A recent article published in the journal JAMA  states that a man’s behavior and his exposure to different environmental factors before conception may determine the development and future health of his offspring, and can result in obesity, diabetes, cardiovascular diseases, cancer, behavioral problems, etc. This is because different experiences, such as exposure to toxic chemicals, alcohol consumption, eating habits or stress are reflected in the sperm memory (it is estimated that sperm has 37.5MB of memory, some say much more). This memory works in the form of epigenetic marks (who marks silence certain gene sequences and activate others so that nascent cells can differentiate), i.e. different molecular signals that act on the genes, regulating their expression. Some of these marks can be inherited, so they will also affect the genes of the direct descendant and subsequent generations.

There is increasing evidence of this fact (see a complete review HERE ). For example, in rodents, it has been shown that exposure of males to different toxins can cause infertility and other diseases in the offspring due to the epigenetic changes induced in the sperm (See HERE ). Also in rodents, it has been shown that the consumption of alcohol in males before breeding is associated with effects such as decreased fetal weight (See HERE ), such as weight gain or breast cancer (See HERE ) before breeding is associated with effects such as decreased fetal weight (See HERE ), altered organ weights, decreased grooming and increased anxiety and impulsivity (See HERE ). Moreover, paternal eating habits were also associated with alterations in the health of the offspring such as weight gain or breast cancer.


The effect of the man’s behavior on his descendants has also been shown in humans. In the last decade, a

series of historical cohort studies in Överkalix, in the north of Sweden, surprisingly revealed that the scarcity or abundance of food during the father’s adolescence resulted, respectively, in a lower or higher risk of early death in their descendants (see HERE ). Two subsequent studies suggest that the timing of the environmental exposure is also important. Thus, both found that men who started smoking before puberty had children with more body fat than the children of those who started smoking later. They also found epigenetic marks in the children related to paternal obesity or with chemotherapy treatments in their fathers (See HERE ).

In this regard, there are signs that some effects on the sperm associated with the father’s lifestyle can be reversed with exercise and dietary changes or bariatric surgery, for example. Thus, although some changes in the sperm may be permanent, the father’s behavior in the months prior to conception could be important.

In our opinion, these findings encourage men as well as women to be aware of the importance of lifestyle habits on the health of future offspring.






Lucia Gómez Tatay

Bioethics Observatory

Catholic University of Valencia