Exclusive breastfeeding for the first six months of an infant’s life is of vital importance for the health of both child and mother, as recommended by The World Health Organisation. Yet, it has been found that PPD, a condition which many mothers suffer from, can result in breastfeeding failure.
As a result, research into prevention and treatment of this widely suffered condition is greatly needed.
The relationship between chronic inflammation and risk of depression has been established in recent studies, with potential causes resulting from the diet due to its essential role in inflammatory development.
Utilising the novel measure of the Dietary Inflammatory Index (DII) to assess this relationship, researchers in the current study sought to investigate the influence of dietary inflammation on postpartum depression prevalence in exclusively breastfeeding women.
The study bridges an important gap between two largely prevalent issues; the reducing incidence of breastfeeding with high occurrence of PPD amongst mothers, and the established relationships between dietary inflammation and psychiatric conditions.
The authors state: "...as the first study to focus on the relationship between DII score and depression in exclusive breastfeeding lactating women in China, our results provide a meaningful reference for better formulation and guidance of lactating diets, thereby improving and maintaining exclusive breastfeeding rates."
A total of 293 Chinese mothers were assessed for six months post-delivery in this cross-sectional study, pairing DII scores utilising Food Frequency Questionnaires (FFQs) with Edinburgh Postpartum Depression Scale (EPDS) scores to measure depression levels.
It was observed that the average rate of depression was 60.1% in the breastfeeding mothers, with an average DII score of 2.32 which suggests most of the participants had a pro-inflammatory diet. This included greater intakes of nutrients such as dietary fat, cholesterol and saturated fats.
Scores were adjusted for potential risk factors such as age, sleep quality and occupational level. Binary regression analysis then showed that the lowest observed DII score was associated with a lower risk of PPD, compared with the highest score.
In addition, when mothers transitioned to the most anti-inflammatory diet from the most pro-inflammatory type, increasing intakes of foods such as wholegrains, fruits and vegetables, risk of PPD reduced by nearly 50%.
The authors conclude: "This suggests that breastfeeding women in China who reduce the inflammatory scores in their diet by adjusting their current dietary patterns seem to have great potential in preventing postpartum depression and thus reducing the risk of interrupting breastfeeding."
Although the study finds a clear link between dietary inflammation measures and PPD, the results may have been affected by recall bias associated with the use of self-assessed FFQs. In addition, this study is a cross-sectional study which only investigated the relationship between DII and depression at one time point and cannot infer the causal relationship between DII score and postpartum depression.
To meet the long-term nature of inflammatory progression, long-term studies are required to determine a causal relationship.
“Evidence suggests that food composition has a direct impact on the levels of neurotransmitters, hormones, inflammatory cytokines, and gut microbiota structure, which are critical to sleep, mood, and behavioural signalling pathways”, explain the researchers, highlighting the importance of diet in causing this inflammation and subsequent depression.
Research has suggested that a diet consisting mostly of red and processed meat, refined grains, sweets and soft drinks, has been linked to increased inflammation. This has been found to impact the immune system and significantly increase pro-inflammatory cytokines which can result in the blocking of neural circuits; a factor which may contribute to depression.
In contrast, a diet rich in fibre, unsaturated fatty acids, vitamins and minerals, have been associated with reduced indicators of inflammation, such as IL-6 and CRP.
“Relationship between Dietary Inflammatory Index and Postpartum Depression in Exclusively Breastfeeding Women”
Hanshuang Zou, Minghui Sun, Yan Liu, Yue Xi, Caihong Xiang, Cuiting Yong, Jiajing Liang, Jiaqi Huo, Qian Lin, and Jing Deng.