Drinking sugar-sweetened beverages may reduce stress while diet beverages sweetened
with aspartame do not, according to a new study
published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.
The study examined the
effects of consuming sugar- and aspartame-sweetened beverages on a group
of 19 women between the ages of 18 and 40. The researchers assigned
eight women to consume aspartame-sweetened beverages, and 11 to drink
sugar-sweetened beverages. For a 12-day period, the women drank one of
the assigned beverages at breakfast, lunch and dinner. The participants
were instructed not to consume other sugar-sweetened drinks, including
fruit juice.
For three-and-a-half days prior to and after the study, participants consumed a
standardized low-sugar diet and stayed at the University of
California, Davis Clinical and
Translational Science Center’s Clinical Research Center.
Before and after the 12-day experimental period, participants
underwent functional MRI screenings after performing a psychological
stress test to gauge the brain’s stress response. They also provided
saliva samples to measure levels of cortisol – a hormone made by the
adrenal glands that typically increases in response to stress.
Researchers found that women who drank sugar-sweetened beverages
during the study had a diminished cortisol response to the stress test
from their baseline, compared to women who were assigned to consume
aspartame-sweetened beverages. Additionally, participants who consumed
sugar-sweetened beverages exhibited more activity in the hippocampus
under stress– a part of the brain that is involved in memory and is
sensitive to stress – than those who drank aspartame-sweetened
beverages. Activity in the hippocampus is thought to play a primary role in
controlling the cortisol stress response.
“This is the first mechanistic evidence that high sugar – but not
aspartame – consumption may relieve stress in humans,” said one of the
study’s authors, Kevin D. Laugero, PhD, of the Western Human Nutrition
Research Center of Agricultural Research Service and UC Davis. “The concern is psychological or emotional stress
could trigger the habitual overconsumption of sugar and amplify sugar’s
detrimental health effects, including obesity.”
“The results also suggest differences in dietary habits may explain
why some people underreact to stressful situations and others
overreact,” he said. Excessive reliance on sugar may abnormally blunt
the ability to mount a stress response. Research has linked over- and
under-reactivity in neural and endocrine stress systems to poor mental
and physical health.
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