia, and feeling overwhelmed and are generally not long-lasting.

Post natal depression is a more serious condition and can affect mothers with mild, moderate or severe symptoms such as sadness and hopelessness, severe mood swings, confusion, guilt, sleeping and appetite changes and even thoughts of suicide.

Unfortunately PND is not a rarity; studies estimate that approximately 10-15% of all new mothers will be affected in some way. In fact, in the year after childbirth a woman is more likely to need psychological help than at any other time in her life. PND is a serious condition not only affecting the new mum, but it can also be debilitating to close relationships and can even affect the level of mother-infant interaction.

There is good news though… Studies suggest that women who have sufficient long chain Omega-3 fatty acid intake during and after pregnancy reduce their risk of developing PND. Omega-3 fatty acids are a type of ‘good’ polyunsaturated fat and are found in three different forms; eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and α-linolenic acid (ALA). Omega-3’s are essential fatty acids as our body is unable to make these fats by itself and we therefore need to consume them from our diet.

Omega-3s, in particular DHA, are important for the development of the brain, eyes and central nervous system of the growing baby. Omega-3s are passed during pregnancy to the baby via the placenta as well as through breast milk once the baby is born. The amount of Omega-3 passed onto the baby is dependent on dietary intake therefore it is essential to ensure your clients are having adequate Omega-3 intake, particularly during pregnancy and breast-feeding.

Regretfully, many Australian women don’t have enough Omega-3 in their diet and so their own stores are drawn upon, leaving her depleted which may increase the risk of PND. Although there is still debate as to its mechanisms, it is believed that Omega-3 fatty acids assist in carrying mood chemicals such as serotonin in the brain. International guidelines recommend that pregnant women consume at least 200mg of DHA each day.

It is recommended that to start increasing your Omega-3 intake 6 months prior to conception to allow time to build up stores.

PND is serious, but it is encouraging to know that there are really simple strategies that women can incorporate in their daily diet to minimise the risk of developing PND.

Don’t be scared to eat fish
Eating fish whilst pregnant can generate fear in many women because of the threat of listeria or mercury poisoning. The truth is that fish should be on the top of your shopping list! Marine animals are the main source of Omega-3 fatty acids in the diet with oily fish having the richest Omega- 3 content.

A serve of salmon, sardines or trout provides over 1000mg DHA while white fish including snapper, tuna or barramundi, and seafood such as scallops and prawns provide approximately 600mg of DHA per serve. Just be sure to limit your intake of predatory fish and flake (shark) and to cook your fish well and there is no reason to shy away from seafood!

Recommended intake: Aim for 2-3 150g serves of low mercury fish per week

Have more eggs
Even though eggs provide less Omega-3 than marine or meat based products, they are still a good source of Omega-3. A standard 60g egg provides approximately 40mg DHA. Some companies are now fortifying their eggs to boost their Omega-3 content. Always check the label of fortified products to confirm Omega-3 quantities, but as a general guide an enriched 60g egg may provide 70mg DHA. Eggs themselves are very nutritious and can form a staple meat alternative in the diet, which is great for vegetarians or for those who have a limited meat intake. Eggs can be incorporated into sandwiches or stir-fries or serve them as the hero of the dish either boiled or scrambled or the humble omelette.

Recommended intake: Aim for 6 60g Omega 3 enriched eggs per week

Try some flaxseed oil
Plant based Omega-3 fatty acids come in the form of ALA from foods such as flaxseed, chia seeds, walnuts, soybeans and canola oil. Our body must convert ALA into EPA and DHA which can then cross the blood brain barrier. This conversion rate is slow and inefficient (less than 10% when compared to the Omega-3 content obtained from fish) and is affected by genetics, gender, age and dietary composition. Of all the plant based sources, flaxseeds are the best source as they contain ~50-60% ALA. Although whole flaxseeds are poorly digested and can only provide ~ 3g ALA, 1 tbsp flaxseed oil can provide up to 10g of ALA, which equates to approximately 400mg DHA. Flaxseed oil is too delicate to cook with so a handy tip is to use it as a salad dressing.

Recommended intake: Aim for 1 tablespoon flaxseed oil per day

Increasing your clients’ Omega-3 intake can be as easy as recommending to eat more fish, eggs and/or flaxseed into their diet. Seek professional help from your health care providers if you would like further information about PND.”

Melanie McGrice is one of Australia’s best known dietitians. She is a highly respected author and health presenter on nutrition and dietary issues – and a lover of great food! Join her free nutrition and wellbeing network at


Image 1 (salmon):

Image 2 (Omega 3 tablets):


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