A poster presented at the American Society for Reproductive Medicine (ASRM) meeting in Salt Lake City has examined the effect of artificial sweeteners on the success of IVF treatment.
Prof. Sir Colin Berry, Emeritus Professor of Pathology, Queen Mary University London (QMUL), said:
“I can’t really comment on the techniques used as there is so little data but I have the general reservation that it is not reasonable to extrapolate from direct exposure of oocytes to a compound, at any level in vitro, to a putative reproductive outcome. All sweeteners are not the same, I would like to know about changes in osmolarity in their system and importantly, what were the measurements of egg quality? How was age (of the donors) dealt with? And so on. It is difficult to say more without more information.”
Dr Jackson Kirkman-Brown, Science Lead, Birmingham Women’s Fertility Centre, said:
“It is difficult to judge this study from the small amount of information available. However, to judge just one dietary component in isolation is difficult as it may reflect many other imbalances in a diet so a more comprehensive analysis of food balance and intake is required.
“Secondly, although the observed egg quality factor is female related, an embryo needs genetic information from the man so it is strange to totally neglect the diet and behaviour of the male partner in the study. Couples will generally eat food together and influence each other’s diet. Particularly in these ICSI cases where sperm quality of the male will already be poor, male health and lifestyle improvements are likely to make a significant difference.
“Overall the guidance that both members of the couple should follow healthy balanced diets remains unchanged. A diet of these kinds would naturally not contain large amount of artificial sweetener or soft drinks with a balance of more water intake. Lots of information on a healthy diet is available to all on the NHS Choices website: http://www.nhs.uk/livewell/healthy-eating/Pages/Healthyeating.aspx ”
Prof. Richard Sharpe, Group Leader of Male Reproductive Health Research Team, University of Edinburgh, said:
“One very obvious confounder in the study that is not mentioned is overweight/obesity, and it applies to both the sugar and artificial sweetener aspects of the study. Obesity in women undergoing assisted reproduction is established to have adverse effects at every stage of the process (https://www.ncbi.nlm.nih.gov/pubmed/23074009). Consumption of sugar-rich beverages has been clearly linked to increased risk of obesity and it might be expected that obese women trying to control their weight might opt to use artificial sweeteners. It therefore seems essential that this huge potential confounder (i.e. Bodyweight/BMI/waist circumference or some such measure) is taken into account in the reported study. Without it, I would be very dubious about the claims.”
Ms Catherine Collins, registered dietitian & spokesperson for the British Dietetic Association, said:
“There is so much missing data from this poster it is hard to qualify it. Although over 5000 oocytes were analysed, the sample size was just over 500 women. Overall, their results show a possible correlation, and definitely no causation can be drawn from the limited dietary data provided.
“Obese women are recommended to lose weight to increase fertility. Artificial sweeteners are used by the health conscious to manage calorie intake and by the overweight attempting to lose weight. No evidence is presented in this abstract to qualify obesity as a confounding factor influencing oocyte quality, nor whether women had issues with PCOS which is linked to increased body weight and known to influence oocyte quality. Failure to address this major confounding factor is a massive oversight. That sugary drinks and sugared coffee are both noted to impair oocyte function I would suggest this points more to an endocrine/PCOS type issue with these women – perhaps type 2 diabetes or PCOS – which would be influenced by glycaemic control (and production of ROS as the PCOS link suggests). Hence sugary drinks are potentially (but not proven) to be of concern, too.
“Secondly an ‘increased frequency’ of soft drink consumption is noted- but not the amount consumed. If there were a relationship between artificial sweeteners of any type and oocyte quality then it would be expected to be dose related. Given the data presented defines neither the portion size nor the frequency of soft drinks it cannot provide meaningful data as to the amount of sweetener consumed by these women sufficient to influence fertility. For any observational data to be meaningful we need to qualify parameters. Does the alleged reduction in oocyte quality relate to top vs bottom quintile? Or to incremental increases in, say, per litre bottle increase in consumption of a soft drink with or without sugar? The lack of information provided to justify the title of the poster is telling.
‘There are many different types of sweeteners and these have different structures and metabolic fate. No attempt is made to define the type of sweetener used. This is also a major oversight.
“Bottom line? A varied and healthy diet is recommended for all women, particularly those with fertility issues, who may also benefit from taking a pregnancy-suitable multivitamin and mineral supplement daily (to minimise the risk of excess vitamin A in early pregnancy). Being overweight impairs fertility, and PCOS and diabetes also have the potential to disrupt your chance of successful conception. This study is interesting, but the lack of information on amount and type of sweeteners makes it nothing more than an observational study which we can’t draw any conclusions from. 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.”
Prof. Adam Balen, Chair of the British Fertility Society, said:
“This is a very interesting study that suggests that the “false promise” of artificial sweeteners that are found in soft drinks and added to drinks, such as coffee, may have a significant effect on the quality and fertility potential of a woman’s eggs and this may further impact on the chance of conception. These findings are highly significant and relevant to our population. There should be more scrutiny of food additives and better information available to the public and, in particular, those wishing to conceive. The environment in which the egg develops is very sensitive to external influences and we shouldn’t underestimate the potential effects of food additives to reproductive health. Couples (both women and men) wishing to conceive should be aware of the importance of healthy nutrition.”
‘Artificial Sweeteners – Do They Bear An Infertility Risk?’ by Halpern et al. presented at the ASRM meeting.
Prof. Sir Colin Berry: “I don’t have any relevant conflicts for this. I have been consulted by both Regulatory Authorities and the Agrochemical and Pharmaceutical industries over Risk vs Hazard.”
Dr Jackman Kirkman-Brown: No conflicts of interest
Prof. Richard Sharpe: No conflicts of interest
Ms Catherine Collins: No conflicts of interest
Prof. Adam Balen: No conflicts of interest