Dr. Keith Roach: MSG and lab rats and obesity, oh my
Dear Dr. Roach: I discovered that when researchers set out to induce insulin resistance and obesity in lab mice, they use monosodium glutamate! Then, reading labels in the grocery store, I found that MSG is in just about everything, from cereal to sausage patties!
So, if MSG causes obesity and insulin resistance in mice, and MSG is in everything we eat, do you think it also might cause obesity and insulin resistance in humans?
Dear D.B.: It’s a good thought. It certainly is true that in laboratory rodents, high doses of MSG can cause resistance to insulin. Researchers had the same thought as you do: Since vast amounts of MSG (650,000 tons per year, worldwide) are consumed, it could have a significant public health impact, were MSG to cause insulin resistance in humans.
The answer isn’t definitively known, but a 2013 study in China (home to more diabetics than any other country) showed that people who consumed more MSG were at lower risk for development of high blood sugar, which is the opposite of the original hypothesis.
Not all of the information obtained from laboratory animals is directly translatable to humans.