Here's What Experts Think
EVA HAMRUD, METAFACT
Saccharin
quickly became extremely popular, mainly due to how cheap it was. It was
particularly widespread during World War II, when real
sugar was in short supply.
Today,
artificial sweeteners are central to the huge market of diet- and sugar-free
food and drinks. Their attraction today is not only how cheap they are, but
their potential to combat the increasing threat of obesity and its associated
health impacts.
Saccharin
is over 200 times sweeter than sugar but has
zero calories. Does this mean that we should replace all sugar with artificial
sweeteners? Or are there more factors to consider?
We
asked 8 experts "Are artificial sweeteners better for you than
sugar?". The consensus was 63 percent 'likely'. Here is what we
found out.
What are artificial sweeteners and how do they work?
Artificial
sweeteners provide the sweet taste of sugar but without the calories. There are
two broad categories of artificial sweeteners: sugar alcohols and
high-intensity sweeteners.
Sugar
alcohols are structurally similar to sugars but less readily metabolized,
whereas high-intensity sweeteners are small compounds many times sweeter than
sugar. The high-intensity sweeteners include saccharin and aspartame.
Even
though artificial sweeteners provide minimal to no calories that does not mean
they are inert. Artificial sweeteners interact with the T1R-family of
sweet-taste receptors in the mouth and gut, which can have metabolic effects.
They may also interact with the bacteria that
make up the gut microbiome. Different sweeteners might differ in their effect
on the body.
Is
there a link between artificial sweeteners and cancer?
Concern
that artificial sweeteners could be carcinogenic stems from a 1978 study which found that rats that
were fed saccharin developed bladder cancer. Since then, it has been shown that
this only happens in rats, and saccharin does not cause cancer
in humans.
Not
just saccharin, but all of the FDA and EU approved artificial sweeteners have
undergone testing both in laboratory animals and
data from humans. None of the approved sweeteners have
any connection to cancer.
Do
artificial sweeteners help you lose weight?
The
main attraction of artificial sweeteners is that they can replace sugar. There
is a huge amount of evidence to suggest that high sugar consumption is bad for
your health. Sugary drinks in particular can lead to weight gain, metabolic diseases, and type 2 diabetes. It follows that swapping sugar
for calorie-free sweeteners could lead to weight loss.
Many
studies have investigated whether replacing sugar with artificial sweeteners
leads to weight loss. A 2018 meta-analysis study, which combined the
results of 56 different studies, concluded that in most cases groups of people
using artificial sweeteners did not lose more weight than those using sugar.
However,
overweight or obese individuals who switched to artificial sweeteners did lose
more weight than their sugar-eating counterparts.
Other meta-analyses have also found
that, on the whole, switching from sugar to sweeteners has a neutral to
positive effect on weight loss. The fact that there is not a clear result may
stem from the complexity of these experiments:
1)
There are many types of sweeteners, each of which may have different effects on
weight loss.
2)
Changes in diet other than the switch to sweeteners could have confounding
effects. Biochemist from the University of Sydney, Dr Kieron Rooney explains that
the whole diet is important because "there is data – in humans – that the
co-consumption of artificial sweeteners with other foods may have an
interaction effect such that the absorption of energy is altered".
3)
It is likely that the impact of sweetener on weight loss depends on the
original weight and diet of the individual, a result that was found in the
2018 meta-analysis study.
Some
scientists have attempted to explain why, on average, people do not lose weight
with artificial sweeteners, and in some cases actually gain weight.
Nutritionist
Dr Cornelie Nienaber-Rousseau explains that
the effect of sweeteners on the food reward system "may contribute to
increased appetite, fuel food-seeking behavior and encourage sugar
cravings." She adds that "non-caloric artificial
sweetener seems to alter the gut microbiome".
Both
of these explanations are plausible, but require more research before we can be
sure of their effects.
Epidemiologist
Gideon Meyerowitz-Katz summarises that "it's
possible that artificial sweeteners might be worse for people than water –
although this is something of an open question – but compared to sugar, all
indications are that artificial sweeteners are probably a bit better."
No
silver-bullet to obesity crisis
Overall,
considering that artificial sweeteners are essentially calorie-free, the data on
their positive health impacts is perhaps a bit disappointing.
This
might explain Professor Jennie Brand-Miller's observation from the University of
Sydney that "the prevalence of obesity and overweight have tripled in [the
last 50 years] despite the popularity of low-calorie sweeteners and their
ubiquity".
On
the flip side, there is plenty of evidence that they are safe and not linked to
any cancers. Whether they have some other effects perhaps on our sugar cravings
or microbiome, remains to be determined.
The
takeaway:
Sugar-free
alternatives, particularly of drinks, could be beneficial to someone who is
trying to lose weight or improve their diet. However, the data suggest that
they are not the healthiest option available – whilst a diet drink might be
better than a sugary one, water might be even better.