Health for life

Researchers may soon be able to add yet another item to the list of exercises well-documented health benefits: A preliminary study suggests that when cancer survivors exercise for several weeks after they finish chemotherapy, their immune systems remodel themselves to become more effective, potentially fending off future incidents of cancer. The finding may help explain why exercise can significantly reduce the chances of secondary cancers in survivors or reduce the chances of cancer altogether in people who have never had the disease.

Laura Bilek, Graham Sharp, and Geoffrey Thiele, all of the University of Nebraska Medical Center, and Daniel Shackelford, Colin Quinn, and Carole Schneider, all of Rocky Mountain Cancer Rehabilitation Institute, analyzed T cells in the blood of cancer survivors before and after a 12-week exercise program. They found that a significant portion of these immune cells converted from a senescent form, which isnt as effective at combating disease, to a naïve form, ready to fight cancer and infections.

Their poster presentation entitled, "Effect of Exercise on T Cells in Cancer Survivors," will be discussed at The Integrative Biology of Exercise VI meeting being held October 10-13 at the Westin Westminster Hotel in Westminster, CO. This popular meeting is a collaborative effort between the American Physiological Society, the American College of Sports Medicine and the Canadian Society for Exercise Physiology. The conference is supported in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, an institute of the National Institutes of Health, GlaxoSmithKline, Inc., Stealth Peptides, Inc., and Seahorse Biosciences.

Exercise and Immunity

Study leader Laura Bilek explains that previous research had turned up a variety of positive associations between exercise and cancer -- notably, that exercise can reduce the risk of getting initial incidence of several different types of cancers, can often improve prognosis in cancer patients, and can reduce the risk of recurrence and secondary cancers survivors of some types of cancers. However, the mechanism behind these phenomena has been unknown.

Since other research has suggested that exercise can remodel the immune system, making it more effective at fighting disease in general, Bilek and her colleagues decided to investigate how exercise affects the immune system of cancer patients. Working with a group of 16 cancer survivors, all but one of who recently finished chemotherapy cancer treatment, the researchers focused on T cells, a type of immune cell that attacks a variety of infectious agents as well as cancer cells. After chemotherapy, previous research had shown that the majority of T cells become senescent, with a decreased ability to fight infections and cancers. However, Bilek says, rebuilding the population of responsive (naïve) T cells is critical for regaining normal immune function and cancer-fighting ability.

The researchers first took blood samples from each of the volunteers to examine how many senescent and naïve T cells each had. Then, these study subjects were all enrolled into 12-week exercise programs at the Rocky Mountain Cancer Rehabilitation Institute. All programs were individualized for the study participants, incorporating elements of cardiovascular exercise, strength and endurance training, and exercises for flexibility, posture, and balance, with extra emphasis in areas where participants were weak.

After the 12-week program, the researchers drew a second blood sample from each volunteer and ran the same T cell analysis.

Another Reason to Work Out Results showed that the ratio of senescent to naïve T cells changed favorably in the majority of participants, with most of the study subjects regaining greater numbers of the naïve variety.

"What were suggesting is that with exercise, you might be getting rid of T cells that arent helpful and making room for T cells that might be helpful," Bilek says.

She adds that this finding highlights the importance of exercise for all, including those with cancer and cancer survivors. These two populations might benefit especially from the heightened "cancer surveillance" -- the ability of the immune system to seek out and destroy budding cancers -- that this study suggests exercise brings, Bilek explains.

"Theres a litany of positive benefits from exercise," Bilek says. "If exercise indeed strengthens the immune system and potentially improves cancer surveillance, its one more thing we should educate patients about as a reason they should schedule regular activity throughout their day and make it a priority in their lives."

Contrary to popular perception, stressors dont cause health problems -- its peoples reactions to the stressors that determine whether they will suffer health consequences, according to researchers at Penn State.

"Our research shows that how you react to what happens in your life today predicts your chronic health conditions and 10 years in the future, independent of your current health and your future stress," said David Almeida, professor of human development and family studies. "For example, if you have a lot of work to do today and you are really grumpy because of it, then you are more likely to suffer negative health consequences 10 years from now than someone who also has a lot of work to do today, but doesnt let it bother her."

Using a subset of people who are participating in the MIDUS (Midlife in the United States) study, a national longitudinal study of health and well being that is funded by the National Institute on Aging, Almeida and his colleagues investigated the relationships among stressful events in daily life, peoples reactions to those events and their health and well being 10 years later.

Specifically, the researchers surveyed by phone 2,000 individuals every night for eight consecutive nights regarding what had happened to them in the previous 24 hours. They asked the participants questions about their use of time, their moods, the physical health symptoms they had felt, their productivity and the stressful events they had experienced, such as being stuck in traffic, having an argument with somebody, or taking care of a sick child.

