In the 1890s, Russian physiologist Ivan Pavlov found dogs salivated not only when they were fed but also could be trained to salivate upon hearing a bell — stimulus that had been associated with food. Now scientists believe such sensory stimuli could also affect our immune systems.
Researchers at University of Duisberg-Essen in Germany fed 32 test subjects a green-colored, lavender-scented strawberry milk. Needless to say the drink had a unique taste.
For three days, half of the subjects took an immunosuppressive drug along with the drink. The others took a placebo. After five days and then again another 11 days later, all the participants received a placebo pill along with the strawberry milk.
Researchers found at both the five day and 16 day mark, patients given the funny tasting concoction had immune systems that were significantly inhibited.
This study showed for the first time that such learned immunosuppression can be repeated in human subjects — providing hope to patients taking immunosuppressive drugs that have potentially dangerous long-term side effects like high blood pressure and kidney failure.