(Republished with permission from the St. Louis Post-Dispatch. This article originally ran in the Health & Fitness section on Tuesday, March 20, 2006.)
By Harry Jackson Jr.
St. Louis Post-Dispatch
Over the past decade, here’s what the scientific, medical and nutrition communities have said about dietary fats: Fats are bad for you; fats are good for you. Fats cause cancer; fats don’t cause cancer. Fats cause weight gain; fats don’t cause weight gain.
Get the picture?
Nothing stirred the confusion more than the recent study sponsored by the Women’s Health Initiative and published last month in the Journal of the American Medical Association. It said that reducing dietary fat didn’t reduce the incidence of breast cancer, colon cancer and other cancers over an eight-year period for the 49,000 women in the study.
While the authors of the study cautioned people not to go out and order hot-fudge sundaes as dessert for a dinner of barbecued ribs and french fries, area scientists weren’t happy with the way the study seemed to dispel the wisdom of curtailing dietary fats.
The study
Local experts say the Women’s Health Initiative study had a few faults.
“The whole cancer-fat connection is based on epidemiology, and there’s not a lot of good data,” said Dr. Anne Goldberg, an endocrinologist and physician with the Washington University School of Medicine. “There are associations, but this study that was done didn’t have enough time to show a cancer difference. In order to see a fat and cancer relationship, you’d need many more years.”
An epidemiological study amounts to researchers watching a lot of people for a long time, jotting notes, talking to them, then extrapolating conclusions.
This was not a controlled study with tests and scientific comparisons, the experts said. The article failed to differentiate between women who smoked and among what kinds of fats they ate – meat fat, vegetable fat, fish fat, olive oil. It failed to say who exercised and who didn’t, who was obese and who wasn’t, whose family had a history of cancer and whose didn’t.
Experts, including the authors who wrote the study, said the findings weren’t to be construed to mean that it’s OK to eat more fats. While fats may be less of a factor in the development of cancer, they’re still a big factor in the development of cardiovascular disease, as well as weight gain.
What is fat?
Fat is oil. Chemically, it’s a long carbon molecule with different configurations of hydrogen molecules attached, and it won’t dissolve in water.
Dietary fat has lots of destinations after it’s eaten. It’s primary use is to burn as fuel.
“Ironically, (fat) is a lightweight way to store fuel,” said Dr. James Shoemaker of St. Louis University School of Medicine. He’s also a biochemist and a molecular biologist and has a doctoral degree in nutrition. “Fat can store fuel without water. If you stored carbohydrate, that takes water, and water weighs more than fat.”
In addition to being stored or burned, fat acts as a shock absorber between organs, as insulation to regulate body temperature, as padding beneath the skin and as a means to dissolve vitamins that don’t dissolve in water.
All types of fat pose two problems:
- Fat causes health issues when it lingers in the bloodstream.
- All fats are high-calorie foods. That’s why some researchers say any fats are bad when you get too much, and good when you get just enough.
The relationship between humans and fat began with ancient human ancestors. Fat was a rare commodity from the animals they hunted, so the human physiology learned to hold onto dietary fats.
But as time marched on, the human body found itself ill-equipped to handle a state of perpetual abundance with most food flavored with fat. That has resulted in obesity and clogged blood vessels.
What people eat
People eat four basic types of fats. Each category has lots of versions, but these are the names you hear:
- Saturated fats are from red meat and poultry.
- Polyunsaturated fats come from vegetables and grains.
- Monounsaturated fats include fish oil and olive oil.
- Trans fats are manufactured fats.
Making good choices
Medical people agree that Americans eat too much fat – way, way too much.
The good news is that food scientists estimate that American fat consumption consists of an enormous amount of added fat, put in or spread on something as an ingredient – some estimate as high as 75 percent.
“I’d say that’s true,” said Shoemaker of St. Louis University. “We need about 1 percent of our diet to come from fat. However, we eat 20, 30, 40 times that amount.”
But if it’s added, it can be removed.
First, don’t submerge food in cooking oil.
“Submerging it in oil adds 200 to 300 calories,” said Goldberg of Washington University.
Second, watch the food labels. Fat in processed food can be avoided by finding healthier alternatives.
Avoid added fat by eating more food that doesn’t come out of a factory, Goldberg said – that means more fruits and vegetables, less red meat, lots of water and no heavy oil cooking. Also, at a minimum exercise according to recommendations from the United States Department of Agriculture – that’s moderately intense activity for 30 minutes a day, most days of the week. A stronger heart pushes blood through blockages and cleaner blood is less likely to cause a blockage.
Goldberg suggested following the “No Fad Diet,” a health guide published by the American Heart Association, as a way to control fat intake.
hjaxson@post-dispatch.com 314-340-8234
Copyright 2006 St. Louis Post-Dispatch, Inc.