When high fructose corn syrup (HFCS) was introduced in the seventies it coincided with a marked rise in obesity in the U.S.

This lead to speculation that there might be a casual connection between HFCS consumption and weight gain. It seemed even more possible when HFCS consumption grew much faster than any other food intake.

What sucrose and high fructose corn syrup have in common, and what distinguishes them from dietary carbohydrates such as starch, is their fructose content. Fructose contributes the same amount of energy as glucose, but it doesn't trigger the same satiety signals.

The sharp rise in the consumption of soft drinks and processed food sweetened with HFCS and sucrose led to a dramatic increase in fructose intake. But this source of energy goes essentially unnoticed.

High fructose corn syrup is made from cornstarch, a glucose polymer. First, enzymatic starch breakdown yields corn syrup which is essentially free glucose. The glucose is then further enzymatically coverted to fructose. After various purification steps, a mixture of 90% fructose and 10% glucose is obtained.

Without going into a lot of details about further processing, the end result is you either get HFCS-55 or HFCS-42. HFCS-55 is mainly used in soft drinks and HFCS-42 is primarily used to sweeten baked goods.

HFCS has largely replaced sucrose in commercial foods in North America. It is cheaper than sucrose, partly because of import tariffs on sucrose and agricultural subsidies to corn producers.

37 men and women in their twenties and in the healthy weight range were recruited to compare the effects of soft drink sweetened with sucrose and HFCS on subsequent food intake.

Another trial that was conducted wanted to know if there were any differences in sugar in solid form versus liquid form.

The results of both of these lengthy trials came to the conclusion that the caloric sweeteners contribute to weight gain if consumed in drinks, but not in solid food.

Two hormones, insulin and leptin, act as satiety signals in the brain and thus are critical to homeostasis. Both insulin and leptin circulate in the blood at levels proportional to body fat content, and enter the central nervous system in proportion to their plasma levels. Low hormone levels increase appetite, and high levels act to reduce energy intake.

Insulin levels rise in response to blood glucose. Insulin-mediated entry of glucose into adipocytes (fat cells) in turn causes the release of leptin. In other words, both insulin and leptin levels react to glucose concentrations. Fructose, on the other hand, does not trigger insulin release. This in turn means that fructose doesn't affect leptin levels either. Since it increases neither insulin nor leptin levels, fructose consumption does not generate the same satiety signals as glucose. The result is overeating and weight gain.

In summary, it was found that the rise in obesity rates with increasing HFCS consumption was no coincidence. The increased popularity of soft drinks and HFCS sweetened convenience food led to a rapid increase in fructose consumption.

It was this excessive fructose intake that fuelled the rapid weight gain, since fructose does not generate the same satiety signals as glucose, it is likely that sweetened drinks are worse than sweet solid foods. That seems to indicate that sucrose has the same effect as high fructose corn syrup.

Most studies looked at soft drinks that were sweetened by calorically sweetened liquids and what the effects were on appetite and weight gain. Now fruit juices and drinks also contain added sweeteners, typically HFCS, so they pose the same obesity risk. But switching to noncalorically sweetened soft drinks is not the answer either, because artificial sweeteners like aspartame have much the same problem.

Now fruit also contains fructose, but this doesn't necessarily mean you should stop eating fruit. It doesn't contain nearly as much fructose as sweetened drinks. Besides it's a valuable source of phytonutrients and fiber. Soft drinks however provide little more than empty calories.

So the conclusion to this controversial subject matter should be clear. Stop drinking soft drinks if you value having good health.

To your good health,

Sonny Julius

Sonnyj@TheSunnySenior.com

www.HealthyIdeas.homestead.com