A New Study Just Linked Creatine To Cancer

Just last week, an alarming study was published. This here to research team tested creatine, one of the most studied supplemental compounds in the world, for its effects on cancer. They ran careful studies and got opposite answers. One found that creatine helped cancer spread through the body faster, the other found that creatine helped the body fight off cancer. Both were legitimate studies, one published in a cell press journal and the other in a nature journal, both out of serious labs and only weeks apart. When findings collide like that, usually one of them turns out to be flawed somewhere, but that does not seem to be what happened here because as of now, both of them still stand up, which leaves a real problem, and it's not just an academic one.

Creatine is one of the few supplements that reliably works, taken by millions daily. Most of them assured for years it's about as safe as anything you can buy. So a credible study saying it may spread cancer is not something anyone can hand wave away as nothing. But the other study is just as solid and it says the opposite, the same molecule but opposite results. How can this be and how should we be thinking about creatine supplementation moving into the future? Let's investigate. Let's start with a study that triggered the need for this episode because it's brand new.

It was published just a few days ago. A team at a medical university in China set out to answer a simple question: what does creatine actually do inside the body during cancer? Not in a dish, but in a living animal carrying a real tumor. They gave creatine to mice at a dose scale to what a person takes and watched where the cancer went. It spread faster. The mice on creatine grew more tumors in their lungs than the mice without it, and they died sooner. That result held up across several different types of cancer, which is the first thing that makes it hard to dismiss because the fluke tends to appear in one model and vanish in the next.

This one did not vanish. Then the team found the reason. Creatine was not making the tumor itself more aggressive, it was acting on a completely different cell. It was acting on platelets. Platelets are the cells that make your blood clot, and you know them from sealing a cut, but they have a second life that has nothing to do with healing. When a tumor spreads, it has to send cells through the bloodstream, and the bloodstream is a brutal place for a loose cancer cell. It is fast, it is full of immune cells hunting for exactly that kind of intruder, and most cancer cells that attempt the crossing are destroyed before they land anywhere.

The ones that survive manage it because they did not travel alone. They pick up an escort. Platelets gather around a circulating tumor cell and coat it, and that coating hides it from the immune system and shields it from the forces carrying through the vessel. The cancer cell crosses hostile water wrapped in a bodyguard, it recruited from the host. That is the machinery the study points at. The Chinese team found that creatine made those platelets more active, which means the escort got better at its job. And when a tumor is trying to spread a better escort is very bad news.

Almost everything I described was measured in mice, but the team did not stop there. Eleven healthy volunteers took creatine for two weeks at 20 grams a day, not outside what people use on the higher end. Afterward, their platelets showed that same shift toward the more active state. The change the researchers had tied to cancer spreading in mice was now showing up in human blood. And here's what keeps this from being a lone alarming paper. It's not alone. For over a decade, in a separate line of research, scientists studying how tumors feed themselves kept finding creatine on the list.

A lab at Rockefeller in 2015 in liver metastasis, a team at the University of Glasgow in 2020 in pancreatic cancer, researchers at the Chinese Academy of Sciences in 2021 in colon and breast cancer, different labs, different continents, different cancers, different mechanisms, all landing on the same uncomfortable idea, creatine as a fuel source might be useful to cancer. The link was strong enough that researchers tried to exploit it in reverse. If tumors lean on the creatine system to grow, then shutting it down should starve them, and experimental drugs have been built to do exactly that.

At MIT in 2017, blocking creatine slowed in aggressive leukemia. At Cancer Research UK's Beatson Institute blocking it slowed prostate cancer, and a drug born out of the Rockefeller work has already moved into human trials against colon cancer. Put it all together and it stops looking like one scary headline and starts to look like a pattern. The safest supplement on the shelf has been turning up exactly where you would at least want it in the biology of how cancer survives and spreads. That is the case against creatine.

And on its own is unsettling, but is only one side of the record. And when you interpret these findings more deeply, the picture you have formed to this point will start to shift a little bit. Go back to the brand new nature study and look at what it actually measured in people. The mice got cancer and it spread. That happened. But the human side never measured cancer at all. What the researchers measured in those 11 people was one thing: whether their platelets got more active. To test whether that could drive cancer, they took the volunteers' platelets, mixed them with mouse melanoma cells, and injected that into mice with disabled immune systems.

Animal stripped of the very defense that fights this kind of spread. So the frightening result, the cancer spreading still happened in mice. The human contribution was a population of platelets lifted out of a person and dropped alongside the cancer. That distinction matters more than it sounds. Measuring that a person's platelets got more active is not the same as measuring that a person got cancer. It's a sign a mechanism might be running, not proof of an outcome. What the study shows in humans is a change in a blood cell, not a change in anyone's odds of contracting disease.

