People who learn how to deal effectively with stress may also strengthen their immune systems, two Los Angeles-area doctors say.
The doctors' "tantalizing preliminary observation" indicates that reductions in "natural killer cell" activity in individuals suffering from stress possibly can be "manipulated," the two said in interviews with The Times.
In fact, stress reduction seems to promote natural killer-cell activity--indicating that a decline in this line of the body's defense network may be at least partially reversible, they said. Natural killer cells are a type of lymphocyte, cells that attack disease-causing bodies such as viruses and bacteria.
Behavioral medicine specialist Dr. David Velkoff and UCLA gerontologist Dr. Richard Weindruch said they charted frequent dramatic increases in killer-cell activity in a study of 10 persons seeking treatment for stress at Velkoff's Santa Monica clinic.
Using a common immunologic test in which leukemia cells are radioactively "tagged" and exposed to natural killer cells from a patient's blood, Velkoff and Weindruch said they found that killer-cell activity had increased up to eight times in patients who had learned to reduce stress and its related ailments through biofeedback and other behavioral medicine techniques. In all 10 cases, killer-cell activity increased, though in two cases the improvements were slight.
"What we're showing is that natural killer-cell activity can be manipulated by our state of mind, that what happens in our world every day and how we relate to that world has impact not just in your heart but in your immune system as well," said Velkoff, who is director of medicine at the Drake Institute for Behavioral Medicine in Santa Monica. " . . . The lay public knows more about the mind and the body than health practitioners do. People know that when they go through negative emotional experiences they get sick more often."
Said Weindruch: "I think the implications are really quite interesting, based not just on our experience alone but what other people are doing in the general area. If indeed you can improve somebody's immunologic status by an effective intervention into stress-related illness, then that's highly significant."
Weindruch, a gerontologist specializing in the study of dietary techniques that increase the life-span of mice, added, "It's been appreciated for centuries that stress invites disease and now we're trying to interpret that in modern terms. . . . It's not really an unexpected kind of result that we're seeing; it's somewhat logical."
Both Velkoff and Weindruch said the study, conducted on their own time and with their own money, needs further confirmation, which they hope to provide with a study of up to 100 patients beginning next year. Velkoff said he hopes to attract funding through a nonprofit research center he will be setting up by the end of the year. They also plan to submit a paper about their preliminary research to a professional journal, the doctors said.
The patients studied were suffering from a variety of stress-related ailments such as high blood pressure but usually continued to work or go about their daily routines, Velkoff said.
Their killer-cell activity was measured at the beginning of treatment for stress and after Velkoff judged a clinical improvement in the patient. None were told that their blood samples were being tested for killer-cell activity and a control group of healthy persons was used to gauge results, Velkoff added.
Weindruch cautioned that the study was not conducted under perfect laboratory conditions and, as a result, the findings are not conclusive.
" . . . One of our control people on a bad day may not be that much different (in killer-cell activity) from one of our patient population, so that's a complicating factor," Weindruch said. "Nevertheless, what we've observed so far is that the patient population, untreated, gives a lower natural killer-cell response than the people who are in our control group. . . . There are complications in this kind of study; like any human study it's problematic. Some of the patients were on medication. How that's all influencing it, nobody knows."
Both Velkoff and Weindruch said, however, that they are encouraged by their findings thus far. And both noted that medical journals are giving more and more space to investigations of relationships between the brain and the immune system.
One important immunology journal recently devoted an entire issue to such relationships, Weindruch said. "Two years ago you didn't see any papers in there dealing with that. It's real, people are trying to unravel how hormones and neuroendocrine factors and lymphocytes are all interacting."
The two doctors said this is their first venture into this particular area of research and both acknowledged that behavioral medicine has its share of skeptics within the medical community, largely because it relies on teaching patients to use their minds to cope with physical problems.
But additional research along the lines of their study could go a long way toward validating behavioral medicine, Velkoff and Weindruch said.
"It may very well be that just as AIDS patients have overt changes in certain lymphocyte subpopulations, we may see the same occuring in people who are stressed out," Weindruch said. "That could have enormous implications, I think, in terms of people monitoring their health and understanding it."