In the early 1970s, in the very laboratory at Harvard Medical School where physiologist Walter Cannon discovered the fight-or-flight response, a young cardiologist named Herbert Benson tested 36 devoted practitioners of meditation, monitoring changes in their oxygen consumption, heart rate, blood pressure and rate of breathing that exactly opposed those of the fight-or-flight response. His 1975 book describing the phenomenon, The Relaxation Response, rocketed to the top of the New York Times bestseller list, and Benson became famous as one of the first Western physicians to stress the importance of the mind in modern medicine.

Benson is the founder and director emeritus of the Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital, where a recent study has shown that meditation, tai chi, yoga, exercise, prayer and a variety of similar practices can alter a person’s gene activity, changing the expression of genes related to stress and inflammation.

Q: Finding that behavior can alter gene expression is rather remarkable, isn’t it? What exactly did the study show?
A: We compared 19 people who had regularly evoked the relaxation response for an average of nine years with 19 people who had never done so. In a scan of each subject’s 50,000 or so genes, we found that the activity of about 2,000 genes differed between the two groups. Among those in the relaxation response group, roughly 2,000 genes active in various stress-related physiological pathways, genes that trigger inflammation and genes that prompt cell death, had been deactivated. There is no evidence that the deactivations are permanent. We believe that daily practice of the relaxation response is necessary to sustain the changes.

Q: Judging by the title of your latest book, Relaxation Revolution: Enhancing Your Personal Health Through the Science and Genetics of Mind Body Healing, it seems you think those gene deactivations could profoundly affect a person’s health.
A: More than 60% of visits to doctors are for stress-related complaints that are poorly treated, if at all, by pharmaceuticals and surgery. To the degree that any disease is caused or worsened by stress, practicing the relaxation response can improve the condition and symptoms.

Q: Your study also showed just how quickly the relaxation response affects one’s genes.
A: That’s right. We taught the control group techniques to evoke the relaxation response and had them practice the techniques for eight weeks. We then found changes in some of the same genes as those in the group that had practiced relaxation techniques for years. The changes were not as profound: Only about 1,500 genes, rather than 2,000 in the long-practicing group, showed changes in expression. But the longer you practice the relaxation response, the greater the effect, it seems.

Q: Do these findings vindicate a field of study that’s often derided as pseudoscience?
A: We know from many years of previous work that the mind has a profound therapeutic effect on the body, but it was wonderful to have the idea confirmed with the most reductionistic criteria we could use: genomics. By reductionistic, I mean the prevailing approach to scientific research that assumes all our understanding about the world can be reduced to its particular parts—in this case, to genes. Showing that the mind can affect the genes is an entirely different level of proof that people don’t expect.

Q: You have said that “It’s all in your head” wasn’t always pejorative.
A: People had long believed that the mind could interact with the body. Then scientists discovered that bacteria caused some diseases. They found, for instance, that penicillin could cure pneumonia. It didn’t matter whether you believed it could or not; it just did. With the emergence of these treatments, medicine came to believe that diseases could be cured and that the mind wasn’t important in this process.

Q: How has this attitude affected your work during the past 40 years?
A: I recognized that to truly win over mainstream medicine, I had to use cutting-edge scientific technology to study the mind body connection. When functional magnetic resonance imaging studies became available, we used them. Now that genomics-based studies are available, we use those. It’s much more difficult to establish the value of the mind body connection using classic scientific methods, because of the complexity of the interactions between them and because the power of belief does play a big role in our responses to treatments. Traditionally, medical science has tried to ignore the power of belief by controlling for it—using a placebo.

Q: What’s the next step for the gene research?
A: We’re repeating our study with people who have specific stress-related conditions—hypertension, irritable bowel syndrome and infertility—to see whether inducing the relaxation response alters the expression of genes related to these conditions. We expect results in a year or so.