Master Life Faster: Newsletter

How Corn is Killing You

Posted in Newsletter by Paul Lem, M.D. on June 17, 2010

Volume 3, Issue 2

“Don’t eat anything your great grandmother wouldn’t recognize as food.”
-Michael Pollan

How Corn is Killing You

What should you eat to achieve optimal health? Food writer and journalist Michael Pollan sums up the scientific evidence in three short phrases:

  • Eat food.
  • Not too much.
  • Mostly plants.

Whole Foods
Sounds simple, doesn’t it? In his book In Defense of Food: An Eater’s Manifesto, Pollan shows that while the advice is simple, the reasons are often far from obvious. Take the first phrase: “Eat food.” It seems self-evident. You wouldn’t eat non-food items like dirt or diamonds. But what Pollan means is you should eat whole foods that have not been processed. For example, an apple is a whole food whereas apple juice is a processed food. Eat the apple, don’t drink the juice. Similarly, oatmeal is a whole food whereas Kellogg’s Corn Flakes is a processed food.

What about buying a steak from the grocery store and barbecuing it yourself? Isn’t steak a whole food? After all, it has one ingredient and it hasn’t been processed. Technically, that’s true. But the problem is the steak came from a cow that grew up eating processed food. Processed corn, to be precise.

Cornfed to Death
What’s wrong with that? The problem is cows are not designed to eat corn, they’re designed to eat grass. When cows are fed a concentrated diet of corn, it leads to a buildup of acid in their stomachs. Acidotic cows paw and scratch their bellies, eat dirt, and suffer from weakened immune systems. Over time, the acid eats away at the stomach wall, allowing bacteria to enter the bloodstream. The bacteria end up in the liver, where they form pus-filled abscesses. At slaughter, 15–30 percent of feedlot cows are found to have abscessed livers. To prevent cows from dying from their corn diet, they are pumped full of antibiotics: Rumensin buffers acid in the stomach, helping to prevent acidosis, and Tylosin, a form of erythromycin, lowers the rate of liver infection.

If corn causes so many complications, why do ranchers feed it to their cows? Like most businesses, it’s all about the money. Cornfed cattle get fatter faster. And thanks to generous government subsidies, corn is dirt cheap. In the 1900s, ranchers raised cows on grass and it took 4–5 years to get cows ready for slaughter. Nowadays, a calf goes from 80 pounds to 1,100 pounds in 14 months by eating tremendous amounts of corn-based carbohydrates, protein, and fat.

While cornfed beef is much cheaper than pasture-fed beef, the two types of meat have dramatically different effects on your health. Cornfed beef is high in saturated fat and the ratio of omega-6 to omega-3 fatty acids is 10:1 (seeds such as corn are high in omega-6, whereas leaves and grass are high in omega-3). In contrast, pasture-fed beef is low in saturated fat and the ratio of omega-6 to omega-3 is 2:1. Why does this matter? Too high a ratio of omega-6 to omega-3 contributes to heart disease because omega-6 helps blood clot, whereas omega-3 helps it flow.

Corn Chips with Legs
As Pollan points out: “You are what you eat eats.” And what we North Americans have become is “corn chips with legs.” So says Todd Dawson, a Berkeley biologist. Dawson discovered this unsettling fact by using a mass spectrometer to analyze human tissues for the ratio of carbon 13 versus carbon 12 (corn plants have higher ratios of carbon 13 compared to other plants, therefore the higher the ratio in a person’s sample the more corn has been in her diet, or in the diet of animals she ate).

In a follow-up experiment, Dawson used his mass spec to determine the proportion of carbon coming from corn in a McDonald’s meal. The results?

  • Soda: 100 percent corn (from high-fructose corn syrup)
  • Milk shake:  78 percent
  • Salad dressing: 65 percent
  • Chicken nuggets: 56 percent
  • Cheeseburger: 52 percent
  • French fries: 23 percent

Considering that one in three kids in the United States eats fast food every day, it’s no wonder that North Americans score so high on the cornfed scale.

Back to the Land
Now that we’ve exposed the insidious effects of corn in your diet, what can you expect if you follow Pollan’s three food rules?

The answer comes from a 7-week experiment conducted by Australian nutritionist Kerin O’Dea. In the summer of 1982, she recruited a group of 10 Aborigines who were overweight and had type 2 diabetes. They were living in settlements near the town of Derby in Western Australia and their diet consisted mainly of flour, sugar, rice, soft drinks, beer, powdered milk, fatty meat, potatoes, and onions. For the experiment, O’Dea and the Aborigines traveled to an isolated region of northwest Australia. The idea was to leave civilization behind and eat only what could be hunted and gathered from the land.

The Aborigines started on the coast, where their diet consisted mainly of seafood, supplemented by birds, kangaroo, and witchetty grubs. After 2 weeks, they moved inland beside a river and their diet included freshwater fish, shellfish, turtle, crocodile, birds, kangaroo, yams, figs, and bush honey.

After 7 weeks in the bush, blood tests showed striking improvements in the Aborigines’ health. Their triglyceride levels had fallen into the normal range and their levels of omega-3 fatty acids had increased dramatically. Everyone in the group lost weight—an average of 17.9 pounds per person—and had lower blood pressure. Signs of diabetes such as glucose tolerance and insulin response to glucose were greatly improved.

You don’t have to move to the Outback and eat grubs to improve your health. All you have to do is eat whole foods, not too much, and mostly plants. It’s time to switch your diet to what Mother Nature intended you to eat.

Pollan M. (2008). In defense of food: An eater’s manifesto. Penguin Press.

Pollan M. (2006). The omnivore’s dilemma: A natural history of four meals. Penguin Press.

O’Dea K. (1984). Marked improvements in carbohydrate and lipid metabolism in diabetic Australian Aborigines after temporary reversion to traditional lifestyle. Diabetes. 33(6): 596–603. Abstract.

Copyright 2010 by Paul Lem, M.D. All Rights Reserved.
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