Lana Hirth, Accredited Practising Dietitian

Does food impact your mood? With more than 1 in 7 new mums and up to 1 in 10 new dads experiencing postnatal depression (PANDA, 2021), it’s worth exploring all options that can help to manage postnatal depression. Or you may have experienced postnatal depression before and planning for baby #2, you’re looking to be proactive at reducing your risk.

You may be asking one of the questions I get asked all the time as a postnatal dietitian:

  • Can what I eat impact my mental health?
  • Are there foods I need to pay attention to for postnatal depression?
  • I had postnatal depression with my first, is there anything I can do to reduce it?

Let’s start with what exactly is postnatal depression.

What is postnatal depression (PND)?

Postnatal depression (PND), or postpartum depression, can occur up to a year from the birth of your baby. These are some key signs that might be associated with postnatal depression according to Beyond Blue:

  • low mood and/or feeling numb
  • feeling inadequate, like a failure, guilty, ashamed, worthless, hopeless, helpless, empty or sad
  • often feeling close to tears
  • feeling angry, irritable or resentful (e.g., feeling easily irritated by your other children or your partner)
  • fear for the baby and/or fear of being alone with the baby or the baby being unsettled
  • loss of interest in things that you would normally enjoy
  • recurring negative thoughts – “I’m a failure”, “I’m doing a bad job”, “My life is terrible”
  • insomnia (being unable to fall asleep or get back to sleep after night feeds) or excessive (too much) sleep, having nightmares
  • appetite changes (not eating or overeating)
  • feeling unmotivated and unable to cope with a daily routine
  • withdrawing from social contact and/ or not looking after yourself properly
  • having thoughts about harming yourself or your baby, ending your life, or wanting to escape or get away from everything.

If you’re having these kinds of thoughts, it’s important to seek support.

You might have already been diagnosed with PND and you’re wondering what impact does nutrition make?

What factors influence postnatal depression?

Our neurotransmitters

There are lots of factors that can contribute to PND, let’s take a look at some of the biological changes that might be occurring in the brain.

We know that your brain’s chemical transmitters can impact your mental health, as these work to relay messages between brain cells. Taking a step back, we know a molecule called BDNF (brain-derived neurotrophic factor) helps to regulate the development of these neurotransmitters.  Lower levels of BDNF have been associated with increased rates of depression.

There are certain factors that cause BDNF to drop, and if we can improve those then the theory is that we can increase our BDNF levels and have a positive impact on our mental health.

Maternal nutrient depletion

This isn’t the whole story and for postnatal depression there are other factors that may be contributing like maternal nutrient depletion. The nutrition demands during pregnancy, labour and postpartum are some of the highest a woman will have in her entire lifetime. If you’re not eating the right foods, or you have higher requirements from being a vegetarian or vegan, or the supplements are not tailored to her individual needs, this can lead to deficiencies in key nutrients such as iron, vitamin D, folate, omega-3, B-vitamins like riboflavin and minerals like selenium.

The role of nutrition in managing PND 

A landmark study in 2017 found that in as little as 12 weeks, changing the way we eat can improve depressive symptoms. The people in this study ate foods based on a modified mediterranean diet which included large amounts of wholegrains, vegetables, fruits, legumes, nuts, fish, with smaller portions of lean red meats, chicken, low fat dairy, eggs, and extra virgin olive oil.

Importantly, it wasn’t one key food that improved people’s symptoms, but it was the pattern of food they ate. They ruled out other factors that could have contributed to improved mood and this was the first study to properly demonstrate the clear link between mood and food.

Five key foods to include if you have postnatal depression

  1. Salmon – Any oily fish like salmon, tuna, sardines, mackerel or herrings are a great source of omega 3. While we can get some plant-based omega-3 from chia seeds and other foods, this ALA form of omega-3 is poorly absorbed by your body and won’t be enough. Eating fish 2-3 times a week will ensure you’re meeting your omega 3 levels. If you’re unable to eat this amount, this is when you might want to discuss with a healthcare professional the right omega-3 supplement and dosage for you.
  2. Nuts – Healthy fats including monounsaturated fatty acids. A 30g serve (10 walnuts, 20 almonds or even 4 brazil nuts to give you selenium) are sufficient to meet your needs and make a good one-handed snack!
  3. Fruit – Eating fruit is a core part of the Mediterranean style diet. Choose whole fresh fruit where possible and aim for 2 serves a day with a serve being 1 medium piece (like an orange) or 2 small pieces (like 2 kiwi fruits).
  4. Leafy greens – While it’s important to eat the rainbow and include a variety of colours on your plate, leafy greens are particularly important for providing folate. Folate is a key micronutrient required for pregnancy and there has been some research to suggest lower folate levels are linked with postnatal depression. Aim for leafy greens like bok choy, choy sum or spinach at least once a day.
  5. Extra virgin olive oil – a good quality Extra Virgin Olive Oil is rich in antioxidants and key to helping manage inflammation levels in your body. It is an essential part of a Mediterranean style diet and is safe to add on salads, vegetables and even to bake and cook. So make sure this is your oil of choice.

There is also some research to suggest targeted amounts of omega-3, riboflavin and selenium to correct maternal depletion may have a positive impact on reducing depressive symptoms in women with postnatal depression. One study even found the higher omega-3 status in the mother, the lower the rates of depression. However, there are risks with over-supplementing, so be sure to consult with your health professional before starting any supplements.

The verdict

If you’re wondering what the role that nutrition can play in your mental health, it plays a huge role! Be sure to include plenty of wholegrains, vegetables, fruits, legumes, nuts, fish and some lean meat, chicken, eggs, reduced-fat dairy and extra virgin olive oil.

One of the keys with nutrition and PND is coming up with a plan for your nutrition needs and how you will reach those goals. If you want individually tailored advice, see an expert postnatal dietitian to help you to elevate your nutrition during this time.

Remember nutrition is just one piece of the puzzle, please reach out to mental health services like PANDA and BeyondBlue.