Saturday, September 6, 2014

Carb v. fat

Michigan weather is up to its usual tricks. I ran the air conditioner yesterday for maybe the 4th or 5th day this year. The high was about 85F. The heat lasted until a strong thunderstorm whipped through at 7 pm. Today the high was 70F and the low tonight is expected to be 55F.

During yesterday's storm the power cut out long enough for my computer to decide to reboot, but no skip in sound from the CD player. I was lucky this time. This morning there were 400,000 without power.

Diets have been in the news lately.

NPR reported on a study that compared a low-carb diet to a low-fat diet. People on the low-carb diet lost a bit more weight and had a bit lower cholesterol. But the study had only 148 participants. That leads to a bigger point – we hear lots of advice about what is the best diet, but, in spite of that noise, diets are not well studied. There is "razor-thin" evidence of what is best for any individual. The studies tend to work with a small number of people for a short amount of time. They don't consider lots of related factors or do much follow-up.

There was a more complete study recently performed at Tulane University and published in the Annals of Internal Medicine. It compared two groups, one on a low-carb diet and one on a low-fat diet. Those in the low-carb group lost about 12 pounds in a year, the low-fat group lost about 4 pounds in the same time. The NPR article doesn't give details of the low-carb diet and the robustness of the study to see if it passes the complaints in the first article.

Another study showed the high-fat diet, with lots of olive oil, cut the risk of heart attack. Yet another study showed that when eating a diet low in refined carbs people burned off 150 more calories a day. That means high-carb, low-fat diets cause us to be hungrier and burn off fewer calories.

In response to those NPR reports Jason Sheehan talks about the role bread plays in our culture. He also talks about considered eating – being aware of and taking joy in food.

One more NPR story, this one is about the growing use of butter in America. We've recognized that margarine is bad for us and slowly returned to butter. Part of that is cholesterol is less of an issue in American kitchens and part is improved science on animal fats. There is also a move towards less processed food.

Some people are now predicting a butter shortage. That's not the case, though exports jumped from zero to 11% since 2000.

From the Detroit Free Press last Sunday is an article about a new drug that lowered the chance of death from heart failure. It was given a sizable article and described as a great advance over current medication and shows big promise. However, I note that it lowers the chance of death by only 20%. It was a large study, so perhaps the science is sound. I'd rather eat healthy and not face heart failure.

In the same edition is an article saying there is a problem in research in heart disease treatments. Those people used in clinical trials for a new treatment tend to be, other than having a particular heart problem, young and healthy. But those who will be taking the medication after approval tend to be older with other existing conditions and with a history of prior heart attacks, strokes, and heart surgery. Does an effective treatment for the young and healthy work for the older, sicker patients? Short answer: nobody knows.

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