The randomised controlled trial was supposed to monitor the effects of daily ingestion of dark chocolate during pregnancy and whether or not it could reduce the incidence of pre-eclampsia in first-time mothers.
Pre-eclampsia is a late stage pregnancy disorder where mothers experience high blood pressure and excess protein in the urine which can cause seizures, kidney dysfunction, impaired liver function and red blood cell breakdown.
After two years of trying, researchers from Australia had to abandon the trial.
No cravings for cocoa
Although more and more research is showing the positive effects of chocolate and cocoa, it would appear some are still wary of consuming too much of the treat.
The trial, which was due to be carried out in Cairns and Atherton Hospitals, North Queensland, needed 1192 participants in order to achieve a 95% confidence level.
The researchers assumed that they would gain 10-12 new participants each week, meaning the results would be ready for collection in two years.
However, the team said that despite their best efforts “recruitment and retention of study subjects proved extraordinarily and unexpectedly difficult”.
After over a year of research, the team only had 42 recruitments, of which only eight women in the chocolate group (n=24) continued on until birth.
The main reason for this has been attributed to the connotations of indulgence, guilt and pleasure that go hand-in-hand with chocolate.
The research team have said that as a result of this, women and their doctors may have found it difficult to believe that chocolate could be used for medicinal purposes.
A simultaneous study that investigated vitamin D levels in pregnant women was able to recruit more than 100 women in six weeks.
Weight gain worries
The study asked women to keep a diary of their weekly consumption of chocolate milk, other chocolate drinks, chocolate pieces from blocks of chocolate, individual or boxed chocolates, chocolate cake, chocolate bars, other chocolate items, soy products, green tea, black tea, coffee, green leafy vegetables and fruits, for one week each trimester.
Women in the chocolate group of the trial were instructed to consume 25 g of dark chocolate with 70% cocoa solids daily.
This was the only dietary instruction the women received and were allowed to continue their existing diets as usual.
However the constant consumption of chocolate put some women off the idea.
It was found that some women withdrew from the study due to “difficulties in consuming dark chocolate on a daily basis, and concerns over weight gain”.
However, others withdrew as a result of their pregnancy cravings and nausea not favouring chocolate.
The team, led by Dr Subashini Gnanendran from College of Medicine and Dentistry at James Cook University, Cairns, have hypothesised that a future study would benefit from flavonoid rich pills to combat issues of personal taste.
They concluded that the issue is definitely still worth investigating but within a well-designed study with sufficient numbers.
‘A randomised controlled trial of consumption of dark chocolate in pregnancy to reduce pre-eclampsia: Difficulties in recruitment, allocation and adherence’
Authors: Subashini Gnanendran, Jemma Porrett, Cindy Woods, Maryke Buttrose, Clare Jukka, Jane Hollins, Stephen Robson and Caroline de Costa