Date:
April 25, 2018
Source:
Medical College of Georgia at Augusta University
Summary:
A daily
dose of baking soda may help reduce the destructive inflammation of autoimmune
diseases like rheumatoid arthritis, scientists say. They have some of the first
evidence of how the cheap, over-the-counter antacid can encourage our spleen to
promote instead an anti-inflammatory environment that could be therapeutic in
the face of inflammatory disease, scientists report.
A daily dose of baking
soda may help reduce the destructive inflammation of autoimmune diseases like
rheumatoid arthritis, scientists say.
They have some of the
first evidence of how the cheap, over-the-counter antacid can encourage our
spleen to promote instead an anti-inflammatory environment that could be
therapeutic in the face of inflammatory disease, Medical College of Georgia
scientists report in the Journal of Immunology.
They have shown that when
rats or healthy people drink a solution of baking soda, or sodium bicarbonate,
it becomes a trigger for the stomach to make more acid to digest the next meal
and for little-studied mesothelial cells sitting on the spleen to tell the
fist-sized organ that there’s no need to mount a protective immune response.
“It’s most likely a
hamburger not a bacterial infection,” is basically the message, says Dr.
Paul O’Connor, renal physiologist in the MCG Department of Physiology at
Augusta University and the study’s corresponding author.
Mesothelial cells line
body cavities, like the one that contains our digestive tract, and they also
cover the exterior of our organs to quite literally keep them from rubbing
together. About a decade ago, it was found that these cells also provide
another level of protection. They have little fingers, called microvilli, that
sense the environment, and warn the organs they cover that there is an invader
and an immune response is needed.
Drinking baking soda, the
MCG scientists think, tells the spleen — which is part of the immune system,
acts like a big blood filter and is where some white blood cells, like
macrophages, are stored — to go easy on the immune response. “Certainly
drinking bicarbonate affects the spleen and we think it’s through the
mesothelial cells,” O’Connor says.
The conversation, which
occurs with the help of the chemical messenger acetylcholine, appears to
promote a landscape that shifts against inflammation, they report.
In the spleen, as well as
the blood and kidneys, they found after drinking water with baking soda for two
weeks, the population of immune cells called macrophages, shifted from
primarily those that promote inflammation, called M1, to those that reduce it,
called M2. Macrophages, perhaps best known for their ability to consume garbage
in the body like debris from injured or dead cells, are early arrivers to a
call for an immune response.
In the case of the lab
animals, the problems were hypertension and chronic kidney disease, problems
which got O’Connor’s lab thinking about baking soda.
One of the many functions
of the kidneys is balancing important compounds like acid, potassium and
sodium. With kidney disease, there is impaired kidney function and one of the
resulting problems can be that the blood becomes too acidic, O’Connor says.
Significant consequences can include increased risk of cardiovascular disease
and osteoporosis.
“It sets the whole
system up to fail basically,” O’Connor says. Clinical trials have shown
that a daily dose of baking soda can not only reduce acidity but actually slow
progression of the kidney disease, and it’s now a therapy offered to patients.
“We started
thinking, how does baking soda slow progression of kidney disease?”
O’Connor says.
That’s when the
anti-inflammatory impact began to unfold as they saw reduced numbers of M1s and
increased M2s in their kidney disease model after consuming the common
compound.
When they looked at a rat
model without actual kidney damage, they saw the same response. So the basic
scientists worked with the investigators at MCG’s Georgia Prevention Institute
to bring in healthy medical students who drank baking soda in a bottle of water
and also had a similar response.
“The shift from
inflammatory to an anti-inflammatory profile is happening everywhere,”
O’Connor says. “We saw it in the kidneys, we saw it in the spleen, now we
see it in the peripheral blood.”
The shifting landscape,
he says, is likely due to increased conversion of some of the proinflammatory
cells to anti-inflammatory ones coupled with actual production of more
anti-inflammatory macrophages. The scientists also saw a shift in other immune
cell types, like more regulatory T cells, which generally drive down the immune
response and help keep the immune system from attacking our own tissues. That
anti-inflammatory shift was sustained for at least four hours in humans and
three days in rats.
The shift ties back to
the mesothelial cells and their conversations with our spleen with the help of
acetylcholine. Part of the new information about mesothelial cells is that they
are neuron-like, but not neurons O’Connor is quick to clarify.
“We think the
cholinergic (acetylcholine) signals that we know mediate this anti-inflammatory
response aren’t coming directly from the vagal nerve innervating the spleen,
but from the mesothelial cells that form these connections to the spleen,”
O’Connor says.
In fact, when they cut
the vagal nerve, a big cranial nerve that starts in the brain and reaches into
the heart, lungs and gut to help control things like a constant heart rate and
food digestion, it did not impact the mesothelial cells’ neuron-like behavior.
The affect, it appears,
was more local because just touching the spleen did have an effect.
When they removed or even
just moved the spleen, it broke the fragile mesothelial connections and the
anti-inflammatory response was lost, O’Connor says. In fact, when they only
slightly moved the spleen as might occur in surgery, the previously smooth
covering of mesothelial cells became lumpier and changed colors.
“We think this helps
explain the cholinergic (acetylcholine) anti-inflammatory response that people
have been studying for a long time,” O’Connor says.
Studies are currently
underway at other institutions that, much like vagal nerve stimulation for
seizures, electrically stimulate the vagal nerve to tamp down the immune
response in people with rheumatoid arthritis. While there is no known direct
connection between the vagal nerve and the spleen — and O’Connor and his team
looked again for one — the treatment also attenuates inflammation and disease
severity in rheumatoid arthritis, researchers at the Feinstein Institute for
Medical Research reported in 2016 in the journal Proceedings of the National
Academy of Sciences.
O’Connor hopes drinking
baking soda can one day produce similar results for people with autoimmune
disease.
“You are not really
turning anything off or on, you are just pushing it toward one side by giving
an anti-inflammatory stimulus,” he says, in this case, away from harmful
inflammation. “It’s potentially a really safe way to treat inflammatory
disease.”
The spleen also got
bigger with consuming baking soda, the scientists think because of the
anti-inflammatory stimulus it produces. Infection also can increase spleen size
and physicians often palpate the spleen when concerned about a big infection.
Other cells besides
neurons are known to use the chemical communicator acetylcholine. Baking soda
also interact with acidic ingredients like buttermilk and cocoa in cakes and
other baked goods to help the batter expand and, along with heat from the oven,
to rise. It can also help raise the pH in pools, is found in antacids and can
help clean your teeth and tub.
The research was funded
by the National Institutes of Health.
Story Source:
Materials
provided by Medical College
of Georgia at Augusta University. Original written by Toni
Baker. Note: Content may be edited for style and length.
Journal Reference:
1. Sarah C. Ray, Babak
Baban, Matthew A. Tucker, Alec J. Seaton, Kyu Chul Chang, Elinor C. Mannon,
Jingping Sun, Bansari Patel, Katie Wilson, Jacqueline B. Musall, Hiram Ocasio,
Debra Irsik, Jessica A. Filosa, Jennifer C. Sullivan, Brendan Marshall, Ryan A.
Harris, Paul M. O’Connor. Oral NaHCO3 Activates a Splenic Anti-Inflammatory
Pathway: Evidence That Cholinergic Signals Are Transmitted via Mesothelial
Cells.
The Journal of Immunology, 2018; ji1701605 DOI: 10.4049/jimmunol.1701605
