This epigenetic regulation happens through methylation und acetylation. Epidemiological studies have shown that people living in the less industrially developed nations suffer from allergies much more seldom than those in the affluent nations.
It is at the level of prevention that most bioengineering efforts ought to be directed, because prevention is better than cure. But the injurious effects of tobacco were still doubted in the nineteen-fifties, not least because of the misleading results of animal experiments.
There are naturally limits to measures of this kind; one could unfortunately hardly introduce a tax on schnitzel to force people to take up a vegetarian or vegan lifestyle. Or, perhaps, target diseases could be identified for vaccine development proactively rather than retroactively.
The home plays an important part in achieving a self-determined pattern of life, as does an intact environment clean air, water, earth, refuse disposal. One example is the new German prevention law starting in health insurances have to spend 7.
There were already some first inklings, but the breakthrough came with the publication of the 'Surgeon General's Report on Smoking and Health' in the year They lived in narrow, damp and filthy dwellings without any fresh water supply or sanitary fittings.