And then there's a body of work pointing the other way. In the same time window, one group was showing creatine help cancer spread. Other researchers were showing the opposite. The most recent was published this April out of UCLA, and it was about dendritic cells, the immune system scouts, the cells that find a tumor and market for destruction. Creatine fed these cells and made them better at their job. And in their hands, creatine did not speed up cancer, it actually shrank it. And it was not isolated. The same lab had shown earlier that creatine also sharpens the killer T cells, the ones that carry out the destruction the scouts call for.

And a separate group found the same pattern in macrophages, the immune cells that engulf threats outright. Three different defenders, three different studies, all pointing the same way. Feed the body's immune cells creatine and they fight cancer harder. One set of rigorous studies says creatine helps cancer spread. Another set, just as rigorous, says it helps the body fight it. Neither side is sloppy, and neither is probably wrong. And that should feel impossible because how can one molecule do both? The answer is that we have been asking the wrong question, and once you see the right one, every study starts to click into place.

Creatine is not a drug. A drug is built to do one thing in one direction. Creatine is a fuel. It is a molecule the body uses to move energy around and it does not care if it was using it. It powers whatever cell takes it in. That single fact by itself dissolves a lot of the contradiction. The study that scared us is likely right because creatine can fuel platelets, and active platelets help cancer spread. The study that reassured us is also right because creatine can fuel the immune cells that destroy cancer. Same fuel but different engines.

One helps the tumor, the other fights it. The fuel was never good or bad. The only question that ever mattered was which cell was using it. And the researchers who found the scare results said as much themselves. Because creatine acts on both tumor helping and tumor fighting cells, they wrote it cannot simply be recommended for or against in cancer. Once you see creatine as a fuel, it makes far more sense because cancer might not be doing anything special with it. It does this with everything. Take glucose, the sugar your body runs on.

Tumors are famous for consuming it in enormous amounts. So reliably that the standard scan used to find tumors works by lighting up places soaking up the most sugar, and yet no doctor tells a patient to stop eating because starving the tumor of sugar means starving every healthy cell too, including the immune cells fighting it. It is like trying to starve an enemy hiding in your house by cutting power to the whole street. The lights go out for them and for everyone helping you. The same goes for protein, which tumors also pull in to build themselves.

We do not tell people to stop eating protein, so it's most probable that creatine belongs on that same list, not in a category of its own, which is why those cancer drugs are not evidence that creatine causes cancer. They are the opposite. Blocking creatine to fight an existing tumor is the same logic as any targeted therapy. Cutting a supply line to a disease that is already there, it tells you the pathway matters once a tumor is growing. It tells you nothing about whether a healthy person taking creatine is planting the seed of one.

And when researchers looked at that question directly in people, the alarm gets quieter still. In 2017, a team at the Mayo Clinic ran a randomized placebo-controlled trial, giving creatine to more than 260 cancer patients, the group you would expect to be most vulnerable if creatine truly fed the disease. They took a standard loading dose of 20 grams per day for five days, then a small daily dose of 2 grams for up to 8 weeks, and were followed for survival for 8 months after. The people on creatine did not die faster.

Their survival was no different from placebo. Add decades of safety data in healthy people at normal doses with no signal of rising cancer, and the picture starts to settle a bit more. The mechanism in a dish may very well be real. The catastrophe in a human being has not yet appeared. Not yet, anyway. So where does that leave the average creatine user? The honest answer is that creatine does not deserve to be treated any differently than glucose or protein when it comes to cancer. A tumor can use it the same way it uses a great many of the ordinary things that keep you alive.

And that has never once been a reason for a healthy person to stop. The single instruction the evidence rules out is the panic one that because cancer cells can use creatine, you should put it down. Followed consistently, that reasoning would have you give up food entirely. For the healthy person, taking creatine to build muscle or protect their brain, which is nearly everyone who takes it, that should be reassuring. But two real questions remain. The first is dose, and there may be a difference between the creatine that your body makes itself and the larger amounts that you swallow as a supplement.

Something the researchers flag but cannot yet answer. The second and more serious is stage. Whether someone who already has active cancer should think about creatine differently. That comes down to dose and duration of exposure, and it's genuinely an open question the researchers themselves raise. For everyone else, the verdict is the one good science it usually reaches. The scary headline may not be fake, but it's not the whole truth. Creatine is a fuel. Cancer uses fuel, but so does the rest of you. Thank you for joining me on today's episode.

If you got something out of this, please like and subscribe. It lets me keep doing these deep investigations moving into the future. Until next time, stay healthy.