Page 22 - Hello Philippines January 2016 'A' Issue

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Daily sugar intake should be cut, study finds
“SUGAR intake should be halved
to just five teaspoons a day,” reports
The Daily Telegraph, while somewhat
confusingly the Mail Online website
says we should be eating less than
seven teaspoons of sugar a day.
Both reports are based on a large
review that looked at the link between
sugar intake and tooth decay. It found
that the incidence of tooth decay is
lower when sugar makes up less than
10% of the total recommended calorie
intake. As a very rough equivalent,
that would correspond to a standard
can of cola.
There was also some poor quality
evidence that showed that dental
decay could be further reduced if sugar
made up less than 5% of calorie intake.
The references to “spoonfuls” of
sugar in the papers is potentially
misleading and unhelpful, as people
could think this only refers to sugar
added to hot drinks.
Sugar is consumed not just in the
form of table sugar, but in high-sugar
foods such as cakes, biscuits and fizzy
drinks. It can also be found in foods
you might assume are sugar-free,
such as tinned chilli and ready-meal
noodles, so it is always a good idea to
check the label.
Sugary foods and drinks not only
cause tooth decay, they are high in
calories and can contribute to your risk
of diabetes and being overweight or
obese.
The current advice is to limit your
added sugar intake to 10% or less of
your daily calories. That’s about 70g
of sugar for men and 50g for women,
although this will vary according
to factors such as size, age and how
active people are.
Where did the story come from? The
study was carried out by researchers
from Newcastle University and the
University of Cambridge. It was funded
by Newcastle University’s Centre for
Oral Health Research and published
in the peer-reviewed Journal of Dental
Research.
The quality of the reporting on
this study was mixed. The Telegraph
reported that researchers recommend
halving the current 10% threshold to
5%, when the study clearly says that
evidence for doing this is “very low
quality”.
The Mail made a similar mistake,
although it did say later in its story
that the evidence for doing this was
unreliable.
The researchers say that dental decay
progresses with age and the effects of
sugars are lifelong. Even low levels of
decay in children are of significance
throughout life, they add.”
HEALTH and Lifestyle food
Both papers also issued conflicting
messages about the recommended
number of teaspoons of sugar people
should have a day – five teaspoons in
the Telegraph and seven teaspoons in
the Mail.
It is possible that this confusion
arose because of a failure to realise
that the recommended daily sugar
intakes vary by gender. Halving the
current 10% recommendation of 70g
for men and 50g for women would lead
to a drop (roughly) of 14 teaspoons to
seven for men, and 10 teaspoons to
five for women.
What kind of research was this?
This was a systematic review looking
at the link between sugar intake
and dental caries (cavities caused by
tooth decay) undertaken on behalf
of the World Health Organization
(WHO). WHO sets guidelines on sugar
intake as a percentage of total calorie
consumption. It currently recommends
that sugar intake should not be more
than 10% of total calories.
The researchers say that it is
widely accepted that sugar is the
most important dietary factor in the
development of dental caries. WHO
commissioned a systematic review
of evidence on this issue in 2010 to
inform and update its guidelines on
sugar intake.
In particular, WHO wanted to know
whether increasing or decreasing sugar
intake affected measures of dental
caries, and whether the evidence
supports a threshold for sugar intake.
Sugar comes in many different
forms, including fructose, sucrose
(table sugar), dextrose and glucose.
It is added to lots of foods, such as
sweets, chocolate, cakes and some
fizzy and juice drinks.
A systematic review is the “gold
standard” of assessing a body of
previously published clinical evidence.
It uses rigorous methods that enable
researchers to identify and assess all
relevant evidence on the issue.
What did the research involve?
The researchers set out to identify the
association between the amount of
sugar consumed and the level of dental
decay. In particular, they searched for
studies looking at the effect of, or link
between, restricting sugar intake to:
• less than 10% of total calorie
intake, compared with more than 10%
• less than 5% of total calorie
intake, compared with 5-10%
The review covers what are called
“free sugars”. These are sugars added
to foods by the manufacturer or
consumer, plus those naturally present
in honey, syrup, fruit juices and fruit
concentrates.
