POHaD: why we should study future fathers.

The growing field of 'Developmental Origin of Health and Disease' (DOHaD) generally reflects environmental influences from mother to child. The importance of maternal lifestyle, diet and other environmental exposures before and during gestation period is well recognized. However, few epidemiological designs explore potential influences from the paternal environment on offspring health. This is surprising given that numerous animal models have provided evidence that the paternal environment plays a role in a non-genetic inheritance of pre-conceptional exposures through the male germ line. Recent findings in humans suggest that the epigenome of sperm cells can indeed be affected by paternal exposures. Defects in epigenetic sperm mechanisms may result in persistent modifications, affecting male fertility or offspring health status. We addressed this issue at the LATSIS Symposium 'Transgenerational Epigenetic Inheritance: Impact for Biology and Society', in Zürich, 28-30 August 2017, and here provide important arguments why environmental and lifestyle-related exposures in young men should be studied. The Paternal Origins of Health and Disease (POHaD) paradigm was introduced to stress the need for more research on the role of the father in the transmission of acquired environmental messages from his environment to his offspring. A better understanding of pre-conceptional origins of disease through the paternal exposome will be informative to the field of transgenerational epigenetics and will ultimately help instruct and guide public health policies in the future.