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Study smoking causes long-lasting DNA damage
Smoking harms our health is widely known. But not only our health suffers, our DNA seems to be damaged. Researchers now found that smoking actually interferes with our DNA. Some of these damages regenerate over time, others unfortunately not.
The researchers at Hebrew Senior Life and Harvard Medical School found in an investigation that smoking can lead to DNA damage. Most of the disease-causing genetic effects disappear after about five years of abstinence from smoking. However, some of the changes never seem to regenerate. The physicians published the results of their study in the journal "Circulation: Cardiovascular Genetics".
Cigarettes harm your health. A new investigation has now revealed that cigarettes can even damage our DNA directly. (Image: simonaphoto / fotolia.com) The negative effects of smoking last up to 30 years
There are clear patterns that smoking harms human DNA. Some of the damage even seems irreparable. The study found compelling evidence that smoking has long-lasting effects on our molecular machinery, the researchers emphasize. "These effects can last up to 30 years," explains Dr. Roby Joehanes of Hebrew Senior Life and Harvard Medical School.
Genetic damage causes heart disease and causes cancer
Genetic damage can cause, for example, heart disease and cancer. Many of the genetic damages are usually inherited. But some are also caused by our daily behavior. Smoking seems to be one of the main causes of genetic damage, the doctors add.
Study examines the data of 16,000 subjects
The scientists examined the data of 16,000 subjects for their study. They found that the process of so-called DNA methylation in smokers can cause chemical alteration to the basic building blocks of the genetic material of a cell. The majority of the negative effects of DNA methylation appear to have regenerated after five years, when people stop smoking. So over time, the body tries to heal the damage of tobacco smoking, says dr. Joehanes.
Subjects had to submit blood samples and fill out questionnaires
The research team examined the blood samples of 16,000 subjects. These samples came from different studies. In all of these studies, people had to give blood samples and fill in questionnaires about smoking, nutrition, lifestyle and general health, the experts explain.
More than 7,000 genes are affected by smoking
The scientists found that the pattern of methylation changes can affect more than 7,000 genes. This corresponds to about one third of the known human genes, explain the authors. Many of the genes have been known to be linked to heart disease and cancer.
How long does the body need to recover from the damage??
When people quit smoking, most of these negative changes regenerate. For successful regeneration sufferers have about five years no longer smoking, say the doctors. However, some of the changes take longer. Thus, smoking leads to long-term alterations of 19 genes, including the so-called TIAM2 gene. The changes need about 30 years to regenerate, scientists say.
Methylation influences the regulation of gene expression
These results are important because methylation affects the regulation of gene expression, the researchers explain. When people quit smoking, the effects of smoking on human DNA can still be determined years later. Smoking is the leading cause of preventable diseases. Worldwide, about six million people die each year from cancer, heart disease, lung disease and other diseases, explain the physicians. These health problems are often due to smoking.
Further research must determine the mechanism of effects
Even decades after people stop smoking, there is a long-term risk to many diseases. These include, for example, some cancers, chronic obstructive pulmonary disease and strokes, the scientists explain. Unfortunately, the mechanisms for these long-term effects are still relatively unclear.
Stop smoking!
The results make it clear that it is important to quit smoking. But many smokers have problems with it. They suffer from withdrawal symptoms or just do not have the will. Perhaps these people could be helped to reduce their addictions by smoking cigarette placebos. Another study recently showed that these placebo cigarettes can reduce the craving for nicotine. But e-cigarettes can also be helpful in quitting, British scientists said. (As)