Monday 2 April 2001

Pic of the day: I'm all for gradual changes in diet. So I've decided to tentatively change to nut chocolate ... Here a naked Fruktnøtt from Freia. (Yes, it means fruit-nut.)

Health nuts

My interest in healthy fat has led me further into the plant kingdom, this time into the nut forest. But first a quick overview ... a brief history of fat, if you excuse.

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In days of yore, life was nasty, brutish and short. The laborer was exhausted not just from overmuch work, but also from partial starvation. Hard manual labor required energy-dense food, such as meat and fat, rather than the medium-energy foods like grains or low-energy like many vegetables. While the brain always runs on sugar, the muscles switch to fat when put to sustained work. Under those conditions, any fat was good fat. It did not stay long in the body, anyway.

During the last few generations, manual labor has become rare. But people still enjoy the foods that were developed to sustain the working man of the past. Particularly many meat-based dinner courses, but also cakes, a miracle of calory density combining fat and sugar with some flour to keep it all together. Cakes are almost completely digestible and deliver fat and sugar to the blood with minimal delay.

During the last generation of the 20eth century, men and women of the western world became aware that fat had a downside. Heart and artery diseases seemed to crop up mostly in those who had a high fat intake, though an inherited disposition seemed to play a role too. Cautiously, more and more people tried to cut down the fat intake, and coronary health started to improve again. Then, a few years ago, it became commonly known that fish fat (poly-unsaturated fat) was not just harmless, but actively good for your hearth. Fish oils, and in particular the Omega fatty acids, became the ruling health craze. Health nuts would gobble the stuff, despite problems with acid reflux. One of my first encounters with the stuff was an elderly man who claimed that it had cured his smoker's legs (restricted blood supply), seemingly a minor miracle.

But the half-life of truths grows ever shorter. When I was a kid, they said that a truth lasted twenty years. Of course, that truth is dead now, and the lifespan is now quite a bit shorter. And so the fish oil is moving aside to allow the plant oils (mono-unsaturated fat) such as olive oil and, most appropriately, nuts. And this is my sermon for you today, dear congregation: NUTS!

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After I found that nuts too have mono-unsaturated fats, I went online to look at nuts and health. To my surprise, I found that nuts was described as one of the most dangerous substances known to man. A young person can literally die from staying in a room where peanuts are served. Tree nuts are known to kill instantly if added to chocolate. Both of these effects seem to be due to anaphylaxis, an extreme allergic reaction that is rare with other food allergies but all too common with nuts.

Nut allergies seem to strike approximately 1 in 100 to 1 in 50 Americans and British. I have rarely heard of it here in Norway, but I am sure it must be here too. In the English-speaking world, nut allergies are on the rise, and hit children down to 2 years for peanuts and 5-7 years for tree nuts. Those who are allergic to one type of nuts may also develop allergy to other sorts, and unlike many food allergies they tend to last for life.

I have to admit, there was a point where I almost decided to not touch a nut again in my life. But then I noticed that the allergy seems to usually develop during childhood, often early childhood. I guess this makes sense, looking at how the immune system works. (For instance, it is now recommended to not give cow milk to infants, so as to avoid milk allergies.)

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But for the lucky ones who have grown up without nut allergy, it seems that nuts are the health heroes of the year. They are brimming with unsaturated fats (or "oil" to use a shorter word which some of you may know from the kitchen). Unsaturated fats are fluid at room temperature, but in nuts the oils are bound up in starches and proteins. The proteins are also healthy, rich in amino acids which we may usually be short of. (Sadly, it is those proteins that cause allergy in children if they reach the immune system before being fully broken down.)

Intriguingly, test persons allowed to snack on nuts did gain less weight than a control group given fried potato chips. As a matter of fact, the nut eaters gained no weight at all. The most likely explanation is that some substance in the nuts - perhaps the oils themselves - trigger a food contentment reflex, making people feel less hungry. Hey, have you ever seen an obese squirrel? :)

In short, health nuts should hurry to eat nuts now, while it is still healthy. But don't give them to the kids.

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(Finally, my apologies to those who have read in vain hoping for an essay on the health benefits and malefits[1] of testosterone. Heh. But the guy with the smoker's legs was right, you know: Unsaturated fats do improve blood circulation, which may come in handy in body parts that depend on a plentiful blood supply. Like, eh, the brain?)

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[1] How come there is a malediction for each benediction, but no malefit for the benefits? It just ain't fair! I refuse to accept this deficiency of the English language! And I urge you all to put the word to good use. Remember, for each benefit there is an equally large malefit! Ahem. I'll go to bed now.