Ask any zookeeper

kw: musings, health, vitamins

I heard an infomercial Sunday in which were made the following points, all true:

• All mammals make their own Vitamin C except primates and guinea pigs.
• An enzyme needed for Vitamin C synthesis was deactivated in the ancestors of these animals.
• A medium-sized dog makes 4,000 mg of Vitamin C daily.
• Animals in the wild don't die of heart attacks or cancer.

The promoter/barker then drew the conclusion: Vitamin C prevents heart disease and cancer. At which point I turned off the radio. The program had an agenda, so the question was not asked, "What do wild animals die from?"

The short answer is, in the wild, they don't get old enough to die from the diseases of aging, heart disease and cancer in particular, but the actual mode of death differs: There are two classes of beasts, carnivores (including omnivores) and herbivores. One could also say, predators and prey. Taking them separately, prey first: They don't get very old, since once a prey animal begins to slow down, a predator kills it. For domestic herbivores, that predator is human, either a hunter or a worker in a slaughterhouse.

My first summer in South Dakota, I worked in a slaughterhouse. The first day I was given a tour. In the coolers where the carcasses hung before being cut up or sold, many had pieces gouged out and purple-ink stamps next to those places. I was told those were inspectors' marks, where they had found somatic cancer. These animals were not corn-fed monstrosities, but supposedly healthy, grass-fed cattle that had walked a few miles every day of their lives! A significant portion of them had cancer already, which would have killed them in a few more years. But beef cattle are killed prior to age two. If you leave any cancer alone, it usually takes more than two years to be the actual cause of death (I had cancer for close to five years before it was discovered and, thankfully, removed).

In the wild, big cats live no more than 10-12 years. Once they slow down, they have a harder and harder time catching prey until they simply starve. In zoos, lions and tigers can live 20-25 years. There, they are at no risk of starving. These cats can give birth shortly after age two, and most lionesses have given birth by age 4. They mature quickly. A twenty-year-old lioness is getting pretty decrepit, but a twelve-year-old? She's slowing down, about like a fifty-year-old person. Not many of those who run the mile in under six minutes as a teen, can run even a ten-minute mile at fifty. In a zoo, they don't have to. Pre-killed beef (or goat) is tossed to them on schedule. So how do zoo lions die? Ask any zookeeper: of heart disease or cancer! Even in those zoos with large, naturalistic enclosures where they have lots of roaming room.

And what about herbivores that are too big for lions: rhinos and elephants? I know elephants best. Even an old elephant, male or female, is too formidable for lions, which won't even try. But about age sixty, their teeth wear out and they starve. It would be an interesting exercise to put crowns (a couple inches thick) on the teeth of an aging elephant to see how long one would live if the teeth lasted longer! Upon autopsy, an elephant will often be found to have died with cancer and arterial plaque, both. But not of it; that isn't what killed them. Yet they make Vitamin C by the pound.

I make it a point to remember infomercial sponsors and avoid their products. If they are paying for 30-to-60-minute radio and TV shows, they are, perforce, charging more for their product to cover those expenses. I don't mind half-minute or one-minute ads. They are a reasonable expense.

How much Vitamin C do we need, then? 60 mg daily is enough for most of us to avoid scurvy. 500 mg or more is enough to cause mild diarrhea (or keep you loose if you're usually constipated). 250 mg seems to be a "sweet spot", an optimum dose, and the vitamin supplement I take contains 200 mg. I am sure I get at least 40 mg in my foods. That seems a sane course.