Of all the foodstuffs that have limited nutritional value and the potential to cause harm, I put soft drinks near the top of the list. The sugar contained in regular beverages has been linked with a range of adverse effects on health including weight gain, metabolic syndrome, type 2 diabetes and cardiovascular disease. And artificial sweeteners such as aspartame also appear to have considerable potential to harm human health. See here for more about this.
One time when the hazardous effects of foodstuffs has particular relevance is during pregnancy. Foods and drink provides the basic building blocks of the growing foetus, and at the same time can exert toxic affects that can affect the pregnancy and future health of the child. I was interested to read a study published this week which looked at the relationship between soft drink consumption and pregnancy outcome in almost 60,000 Danish women [1]. The pregnancy outcome assessed in this study was ‘pre-term delivery’ – defined as delivery before 37 weeks of gestation (normal gestation is 40 weeks).
For sugar-sweetened beverages, there was no relationship between level of consumption and risk of pre-term delivery (in other words, higher levels of sugary soft drink consumption were not associated with an increased risk of pre-term delivery).
It was a different story for artificially sweetened drinks though:
Compared to those drinking no artificially sweetened drinks, those having 1 or more servings of artificially sweetened drinks a day were found to be at a 38 per cent increased risk of pre-term delivery. Consumption of 4 or more servings a day was associated with an increased risk of 78 per cent.
So-called ‘epidemiological’ studies of this nature cannot be used to conclude that artificially sweetened drinks cause pre-term delivery. However, as the authors of the study point out, length of gestation may be affected by exposure to methanol [2,3]. Methanol is a known nerve toxin, which can be metabolised in the body to form formic acid (another never toxin), as well as formaldehyde (which is what is used to preserve dead bodies). It’s also a constituent of aspartame (the most ubiquitous artificial sweetener).
It’s unlikely that we’ll ever know if artificial sweeteners worsen pregnancy outcomes. However, given their ability for a myriad of toxic effects within the body, my advice would be to avoid them like the plague (pregnant or not).
References:
1. Halldorsson TI, et al. Intake of artificially sweetened soft drinks and risk of preterm delivery: a prospective cohort study of 59,334 Danish pregnant women. Am J Clin Nutr 30 June 2010 [epub ahead of print]
2. Burbacher TM, et al. Chronic maternal methanol inhalation in nonhuman primates (Macaca fascicularis): reproductive performance and birth outcome. Neurotoxicol Teratol 2004;26:639-50
3. Trocho C, et al. Formaldehyde derived from dietary aspartame binds to tissue components in vivo. Life Sci 1998;63:337-49
