Death By Fructose: The Toxin To Avoid

Fructose consumption is detrimental, even poisonous, to one’s health. However, what many people continue to overlook, is that there are many different types of sugar. And one of these, fructose, is by far the most detrimental to your health. Excess fructose, I would argue, could be classified as chronically toxic. Meaning that a small, infrequent overdose of fructose likely won’t cause problems. But, a lifetime of fructose, in excess, can cause diseases of a wide variety.

What exactly is fructose? Well, to answer that question, we need to get into a little bit of chemistry. There is glucose, which is used by every cell in the body. And then there is fructose, which is processed almost entirely by your liver. The main transporter for fructose is called GLUT5.

As has been noted in many scientific papers, there are many parallels between fructose and alcohol, which everyone recognizes as toxic. It strikes me as continuously odd that fructose remains largely unrecognized as a potential toxin. Even though nonalcoholic fatty liver disease, sugar consumption and diabetes rates continue to climb, fructose is largely ignored. This boggles my mind.

Furthermore, when one looks at diets that are successful, they all have one common denominator. What is this? They all eliminate large amounts of dietary fructose. Fructose was initially thought to be advisable, because it does have a low glycemic index. This was before we understood its negative biochemical effects. It was also shown that chronically high consumption of fructose leads to hepatic and extrahepatic insulin resistance. Fructose has also been linked to obesity, type 2 diabetes, and high blood pressure.

If you recognize this as the common cluster of western diseases and risk factors, you are correct. Lets now look at ALL the negative effects of fructose on human physiology.

Does that look good to you? It doesn’t look good to me. Fructose does not lend the same satiety signal to your brain, meaning that you don’t realize you just ingested all the calories that you actually did. The best example of this, is seen in a can of soda, which typically contains 70g (!) of sugar.

What’s more disturbing, is that a recent study showed that companies flat out LIE about the amount of fructose in their products. Right on the labels! Drinks advertised as containing no high fructose corn syrup, sometimes contain MORE fructose than the drinks that DID list it on the label. And if you think fructose is only a problem in soda, think again.

Fruit juices are loaded with fructose, and there are a large amount of fruits (of course, the ones we tend to crave) that have fairly high levels of fructose. Honey is one food that is not ideal, due to its high fructose content. I am aware that many will be displeased by this fact, but the science is fairly straightforward.

What does this all mean? Should you avoid fruit altogether? And why is fructose so bad? Well, the main reason why we eat so much of it, is because fructose is the sweetest tasting of all sugars. Its sweet taste can be found in foods like honey, bananas, apples, dates and many other fruits.

However, as we’ve shown, fructose is more widely known for its use in high fructose corn syrup. High fructose corn syrup is a mix of glucose and fructose. What begins to be troubling is that just about everything in our food supply, from soda, to fruit juice, to desserts, to cookies, to even BREAD, contains this blend.

High fructose corn syrup, because of its biochemistry and because of its unnatural addition to ALL of our foods, has become a real threat to maintaining a healthy lifestyle. Since we added high fructose corn syrup to our foods in the 1970s, our diet has changed from more traditional meals of meat and vegetables, to ones based on refined carbohydrates.

Our genome was arguably not set up for this. Over time, we likely ate a low-ish carbohydrate diet, at times likely even ketogenic, when food wasn’t available for periods of time. Now we have convenience stores on every corner, offering liquid sugar, high carbohydrate “franken-foods” and high fat, high sugar foods. Is that progress? I view it as regression.

Unsurprisingly, fructose consumption has been correlated with cancer. However, in the interest of full scientific rigor, correlation does not equal causation. However, there are many causative problems with fructose consumption. The cross-linking of proteins is one problem. As this process occurs, diseases of aging become inevitable.

What are some of these diseases? How about: atherosclerosis, hypertension, erectile dysfunction, kidney disease, stiffness of joints and skin, arthritis, cataracts, retinopathy, neuropathy, Alzheimer’s and many, many more. Here is a graph, showing exactly how high levels of sugar correlate with dementia.

That’s right; lots of fructose may lead directly to dementia. Have I scared you off of that sugar water you may be consuming? In 2010, it was very clearly stated by scientific researchers that “in the amounts currently consumed, fructose is hazardous to the cardiometabolic health of many children, adolescents and adults.” In those 4 years, the data has only gotten worse.

Below, we see a schematic which shows EXACTLY how fructose factors in to our now-diseased population. Stopping this cycle is easiest when you simply limit your dietary amount of fructose. All other possible interventions are more complicated, or impossible. It is quite a simple solution, but the rewarding nature of food makes it hard for some individuals to stop.

The liver-damaging effects of fructose are also well-documented. Hepatic dysfunction is not desirable, and nonalcoholic fatty liver disease (NAFLD) in children is rising. NAFLD is directly linked to fructose consumption, either by ingestion of soda or fruit juice. Fructose is somewhat similar to grains, in that it is largely useless for the body to consume the substance. However, it is actually worse than grains, because fructose in large amounts becomes toxic.

Sadly, I see this misunderstood in the paleo community all the time. Just because it is “Paleo” doesn’t mean you should consume 10 pieces of fruit per day. The same thing happens with nuts. People tend to overdose on these items, when in reality, a balanced, well-rounded diet would work much better.

So, have I convinced you to stay away from fructose yet? Does it make you feel good that fructose is one of the most likely suspects for the current $245 billion per year that we spend on diabetes? I wouldn’t imagine so. Sugar, mainly fructose, is also quite heavily marketed towards children. We need to stop that practice, immediately, if we have any hope for a healthy future.

As Dr. Robert Lustig has stated, fructose is simply alcohol “without the buzz”. Nearly everything else about the substance is the same. Fructose does not generate an insulin response, which is part of why it’s so dangerous. When we don’t know we’ve eaten something, such as in the case of the body’s hormonal response to fructose, we run the increased risk of overconsumption. Hormonally, fructose causes reductions in insulin, a reduction in leptin (so you feel less full), and increases the expression of the hormone ghrelin (so you feel hungrier). Not a good combination.

Here we see the leptin resistance, dyslipidemia, increased triglycerides, muscle insulin resistance, and other negative effects – all from the biochemistry of fructose ingestion. Does it still seem like a good idea to be consuming fructose? It offers no benefits, and only negative consequences. It is possible, though difficult, to consume small amounts of fructose. The difficulty lies in the fact that the sweetness of fructose, which, evolutionarily, meant nutrient-rich foods, is hard for humans to simply consume just a little bit of.

What are your views on fructose? Do you include it in your diet? Do you eat lots of fruit? Let me know in the comments!

This article originally appeared on PaleoHacks.