The scientists at Hebrew SeniorLife 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. Some of the changes, however, never seem to regenerate. The physicians published the results of their study in the journal "Circulation: Cardiovascular Genetics".
The negative effects of smoking are up to 30 years on
There are clear patterns that smoking of human DNA hurts. Some of the damage seem to be irreparable. The study has found compelling evidence that smoking has a long-lasting impact on our molecular machinery, the researchers stress. "These effects can last up to 30 years," explains Dr. Roby Joehanes of Hebrew Seniorlife and Harvard Medical School.
Genetic damage leads to hereditary diseases and causes cancer
Genetic damage can cause, for example, hereditary diseases and cancer. Many of the genetic defects are normally inherited. Some of them are also caused by our daily behavior. Smoking seems to be one of the main reasons for the development of genetic damage, the doctors add.
Study investigates the data of 16,000 subjects
The scientists studied the data for their studyof 16,000 subjects. They found that the process of so-called DNA methylation in smokers can cause chemical alterations to the basic building blocks of a cell's genetic material. The majority of the negative effects of DNA methylation seem to have regenerated after five years, when those concerned quit smoking. The body is trying to cure the damage of tobacco smoke over time, says Dr. Joehanes.
subjects had to submit blood samples and fill questionnaires
The research team examined the blood samples of 16,000 subjects. These samples were taken from several studies. In all these studies, people had to submit blood samples and fill out questionnaires on smoking, diet, lifestyle and general health, the experts explained.
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 a third of the known human genes, explain the authors. Many of the genes were known to have a link with hereditary diseases and cancer.
How long does the body need to recover from the damage?
When people quit smoking, most of these negative changes are regenerating. For successful recovery, sufferers need to stop smoking for about five years, say the medic. However, some of the changes last longer. Thus, smoking leads to long-term changes of 19 genes, including the so-called TIAM2 gene. The changes need to regenerate about 30 years, say the scientists.
Methylation influences the regulation of gene expression
These results are important because the methylation influences the regulation of gene expression, the scientists explain. When people quit smoking, the effects of smoking on human DNA can be detected years later. Smoking is the most common cause of preventable diseases. Around 6 million people worldwide die from cancer, heart disease, pulmonary disease and other diseases, the medical experts say. These health problems are often attributable to smoking.
Further research needs to determine the mechanisms of impact
Even decades after people have quit smoking, a long-term risk remains for many diseases. These include, for example, some cancer diseases, chronic obstructive pulmonary disease and stroke, the scientists explain. The mechanisms for these long-term effects are still relatively unclear.
The results make it clear that it is important to stop smoking. Many smokers have problems with it. They suffer from withdrawal symptoms or simply do not have the will to do so. Perhaps these people could be helped to reduce their addiction by smoking cigarette placebos. Another study recently showed that these placebo cigarettes can reduce the craving for nicotine. But also e-cigarettes can be helpful in stopping, noted British scientists.(as)
Smoking our health harms is widely known. But not only does our health suffers, even our DNA seems to take damage. Researchers now found out that smoking actually affects our DNA.Some of these damages are regenerating over time, others are not.