The Truth About Breastfeeding

Cabbage leaves have long been touted as a treatment for engorged breasts. Slipping a couple inside your bra might stain your clothes and make you smell a bit funny, but surely that’s a small price to pay for the relief they’ll provide? Encouragingly, a quick perusal of the internet suggests there is medical evidence that they work. Several sites, including some written by doctors, cite studies that purport to demonstrate their effectiveness in lessening the discomfort of an extra-full bosom.

Like most breastfeeding mothers, I have suffered from my fair share of milk over-supply problems, particularly when C started to sleep longer at night. Would a trip to the greengrocers have helped? Past experience had taught me not to simply take a website’s word for it, so I decided to do some investigating of my own.

A study in medical journal Birth is widely reported as providing evidence supporting the use of cabbage leaves for engorgement¹. The experiment involved 120 mothers, who took part in the research during their post-partum hospital stay. 60 of the women applied cabbage leaves after a feed, leaving them in place until they had reached body temperature. This process was repeated for a total of four feeds, and after each application the women were asked to report whether they felt their breasts were engorged. A control group of 60 women, who did not use cabbage leaves, were also asked to report whether their breasts were engorged. The percentage of women who reported experiencing engorgement went as follows:

• after the 1st feed, 54% of the cabbage group and 52% of the control group;
• after the 2nd feed, 51% of the cabbage group and 57% of the control group;
• after the 3rd feed, 49% of the cabbage group and 51% of the control group;
• after the 4th feed, 54% of the cabbage group and 59% of the control group.

To at least one medical professional (see above), these figures apparently amount to women saying they ‘experienced greater relief’ when using the leaves. It’s actually pretty obvious that they say no such thing. The difference between the two groups is very small indeed, and it is not statistically significant, so the only appropriate conclusion is that there is no support for the hypothesis that cabbage leaves prevent engorgement.

The authors performed a follow-up 6 weeks later, documenting the length of time for which women exclusively breast fed, and found that it was significantly longer for women who were in the cabbage leaf treatment group: they breastfed exclusively for an average of 36 days, compared to 30 in the control group. (They also mentioned that in the cabbage group fewer women stopped breastfeeding in the first week, and that more were breastfeeding at this point, although neither of these differences was significant.) Why might this be? Because these ladies applied cabbage leaves for a few hours shortly after their babies were born? The authors think this is unlikely. They conclude in their discussion:

‘…we cannot rule out the possibility that cabbage leaves had a direct effect on breast engorgement, and that this may have contributed to the increased breastfeeding success in the experimental group. However, we consider that the positive effect was more likely to have been mediated by psychological mechanisms.’

So, rather than the cabbage leaves containing something that encourages or enables women to breastfeed for longer (and, as you may have noticed, exclusive breastfeeding rates in both groups were considerably lower than the current recommendations), the difference was probably down to the psychological feel-good factor of having received treatment.

Several other studies have examined the effects of cabbage leaves in various ways, in an attempt to work out why exactly they are believed to relieve engorgement. One hypothesis is that they are cooling. The results of one study support this: an experiment comparing chilled gelpaks with chilled cabbage leaves found them to be equally effective at relieving pain². By contrast, another study found that in fact chilling made no difference, and that room temperature cabbage leaves were just as good³. In both cases, the lack of a control group meant that the relatively small improvements reported by the mothers could simply be due to the placebo effect or natural remission of the condition (the problem lessening over time), a fact acknowledged by the authors.

There are two further problems with these studies: firstly, they relied on subjective reports of pain, rather than an objective measure of physical engorgement; secondly, they failed to monitor the effect that feeding had on engorgement. A trial assessing the effectiveness of cabbage leaf extract addressed these issues, with interesting results⁴. Two creams, one containing the cabbage leaf extract and one acting as a control, reduced self reports of pain and hardness of breast tissue (measured using a device called a Roberts Durometer) by a small amount. There was no difference between the groups: whether or not the cream contained cabbage extract made no difference to the results. Yet again, we have evidence of a potential placebo effect: the mere fact of treatment, whatever it was, appeared to reduce symptoms. The women fed their babies, and the measurements were taken again. This produced a much greater reduction in reported pain and breast hardness, leading the authors to conclude that the best course of action for relieving engorgement is frequent feeding.

So, it seems the evidence for the effectiveness of cabbage leaves is virtually non-existent. No one has yet been able to elucidate how they might work, and every study conducted so far has concluded that positive results are more likely to be due to the psychological impact of medical attention than a magical property of the cabbage. Applying them may be of limited psychological benefit (as much as using a placebo cream or chilled gelpak) but it does not seem appropriate for medical professionals to recommend them, particularly when a much better course of action is simply to feed your baby. As Roberts, Reiter and Schuster conclude in their cabbage leaf extract paper, ‘until a scientific foundation for their action is established, their use remains questionable’⁴.

1. Birth. 1993 Jun;20(2):61-4.
2. J Hum Lact. 1995 Mar;11(1):17-20.
3. J Hum Lact. 1995 Sep;11(3):191-4.
4. J Hum Lact. 1998 Sep;14(3):231-6.