Aspartame has been subject to more scare stories than any other sweetener, ranging from allergies and premature births to liver damage and cancer.
It is low-calorie (4kcal/g) and up to 200 times sweeter than sugar. Thousands of foods and drinks around the world use it as a sugar substitute, including cereals, sugar-free chewing gum, low-calorie (diet) soft drinks and tabletop sweeteners.
Aspartame has been extremely controversial since its approval for use by several European countries in the 1980s. A 1996 report suggested a link between aspartame and an increase in the number of diagnosed brain tumours. However, the study had a very little scientific basis and later studies showed that aspartame was in fact safe to consume.
The European Ramazzini Foundation of Oncology and Environmental Sciences has published several long-term studies (2006, 2007) linking the consumption of aspartame with an increase in cancers, namely lymphomas and leukaemias, in rats.
Following these studies, the US National Cancer Institute conducted a study of nearly half a million people, comparing those who consumed drinks containing aspartame with those who did not. Results of the 2006 study found that aspartame did not increase the risk of leukaemia, lymphoma or brain cancer.
Amid the continuing disquiet, the European Food Safety Authority (EFSA) conducted a comprehensive review of the evidence in 2013 and concluded that aspartame was safe for human consumption, including pregnant women and children.
When digested, aspartame is quickly and completely broken down into by-products – including phenylalanine, aspartic acid and methanol – which then enter our system through normal routes. Hardly any aspartame enters the bloodstream.
However, the panel said the ADI did not apply to people with phenylketonuria (PKU) – a rare genetic disorder where the body cannot break down phenylalanine. People who have this condition need to closely monitor their phenylalanine intake.
The EFSA report stated that: “PKU mothers with poorly controlled phenylalanine intake in their diet during pregnancy may give birth to babies with congenital heart diseases, microcephalus and impaired neurological function.”
It is worth noting that phenylalanine occurs naturally in many protein-rich foods, such as milk, eggs and meat. Tabletop sweeteners containing aspartame or aspartame-acesulfame K must be marked with: “contains a source of phenylalanine”.
Acceptable daily intake: 40mg per kg of body weight.
Find out what the latest scientific evidence says about these other common artificial sweeteners: