Michael Pollan, author, most recently, of the excellent Omnivore's Dilemma, has a long attack on "nutritionism" in the latest NYT Magazine. This bit is particularly on point:
It might be argued that, at this point in history, we should simply accept that fast food is our food culture. Over time, people will get used to eating this way and our health will improve. But for natural selection to help populations adapt to the Western diet, we'd have to be prepared to let those whom it sickens die. That's not what we're doing. Rather, we're turning to the health-care industry to help us “adapt.” Medicine is learning how to keep alive the people whom the Western diet is making sick. It's gotten good at extending the lives of people with heart disease, and now it's working on obesity and diabetes. Capitalism is itself marvelously adaptive, able to turn the problems it creates into lucrative business opportunities: diet pills, heart-bypass operations, insulin pumps, bariatric surgery.
There's similar chapter in The Omnivore's Dilemma about our treatment of cows. The short version of this is that we've taken an animal accustomed to feeding on forage and forced it to digest grain. Corn, after all, is cheaper, more plentiful, more engineerable, less land-intensive, and more subsidized than grass. But cows haven't evolved to eat corn. And so we drug 'em.
Bloat is perhaps the most serious thing that can go wrong with a ruminant on corn. The fermentation in the rumen produces copious amounts of gas, which is normally expelled by belching during rumination. But when the diet contains too much starch and too little roughage, rumination all but stops, and a layer of foamy slime forms in the rumen that can trap the gas. The rumen inflates like a balloon until it presses against the animal's lungs. Unless action is taken quickly to relieve the pressure, the animal suffocates.
A concentrated diet of corn can also give a cow acidosis. Unlike our own highly acidic stomachs, the normal pH of a rumen is neutral. Corn renders it acidic, causing a form a bovine heartburn...Acidotic animals go off their feed, pant and salivate excessively, paw and scratch their bellies, and eat dirt. The condition can lead to diarrhea, ulcers, bloat, rumentitis, liver disease, and a general weakening of the immune system that leaves the animal vulnerable to the full panoply of feedlot disease[...]
Cattle rarely live on feedlots for more than 150 days...Over time, the acids eat away at the rumen wallo, allowing bacteria to enter the animal's bloodstream. These microbes wind up in the liver, where they form abscesses and impair the liver's function. Between 15 and 30 percent of feedlot cows are found at slaughter to have abscessed livers...in some pens, the figure runs as high as 70 percent.
What keeps a feedlot animal healthy -- or healthy enough -- are antibiotics. Rumensen buffers acidity in the rumen, helping to prevent bloat and acidosis, and Tylosin, a form of erythromycin, lowers the incidence of liver infection. Most of the antibiotics sold in America today end up in animal feed...public health advocates don't object to treating the animals with antibiotics; they just don't want to see the drugs lose their effectiveness because factory farms are feeding them to healthy animals to promote growth. But the use of antibiotics in the feedlot confounds this distinction. Here the drugs are plainly being used to treat sick animals, yet the animals probably wouldn't be sick if not for the diet of grain we feed them.
When I first came across that passage, I was suitably shocked and outraged, and in fact stopped eating meat for a few months (a practice I've since been unable to maintain). It didn't occur to me that this strategy of using powerful drugs as health maintenance devices in service of an unhealthy but cheaper diet is precisely what we're all doing with Lipitor, and Tums, and all the rest.