It is well established that the health of children is affected by both inheritance and by the environment.
But in addition, there are intermediary factors - an epigenetic heritage. These are non-genetic influences on gene expression that can have effects several generations later.
Environmental hazards, tobacco smoke and stress can affect the genes of offspring.
"There are both biological and genetic background factors [in health], but previously it has not been systematically researched in transgenerational inheritance. We know that it occurs in animals, but if we can show that epigenetic inheritance occurs in humans, it will be of great importance for scientific thinking as well as for preventing disease,” says Professor Olli Raitakari of the University of Turku.
Olli Raitakari is a professor of cardiovascular medicine, and the field of cardiovascular disease research which gave rise to the idea of epigenetic research.
"In the 1970s, it was noted that Finnish men topped statistics on cardiovascular disease. Then, already, it was known that the disease progress began early, and so one should investigate the risk factors," Raitakari explains.
Research into these cardiovascular factors began with 3,596 children in Turku, Helsinki, Kuopio, Tampere and Oulu in 1980 and continued for several years.
Today, these test subjects are between 40-50 years old. Their parents are on average 75 years old, and the original subjects have already had their own children.
"We can therefore examine the health of the original test subjects, their parents and their children. It is unique to simultaneously investigate almost 13,000 people, over three generations," Professor Olli Raitakari points out.
The first letters with the invitation to the survey were sent out last week. Field research is to be carried out this year and next year in all five of the cities where the original cardiovascular research took place.
Groundbreaking but costly
Raitakari's research group has received a grant of 2.5 million euros from the European Research Council, which is enough for data collection and sampling. However, funding is still needed for the analysis of all samples. Total costs for the project is estimated at 13 million euros.
"The research hypothesis is nevertheless so groundbreaking that we believe that we will probably receive additional funding. If we can prove the connection, it would have an important scientific significance and be a revolutionary discovery," Raitakari told Yle.
Inherited problems from alcohol and tobacco?
It is known from previous animal research that populations adapt to changes in the environment.
Raitakari mentions the example of fish in a tank. If you reduce the oxygen content in the tank, soon after generations fish arise with gills adapted to an environment with lower levels of oxygen.
These changes are transferred to the next generation through epigenetic inheritance. Changes occur in the gametes, or sex cells.
It is common that women who smoke or drink stop as soon as they start trying to get pregnant or at latest when expecting children. According to Professor Raitakari, the same may one day be standard advice to would-be fathers.
"Our theory is that predispositions can be transferred to the next generation via sperm. If that is the case, men should stop smoking and drinking before having children, otherwise their offspring may be adversely affected"
The first research results that may either support or disprove the research hypothesis could be in by 2020.