Reuters recently reported here that the US Government has added the chemical formaldehyde to its official list of cancer-causing agents. You’ll learn from the Reuters piece that formaldehyde is found in things like some plastics and embalming fluid. But what you won’t learn from the piece is that it can be derived from our diet too.
Once source of formaldehyde is methanol (also known as ‘wood alcohol’), which the body can form from the digestion of the artificial sweetener aspartame (Nutrasweet, Equal, Canderel). It has been demonstrated in animals that low-level ingestion of aspartame can lead to formaldehyde accumulation in the various parts of the body including the liver and brain [1]. In addition, several human studies have found that chronic, low-level formaldehyde exposure has been linked with a variety of health issues including headaches [2-4], fatigue [2,3], chest tightness [4], nausea and lack of concentration [2], seizures and behavioural impairment [4].
While long-term studies of the effects of aspartame have not been performed in humans (one might ask why…), they have been done in animals. In one study, researchers fed aspartame to rats from the age of 8 weeks until they died [5].
Rats consuming aspartame were found to be at significantly increased risk of several forms of cancer including lymphoma and leukaemia (cancer of the white blood cells).
An increased risk of these conditions was found even at levels of aspartame intake lower than the official upper limit for humans: While in Europe intakes of 40 mg of aspartame per kg of body weight per day are considered safe, an increased risk in cancer was seen in rats consuming just half this amount.
In Europe, the body entrusted with assessing the safety of aspartame is the European Food Safety Authority (EFSA). Recently, two European members of parliament (MEPs) accused the EFSA of not assessing scientific data on aspartame properly, and even losing crucial information. You can read more about this here.
Here’s a couple of things we can be quite confident in, though:
Consuming aspartame increases formaldehyde exposure.
Formaldehyde causes cancer.
My advice would be to avoid aspartame (unless, of course, you don’t care whether you get cancer or not).
References:
1. Trocho C, et al. Formaldehyde Derived From Dietary Aspartame Binds to Tissue Components in vivo. Life Sciences 1998 63;5:337
2. Main DM, et al. Health Effects of Low-Level Exposure to Formaldehyde. Journal of Occupational Medicine 1983 25;896-900
3. Olsen JH, et al. Formaldehyde induced symptoms in day care centers. American Industrial Hygeine Association Journal 43;5 366-370
4. Burdach S, et al. Damages to health in schools. Complaints caused by the use of formaldehyde-emitting materials in school buildings. Fortschritte Med 1980;98(11):379-384
5. Soffritti M, et al. First experimental demonstration of the multipotential carcinogenic effects of aspartame administered in the feed to Sprague-Dawley rats. Environ Health Perspect. 2006;114(3):379-85