Friday, April 23, 2010

How high heat turns good food bad

A new study found that foods cooked at high temperatures may harm your metabolism, increasing the likelihood of type-2 diabetes and cardiovascular disease.

Researchers, who published their results in a recent issue of the American Journal of Clinical Nutrition, fed two groups the same foods cooked differently -- one with low temperatures and another at high heats. Researchers found that "one month of consuming the high-heat-treated diet induced significantly lower insulin sensitivity and plasma concentrations of long-chain omega-3 fatty acids and vitamins C and E."

In other words, foods cooked at high temperatures are probably bad for your health.

Another recent study by researchers at the University of Texas found that well-done meat and fried, grilled and barbecued meat can increase your likelihood of bladder cancer. University of Minnesota School of Public Health scientists found last year that charred meat can increase the risk of pancreatic cancer.

Another phenomenon related to cooking method and temperature is that different oils contain different "smoke points" -- the temperatures at which specific oils turn toxic at the molecular level. For example, canola oil becomes unhealthy at 440 degrees, while safflower oil goes bad at 318 degrees.

Unfortunately, the healthiest oil has the lowest smoke point. Extra-virgin olive oil -- the only kind on the Spartan Diet -- goes from superfood to carcinogen at tempuratures as low as 280 degrees (olive oil smoke points vary by type and brand). That's not very hot. (It's also one reason why boiling or steaming foods that contain olive oil is so safe -- the boiling point of water is 212 degrees.)

You should know that almost all restaurants cook foods at extremely high temperatures, oblivious to research about frying, grilling and barbecuing, as well as cooking-oil smoke points. That's one of the reasons cooked restaurant food is likely to be bad for your health. Pizza restaurants, for example, make pies with olive oil, then bake it at over 500 degrees -- some even as hot as 800 degrees! It tastes great, but if you walk out of a pizza place feeling like you've been hit by a truck, that overheated olive oil is probably one of the reasons.

Scientists have identified specific risks involved with cooking specific kinds of foods at high temperatures. Their findings are limited because that's how good science works. But as someone who eats food, you should understand that, in addition to specific risk of type 2 diabetes, cardiovascular disease and bladder and pancreas cancer, it's likely food cooked too hot is generally and broadly bad for your health, even if you never get the specific ailments scientists narrowly identified.

The Spartan Diet takes all this research into account. Spartan Diet foods are never fried, grilled or barbecued, only baked, poached, steamed, boiled or lightly sauteed using the lowest heat setting. And when olive oil is involved, the temperature of Spartan Diet foods never exceeds about 270 degrees.

It takes longer, but the result is healthier food that also tastes better.