A new review of existing studies published in The BMJ finds that sugary drinks
that contain fructose raise the risk of type 2 diabetes more than other
fructose-containing foods.
New research finds that 'nutrient-poor' sweetened drinks
have a harmful effect on metabolic health when they add excess energy.
A range of recent studies has pointed out the potential
health risks of sugary drinks. Studies have confirmed that there is a link between sugary drinks
and obesity, as well as cautioning that as few as two sugary drinks per week may raise
the risk of type 2
diabetes considerably.
Now, a comprehensive review of existing research confirms
that fructose-containing drinks can increase the risk of type 2 diabetes more
than other foods that contain fructose.
Dr. John Sievenpiper, a researcher in the Clinical Nutrition
and Risk Factor Modification Centre of St. Michael's Hospital in Toronto,
Canada, is the lead author of the study.
In their paper, Dr. Sievenpiper and colleagues quote
other studies which have focused on fructose in particular as a threat to
cardiometabolic health.
Although some research has suggested that fructose might be
a good alternative to sugar, especially for people who are already living
with diabetes,
more recent studies have pointed out that "fructose could be particularly
detrimental to metabolic health, and even more so than other sugars."
As the researchers explain, fructose is a natural ingredient
in several foods, such as fruits, natural fruit juice, honey, and even some
vegetables. However, some food manufacturers artificially add the compound to
soft drinks, desserts, cereals, and other baked foods.
In the new study, Dr. Sievenpiper and team wanted to see how
different "food sources of fructose-containing sugars" affected the
glycemic control of both people with diabetes and people who do not have the
condition.
Foods with fructose and metabolic
health
To find out, the researchers analyzed the conclusions of 155
studies that looked at how different food sources affected peoples' blood sugar
levels. The researchers followed the participants, some of whom had diabetes,
for up to 3 months.
During this time, the researchers also assessed the
participants' glycated hemoglobin — that is the amount of sugar that is
attached to red blood cells — as well as their glucose and insulin levels
after a period of fasting.
Dr. Sievenpiper and team divided the 155 controlled
intervention studies into four groups based on their design.
·
Substitution studies compared the energy derived from sugars
with that from other carbohydrates.
·
Subtraction studies removed sugar-derived energy from the
participants' diet and compared it with a regular diet.
·
Addition studies added glucose-derived energy to the diet
and compared it with a non-sugar-enhanced diet.
·
Ad libitum studies
replaced the energy from sugars with other nutrients that the participants were
free to consume at will.
The reviewers assessed the bias and the level of certainty
of these studies.
Sweetened drinks vs. other sugary
foods
Overall, the review found that most of the fructose-containing
sugary foods do not harm blood sugar levels when they do not add excess calories. Some of the studies, however, found a harmful effect
on fasting insulin levels.
In fact, fruit and fruit juice, which are high in fructose,
may even benefit the blood sugar and insulin levels of those with diabetes,
when these foods do not add excess calories, the review suggests.
However, some "nutrient-poor"
foods that add excessive energy to the diet, such as sweetened drinks and fruit
juice, have a harmful metabolic effect.
The researchers hypothesize that the higher content of fiber
in fruit, for example, may partly explain this difference, because they slow
down the release of glucose. Also, fructose has a lower glycemic index than
other carbohydrates.
"These findings might help guide recommendations on
important food sources of fructose in the prevention and management of
diabetes," says the study's lead author.
"But the level of evidence is low," he cautions,
"and more high-quality studies are needed." Therefore, Dr.
Sievenpiper and his colleagues conclude:
"Until more information is available, public health
professionals should be aware that harmful effects of fructose sugars on blood
glucose seem to be mediated by energy and food source."
No comments:
Post a Comment