Is Fructose Actually Bad for You?

Fructose

To answer this question correctly, I would respond by saying…that depends.Fructose is a type of sugar found in honey and in many types of fruits and vegetables. Fructose is a simple sugar and is directly digested into the blood from the upper intestine. Most fructose is consumed as high fructose corn syrup which is typically used as a sweetener in foods, soda, and fruit drinks.

It is different from other types of sugars in that it is low on the glycemic scale and does not stimulate insulin secretion to the same extent as other sugars. Therefore, it has been postulated that fructose intake may be reasonably desirable in people who are obese or diabetic.

This is where the controversy begins, as previous evidence has indicated that fructose consumption can increase the production of LDL cholesterol and triglycerides which can cause fatty liver disease and insulin resistance.

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New research involving a meta-analysis of studies looking at the consumption of fructose indicated that fructose did not seem to raise triglyceride levels after a meal. Let’s look a bit deeper at this for a moment.

This research looked at two different types of studies. In 14 of these, the participants were fed substituted fructose while removing all other sources of carbohydrates from their diets and the other two studies were conducted upon people who ate added fructose in addition to the other carbohydrates they were already consuming. After each feeding, triglycerides were measured.

This study clearly indicated that fructose did not alter triglyceride levels in the participants who had this sugar substituted for all the other carbohydrates in their diet.

However, the people who simply ate the added fructose in addition to the other sugars in their diet experienced a substantial increase in triglyceride levels. Since most people eat this way, perhaps it would be fair to assume that consuming added fructose from sweetened foods or drinks can increase blood triglyceride levels.

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A note of caution regarding this meta-analysis is that most of the data collected came from one trial as the others were quite small!

Previous research has reliably indicated that the consumption of high fructose corn syrup can increase triglycerides and influence key hormones like leptin and ghrelin which regulate long term energy metabolism. Decreases in circulating levels of these hormones can lead to excessive caloric consumption.

In people who are overweight, obese, or have diabetes, the consumption of high fructose corn syrup is a very bad idea in my opinion as this practice can aggravate abdominal fat storage and elevate triglycerides, LDL cholesterol, and levels of inflammation. This can increase the risk of heart disease, hypertension, and stroke.

The best way to do this is avoid soda, fruit drinks, and foods containing high fructose corn syrup.


Sources:
Castillo, S., “Does Fructose Just Have A Bad Rap?” Prevention web site; http://www.prevention.com/health/health-concerns/fructose-not-risk-factor-cardiovascular-disease, last accessed Jan. 15, 2014.
Wang, D., et al., “Effect of fructose on postprandial triglycerides: A systematic review and meta-analysis of controlled feeding trials,” J Atherosclerosis 2013.
Teff, K., et al., “Dietary Fructose Reduces Circulating Insulin and Leptin, Attenuates Postprandial Suppression of Ghrelin, and Increases Triglycerides in Women,” The Journal of Clinical Endocrinology & Metabolism. June 1, 2004; 89(6).