The Genetic Chain Gets Longer

November 15th, 2012 by Andrea Bennett

Can your bad health decisions have genetic ramifications for your grandchildren?

Brought to you by Liberty Mutual's
The Responsibility Project

Think the damage done by the irresponsible things you do to your body stops at the end of your lifetime? Think again. A new study suggests that some of the characteristics you acquire during your lifetime can be passed on as far as your grandchildren.

The central premise of the study, conducted by Virender Rehan of the Los Angeles Biomedical Research Institute, insists that the way your genes are expressed can be switched on and off. This phenomenon, known as epigenetics, refers to the regulation of gene expression by the chemical modification of the histone proteins in which DNA is wrapped. As reported by The Economist, “This modification is either the addition of methyl groups…or of acetyl groups. Methylation switches genes off. Acetylation switches them on. Since, in a multicellular organism, different cells need different genes to be active, such regulation is vital.” The suggestion that an epigenetic switch could be transmitted down multiple generations, as proposed by the study, is shocking because it seemingly contradicts Darwinism.

In the study, which was published in BioMed Central Medicine, Rehan and his team injected rats with nicotine when they were six days pregnant, and then monitored their 22-day pregnancies and allowed them to raise their pups for three weeks. After examining the offspring, it was found that the pups of the treated mothers had asthmatic lungs. Molecular analysis revealed high levels of receptor molecules for nicotine. These findings were not surprising, but of more interest to Rehan’s team was that similar results came through when studying the grand-pups of the treated rats.

These results pose a serious challenge to the generally accepted belief that, “When you get an embryo, it’s starting with a clean slate,” said Dr. Richard Saffery, who runs an epigenetics lab at the Murdoch Children’s Research Institute in Australia.

In a BioMed Central release, Rehan said that his team’s findings are proof that education about the dangers of smoking and interventions aimed at mothers-to-be need to take into account the possibility that nicotine use can affect the children and even grandchildren of smokers.

What do you think – will these results be enough to get expectant mothers to stop smoking? Or do you think we should avoid shaming mothers, regardless of their behavior? Weigh in here.