Alright! Here is the fourth and final part of this sweet discussion! In the last post I told you that sugar is sugar is sugar but promised to break it down a little more for you. Here is the original question along with some details about fructose and glucose and some concluding thoughts.
I fastidiously read labels to avoid corn syrup (and glucose syrup if I can). At home, often use alternate sweeteners like honey, maple syrup and agave nectar but wondering if rice syrup is that much better than corn syrup or liquid sugar as it seems to crop up a lot in processed foods at health food shops. At home in England, we buy sugar free (sweetened with juice) and whole grain ‘snacks’ for the kids but the best in Canada we could find was bars where the second ingredient was organic brown rice syrup. So just wondering…
Question, Part 4:
So if sugar is sugar is sugar, then why does high fructose corn syrup get such a bad rap?
Answer, Part 4:
First, a couple of definitions:
- Sucrose, or table sugar: Glucose joined to fructose. 50% glucose, 50% fructose. The glucose and fructose must be separated before being absorbed.
- High fructose corn syrup (HFCS): Mix of glucose and fructose side by side. 40% or 55% is fructose and the rest is glucose.
Fructose occurs in nature. The majority of fruits contain 40-55% fructose as a percentage of total sugar. Agave syrup, honey, and fruit juice concentrate are also sources of fructose often added to foods.
Added fructose can also come in the form of HFCS. Commercial HFCS is between 40‐55% fructose, just like fruits. Sucrose contains 50% fructose.
Why Does HFCS get a bad rap?
Since its introduction in 1970, high fructose corn syrup has largely replaced sucrose because of its low cost. Obesity rates have been increasing along with increased use of HFCS so some people have theorized that HFCS is the cause of obesity.
However, the average calorie intake has also increased by 24% since 1970.
And guess what?
High calorie intake is definitely associated with obesity. In fact, a calorie is a calorie whether from glucose, fructose, or a combination of both.
Also, HFCS and sucrose have similar metabolic effects, BUT fructose and glucose can have different effects because they are absorbed and metabolized differently.
Glucose requires a transporter to be absorbed, requires insulin to be taken up by cells, and has a feedback control mechanism on its metabolism.
Fructose does not.
The lack a feedback control in fructose metabolism can lead to negative health effects under certain conditions. In human and rodent studies, high consumption of fructose (over 100g at a time) has resulted in increased triglycerides, LDL and HDL cholesterol, fasting glucose, blood pressure, and visceral fat. These findings are interesting, but perhaps not realistic because fructose is usually consumed along with glucose and on average, people consume 49g of fructose per day (not 100g in one sitting). These studies reflect acute metabolic overload rather than what occurs with consistent long-term intake of fructose.
But these are the studies that make news headlines and freak people out.
When fructose is consumed as sucrose or HFCS, other factors need to be considered. There are obviously effects associated with fructose consumption but the simultaneous consumption of glucose can mitigate some of the effects. Studies have shown that in normal people, normal amounts of fructose consumed as part of sucrose or HFCS, is metabolized normally and should not cause negative health effects.
HFCS and sucrose both made up of fructose and glucose and are pretty much nutritionally equivalent. Eating too much of either one will cause weight gain.
Fructose when consumed without glucose and in very large amounts can cause many negative health effects. This does not occur when fructose is consumed as part of sucrose of HFCS.
What You Need to Know
Try to keep overall sugar intake low by cutting down on added sugars and also by being aware of foods that are high in sugars. These include:
- Soft drinks and other sweetened drinks like iced tea, energy drinks, sports drinks, and fruit drinks
- Sweets such as candies and chocolates
- Pastries, pies, cakes, cookies, brownies, danishes, muffins…
- Many breakfast cereals – compare the sugar content in a few of your favorite cereals and choose the one that has the least sugar
- Dairy desserts such as ice cream, flavored yogurt, chocolate milk, puddings…
When you need a sweet treat, go for:
- Watermelon or other fruits
- A small piece of dark chocolate
- Raisins with peanut butter and celery
- Apples with a slice of cheese
- A piece of whole grain toast topped with applesauce
- A smoothie made with plain yogurt and your favorite frozen fruits
- Is Brown Rice Syrup Better than Sugar? Part 1
- Is Brown Rice Syrup Better than Sugar? Part 2
- Is Brown Rice Syrup Better than Sugar? Part 3