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Good Calories, Bad Calories

For the last thirty years, medical advice on obesity has been very clear. Eat less and exercise. But what if that was all wrong, a big fat lie, as Gary Taubes would put it? Mr. Taubes is an award- winning science writer based in New York, and in his latest book, Good Calories, Bad Calories, he explores the history of diet and exercise advice from the late nineteenth century until the present. According to his research, eating fatty foods doesn't lead to heart disease, cholesterol levels aren't something to worry about, and exercise doesn't help you lose weight. In fact, according to Mr. Taubes, everything the medical profession advocates, in terms of eating and exercise, is at best a waste of time, and at worst, may actually be killing us. He says it isn't fat we should be worrying about, but instead carbohydrates, especially white flour and white sugar. He thinks the current obesity epidemic, the rising levels of diabetes, even cancer and Alzheimer's disease, may all be a result of our modern diet of carbs and sugars.

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Related Links

The Soft Science of Dietary Fat, article by Gary Taubes from Science Magazine in 2001
'What if it's all been a big fat lie?' Taubes article in the NY Times that spawned the book
Knopf Page on the Book
Interview with Gary Taubes - includes links to critical articles that challenge his hypothesis

Birds that Timeshare

Band-rumped Storm-petrel, courtesy Mark Bolton.

The Band-rumped Storm-petrel is a small sea bird that lives on and around tropical islands, and has found out how to conduct the perfect timeshare. Each of these birds only spends half the year on an island to mate and nest. When the season is over, they move out to sea and another group of petrels move in to the same nests. Dr. Vicki Friesen, a professor of biology at Queen's University, thought this was a unique type of behaviour and wondered if the two groups had evolved into different species. She then decoded the family tree of these birds and found that they help prove a 150-year-old theory of how one species becomes two, first suggested by Charles Darwin.

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Related Links

Vicki Friesen's Homepage
Media Release from Queen's University
News story from CBC.ca
Research Paper in Proceedings of the National Academy of Science

Beer from Chocolate

Ancient Beer Bottle, drawing by Yolanda Tovar. Image courtesy of PNAS/National Academy of Sciences

Three thousand years ago, in what is now Honduras, the locals had a taste for beer. But not just any beer. These brewers were making their beverage from the cacao plant, the same tree we now use to create chocolate. That's the conclusion of a study by Dr. John Henderson, a professor of Anthropology at Cornell University. Dr. Henderson has been studying the archaeology of Puerto Escondido and has found pottery dating back to 1150 B.C.E. These pots contain traces of theobromine, a chemical compound only found in the cacao plant. But unlike later pots from the same region, these old vessels weren't used for making the local form of hot chocolate. Instead, they were probably used to ferment the pulp of the cacao fruit, which would have lead to cacao beer instead.

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Related Links

Dr. Henderson's paper in PNAS
News release from Cornell University
Dr. Henderson's Homepage

Fainting Astronauts

Equipment used to measure an astronaut's blood pressure, courtesy University of Waterloo

When astronauts come back from long duration space missions, the return to Earth can be a challenge. Many of them suffer from dizziness and are prone to fainting, until they settle back onto the planet. With the possibility of trips to the Moon, or to Mars, NASA's very interested in understanding why some astronauts faint, while a few don't succumb. So they have commissioned various scientists to study the phenomenon. Dr. Richard Hughson, from the University of Waterloo, heads up one team looking at the effects of long duration space flight on the human body. At the latest shuttle return, he was present to examine Clay Anderson, the astronaut who'd been on the International Space Station for 152 days.

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Related Links

Dr. Hughson's Homepage
Space Research in Dr. Hughson's Lab
Canadian Space Agency page on the work
Dr. Hughson's previous interview on Quirks & Quarks (Oct. 29, 2005)

Science Fact or Fiction: Sex During Pregnancy

And now, another episode of our new feature, Science Fact or Science Fiction. From time to time, we'll present a commonly held idea or popular saying, to a Canadian scientist - and ask them to set us straight on whether we should believe it or not.

And today's is one we've all heard before: sex during pregnancy can induce labour.

For the scientific lowdown, we go to Dr. Peter Mitchell, professor of obstetrics and gynecology at the University of Alberta in Edmonton. He says it's mostly fiction.

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Theme music copyright Raphaël Gluckstein. Creative Commons License by-nc-nd-2.0
Musical stings courtesy of Beatsuite.com Music Library.