Can stress promote cancer?

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Chronic stress is unhealthy. It has a negative effect on the effectiveness of the immune system, increases blood pressure and, in extreme cases, can even trigger a heart attack. Experts have been discussing for a long time that stress could also promote the development of cancer. Now, for the first time, a large British study is providing clear indications that this could apply to at least some types of cancer.

Participants who were under constant stress had a 32 percent higher risk of dying from cancer during the course of the examination. The probability of dying of leukemia increased the most for those under stress: it was almost four times as high as for less stressed participants in the study. It was always about 2.5 times as high for death from an esophageal or prostate tumor, and almost twice as high for colon cancer.

What happens when there is a lot of stress?

This is the result of scientists working with study author David Batty from the Department of Epidemology and Public Health at University College London. The researchers evaluated data from more than 160,000 participants between the ages of 16 and 109. 16,000 people died within the study period of almost ten years, more than 4000 of them from cancer.

In the course of the study, the subjects were examined and questioned annually. In addition to smoking, alcohol, diet and exercise habits, the researchers also recorded the participants' stress level. The scientists used a standardized questionnaire, the General Health Questionaire, for this purpose. Study participants with a value above 6 out of 12 possible units rated them as severely stressed. This group included a total of around 11,000 participants.

Unhealthy lifestyle

In their calculations, the researchers took into account as much as possible that stress is often associated with an unhealthy lifestyle - for example, higher alcohol or tobacco consumption, less exercise and less healthy diet. And these in turn favor the development of cancer.

However, the relationship between lifestyle, stress and cancer is so complex that it may not be possible to fully calculate it, the authors point out.

Weakened defense

So far, researchers can only speculate about how stress could directly promote cancer. In their study, the authors write that stress may weaken the body's defense against cancer. On the one hand, stress can inhibit the killer cells that are responsible for destroying degenerate cells. On the other hand, higher levels of the stress hormone cortisol could have a negative effect on the repair mechanisms in the cells.

Causal studies necessary

"No specific recommendations can yet be derived from the results, such as faster psychotherapeutic help for stressed people," says Batty. The next step is to examine more closely how stress influences tumor formation.

The German Cancer Research Center in Heidelberg would also like to start a major study on the subject soon.

Stress is often homemade

Most perceive stress as a condition that is the result of external circumstances - for example, a heavy workload or a difficult family situation. In fact, however, the inner attitude plays a central role in the perception of stress. Stress is often homemade - as a result of excessive demands on yourself or unnecessary negative expectations and fears.

On the one hand, this is a matter of disposition, but on the other hand, it can also be changed by practicing positive thinking patterns. Learning and practicing relaxation techniques can also help reduce the negative effects of stress.

Source: Batty D. et al .: Psychological distress in relation to site specific cancer mortality: pooling of unpublished data from 16 prospective cohort studies, BMJ 2017, doi: https://doi.org/10.1136/bmj.j108.

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