• Kirk Hartley

Epigenetics – A New Example – Possible Multi-generational Impacts from Nicotine

Epigenetics continues to change and shape thinking on disease processes and causation. It’s an important topic for product liability lawyers – and corporate lawyers and insurers – for today and tomorrow.

A new example even shows up in the current issue of The Economist. The article highlights new research suggesting that nicotine cause epigenetic changes with multi-generational impacts. The impact? Asthma in the children and grand-children of mothers who take in nicotine. The ScienceDaily summary is here, and the paper itself is here.

The study is in rats, and it’s early yet, but the findings certainly are intriguing in an age when our children are experiencing apparent increases in some forms of asthma. The published article states the conclusion as follows:

"Germline epigenetic marks imposed by exposure to nicotine during pregnancy can become permanently programmed and transferred through the germline to subsequent generations, a ground-breaking finding that shifts the current asthma paradigm, opening up many new avenues to explore."

Reading the news certainly was enough to make me wonder about a possible link between my mother’s former smoking (and my former smoking), and the occasional asthma attacks suffered during soccer games by one of my otherwise athletic and apparently healthy daughters.

Imagine children and grand-children as plaintiffs against big tobacco. The distributors of disease in a stick will not be able to trot out the usual defenses. Perhaps I’ve missed something, but I’m not aware of a single big tobacco warning about possible harms to children or grandchildren.

Also, consider the risk and possibilities for other industries. And when thinking about warnings and foreseeability, consider the following underlined sentence from an excerpt from the Economist article:

"ONE of biology’s hottest topics is epigenetics. The term itself covers a multitude of sins. Strictly speaking, it refers to the regulation of gene expression by the chemical modification of DNA, or of the histone proteins in which DNA is usually wrapped. This modification is either the addition of methyl groups (a carbon atom and three hydrogens) to the DNA or of acetyl groups (two carbons, three hydrogens and an oxygen) to the histones. 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.

What has got a lot of people excited, though, is the idea that epigenetic switches might be transmitted down the generations. Some see this as contrary to Darwinism, since it would permit characteristics acquired during an organism’s lifetime to be passed on to its offspring, as suggested by a rival theory of evolution put forward by Jean-Baptiste Lamarck. This is an exaggeration. The DNA sequence itself is not being permanently altered. Even those epigenetic changes that are inherited seem to be subsequently reversible. But the idea that acquired characteristics can be inherited at all is still an important and novel one, and a worrying example of the phenomenon has been published this week in BioMed Central Medicine.

The study in question, by Virender Rehan of the Los Angeles Biomedical Research Institute, and his colleagues, was of the intergenerational effects of nicotine. It was done in rats, but a rat’s physiology is sufficiently similar to a human’s to suspect the same thing may be true in Homo sapiens. In a nutshell, Dr Rehan showed that if pregnant rats are exposed to nicotine, not only will their offspring develop the asthma induced by this drug, so will the offspring of those offspring.

When did Jean-Baptiste Lamarck argue for his hypothesis about the biological process we now call epigenetics? He lived from from 1744-1829, and argued his theories beginning at least by the early 1800s. Wikipedia summarizes as follows:

"In the modern era, Lamarck is widely remembered for a theory of inheritance of acquired characteristics, called soft inheritance, Lamarckism or use/disuse theory.[4] However, his idea of soft inheritance was, perhaps, a reflection of the folk wisdom of the time, accepted by many natural historians. Lamarck’s contribution to evolutionary theory consisted of the first truly cohesive theory of evolution,[5] in which an alchemical complexifying force drove organisms up a ladder of complexity, and a second environmental force adapted them to local environments through use and disuse of characteristics, differentiating them from other organisms.[6]"


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