The researchers searched various
literature databases for relevant
studies published since 1950 in any
language. They included clinical trials
that looked at the effect on dental
caries of diets containing different
sugar content that had a timescale of
at least one year.
They also included observational
studies that reported changes in sugar
intake and information about dental
decay. Participants in the studies were
from all over the world and in all age
groups.
The papers were assessed twice
to see if they met review criteria.
Researchers graded the quality of the
studies as high, moderate, low or very
low using an internationally accepted
and validated system called GRADE.
GRADE takes into account factors such
as the consistency of results across
available studies, the size of the effect, one of the study’s authors, Paula
the evidence of a dose response and
the strength of the association.
From 5,990 papers identified, the
researchers included 55 studies that
met the study criteria, 50 of them
conducted in children. They did not
identify any randomised controlled
trials (RCTs). This is probably because
randomising an individual to consume
levels of sugar that could potentially
be harmful would be considered
unethical by most research institutes.
What were the basic results? The
full results of each of the identified
studies are extensive and cannot be
summarised here.
The overall results were:
• 42 out of 50 of the studies in
children, and 5 out of 5 in adults,
reported at least one positive
association between sugars and dental
decay
• there was “moderate quality”
evidence showing a lower risk of
dental decay when sugar intake is less
than 10% of calorie intake, compared
with more than 10%
• there was “very low quality”
evidence showing a lower risk of
dental decay when sugar intake is less
than 5%, compared with 5-10% of
calorie intake
How did the researchers interpret
the results? The researchers say that
dental decay progresses with age and
the effects of sugars are lifelong. Even issue.
low levels of decay in children are of
significance throughout life, they add.
While the evidence for a limit of
10% less sugar intake is moderate,
they suggest there “may be benefit
in limiting sugars to less than 5% to
minimise the risk of dental caries
throughout the life course”.
They also point out that while
fluoride has a protective role, the
association between sugar and dental
caries remains.
In an accompanying press release,
Moynihan, Professor of Nutrition and
Oral Health at Newcastle University,
said: “People now expect to keep their
teeth into old age and, given that
the effects of sugars on our teeth are
lifelong, then limiting sugars to less
than 5% of the calories we eat would
minimise the risk of dental caries
throughout life.
“In the past, judgements on
recommended levels of free sugars
intake were made based on levels
associated with an average of three or
fewer decayed teeth in 12-year-olds.
However, tooth decay is a progressive
disease – by looking at patterns of
tooth decay in populations over time,
we now know that children with less
than three cavities at age 12 go on to
develop a high number of cavities in
adulthood.
“Part of the problem is that sugary
foods and drinks are now staples in
many people’s diet in industrialised
countries, whereas once they were
an occasional treat for a birthday or
January 2016 – No. 01 • UK & Europe Edition
Christmas. We need to reverse this
trend.”
Conclusion. This was a systematic
review that considered all the evidence
on the relationship between dental
decay and sugar intake dating back
more than 60 years.
It is worth noting that the
researchers did not identify any
randomised controlled trials – the gold
standard of clinical evidence – on the
However, given the detrimental
effect that a high sugar intake is
known to have on health, there are
likely to be practical and ethical issues
around randomising people to long-
term intakes of high or low added
sugar purely to look at who was more
likely to develop tooth decay.
That said, the review is a timely
reminder that sugar intake is
associated with dental decay and that
this association remains despite the
introduction of fluoride toothpaste
and, in some countries, fluoridated
water. It would not be safe to assume
that access to a fluoridated water
supply means you can have your fill of
sweet foods.
The evidence for lowering sugar
intake to less than 5% of calorie intake
came from three population surveys
carried out in Japan in 1959 and 1960,
and is considered very low quality. It
is therefore debatable whether current
advice will be altered.
Sugary foods and drinks not only
cause tooth decay, they are high in
calories and can contribute to people’s
risk of diabetes and being overweight
or obese.
The current advice is to limit your
added sugar intake to 10% or less of
calories a day. That’s about 70g of
sugar for men and 50g for women,
although this will vary according
to factors such as size, age and how
active people are.
Foods and drinks high in sugar
should only be consumed in small
amounts. n NHS Choices