Amongst all the synthetic sweeteners Aspartame has been able to capture substantial market till recently because of its inherent properties to satisfy consumers regarding its efficacy in simulating taste of natural sugar and its relatively low cost. Its major competitor Sucralose, though sweeter by three times, costs 10 times more making the industry opt for the former. However use of Aspartame, permitted in all foods in countries like the US, is self-limiting because it is stable only at a pH of about 4.3 and its major is restricted to soft drinks with pH range between 3 and 5. It is also unstable under alkaline conditions and at high temperatures making it an unsuitable candidate for use by the bakery industry. At a pH of 7 the half life of Aspartame is hardly a few days while at pH 4.3 it can be as high as 300 days.
Though Aspartame was discovered as early as 1965, its widespread use became common from 1996 onwards with the USFDA clearing it for use in all food products. This makes sense because it cannot be used in many products because of pH conditions and temperature of processing. Still it is believed that over 6000 products contain Aspartame singly or in admixture with Saccharine or Acesulfame in about 90 countries in the world. Relatively high ADI of 50 mg per kg body weight for adults make it suitable for many products and generally an average consumer takes less than 10% of the ADI through products containing this synthetic sweetener. As such there ought not to be any safety scare while using Aspartame by the food processing industry.
One of the serious apprehensions while using Aspartame as a sweetener is its break down products that may accumulate in products standing on the retail shelf for long or others which have undergone severe processing conditions. The artifacts in such products include Phenylalanine and Methanol. While Phenylalanine may pose heath risks for consumers with the genetic disorder Phenylketonuria, Methanol is a toxic substance considered highly harmful beyond a certain concentration. Of course suitable label declaration can forewarn consumers suffering from Phenylketonuria regarding the potential harmful effect it can have on them but presence of Methanol evokes fears about its likely impact on health. What is not realized in this debate is that concentration of Methanol that can cause injury has to be much higher than what is generated in products containing Aspartame. Added to this human blood, urine, saliva and exhaled air do contain methanol and many fruits have methanol as a natural constituent.
A recent controversy regarding the safety of consuming a particular diet drink from a beverage major containing Aspartame has brought back the memories of earlier skirmishes between pro and anti Aspartame lobbies during nineteen eighties and nineties. Though it has some political and economic implications, EU is not taking any chance and has undertaken urgent review of the safety of Aspartame in the light of some new studies linking its consumption to premature births and cancer. The European Food Safety Authority (EFSA) and the UK's Food Standards Agency (FSA), have categorically ruled out any link between Aspartame and any health disorder.
The focus has been on the likely toxic effect of Methanol, a nerve toxin, generated in the products on human health as formic acid and formaldehyde are formed when Methanol is metabolized in the body and these metabolites are also strong nerve toxins. According to a most recent medical review "weight of the existing scientific evidence indicates that Aspartame is safe at current levels of consumption as a non-nutritive sweetener". Of course there could be many non-believers in such assertions because of the enormous economic stake the Aspartame manufacturing industry has in safe guarding its interests. One can only hope that the review being undertaken by EU which can be expected to bring out a balanced conclusion, will settle this issue once for all.