family members are panicking about recent headlines claiming
that diet sodas cause Alzheimerís disease. While I would
love for them to drink fewer sodas, I have to be honest: The
headlines were misleading, and the new study they refer to has
study did not prove that artificial sweeteners cause stroke,
Alzheimerís disease or any type of dementia. In fact, this
kind of study design cannot prove causation. To be fair, the
authors were careful to say that the study was not "able
to prove cause and effect and only shows a trend among one
group of people."
news articles didnít reflect this.
researchers studied nearly 2,000 men and women ages 45 and
older for stroke and about 1,500 people over age 60 for
dementia. They tracked how much and what kinds of soda the
subjects were drinking and monitored their health for a
study determined that drinking sugary beverages was not
associated with stroke or dementia. But it found that for
people who drank one artificially sweetened soda a day, the
risk of stroke or dementia was nearly three times higher than
it was for people who consumed less than one diet soda a week.
important to bear in mind that drinkers of sugary sodas may
have died from other causes such as heart disease and
complications of diabetes, and thatís why they donít show
up in the results section as victims of stroke and dementia.
This phenomenon is known as survival bias. Not mentioning it
can be misleading.
different study by the same researchers, people who drank
sugary drinks such as sodas and fruit juice were found to have
a smaller brain volume, as well as smaller hippocampi, the two
horseshoe-shaped parts of the brain that are crucial to
memory. In that study, people who drank sugary drinks were
more likely to have memory problems.
study published in the journal Stroke on April 20 included
mostly white Americans, making it tricky to apply the results
to people of color who have different genetic and social risk
factors for stroke and dementia.
study emphasizes the "relative risk" of stroke and
dementia in people who drink diet sodas. One problem with
reporting results using the relative risk is that it can make
the likelihood of something happening seem bigger than it
truly is. As Iíve said in previous Debunked columns,
relative risk tells you how more or less likely a disease
occurs in one group compared with another. Relative risk does
not tell you the actual likelihood that something will happen
measurement is "absolute risk," which tells your
actual risk of developing a disease. Where the relative risk
says the risk of dementia and stroke is three times higher in
one group, the absolute risk says the actual likelihood of
developing stroke and dementia is quite low: 3 percent
suffered a stroke and 5 percent developed dementia.
studies have found that artificial sweeteners interfere with
good bacteria in the gut and are linked to weight gain and
diseases of the veins and arteries.
our knowledge, our study is the first to report an association
between daily intake of artificially sweetened soft drink and
increased risk of both all-cause dementia and dementia because
of Alzheimerís disease," the researchers said.
doesnít mean that sugary sodas are a healthier option.
Almost a third of Americans drink one or more sugary sodas or
sweetened drinks a day, according to a 2016 report by the
Centers for Disease Control and Prevention. Diets high in
sugar are linked to heart disease, obesity and diabetes, among
this study didnít prove that sugary sodas cause stroke and
dementia, the scientists did say their results call for more
research on the health effects of artificial sweeteners. In
the meantime, water is a good option.