A new study has shown the important role dietary supplements can play in helping to reduce a mum's risk of developing post-natal depression.

Dietary supplements including blueberry extract dramatically reduce the risk of post-natal depression, according to a US study.

Designed to counter the mood-altering brain changes that occur after a woman gives birth to a baby, a nutritional kit of three supplements virtually eliminated the "baby blues" among women at Toronto's Centre for Addiction and Mental Health (CAMH).

The nutritional kit consisted of three supplements: amino acids tryptophan and tyrosine, and a blueberry extract juice.

It's common for women to experience low mood in the first few days after birth, however, when the symptoms don't resolve quickly a woman is at greater risk of antenatal depression.

Dr Jeffrey Meyer, who heads the Neuroimaging Program in Mood & Anxiety at CAMH says nutrition-based treatments based on neurobiology are rare but represent a "promising" new way to treat the one in 10 Australian women who will experience antenatal depression.

All three supplements were carefully selected to compensate for a surge in the brain protein MAO-A, which occurs in the early postpartum phase.

MAO-A breaks down three brain chemicals that help maintain mood: serotonin, norepinephrine and dopamine. When these chemicals are depleted, it can lead to feelings of sadness.

Levels of this protein peak five days after giving birth, the same time when postpartum blues are most pronounced.

The study included 21 women who received the supplements over three days after giving birth and a comparison group of 20 mothers who did not.

On day five - when the baby blues peak - the women underwent tests to assess the supplement kit's effect on mood.

Women who were not taking the supplements had a significant increase in depression scores. In contrast, women taking the dietary supplements did not experience any depressed mood.

"We believe this is the first study to show such a strong, beneficial effect of an intervention in reducing the baby blues at a time when postpartum sadness peaks," says Dr Meyer.

The study is published in journal the Proceedings of the National Academy of Sciences (PNAS).

Since severe "baby blues" significantly heighten the risk of postpartum depression, this supplement kit is anticipated to be an integral part of a dietary supplement regimen that health-care providers could one day recommend widely to mothers, the researchers said.