Thread by @Sam_Apple1

Thread: 1/25: Can sugar be thought of as a cause of cancer? I explore this question in my new book Ravenous: amzn.to/3eJi4L2 (Pub date is 5/25. If it looks interesting, pre-orders are a huge help!)

Thread: 2/25: I think the evidence points strongly in the direction of “yes” — sugar can be thought of as a cause of cancer. But I also think there are some important nuances to the science that are sometimes easy to overlook.

Thread  3/25: Before discussing whether sugar causes cancer, you have to clarify the definition of “sugar.”  By "sugar," I don't mean "blood sugar," or glucose. I  mean "sucrose"—the sweet white stuff. It's a molecule of glucose bonded to a molecule of fructose.

Thread 4/25: This can be confusing. After all, cancer cells famously slurp up a lot of glucose—this is the Warburg effect I write about in Ravenous. And too much glucose in your blood is not a good thing. So you'd think the problem would simply be eating lots of glucose.

Thread 5/25: But what we really want to know is how our cells end up overeating all that glucose. There’s always glucose in our blood, but (broadly speaking) our cells wait for instructions to eat it.

Thread 6/25: So, when cells are eating more glucose than they should, the first question to ask is: How are they pulling off this trick? How are they cheating the body’s food distribution system?

Thread 7/25: The most obvious suspect is the hormone insulin: which gives our cells the instruction to take up the glucose that is always circulating in our blood.

Thread 8/25: And, sure enough, there is a robust body of literature strongly connecting elevated insulin levels to many different types of cancer: nature.com/articles/s4156… -see also bit.ly/3w44r06

Thread 9/25: Most deadly cancers have a mutation in the pathway that insulin activates in a cell. These mutations make cancers cells more responsive to insulin. And cancer cells are often covered in insulin receptors. Some cancers won't even grow in the in a culture w/o insulin.

Thread 10/25: Elevated insulin will also drive obesity, which has been linked to more than 600,000 cases cancer in the U.S. each year—it's now overtaking smoking the greatest risk factor for preventable cancers. bit.ly/3bqMnFJ

Thread 11/25: If you consider that even those who are not deemed “obese” still typically show signs of the underlying metabolic syndrome that leads to elevated insulin, you start to see that this is a question for almost all of us. unc.live/3fpLyxQ

Thread: 12/25: That excess insulin drives cancer shouldn’t be surprising: Insulin is a growth factor that tells our cells to eat glucose. Cancer is problem of growth marked by excess glucose consumption. (A PET scan for cancer shows where glucose is being over consumed.)

Thread: 13/25: Though insulin could be driving mutations that initiate cancer, we can't say for certain. A more widely accepted model points to excess insulin breathing life into microscopic tumors that might otherwise never survive or  become a threat. (See Ravenous excerpt.)

Thread: 14/25: Given the strong evidence linking excess insulin to cancer--which I don't think is even controversial at this point--what we really need to know is how almost all of us have ended up with too much insulin in our blood.

Thread 15/25: And this brings us back to sugar. Because  sugar --the combination of glucose and fructose --drives the metabolic problems that lead to elevated insulin more effectively than any other molecule. pubmed.ncbi.nlm.nih.gov/31935149/ (Drinking sugar appears to be worst of all.)

Thread: 16/26: You don't even to agree with almost any of the above to see a sugar—cancer connection. That too much sugar leads to obesity is accepted by almost everyone. And virtually everyone agrees that obesity is a risk factor for cancer.

Thread 17/25: So, to summarize: Excess sugar leads to elevated insulin. Incipient tumors, often covered in insulin receptors and harboring mutations that make them hyper-responsive to insulin, take advantage. They consume more glucose, turn on the Warburg effect, and grow.

Thread 18/25: When I started writing Ravenous. I thought that was the basic story. In recent years, the evidence of a sugar-cancer connection has grown even stronger.

Thread 19/25: While most of the fructose from sugar is metabolized in the liver, some cancers appear to consume fructose directly, and the fructose revs up the glucose consumption and Warburg metabolism even without raising insulin. cancerandmetabolism.biomedcentral.com/articles/10.11…

Thread 20/25 "If you want to make a cancer happy,” the fructose researcher Richard Johnson told me, “feed it fructose.”

Thread 21/25 There is plenty of observational data for a sugar-cancer connection as well, though such studies are not strong evidence by themselves.

Thread 22/25 This doesn’t mean that a little sugar each day causes cancer, just as smoking lightly might not cause cancer. And it doesn’t mean that sugar is responsible for all insulin-related cancers, just as smoking is not responsible for all lung cancers.

Thread 23/25: But I do think there is enough evidence to speak about cause. How much sugar is too much? It’s really going to be different for each person. If you’re showing signs of metabolic syndrome, as most of us are, it’s probably too much.
mayoclinic.org/diseases-condi…

Thread 24/25: Michael Pollak, of the Division of Cancer Prevention at McGill, told me sugary drinks are "among the most unhealthy foods that you could imagine." He said it’s okay to have a little sugar, but it should be consumed as a condiment, “in the same way we have pepper.”

Thread 25/25: Is anyone still reading this? I'm bad at Twitter. If you found this interesting, pease, um, check out Ravenous: amzn.to/3eJi4L2 pre-orders =❤️ Thanks!