However, no change suggested to daily intake recommendations
By WORLD HEALTH ORGANIZATION (WHO)
The International Agency for Research on Cancer (IARC) and the Joint Expert Committee on Food Additives (JECFA) of the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) have released assessments on the health impacts of aspartame, an artificial sweetener commonly used since the 1980s.
The IARC has classified aspartame as possibly
carcinogenic to humans due to “limited evidence” for carcinogenicity,
particularly for a type of liver cancer. The JECFA, however, reaffirms the
acceptable daily intake of aspartame at 40 mg/kg body weight, citing no
compelling reason to alter the previously established guidelines.
Assessments of the health impacts of the
non-sugar sweetener aspartame have been released by the International Agency for
Research on Cancer (IARC) and the World Health Organization (WHO) and the Food and Agriculture
Organization (FAO) Joint Expert Committee on Food Additives (JECFA).
Citing “limited evidence” for carcinogenicity
in humans, IARC classified aspartame as possibly carcinogenic to humans (IARC Group 2B) and JECFA reaffirmed the
acceptable daily intake of 40 mg/kg body weight.
Aspartame is an artificial (chemical)
sweetener widely used in various food and beverage products since the 1980s,
including diet drinks, chewing gum, gelatin, ice cream, dairy products such as
yogurt, breakfast cereal, toothpaste and medications such as cough drops and
chewable vitamins.
“Cancer is one of the leading causes of death globally. Every year, 1 in 6 people die from cancer. Science is continuously expanding to assess the possible initiating or facilitating factors of cancer, in the hope of reducing these numbers and the human toll,” said Dr Francesco Branca, Director of the Department of Nutrition and Food Safety, WHO.
“The assessments of aspartame have indicated
that, while safety is not a major concern at the doses which are commonly used,
potential effects have been described that need to be investigated by more and
better studies.”
The two bodies conducted independent but
complementary reviews to assess the potential carcinogenic hazard and other
health risks associated with aspartame consumption. This was the first time
that IARC has evaluated aspartame and the third time for JECFA.
After reviewing the available scientific
literature, both evaluations noted limitations in the available evidence for
cancer (and other health effects).
IARC classified aspartame as possibly
carcinogenic to humans (Group 2B) on the basis of limited evidence for cancer
in humans (specifically, for hepatocellular carcinoma, which is a type of liver
cancer). There was also limited evidence for cancer in experimental animals and
limited evidence related to the possible mechanisms for causing cancer.
JECFA concluded that the data evaluated indicated no sufficient reason to change the previously established acceptable daily intake (ADI) of 0–40 mg/kg body weight for aspartame. The committee therefore reaffirmed that it is safe for a person to consume within this limit per day.
For example,
with a can of diet soft drink containing 200 or 300 mg of aspartame, an adult
weighing 70kg would need to consume more than 9–14 cans per day to exceed the
acceptable daily intake, assuming no other intake from other food sources.
IARC’s hazard identifications are the first
fundamental step to understand the carcinogenicity of an agent by identifying
its specific properties and its potential to cause harm, i.e. cancer. IARC
classifications reflect the strength of scientific evidence as to whether an
agent can cause cancer in humans, but they do not reflect the risk of
developing cancer at a given exposure level.
The IARC hazard evaluation considers all
types of exposures (e.g. dietary, occupational). The strength-of-evidence
classification in Group 2B is the third highest level out of 4 levels, and it is generally used either
when there is limited, but not convincing, evidence for cancer in humans or
convincing evidence for cancer in experimental animals, but not both.
“The findings of limited evidence of carcinogenicity
in humans and animals, and of limited mechanistic evidence on how
carcinogenicity may occur, underscore the need for more research to refine our
understanding on whether consumption of aspartame poses a carcinogenic hazard,”
said Dr Mary Schubauer-Berigan of the IARC Monographs program.
JECFA’s risk assessments determine the
probability of a specific type of harm, i.e. cancer, to occur under certain
conditions and levels of exposure. It is not unusual for JECFA to factor IARC
classifications into its deliberations.
“JECFA also considered the evidence on cancer
risk, in animal and human studies, and concluded that the evidence of an
association between aspartame consumption and cancer in humans is not
convincing,” said Dr. Moez Sanaa, WHO’s Head of the Standards and Scientific
Advice on Food and Nutrition Unit.
“We need better studies with longer follow-up
and repeated dietary questionnaires in existing cohorts. We need randomized
controlled trials, including studies of mechanistic pathways relevant to insulin regulation,
metabolic syndrome, and diabetes, particularly as related to carcinogenicity.”
The IARC and JECFA evaluations of the impact
of aspartame were based on scientific data collected from a range of sources,
including peer-reviewed papers, governmental reports and studies conducted for
regulatory purposes. The studies have been reviewed by independent experts, and
both committees have taken steps to ensure the independence and reliability of
their evaluations.
IARC and WHO will continue to monitor new
evidence and encourage independent research groups to develop further studies
on the potential association between aspartame exposure and consumer health
effects.
