But the strategy -- known as positive affect and self-affirmation, or just positive affirmation -- didn't always lead to obvious health benefits. And it's unclear whether any improvements in lifestyle would have continued after the extra encouragement stopped.

"In general, the idea is that as people feel positively about what they're doing, they're more likely to be energized and sustain that over time," said Dr. Geoffrey Williams from the University of Rochester, New York, who wrote a commentary published with three new studies on positive affirmation in the Archives of Internal Medicine.

The studies addressed health goals in three groups of patients. In one, African-Americans with high blood pressure were encouraged to stick more closely to their medication plan. In the other two, people who had asthma or who'd recently had a stent inserted into blocked arteries agreed to exercise more.

All patients were given workbooks and made contracts with doctors about their goals.

Half of the participants in each study -- the positive-thinking groups -- also received small gifts in the mail, and were encouraged to incorporate things that made them happy into their everyday lives and to think about proud moments when they were having trouble sticking to their goals.

In the high blood pressure study, the extra encouragement led to limited success. Slightly more people in the positive-thinking group took their medications; in total, that group took 42 percent of its recommended doses, compared to 36 percent in the "control" group. But there was no difference in changes in blood pressure between the groups after a year.

The researchers calculated that 16 hypertensive patients would need to get the extra support, encouragement and gifts for one more to adhere to a medication plan.

The intervention had no clear effect on physical activity in asthma patients. Regardless of whether or not they were given the encouragement and told to think positively, the patients burned an extra 400 calories per week on average by the end of the year-long study.

There was some benefit in patients who received extra exercise encouragement after having a stent inserted. More than half of them surpassed the goal of burning an extra 336 calories per week after a year, compared to just over one-third of patients who were taught about exercise, but didn't get positive affirmation.

"Overall it's safe to say that self-affirmation... can help patients to engage in healthy lifestyle behaviors," said Dr. Gbenga Ogedegbe from the New York University School of Medicine, part of the NYU Langone Medical Center, and the lead researcher of the blood pressure study.

The theory of improving health and lifestyle through upbeat thinking is related to the "positive psychology" movement, which encourages the study of happiness, rather than focusing only on mental illness.

Ogedegbe said it's possible that combined with other behavioral strategies and improvements in care, positive thinking and affirmation can lead to actual reductions in blood pressure in some hypertensive patients, as well as other health benefits. But it's unclear from this study if that's the case.

One limit of all the new studies, according to Williams, is that they didn't track whether patients continued to take their medication and exercise after the extra encouragement and gifts stopped -- which would be important if the strategy was going to be useful in the real world.

"We need people to be able to carry this out themselves after we have (finished) working with them," Williams told Reuters Health.

Ogedegbe said that he and his colleagues are currently looking at how well the strategy works in combination with other health interventions, as well as how costly it would be outside of a research study.

For now, he told Reuters Health, "The simple message is that patients have to remain positive, even in the face of obstacles."

SOURCE: bit.ly/fO01ME Archives of Internal Medicine, online January 23, 2012.

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