i***@aol.com
2014-09-19 08:33:56 UTC
Artificial sweeteners’ sour note
BY DEBORAH NETBURN
9/18/2014
Diet sodas and those packets of artificial sweetener you put in your
coffee may not be as benign as we thought, a new study suggests.
High doses of artificial sweeteners such as saccharin, sucralose and
aspartame can change the population of healthy gut bacteria in mice, and
in some humans. That makes it harder for their bodies to metabolize
sugar, according to a study published Wednesday in the journal Nature.
“These results should prompt additional study and debate on the massive
use of artificial sweeteners,” said Eran Segal, a computational
biologist at the Weizmann Institute of Science in Israel and a senior
author of the paper.
Artificial sweeteners are not digested by the human body, which is why
they have no calories. However, they still must pass through our
gastrointestinal tract, where they encounter the vast ecosystem of
bacteria that thrive in our guts. These bacteria play an important role
in our physiology, including how we process glucose and other sugars.
To find out whether artificial sweeteners affect healthy gut bacteria,
the researchers embarked on a series of experiments.
First they added saccharine, sucralose or aspartame to the drinking
water of different groups of mice. Other groups of mice got real sugar
in their water, and a control group got plain water.
After 11 weeks, the mice that got artificial sweeteners showed higher
levels of glucose intolerance compared with the others — a sign that
their bodies were doing a worse job of processing sugar. This causes
blood sugar to be too high, often a precursor to Type 2 diabetes.
To see whether the gut microbiome had anything to do with the link
between drinking artificial sweeteners and developing glucose
intolerance, the researchers gave the mice antibiotics to wipe out their
gut bacteria. After that, all the groups were able to metabolize sugar
equally well.
Next, the researchers transplanted gut bacteria from mice that had
consumed saccharin into mice that had no gut bacteria of their own. Six
days later, those mice had lost some of their ability to process sugar.
Genetic analysis revealed that the composition of the gut bacteria in
mice had indeed changed after exposure to the artificial sweetener —
some types of bacteria became more abundant, while others shrank.
The most obvious question is whether artificial sweeteners would have
the same effect in humans. The researchers made some preliminary
attempts to answer this question.
First, they looked at a group of 381 people who are involved in an
ongoing clinical nutritional study and found that the gut bacteria of
those who regularly consumed artificial sweeteners looked different from
those who did not. They also found correlations between people who use
artificial sweetener and those who weighed more and had higher fasting
blood sugar, a condition that can cause heart problems, kidney disease,
eye issues and other health problems.
But they couldn’t say that either artificial sweeteners or gut bacteria
were causing weight gain or high blood sugar levels. (It should be noted
that the InterAct study of 350,000 people in Europe found no
relationship between artificial sweetener consumption and any health
problems.)
Finally, the researchers gave seven people high doses of artificial
sweeteners
— the equivalent of 40 cans of diet soda a day. By the end of the week,
four of them lost some of their ability to metabolize sugar. The other
three saw no change.
Although the human aspect of this study is interesting, it is far from
conclusive, other researchers said.
Sridevi Devaraj, an associate director of Texas Children’s Microbiome
Center in Houston, said she would like to know whether the pre-diabetes
symptoms that the mice developed after consuming artificial sweeteners
would lead to full-blown diabetes over time.
“The jury is still out with regards to whether these sweeteners actually
cause weight gain,” said Devaraj, who was not involved in the new
research. “It begs for a really good study in humans.”
The original researchers agree. “We are not at the point to make a
change, but we are at a point to promote discussion in the medical,
scientific and general community,” said Weizmann’s Dr. Eran Elinav, the
co-senior author of the study.
***@latimes.com
BY DEBORAH NETBURN
9/18/2014
Diet sodas and those packets of artificial sweetener you put in your
coffee may not be as benign as we thought, a new study suggests.
High doses of artificial sweeteners such as saccharin, sucralose and
aspartame can change the population of healthy gut bacteria in mice, and
in some humans. That makes it harder for their bodies to metabolize
sugar, according to a study published Wednesday in the journal Nature.
“These results should prompt additional study and debate on the massive
use of artificial sweeteners,” said Eran Segal, a computational
biologist at the Weizmann Institute of Science in Israel and a senior
author of the paper.
Artificial sweeteners are not digested by the human body, which is why
they have no calories. However, they still must pass through our
gastrointestinal tract, where they encounter the vast ecosystem of
bacteria that thrive in our guts. These bacteria play an important role
in our physiology, including how we process glucose and other sugars.
To find out whether artificial sweeteners affect healthy gut bacteria,
the researchers embarked on a series of experiments.
First they added saccharine, sucralose or aspartame to the drinking
water of different groups of mice. Other groups of mice got real sugar
in their water, and a control group got plain water.
After 11 weeks, the mice that got artificial sweeteners showed higher
levels of glucose intolerance compared with the others — a sign that
their bodies were doing a worse job of processing sugar. This causes
blood sugar to be too high, often a precursor to Type 2 diabetes.
To see whether the gut microbiome had anything to do with the link
between drinking artificial sweeteners and developing glucose
intolerance, the researchers gave the mice antibiotics to wipe out their
gut bacteria. After that, all the groups were able to metabolize sugar
equally well.
Next, the researchers transplanted gut bacteria from mice that had
consumed saccharin into mice that had no gut bacteria of their own. Six
days later, those mice had lost some of their ability to process sugar.
Genetic analysis revealed that the composition of the gut bacteria in
mice had indeed changed after exposure to the artificial sweetener —
some types of bacteria became more abundant, while others shrank.
The most obvious question is whether artificial sweeteners would have
the same effect in humans. The researchers made some preliminary
attempts to answer this question.
First, they looked at a group of 381 people who are involved in an
ongoing clinical nutritional study and found that the gut bacteria of
those who regularly consumed artificial sweeteners looked different from
those who did not. They also found correlations between people who use
artificial sweetener and those who weighed more and had higher fasting
blood sugar, a condition that can cause heart problems, kidney disease,
eye issues and other health problems.
But they couldn’t say that either artificial sweeteners or gut bacteria
were causing weight gain or high blood sugar levels. (It should be noted
that the InterAct study of 350,000 people in Europe found no
relationship between artificial sweetener consumption and any health
problems.)
Finally, the researchers gave seven people high doses of artificial
sweeteners
— the equivalent of 40 cans of diet soda a day. By the end of the week,
four of them lost some of their ability to metabolize sugar. The other
three saw no change.
Although the human aspect of this study is interesting, it is far from
conclusive, other researchers said.
Sridevi Devaraj, an associate director of Texas Children’s Microbiome
Center in Houston, said she would like to know whether the pre-diabetes
symptoms that the mice developed after consuming artificial sweeteners
would lead to full-blown diabetes over time.
“The jury is still out with regards to whether these sweeteners actually
cause weight gain,” said Devaraj, who was not involved in the new
research. “It begs for a really good study in humans.”
The original researchers agree. “We are not at the point to make a
change, but we are at a point to promote discussion in the medical,
scientific and general community,” said Weizmann’s Dr. Eran Elinav, the
co-senior author of the study.
***@latimes.com