Question: Is the artificial sweetener aspartame bad for you?
Answer: Aspartame is one of the most thoroughly tested food additives in history. A truckload of safety reviews have been conducted by international authorities, all of which, until recently, have concluded aspartame was safe for human consumption.
Aspartame (E951) is about 200 times sweeter than sugar, so only minimal quantities are needed. It provides manufacturers with an effective way of lowering the energy content of drinks, desserts, sweets, chewing gums and other energy-reduced food products and has been used in a range of foods and drinks, such as Coca-Cola and Pepsi, and in toothpaste and some medications, since the 1980s. For much of that time, concerns about its safety have been raised, assessed, reviewed, re-reviewed and pooh-poohed by various health authorities.
However, in July, the International Agency for Research on Cancer (IARC) and the Joint United Nations Food and Agriculture Organisation/World Health Organisation expert committee on food additives released its findings after reviewing aspartame and its potential health risks.
This is the first time the IARC has assessed aspartame as part of a programme to identify and evaluate preventable causes of cancer in humans. It has reviewed more than 1000 agents since 1971.
It found limited evidence that aspartame is carcinogenic in humans and limited evidence from animal and experimental studies as well.
As a result, it has classified aspartame as “possibly carcinogenic”, placing it in group 2B of its hazard classification system alongside other possibly carcinogenic agents such as bitumen (used in asphalt) and car exhaust fumes, as well as other surprising entries such as aloe vera whole leaf extract.
However, the FAO/WHO expert committee found insufficient evidence linking aspartame to the risk of cancer. It concluded that the previously established acceptable daily intake of 0-40mg per kilo of body weight should not change. For an adult weighing 70kg, that is equivalent to drinking 9-14 cans of diet soft drinks daily.
By placing aspartame in group 2B and labelling it as “possibly carcinogenic”, the IARC is essentially saying the strength of evidence linking aspartame to cancer is limited but not convincing. The classification relates to the strength of scientific evidence, not the measurable risk of developing cancer when exposed to aspartame or, for example, bitumen.
Added to that, researchers still do not understand how, biologically, aspartame might cause cancer to develop.
The IARC’s Mary Schubauer-Berigan said the findings of limited evidence of carcinogenicity in humans and animals, and of limited mechanistic evidence of how carcinogenicity may occur, underscored the need for more research. “We need to refine our understanding on whether consumption of aspartame poses a carcinogenic hazard,” she said.
Undoubtedly, some parties will call for a ban on aspartame, and others (such as food manufacturers) will continue to claim that it is safe. It is worth keeping the potential risk of aspartame in perspective. Alcoholic beverages are classified by the IARC as a Group 1 carcinogen, meaning there is enough evidence to conclude they do cause cancer in humans. And most New Zealanders routinely drink wine, beer, cider, and even alcohol-containing kombuchas without a second thought about their proven cancer-causing effects.
Ideally, we should drink mostly water and unsweetened drinks and opt for whole foods that are as close to their natural form as possible. Aspartame is artificial and typically turns up in the types of ultra-processed foods we should either avoid or limit significantly.
So, by choosing primarily whole foods and trying to limit ultra-processed foods, avoiding unnecessary and possibly harmful artificial sweeteners is likely to take care of itself.
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