This is your brain on fructose

Sweet Surrender

Sugar intake creates cravings that prompt further sugar intake.

And now we find (no surprise) that fructose intake sets the same cycle in motion. But if you enjoy a soft drink now and then, and you’d like to do so without jumping on the merry- go-round of craving, an HSI member offers a sweet suggestion.

The ups and downs

You can thank your lucky hormones you don’t weigh 800 pounds.

During a meal, your levels of the hormones insulin and leptin rise, triggering a feeling of being full. So unless you’ve paid for an all-you-can-eat buffet, you stop consuming. Later, your level of ghrelin, another hormone, begins to rise, prompting hunger.

It’s a good system. It controls, rewards, and protects. It’s also easy to undo.

In the e-Alert “Soft and Sweet” (6/22/04), I told you about a study in which nutrition researchers at the University of California, Davis, examined the effects that fructose beverages have on insulin, leptin, and ghrelin levels in subjects of normal weight.

Blood samples showed that insulin and leptin levels were lower, and ghrelin levels were higher in subjects who drank fructose beverages compared to subjects who drank glucose beverages. Researchers concluded that these hormonal responses to heavy fructose consumption could lead to excessive caloric intake, weight gain, and obesity.

A research team at Johns Hopkins University School of Medicine recently added additional evidence to that finding.

In animal studies, the Hopkins team demonstrated that the brain metabolizes fructose faster than glucose, so its effects are more strongly felt. This depletes cellular levels of a key energy-storage molecule known as ATP. The result: Appetite increases.

The authors write: “The fact that fructose metabolism by the brain increases food intake and obesity risk raises health concerns in view of the large and increasing per capita consumption of high fructose sweeteners, especially by youth.”

And they could have added: especially in soft drink consumption.

Zweet stuff

Just a couple of weeks ago, in the e-Alert “Counting Empty Calories” (3/30/09), I told you about a four-year study in which researchers followed the soda-drinking habits of more than 6,000 subjects. Results showed that those who drank one or more sodas each day were much more likely to develop obesity, increased waist circumference, impaired fasting glucose, higher blood pressure, and higher triglyceride levels.

In response to that e-Alert I received this e-mail from an HSI member named Linda.

“Jenny, for those of us who love the occasional soft drink, I have found a great alternative. It’s called Zevia. You may have heard of it. It comes in Cola, Lemon-Lime, Root Beer and Orange. It’s sweetened with Stevia and contains NO HFCS, sugar, other artificial sweetener or phosphoric acid, even the Cola flavor.

“I have severe Candida and was thrilled to find a cola drink that was safe for me to drink with none of the negative side effects of regular or diet colas.”

As many HSI members already know, stevia is a South American herb that’s been used for centuries as a sweetener. Just recently, the FDA has reclassified stevia so it can be used as a food additive in soft drinks. (For years, FDA officials said there were safety concerns with stevia, even though they allowed it to be used as a “dietary supplement.” But when the Coca Cola Company wanted to put stevia to use, the FDA genuflected and changed the food additive restriction.)

Here’s what another HSI member had to say about stevia in a previous e-Alert.

Arline: “The best sweetener for diabetics is Stevia. It is a plant extract and I am a diabetic and have been using it for years. You can even cook with it in powder form. I use the liquid to sweeten drinks, etc.”

If you have blood sugar issues, talk with your doctor before using stevia or stevia-sweetened products. You can find more information about Zevia at zevia.com.

Sources:
“Dietary Fructose Reduces Circulating Insulin and Leptin, Attenuates Postprandial Suppression of Ghrelin, and Increases Triglycerides in Women” Journal of Clinical Endocrinology and Metabolism, Vol. 89, No. 6, 6/4/04, jcem.endojournals.org
“Effect of Glucose and Fructose on Food Intake Via Malonyl- CoA Signaling in the Brain” Biochemical and Biophysical Research Communications, Published online ahead of print 3/3/09, sciencedirect.com