The weight of evidence hints at
benefits, but the full picture has yet to emerge
BMJ
There is no compelling evidence to
indicate important health benefits of non-sugar sweeteners, and potential harms
cannot be ruled out, suggests a review of published studies in The BMJ today.Growing concerns about health and quality of life have encouraged many people to adopt healthier lifestyles and avoid foods rich in sugars, salt, or fat.
Foods and drinks containing non-sugar sweeteners rather than regular ("free") sugars have therefore become increasingly popular.
Although several non-sugar
sweeteners are approved for use, less is known about their potential benefits
and harms within acceptable daily intakes because the evidence is often limited
and conflicting.
To better understand these potential
benefits and harms, a team of European researchers analyzed 56 studies
comparing no intake or lower intake of non-sugar sweeteners with higher intake
in healthy adults and children.
Measures included weight, blood sugar (glycaemic) control, oral health, cancer, cardiovascular disease, kidney disease, mood and behavior.
Studies were assessed for bias and certainty of evidence.
Overall, the results show that, for
most outcomes, there seemed to be no statistically or clinically relevant
differences between those exposed to non-sugar sweeteners and those not
exposed, or between different doses of non-sugar sweeteners.
For example, in adults, findings
from a few small studies suggested small improvements in body mass index and
fasting blood glucose levels with non-sugar sweeteners, but the certainty of
this evidence was low.
Lower intakes of non-sugar
sweeteners were associated with slightly less weight gain (-0.09 kg) than
higher intakes, but again the certainty of this evidence was low.
In children, a smaller increase in
body mass index score was seen with non-sugar sweeteners compared with sugar,
but intake of non-sugar sweeteners made no differences to body weight.
And no good evidence of any effect of non-sugar sweeteners was found for overweight or obese adults or children actively trying to lose weight.
The researchers point out that this
is the most comprehensive review on this topic to date, and will inform a World
Health Organization guideline for health experts and policy makers.
However, they stress that the quality of evidence in many of the studies was low, so confidence in the results is limited. And they say longer term studies are needed to clarify whether non-sugar sweeteners are a safe and effective alternative to sugar.
In a linked editorial, Vasanti Malik
at Harvard T.H. Chan School of Public Health agrees that more studies are
needed to understand the potential health effects of non-sugar sweeteners and
to guide policy development.
Based on existing evidence, she says
use of non-sugar sweeteners as a replacement for free sugars, particularly in
sugar sweetened drinks, "could be a helpful strategy to reduce
cardiometabolic risk [chances of having diabetes, heart disease or stroke]
among heavy consumers, with the ultimate goal of switching to water or other
healthy drinks."
"Policies and recommendations
will need updating regularly, as more evidence emerges to ensure that the best
available data is used to inform the important public health debate on sugar
and its alternatives," she concludes.
