Wednesday, September 16, 2009

Fruit hoaxes

Here is a law that hasn’t been broken since the internet started: Health warnings about food received via email will be a hoax. Yes, that includes those about margarine, Diet Coke, artificial sweeteners, and even the very positive one about bananas.

A recent one proclaimed that fruit should only be eaten on an empty stomach, and never after a meal. A quote from this ludicrous email: “Let’s say you eat two slices of bread and then a slice of fruit. The slice of fruit is ready to go straight through the stomach into the intestines, but is prevented from doing so. In the meantime the whole meal rots and ferments and turns to acid”.

So, let me get this right – when I eat a banana sandwich, the bread races to the pyloric sphincter (where the stomach joins the small intestine) and road blocks the banana from traveling any further? The banana then looks forlorn because it is locked in the stomach and decides to ferment to pass the time.

Embarrassingly out-of-date

This notion would have had some credibility in the 18th century. Then, along came a bloke called William Beaumont who did a range of experiments in the 1820s on another human being called Alexis St Martin. Later Beaumont published a book in 1833 called Experiments and Observations on the Gastric Juice and the Physiology of Digestion detailing how he proved that all mixes of food was digested. Nothing rotted or fermented. Every physiology book in the 176 years since has agreed with Beaumont.

You can eat fruit any time of the day, seated or standing, in any season of the year, and in either hemisphere. Gets digested the same. Whenever you read a claim that food rots, putrefies or ferments in your guts, it is just someone going public about not having a clue about basic biology. And that is their right in a democracy. Sadly.

The fruit salad tree

Harry Tomlinson, by all accounts a good and honest bloke, awoke to find that his apple tree was now growing plums and blackberries. The tree in his garden in northern Wales had been growing apples for 30 years before other fruit appeared. He got some publicity back in 2005, with at least one journo asking a horticulturist for an explanation for the “fruit salad” tree. Then someone did the smart and obvious thing. They looked at the tree. You see, Harry was 94 years old, and his sight may not be the best. He was informed by a visiting horticulturist that the maverick fruit had been pasted on the apple tree. Harry wasn’t too pleased. “I think it’s a rotten trick” he told the BBC.

What does it all mean?

It means that some people enjoy fooling others. You have heard the old pearler about only being able to eat fruit before 12 noon. That came from Harvey and Marilyn Diamond, written in their silly book Fit for Life.

I always ask the question “Would this sound logical in a hunter-gatherer lifestyle?” In other words, does it make sense if we consider how people lived 5000 years ago? How would anyone know it is 12 noon five thousand years ago? If a protein meal offered itself early one morning, would it make sense to tell your neighbour “Leave the fish be Joe, it’s way too early to eat protein.”

The digestive tract is very clever. The body is designed to digest all types of food at any time because that made it so much easier for humans to survive.

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