Artificial sweeteners may reduce fertility

Artificial sweeteners found in soft drinks may reduce female fertility, a study suggests.

Research presented at the American Society for Reproductive Medicine's (ASRM) Scientific Congress linked consumption of sweeteners with a lower chance of IVF success. However, experts say conclusions should not be drawn until the full details of the study are available.

'A state of good health, including a healthy diet, is essential to IVF success. We need to educate our patients on pesticides and sweeteners,' said Dr Owen Davis, President of the ASRM, who was not involved in the study.

Researchers from the Federal University of Sao Paulo interviewed 524 women between 2012 to 2014 about their nutritional habits prior to undergoing IVF with ICSI (intracytoplasmic sperm injection) treatment. They then compared these answers with observations of egg and embryo quality from the 5548 oocytes which were retrieved from this group.

They found women who regularly drank diet soft drinks or used artificial sweetener in their coffee showed decreased egg quality, embryo quality, and reduced implantation and pregnancy rates. Regular consumption of either soft drinks or coffee containing sugar also appeared to decrease egg quality.

However, the full details of the study are not yet available, and some experts have questioned the findings. It is not yet known whether older age and obesity were taken into account. Both factors can negatively impact the success of assisted reproductive technologies, and obesity may be related to overconsumption of sugar or of diet soft drinks (in an attempt to control weight).

'It is difficult to judge this study from the small amount of information available,' said Dr Jackson Kirkman-Brown of Birmingham Women's Fertility Centre, who was not involved in the study. 'However, to judge just one dietary component in isolation is difficult as it may reflect many other imbalances in a diet.'

Other experts have pointed out that the types of sweetener involved, the portion size, and the frequency of consumption were not detailed by the researchers. Furthermore, as couples tend to eat together, the male partner's sperm quality may also be affected by shared diet factors.

Ms Catherine Collins, a spokesperson for the British Dietetic Association, called the study 'interesting' but added that it was 'nothing more than an observational study, which we can't draw any conclusions from'. She added: 'If you're keen to get pregnant, then cutting out sugar from your drinks is a positive contribution to reducing calorie intake and managing blood sugar. This study doesn't provide convincing evidence that artificial sweeteners are a risk, if you find going 'cold turkey' on your sweetened drinks is too difficult.'