High Fructose Corn Syrup and the Growth of Colorectal Tumors

Today’s post is a little off topic but I can’t not share this research[i] with you, especially considering the post I wrote a few weeks back about “lysogenic” bacteria.  If you remember, it was about those types of bacteria that carry dormant viral DNA in them, which, when subjected to the right environmental circumstances, produce bacteriophages (viruses that kill bacteria) that kill their own bacterial hosts.  One of the factors that triggers this phage production is fructose.  The exact metabolic purpose of this is still unknown, but certainly there exists the possibility that the huge increase in our fructose consumption in the last 30+ years or so (from the addition of high fructose corn syrup (HFCS) in so many foods)  has adversely altered our bacterial microbiomes by excessively stimulating this production of bacteriophages.

In that post, I pointed out that, “…since the 1970s, and the ever-increasing inclusion of high-fructose corn syrup (HFCS) into our diets, our consumption of this sugar has increased fourfold.”  According to the Food Research and Action Center, “Obesity rates have more than doubled in adults and children since the 1970’s…The latest data indicate that 39.6 percent of U.S. adults are obese. (Another 31.6 percent are overweight…)”[ii]  A 2017 article[iii] on Medical News Today about research conducted by scientists from Imperial College London, in collaboration with the World Health Organization, points out that, “…obesity in children and teenagers is 10 times higher now than it was in 1975, and that 5 years from now, more will be obese than underweight.”  The study was massive:  1000 researchers looked at the records of 130 million people living in 200 countries around the world, and found: “… in 1975, there were 5 million girls who were obese, and in 2016, this number rose to 50 million. The report counted 6 million boys with obesity in 1975, but this number spiked to 74 million in 2016. Last year, an additional 213 million children and teenagers were found to be overweight.”

There isn’t actually much controversy over whether or not all the added fructose is a part of the reason for this increase in obesity – and subsequent type 2 diabetes rates.  How much it’s a factor though is of course still unknown.

Bearing all this in mind then:  I found a recent article out of the Baylor College of Medicine and Weill Cornell particularly interesting.  The study, which was published in the journal, Science, looked at the relationship between the consumption of even a “moderate” amount of HFCS (the equivalent of about 12 ounces of soda per day) and the growth of intestinal tumors.  Says one of the authors, “”An increasing number of observational studies have raised awareness of the association between consuming sugary drinks, obesity and the risk of colorectal cancer…The current thought is that sugar is harmful to our health mainly because consuming too much can lead to obesity. We know that obesity increases the risk of many types of cancer including colorectal cancer; however, we were uncertain whether a direct and causal link existed between sugar consumption and cancer.”[iv]

To find out more about this potential link between fructose and colon cancer, the researchers created a mouse model wherein they delete a gene responsible for creating a protein called APC.  Without APC, “…normal intestinal cells neither stop growing nor die, forming early stage tumors called polyps.  More than 90 percent of colorectal cancer patients have this type of APC mutation.”

When given sugar water (with HFCS) to drink at will, the APC mice rapidly became obese.  To prevent this, and to model humans drinking one can of soda, they limited the daily sugar water to a mouse equivalent.  After 2 months of this limited amount, the mice did not become obese but they did develop tumors that were “larger and of higher-grade” than the mice given regular water to drink.  The APC mice that were treated with the HFCS, “…showed a substantial increase in tumor size and tumor growth in the absence of obesity and metabolic syndrome.  HFCS increased the concentrations of fructose and glucose in the intestinal lumen and serum [blood], respectively, and the tumors transported both sugars.” [i]

Summarizing their findings, the lead researcher states, “These results suggest that when the animals have early stage of tumors in the intestines — which can occur in many young adult humans by chance and without notice — consuming even modest amounts of high-fructose corn syrup in liquid form can boost tumor growth and progression independently of obesity….[O]ur findings in animal models suggest that chronic consumption of sugary drinks can shorten the time it takes cancer to develop. In humans, it usually takes 20 to 30 years for colorectal cancer to grow from early stage benign tumors to aggressive cancers.”

Another scientist involved in the work states, “This observation in animal models might explain why increased consumption of sweet drinks and other foods with high sugar content over the past 30 years is correlating with an increase in colorectal cancers in 25 to 50-year-olds in the United States…”

Remember though too how rapidly the mice which were allowed as much sugar water as they chose to drink became obese.  And remember too that fat excretes huge amounts of pro-inflammatory chemicals.  So while the accelerated tumor growth was independent of weight gain, obesity is only going to worsen the issue.

To find out how the fructose led to this increased tumor growth, the scientists investigated further and found high levels of fructose and glucose (both of which are found in sugary sodas) left in the colon – and in the blood.  Cancerous tumors eat sugar.  Further experimentation showed that, “…colorectal cancers utilize high-fructose corn syrup, the major ingredient in most sugary sodas and many other processed foods, as fuel to increase rates of tumor growth….While many studies have correlated increased rates of colorectal cancer with diet, this study shows a direct molecular mechanism for the correlation between consumption of sugar and colorectal cancer.”

So to sum up, it appears that our increasing consumption of HFCS may be in part not only responsible for microbiome alterations, but also the ever increasing rates of obesity and type 2 diabetes found around the globe…as well as the increasing rates of colorectal cancers.   I obviously don’t know how all this is intertwined (after all, biome depletion also leads to increased inflammation, alterations in how food is digested, and so forth), but I’m sure it is somehow all connected.  How much of the guilt HFCS bears is still unknown, but certainly, I think we know enough to absolutely avoid the stuff in our diets.

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[i] Marcus D. Goncalves, Changyuan Lu, Jordan Tutnauer, Travis E. Hartman, Seo-Kyoung Hwang, Charles J Murphy, Chantal Pauli, Roxanne Morris, Sam Taylor, Kaitlyn Bosch, Sukjin Yang, Yumei Wang, Justin Van Riper, H Carl Lekaye, Jatin Roper, Young Kim, Qiuying Chen, Steven S. Gross, Kyu Y. Rhee, Lewis C. Cantley, Jihye Yun. High-fructose corn syrup enhances intestinal tumor growth in mice. Science, 2019; 363 (6433): 1345-1349 DOI: 10.1126/science.aat8515

[ii] http://frac.org/obesity-health/obesity-u-s

[iii] https://www.medicalnewstoday.com/articles/319710.php

[iv] https://www.sciencedaily.com/releases/2019/03/190321141924.htm