Research
Helpful Bacteria
Part 2
Kefir May Bolster Lactose Tolerance In Intolerant People
5-30-2003
COLUMBUS, Ohio – For lactose intolerant adults, drinking
fermented milk either eliminated or drastically reduced
symptoms related to lactose intolerance. Researchers think
that microbes in this fermented milk – called kefir
– possess the enzyme that is necessary to digest lactose.
Kefir is a little known, and slightly more expensive, alternative
to milk. It contains a multitude of bacteria that are thought
to break down lactose in the digestive tract.
"Many
health claims exist for kefir, including the enhancement
of the immune system and improved digestive health, particularly
with regard to lactose digestion," said Steven Hertzler,
a study co-author and an assistant professor of medical
dietetics at Ohio State University.
"We
wanted to find out if kefir would improve lactose digestion.
The research showed that it did."
The
study appears in a recent issue of the Journal of the American
Dietetic Association. Hertzler conducted the study with
Shannon Clancy, a clinical dietitian at Toledo Hospital
in Toledo, Ohio.
Kefir
tastes slightly on the tart side and has the consistency
of liquid yogurt. To manufacture kefir, producers add clusters
of starchy carbohydrate – kefir grains – that
contain healthy bacteria and are left to ferment in milk.
The grains are filtered out while the live cultures remain.
|
|
The researchers asked 15 adults to consume five separate
test foods: 2 percent milk; plain kefir; raspberry-flavored kefir;
plain yogurt; and raspberry-flavored yogurt. Each food was eaten after
a 12-hour fast and followed up by a series of breath hydrogen tests
every hour for eight hours. Participants were asked to record any
symptoms of lactose intolerance for eight hours after eating each
food.
Past studies by other scientists have shown that eating
fermented dairy products, such as yogurt, improves lactose digestion.
Participants in the current study reported having little or no symptoms
associated with lactose intolerance after eating both types of yogurt
and kefir. Flatulence was the most-reported symptom. Drinking kefir
reduced flatulence frequency by more than half, compared to milk.
Breath hydrogen levels were also significantly lower
after consuming the plain and flavored kefir than after drinking milk.
Flatulence is the biggest complaint among lactose-intolerant people,
Hertzler said, and breath hydrogen is indicative of excessive gas
in the digestive tract.
While it's known that lactose intolerant people can
tolerate yogurt – it contains healthy bacteria that break down
lactose – there has been relatively little scientific information
about the potential benefits of kefir.
Kefir might be a better option than yogurt for some
lactose intolerant people, Hertzler said, adding that, like yogurt,
kefir is a good source of calcium, potassium and protein. But kefir
also contains a wider array of microorganisms than yogurt does.
"Both kefir and yogurt improve lactose digestion
simply because some of the bacterial cells give up their lives in
the intestinal tract, release their enzymes and digest the lactose,"
Hertzler said. "It's a one-shot deal. However, kefir has additional
microorganisms that may be able to colonize the intestines and benefit
health further by protecting the intestine against disease-causing
bacteria."
Hertzler said he hopes to conduct further studies
that explore kefir's potential for improving health.
This study was funded by a grant from Lifeway Foods,
Inc., a company that manufactures kefir. Hertzler has no financial
connections to Lifeway Foods, Inc.
This story has been adapted from a news release issued
by Ohio State University, www.acs.ohio-state.edu/units/research.
Next - Back
to Table of Contents for Helpful Bacteria, Part 2