Is Fructose Making You Feel Hungry All The Time?
You just ate a bowl of cereal for breakfast two hours ago. Now you're starving. And when you see the glazed doughnuts in the break room, you can't resist.
Should you kick yourself for having low willpower? Or maybe … just maybe … should you blame that bowl of fructose-sweetened cereal?
It might surprise you to learn that more and more evidence implicates the cereal — not you. In two separate studies, Kathleen Page and her team at the University of Southern California uncovered evidence linking fructose — the type of sweetener used in many cereals, as well as sodas and thousands of other processed foods — to increased hunger.
In their most recent study, Page and her team asked 24 people to drink a beverage containing either glucose or fructose. Then the researchers performed functional magnetic resonance imaging (fMRI) scans of the participants' brains as they viewed pictures of a variety of foods (for instance, chocolate cake) and described how hungry they were.
The researchers say participants who drank the fructose drink reported higher levels of hunger. In addition, fructose caused a stronger reaction in the nucleus accumbens, a "reward" center of the brain, increasing the participants' desire to eat.
In earlier research, Page and her team asked 20 people to drink beverages containing glucose or fructose. Then the researchers measured changes in blood flow to the hypothalamus, which plays a key role in regulating hunger. Glucose, but not fructose, caused a significant slowing in the activity of this brain region. The same study also showed that people drinking the fructose experienced a much smaller surge of insulin, a hormone that promotes a feeling of fullness.
Page says, "These studies have important public health implications in a society that is inundated with high-sugar foods and tantalizing food stimuli."
While she stresses that her team's findings are preliminary, this is just the latest research indicating that fructose — and especially high fructose corn syrup, or "fructose on steroids" — is bad news. Here are some other good reasons for cutting fructose-sweetened processed foods out of your life:
- Fructose causes changes in your skin collagen that can result in saggy skin and wrinkles.
- Researchers have linked fructose to pancreatic cancer. Their findings showed that "cancer cells can readily metabolize fructose to increase proliferation."
- Fructose increases your "bad" cholesterol and impairs your liver function.
- Epidemiological research suggests that high fructose corn syrup is a prime culprit in the current epidemic of diabetes.
- High fructose corn syrup also causes the formation of high levels of substances called advanced glycation end products (AGEs), which speed up aging.
And here's one final reason to say au revoir to fructose: You don't need it. It has virtually no nutritional value, so there's no biological downside to giving it the boot. The only time fructose is worth eating is when it's contained in natural foods, which also provide you with fiber, vitamins, minerals, and other nutrients your body needs.
So here's what I suggest: Go fructose-free, except for the natural fructose in fruits and honey. In particular, avoid foods containing high fructose corn syrup. (Read labels carefully, because manufactures sneak fructose into the most surprising places.)
At a minimum, you'll be healthier when you do this. You'll also look younger. And if you're lucky, you'll find it far easier to resist the siren song of those break room doughnuts.