A daily dose of baking soda may help reduce the destructive inflammation of autoimmune diseases like rheumatoid arthritis, a study has found for the first time.
Researchers from Augusta University in the US showed that the cheap, over-the-counter antacid can encourage our spleen to promote an anti-inflammatory environment that could be therapeutic in the face of inflammatory disease.
The study, published in the Journal of Immunology, showed 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.
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 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, researchers said.
"Certainly drinking bicarbonate affects the spleen and we think it's through the mesothelial cells," said Paul O'Connor, renal physiologist at Augusta University.
After drinking water with baking soda for two weeks, the population of immune cells called macrophages in the spleen, as well as the blood and kidneys, 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 researchers 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 said.
Significant consequences can include increased risk of cardiovascular disease and osteoporosis.
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.
Researchers found that numbers of M1s reduced and M2s increased in their kidney disease model after consuming the baking soda.
When they looked at a rat model without actual kidney damage, they saw the same response. Volunteers who drank baking soda in a bottle of water also had a similar response.
"The shift from inflammatory to an anti-inflammatory profile is happening everywhere," O'Connor said.
The shifting landscape 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.