Josh Hamilton
Nutritionists call it a kink.
It’s just a type of configuration, a small bend in the carbon-to-carbon double bond of a fatty acid’s molecular structure.
When the kink is present in the molecule, called a cis unsaturated fatty acid, the substance liquifies at room temperature.
When the kink is missing though, this chemically identical molecule does something much different. Its straightened form allows it to pack together more closely, increasing the melting point and becoming a solid at room temperature.
That fact made this form of fatty acid, called trans fat, extremely valuable to the food industry in the 20th century.
But the absence of that little kink is also an important factor in the way the human body processes trans fats, according to University dietitian Lisa Eberhart.
“It looks like saturated fat to the body,” Eberhart said.
And that can have a big impact on human health, often in the form of coronary heart disease.
According to Jon Allen, food science professor and coordinator of the nutrition program, the types of fats people eat have an impact on how cholesterol circulates in the blood.
Allen said there are two basic types of cholesterol — low-density and high-density lipoprotein — that can have different effects on the body.
As HDL, or good cholesterol, travels through the bloodstream, it actually attracts other cholesterol like a magnet and sends it to the liver. There, the cholesterol is processed and excreted.
LDL, or bad cholesterol, has the opposite effect. Allen said it actually sends cholesterol away from the liver and stores it in body tissue.
Saturated fats, like in butter, increase levels of LDL, while unsaturated fats, present in olive oil, lower it. But Allen pointed out that trans fats are a “double negative,” lowering levels of good cholesterol and raising levels of bad cholesterol.
“They tend to have a greater impact than even saturated fats in this balance of good and bad cholestrol in the blood,” Allen said.
That balance is important to maintain, Allen said, especially since the body needs to consume a certain amount of fat all the time.
But unlike other fats, Eberhart pointed out that there is no physical need for trans fat.
That’s why Eberhart has worked with University Dining to remove trans fats from its menu. Although Eberhart said all of the grilling and frying oil in the dining hall is trans fat free, they’re still working to find a suitable substitute for butter.
Eberhart said trans fats are so unhealthy that some areas, like New York City and Philadelphia, are even banning them altogether.
“It was trying to change people’s diets through legislation,” Eberhart said. “It’s an emergency. We are so unhealthy and so fat.”
But Allen said that in some cases “the regulations may go beyond the science.”
The bottom line, he said, is that eating behavior can often do more harm than the food itself.
“Almost everything we eat is really quite good for us. As long as you balance everything out, we have processes to deal with things that occur in food,” he said. “Food is not what’s killing people.”
Allen also pointed out, not all trans fats are bad. Beef and meat from similar animals has a moderate amount of trans fat and even has some anticancer properties.
But as a general rule, Eberhart said, consumers should watch the level of processing in food.
“You’re always safe eating foods that are as close to natural as possible,” Eberhart said. “There more we do to a food, the more likely it is to have trans fat.”
Allen said the food industry is still working to find cost-effective alternatives for trans fats after evidence has shown their negative health effects.
“There’s a balance between health and functionality,” Allen said. “There’s a cost-benefit analysis for all of this.”
He also said that because they were originally introduced to increase the longevity of products — consumers should keep this in mind as they shop.
“If [consumers] go for low trans fats, they need to make sure foods are relatively fresh,” he said.