Sara is quite correct, of course. To add to her observations:Zizzle wrote:They mostly died from infectious causes, but perhaps nutrient deficiencies also played a role? They also didn't have our exposures to chemical toxins, modern-day bacteria mutations, indoor living, etc, so they truly were a different breed of people.
Aren't you making some assumptions of convenience there, about how they died? Short-faced bears, and sabre-toothed tigers were pretty aggressive predators, and could easily outrun humans, so it's no wonder that the average life expectancy was short. And when you spend a large percentage of your time stabbing large animals with spears, or using clubs to fend off other predators who are intent on taking your kill away from you, serious injuries are quite common, and bites especially, often lead to fatal bacterial infections, as you mentioned. However, basically all types of bacterial strains that we have today, were common back then. Yes, they have changed over the years, but strangely, the ones that we find to be "antibiotic-resistant" today, have changed very little since pre-historic times, (contrary to popular assumptions).
I'm not disputing that many of them died from bacterial infections - I'm disputing your suggested reasons. They didn't die young because they were unhealthy - they died young because they were unlucky. The records suggest that when those people didn't get eaten by a predator, or befall some unfortunate accident, or succumb to a bacterial infection, they actually had a very good life-expectancy potential. Probably, though, few of them ever reached that point, because of their hazardous lifestyle.
In general, when comparing examples within a species, the taller, bigger-boned, more muscular, more generally robust examples, are not the ones who are prone to a lower life expectancy. It is also a fact that the larger the organism, the longer the lifespan. That general rule works pretty reliably all the way from amoeba, to whales. Therefore, the shorter-statured, less robust trend that began when animal protein was replaced by plant protein, automatically dictated a shorter life-expectancy potential for us. I'm not talking about average life-expectancy - I'm talking about life-expectancy potential, which is the general, ultimate lid on maximum life expectancy. Today, for example, that practical potential is approximately 115 years. Because of the changes that have occurred in our diets, our maximum life expectancy is much less today, than it would have been if our species had been able to continue to eat a paleo diet for the last 10,000 years or so.
You're forgetting that all we have to do, to get a negative ruling on LC, is to have a lymphocyte count below 21. Unfortunately, the lymphocyte count for a normal intestine is 5, not 20. The medical community just ignores everything in between - it's no man's land. Obviously, there's something wrong with that picture. That reminds me a lot of the classic diagnostic criteria for celiac disease - it's simply incorrect, because it's glaringly incomplete.Did her excess lymphocytes go away, despite a diet that may have included cruciferous vegetables?
In fact, I'll go so far as to say that the people whose average intestinal lymphocyte count falls in this "ignored range" are synonymous with the people who show low-level markers of celiac diseae, but don't qualify for a diagnosis, because of the arbitrary, (yet rigid), criteria required for a diagnosis. They are in the early stages of the disease, but they're simply undiagnosable, because of the inappropriate, (capricious), criteria used by the medical community for diagnosing the disease. IOW, they can't be diagnosed until they're as sick as a dog, because the medical community refuses to recognize a disease until it is fully developed.
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) eat the quantities of them that I used to. 
I see the lymphocytes as a marker of the disease, which happens to be the only evidence modern medicine has that there is a disease process going on. The body is doing what it can to heal the intestinal damage, by allowing the lymphocytes to proliferate and do battle against an unrecognized foe (or recognized, in the case of food sensitivities like gluten). This, of course, feeds into my belief that autoimmune diseases are not the body mistakenly attacking itself. They are the body attacking a foreign invader or antigen, which happen to be taking up residence in our cells, so our cells become the innocent bystanders of the immune system trying to defend its host. In MC (or Lupus, RA, etc), the reason we never fully heal, is that we cannot rid our body 100% of the offending pathogens or antigens. 
