> A person in the middle ages wouldn't be surrounded by a toxic environment

Are you serious? You don't think living in a tiny room with 10 family members and all kinds of animals (along with all of the lice, fleas, diseases, etc. that go along), with a wood fire filling the whole place with eye-stinging, lung-choking smoke, was a "toxic environment"? You'd be eating mostly grains, with very occasionally some meat, and if it spoiled you'd still figure out some way to eat it, because otherwise you'd be going hungry altogether (and that would happen anyway, in poor harvest years). The water would be whatever you had nearby, probably infected with all kinds of pathogens from the excrement that would inevitably wind up there. You'd maybe have a sweat bath or sponge bath once every week or two if you were lucky, using the same water for the whole family. You certainly wouldn't have more than a few changes of clothes, which you'd wear for days or weeks at a time.

I suggest you spend some time with rural peasants in a developing country before arguing about toxic environments or nutrient-deprived food.

I guess the difference here is that you are assuming they are drinking excrement filled water, where I was thinking they are drinking fresh water. There is probably a large difference between those that began to live in more crowded cities and those that were still in more pristine country side. It is not clear cut whether people were smaller in the middle ages. http://researchnews.osu.edu/archive/medimen.htm Bathing or changing clothes is really a social aspect that is not that important for health.

I live in the USA on a small farm in an ordinary, modern house . Yesterday I removed two ticks from my body. In a few weeks, I'll be doing it daily, and checking my son for ticks at every change of clothing (he knows to kill the ones he finds, but he can't check his own back). We mostly have wood ticks, but there can be deer ticks along with them. Deer ticks carry Lyme Disease.

This is just a simple example of how bathing/changing clothes can affect your health. In the middle ages, you would have been walking in pathogen soup in all those dirty, sweat/urine/etc laden clothes you couldn't change out of.

Don't discount the impact of simple cleanliness. Pristine countryside? Doesn't exist. Go travel to one of those beautiful vistas you see in paintings, untouched by humanity and drink the clear stream water. Then spend the next few days doubled over in pain from all the parasites that live in the water, having arrived there from animal feces.

The odds of a healthy individual becoming ill from drinking water in pristine wilderness is actually extremely low. There is really no evidence for your assertion that you will automatically become ill from drinking unfiltered water once. My understanding is there is little risk if the water is not under upstream human or livestock use. http://www.wemjournal.org/wmsonline/?request=get-document...

Very few people in the “middle ages” lived in pristine wilderness. The vast majority were, and always have been, rural peasants in feudal or semi-feudal societies, working as serfs or sharecroppers or slaves, either on tiny individual plots, or on plantations. They became ill constantly, and most children died before age 5. You seem to be imagining some kind of hunter-gatherer society.

Hunter-gatherer-pastoral society- You are probably right. I would like to see some more scientific information on the subject if you have any.

> fresh water ... pristine country side

Nah, in the middle ages you'll be drinking whatever water is in your village's stream or watering hole, and you'll be glad for it too, after you carry it half a mile on your back to your house. If that water gets contaminated with cholera, you'll blame the sickness on the wrath of an angry god, or perhaps a jealous neighbor who witched you.

> Bathing [...] is not that important for health.

What???

Speak for yourself, the nutrient rich food and especially the variety I eat each day was not available in the middle ages. Remember that people in the those times where much shorter (as proved by the shorter beds), this is the result of malnutrion.

Toxicity is likely to be higher then, open or no sewage systems, very low hygiene (people didn't bathe, lots of animals) and remember they used woodstoves in side the house!

sewage systems are necessary for sanitation in cities. Most people were living in the country side. "hygiene" is largely a social aspect that doesn't effect health much. Some researchers claim people did not lose height in the Middle Ages at all. Variety of food is not that important- we just need to get all the required nutrients in the foods we eat. Great to hear you are able to go against the modern trends and eat nutrient rich food.

The woodstoves were actually somewhat good for health as the smoke killed the bugs. Obviously the smoke also damaged the lungs and eyes.

I've just finished reading a history of medicine that claims that medicine's impact on prolonging life is miniscule, maybe 2% of the increase in live expectancy.

The biggest impact is childhood (and prenatal) nutrition and basic sanitation. So if you did get sent back to the middle ages, the diseases would be much less likely to kill you as you are generally much more robust as a result of your late 20th century upbringing, and you'd be less likely to get them as you would understand how they spread e.g. avoiding drinking water with human excrement in it. And of you course you didn't die in childbirth or shortly after, by conveniently being in a different century, which will put you above average in life span too.

And the big message from the book: avoid the doctors. They would actively be weakening you via bleeding, laxatives and emetics, right up until about the 1920s.

I would like to point out that they used lead for drinking vessels sometimes...

Lead has been used in drinking water pipes much more recently than the middle ages: http://eh.net/bookreviews/library/1233 .