"Most social-science surveys are based on long retrospective accounts of your life in the past month or maybe the past week," Almeida said. "By asking people to focus just on the past 24 hours, we were able to capture a particular day in someones life. Then, by studying consecutive days, we were able to see the ebb and flow of their daily experiences."

The researchers also collected saliva samples from the 2,000 individuals at four different times on four of those eight days. From the saliva, they were able to determine amounts of the stress hormone, cortisol. They then linked the information they collected to data from the larger MIDUS study, including the participants demographic information, their chronic health conditions, their personalities and their social networks.

"We did this 10 years ago in 1995 and again in 2005," Almeida said. "By having longitudinal data, not only were we able to look at change in daily experiences over this time but how experiences that were occurring 10 years ago are related to health and well being now."

The team found that people who become upset by daily stressors and continue to dwell on them after they have passed were more likely to suffer from chronic health problems -- especially pain, such as that related to arthritis, and cardiovascular issues -- 10 years later.

"I like to think of people as being one of two types," Almeida said. "With Velcro people, when a stressor happens it sticks to them; they get really upset and, by the end of the day, they are still grumpy and fuming. With Teflon people, when stressors happen to them they slide right off. Its the Velcro people who end up suffering health consequences down the road."

The results appear online in the current issue of Annals of Behavioral Medicine

According to Almeida, certain types of people are more likely to experience stress in their lives. Younger people, for example, have more stress than older people; people with higher cognitive abilities have more stress than people with lower cognitive abilities; and people with higher levels of education have more stress than people with less education.

"What is interesting is how these people deal with their stress," said Almeida. "Our research shows that people age 65 and up tend to be more reactive to stress than younger people, likely because they arent exposed to a lot of stress at this stage in their lives, and they are out of practice in dealing with it. Younger people are better at dealing with it because they cope with it so frequently. Likewise, our research shows that people with lower cognitive abilities and education levels are more reactive to stress than people with higher cognitive abilities and education levels, likely because they have less control over the stressors in their lives."

While stress may be a symptom that a persons life is filled with hardship, it could also simply mean that the person is engaged in a wide variety of activities and experiences.

"If this is the case, reducing exposure to stressors isnt the answer," said Almeida. "We just need to figure out how to manage them better."

Optimistic older adults face greater risk of disabilities and death

Older people who have low expectations for a satisfying future may be more likely to live longer, healthier lives than those who see brighter days ahead, according to new research published by the American Psychological Association.

"Our findings revealed that being overly optimistic in predicting a better future was associated with a greater risk of disability and death within the following decade," said lead author Frieder R. Lang, PhD, of the University of Erlangen-Nuremberg in Germany. "Pessimism about the future may encourage people to live more carefully, taking health and safety precautions." The study was published online in the journal Psychology and Aging.

Lang and colleagues examined data collected from 1993 to 2003 for the national German Socio-Economic Panel, an annual survey of private households consisting of approximately 40,000 people 18 to 96 years old. The researchers divided the data according to age groups: 18 to 39 years old, 40 to 64 years old and 65 years old and above. Through mostly in-person interviews, respondents were asked to rate how satisfied they were with their lives and how satisfied they thought they would be in five years.

Five years after the first interview, 43 percent of the oldest group had underestimated their future life satisfaction, 25 percent had predicted accurately and 32 percent had overestimated, according to the study. Based on the average level of change in life satisfaction over time for this group, each increase in overestimating future life satisfaction was related to a 9.5 percent increase in reporting disabilities and a 10 percent increased risk of death, the analysis revealed.

Because a darker outlook on the future is often more realistic, older adults predictions of their future satisfaction may be more accurate, according to the study. In contrast, the youngest group had the sunniest outlook while the middle-aged adults made the most accurate predictions, but became more pessimistic over time.

"Unexpectedly, we also found that stable and good health and income were associated with expecting a greater decline compared with those in poor health or with low incomes," Lang said. "Moreover, we found that higher income was related to a greater risk of disability."

The researchers measured the respondents current and future life satisfaction on a scale of 0 to 10 and determined accuracy in predicting life satisfaction by measuring the difference between anticipated life satisfaction reported in 1993 and actual life satisfaction reported in 1998. They analyzed the data to determine age differences in estimated life satisfaction; accuracy in predicting life satisfaction; age, gender and income differences in the accuracy of predicting life satisfaction; and rates of disability and death reported between 1999 and 2010. Other factors, such as illness, medical treatment or personal losses, may have driven health outcomes, the study said.

The findings do not contradict theories that unrealistic optimism about the future can sometimes help people feel better when they are facing inevitable negative outcomes, such as terminal disease, according to the authors. "We argue, though, that the outcomes of optimistic, accurate or pessimistic forecasts may depend on age and available resources," Lang said. "These findings shed new light on how our perspectives can either help or hinder us in taking actions that can help improve our chances of a long healthy life."