This document discusses aspartame, an artificial sweetener. It provides information on what aspartame is, its history of use, recommended limits, potential benefits and risks. While FDA has concluded that aspartame is safe, some studies have linked it to health issues. Further unbiased review may be needed to address controversies around its metabolic breakdown and potential formaldehyde exposure.
2. What is Aspartame??
An artificial, non-saccharide low calorie sweetener
used as sugar substitute in some food and
beverages.
200 times sweeter than sugar
Chemically it is L-aspartyl-L-phenylalanine methyl
ester
Molecular formula: C14H18N2O5
Mol. Wt 294
3. History at a glance
Aspartame was discovered serendipitously by Dr.
James Schlatter (G.D. Searle pharmaceutical) in 1965
while he was working on antiulcer drug.
Regulated by US-FDA
Approved by FDA in 1974 for restricted use in dry
foods.
Petition filed by Searle pharmaceuticals for use in
carbonated beverages in 1982
First carbonated beverages containing Aspartame
sold in Fall 1983.
Eventually approved as general sweetener in 1996
4. In the market
Widely marketed and available as:
Nutrasweet® - Chemically pure aspartame
Equal®: Packets of 33 mg
Tablets of 19 mg
Equal consist of dextrose with maltodextrin and
aspartame
5. Recommended uses and limits
Suggested to be used for
Various foods and beverages
Chewable multi-vitamins
Pharmaceuticals
ADI for aspartame is 50 mg/kg of body weight (3500
mg/day for 70 kg individual), it falls under OEB
category 1 (OEL being >1 mg/ m3) and it is
considered safe for human consumption
Accordingly an individual will have to consume 97
packets of tabletop sweetener to reach these ADI
value.
6. Anticipated toxicity
As a whole considered “safe” at recommended levels,
however the primary concerns are centered upon its
chronic usage or ingestion of very large single dose >10 g
especially in Phenylketonurics (PKU)
Phenylketonuria is a rare congenital condition in which a
baby is born without the ability to properly metabolize an
amino acid called phenylalanine, due to lack of hepatic
enzyme phenylalanine hydroxylase
Lactating women should avoid aspartame in diet if child is
PKU
7. Benefits
Sugar substitutes with low calorie
No contribution to obesity and thus may help in
losing weight
Helps to prevent high blood pressure
Diabetic can satisfy his craving for sweet using
such artificial sweeteners
8. Associated Risks
Most of the adverse conditions are due to its metabolic
products: methanol, formaldehyde, phenylalanine etc.
Formaldehyde has been shown to be very toxic at very
small concentrations and is considered as occupational
carcinogen by NIOSH.
Independent studies carried out over a decade from
1998-2007 links aspartame to various adverse conditions
like painful fibromyalgia, brain tumors, memory loss,
Lymphomas, leukemias and many other complication.
9. Toxicity studies
There is no acute toxicity. Aspartame is safely consumed in single dose < 10 gm
except in case of phenylketonurics.
There have been some case reports of adverse effects upon chronic use of
aspartame, especially the metabolic fate of aspartame has been a concern due to
formation of methanol and formaldehyde both of which are known to be toxic.
Also carcinogenic potential have been evaluated in numerous studies with positive
as well as negative results but FDA has always concluded that Aspartame is safe for
general use as sweetener and there is no need to review the previously established
ADI value.
But the safety of aspartame still remains questionable
since it appears that food industry has a profound
influence on these safety studies on aspartame
10. Animal Toxicity Studies
A studies performed by Soffritti et al. in 2005 and sequel studies in
2007/2008 which support the previous studies and reinstated the
consclusions.
Aspartame was administered to 8 week old male and female rats in
groups of 100-150/sex/group at 100,000; 50,000; 10,000; 2000; 400;
80; and 0 ppm till their natural death.
With increased incidence of malignant tumor bearing animals with
significant positive trend, aspartame was shown to be a
multipotential carcinogen even at daily dose of 20 mg/kg body
weight.
However in a review by Magnuson B, et al. they pointed out various
flaws in studies performed by Soffritti, et al
The reviewers Magnuson B and Williams GM worked for Burdock
group which managed independent review and was financially
supported by Ajinomoto company Inc. a producer of aspartame.
11. Exposure assessment
It has been shown in one of the study that 1 liter diet soda
consist of about 600mg of aspartame as studied using
HPLC analytical method.
Each molecule of aspartame gives a molecule of
phenylalanine and methanol.
This corresponds to 10 mg/kg of aspartame for a 60 kg
individual
600 mg of aspartame (Mol. Wt 294) converts to 65.4 mg
methanol (Mol. Wt. 32) which further gets converted to
61.3 mg of formaldehyde (Mol. Wt. 30)
12. Exposure assessment…. cont
This is based upon simple correlations of their molar weight as follows:
Similarly 65.4 mg of methanol converts to 61.3 mg of formaldehyde
However only 70-75% of methanol is absorbed from aspartame and of which
90% converts to formaldehyde
Thus 61.3 x 72.5% x 90% = 39.99 mg of formaldehyde exposure from 1 liter
diet soda (approximately three 12 oz cans of soda)
Amount of formaldehyde causing irreversible genetic damage to human is
shown to be 3.375 mg/ m3 or 33.75 mg/day
Thus a person consuming 3 cans of diet soda per day may be exposed to
significant amount of formaldehyde which may accumulate in the body
13. Risk/Benefit analysis
As per FDA’s conclusion for various studies
Aspartame still remains safe for human
consumption at recommended ADI.
However since aspartame is a widely used
consumer product an unbiased review by
independent panel of scientist is also necessary
to answer the unsettled controversies especially
those related to metabolic fate of aspartame and
thereby exposure to formaldehyde (recognized as
carcinogen by NIOSH)