The Hidden Dangers of Fructose
>We all know that sugar is bad for us right? One of the first things we recommend to new clients is to remove all simple sugars and refined foods from the diet, just this step alone yields enormous results and health improvements. But what about fructose?
Many people get thrown by the name, after all fructose is found in fruits, so how bad can it be? The truth is that fructose, added as a sweetener to our foods and drinks is fuelling many of today’s chronic diseases including high blood pressure, cancer, obesity and insulin resistance.
What is Fructose?
Fructose, or fruit sugar, is a simple monosaccharide found in many foods. It is fructose that is responsible for the sweet taste of fruits, berries and naturally occurring sweeteners like honey.
| Food | Amount (mg / 100g) |
|---|---|
| Bananas | 4,850 |
| Grapes | 8,130 |
| Apples | 5,900 |
| Orange | 2,250 |
| Blueberry | 4,970 |
| Tomato | 1,370 |
| Onion | 1,160 |
| Cabbage | 1,650 |
| Asparagus | 1,000 |
| Carrot | 1,000 |
| Brussels Sprouts | 930 |
There is nothing in itself bad about fructose. As the name might suggest it forms a component of fructooligosaccharides, the form of fibre necessary for good digestive health and bacterial balance. As with many things, it is the quantity and the source that are key, and fructose is no exception. Increasingly fructose is being extracted, crystallised and sold to the processed food industry as a sweetener that is almost twice as sweet as table sugar and inexpensive. This is where the problems start.
But Why the Fuss?
It seems that we don’t do anything by halves!
Until the introduction of the standard aussie diet our intake of fructose was limited to what we consumed from fresh fruits and vegetables, typically around 15 grams per day. From 1970 to 1997 the American daily fructose intake has climbed to 81 grams per day per person(Gaby). The driver for this massive increase in fructose intake is the switch by manufacturers to the use of fructose and high fructose corn syrup in almost every form of processed food or drink. An average 600 ml can of soft drink contains 32.6 grams (over 6 teaspoons) of fructose.
The reason manufacturers have swapped to fructose and high fructose corn syrup from sugar has nothing to do with our health! As a sweetening agent processed food manufacturers prefer HFCS because it is inexpensive and mixes well in many foods(Gaby). The fructose and high fructose corn syrup used in processed foods has also been separated from the fibre which it normally is found with in fruits and vegetables.
What’s so bad about Fructose?
Where do we start!
There are a growing number of studies that suggest that high levels of fructose consumption, in it’s guise as high fructose corn syrup or just plain fructose are one of the major factors behind our obesity and diabetes epidemics. There are a number of reasons for this:
- Fructose increases body fat – The digestion, absorption and metabolism of fructose are different to that of glucose. Where glucose can used by nearly every cell in the body in the production of energy, fructose can only be metabolised by the liver. Unfortunately, when it hits the liver fructose has a tendency to increase the bodies production of triglycerides or fats (Bray).
- Fructose does not signal satiety – There are many things in the human body that are controlled by hormones and appetite is one of them. We have previously spoken about leptin as one of the hormones involved in regulating appetite, higher leptin levels (except in cases of leptin resistance) leading to a feeling of fullness. Another of these hormones is ghrelin, levels of ghrelin are highest before a meal and decrease after eating. When we consume fructose these important hormonal signalling pathways are impaired: leptin does not increase (Basciano) and ghrelin levels do not go down (Kilgore) preventing the feeling of fullness that normally accompanies eating. This in turn leads to increased appetite and overeating in an effort to feel full.
- Fructose consumption reduces immune system function – Our immune system is the front line of defence in protecting us from both internal and external pathogens. A healthy, functioning immune system will reduce the chances of getting sick and reduce the length of time that we stay sick! It’s not just colds and flus that we’re talking about here either. Our immune system is vital in cleaning up the cell mutations that lead to cancer. In studies, the consumption of fructose, along with other forms of sugar, significantly decreased the capability of the immune system to destroy bacteria (Sanchez).
- Fructose promotes ageing – Like ageing and wrinkled skin? I thought not! Studies on rats showed that excessive, long term consumption of fructose decreased levels of the type of collagen that prevents wrinkles from forming (Levi). I’m sure most of us aren’t wanting to make ourselves look older as a result of drinking a fructose flavoured sports beverage after a pump class at the gym.
What to do with a sweet tooth?
Obviously the first task is to eliminate any processed sources of fructose from the diet. Fructose is regularly used in pastries, jams, jellies, soft drinks and sports drinks so be sure to read labels properly.
A healthy alternative, for those sweet cravings, is to include two to three serves of fruit in the diet per day.
Want More Info?
If you would like more information or assistance in reviewing your diet to reach your health goals and obtain optimum wellness contact us today on 07 3800 1993 to arrange a consultation with our naturopath.
Resources Consulted
- Basciano H, Frederico L, Adeli K. “Fructose, insulin resistance, and metabolic dyslipidemia.” Nutrition and Metabolism 2.5 (2005)
- Bray, G. A., et al. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. American Journal of Clinical Nutrition. 79(4):537-543, 2004.
- Gaby, A. R. Adverse effects of dietary fructose. Alternative Medicine Review. 10(4):294-306, 2005.
- Kilgore C, “Fructose Is Metabolized Like Fat; Leads to Obesity, Expert Says” 13 Nov 2009. http://www.medconnect.com.au/tabid/84/ct1/c334275/Fructose-Is-Metabolized-Like-Fat-Leads-to-Obesity-Expert-Says/Default.aspx (21 September 2001)
- Levi, B., et al. Long-term fructose consumption accelerates glycation and several age-related variables in male rats. Journal of Nutrition. 128(9):1442-1449, 1998
- Sanchez, A., et al. Role of sugars in human neutrophilic phagocytosis. American Journal of Clinical Nutrition. 26(11):1180-1184, 1973.