This study shows that there are more stem cells available in the gut when fed a high fat diet. To jump from evidence of greater stem cell abundance/activity straight to cancer is what most would call “Story Time”. Story time is when researchers start to speculate wildly and pretty much divorce themselves from the data whenever it suits them. Great for brainstorming new things to research, but it should never be the basis of entire news articles for the layperson who cannot differentiate between pure speculation and what the evidence actually says.
An alternate explanation (and one I personally feel to be more in line with basic biology) is that the high fat diet is overall less stressful on the gut, thereby sparing stem cells from having to repair as much damage day-to-day, and thus resulting in greater available un-utilized stem cells for these researchers to detect and manipulate. The metabolism of the intestine is fueled primarily by the catabolism of carbohydrates and carbohydrate precursors like amino acids. Fat largely bypasses the enterocyte to enter the lymph system (the degree to which this happens depends on fatty acid chain length in most species, so the point raised by others regarding the type of fat is very important) to be metabolized first not by the gut but by the liver. Higher fat diets mean lower carbohydrate and/or protein (protein being made of amino acids, many of which can be used to synthesize carbohydrates when catabolized), and as we all know higher carbohydrate diets have been tenuously linked with all sorts of pro-oxidation metabolites and indices of poor gut health like inflammation. Things that would require a higher level of chronic stem cell utilization for repair of oxidation caused damage. This paper is more evidence of the protective effects of fat specifically on gut health, than any evidence of harm from cancer or otherwise.
Never mind the fact that this is ultimately a rodent and cell culture study. Just yesterday ARS had an article showing just why mouse model work is next to worthless as a direct extrapolation to human medicine. From that article
One of the women in the study had complete loss of function from a gene called PRDM-9, which determines where maternal and paternal chromosomes recombine (exchange genetic material) during meiosis. As far as genetic fitness of a species is concerned, this recombination is probably the single best thing about reproducing sexually as opposed to any alternative. PRDM-9 knockout mice are sterile, but this woman was not.
Genes drive our biology, and if genes of fundamental importance to mice can be essentially irrelevant to humans, we should be very careful when extrapolating evidence between the species. Even if, for the sake of argument, we assume that the authors preferred narrative is true all it really tells us is that mice should avoid a 60% fat diet, and that it might be worth looking into the effects of a 60% fat diet in humans. But then you would have to reconcile this assertion with indigenous populations like the Inuit mentioned by someone else who consume diets where essentially all of their calories come from fat, or the Masi who (the men anyway) live almost entirely on milk and blood from cattle which is also very low in carbohydrate and thus resulting in a predominance of calories coming from fat.
Researchers delivered a modified RNA that encodes a telomere-extending protein to cultured human cells. Cell proliferation capacity was dramatically increased, yielding large numbers of cells for study.
…The newly developed technique has an important advantage over other potential methods: It’s temporary. The modified RNA is designed to reduce the cell’s immune response to the treatment and allow the TERT-encoding message to stick around a bit longer than an unmodified message would. But it dissipates and is gone within about 48 hours. After that time, the newly lengthened telomeres begin to progressively shorten again with each cell division.
This is very important because the big danger in telomere lengthening is the immortalization of cells, meaning cancer. Telomere lengthening is old hat but the transcience factor is huge for anti-cancer and immune response. Reason being that transient telomere lengthening allows for a rejuvenation of cells without tumorigenesis. Safely reverting the senescence response is absolutely crucial to ending aging. However if this telomere lengthening increases lifespan, then there’s more time in which you may develop cancer or other illness from a mutation. Does this technique increase the chances of cancer above what you’d expect solely from having lived for a longer duration?
This could be the key to making it economical and practical to grow beef or chicken muscle in a manufacturing facility… Vegetarians, how do you feel about sustainable lab-cultured meat?
You’ve seen the bone marrow donation process in medical dramas, right? As I recently discovered, the needle-to-the-hip donation is pretty outdated. Here’s why modern donation is a whole different ballgame.
A couple of months ago, I got a call from the [US] National Marrow Donor Program, letting me know that someone potentially needed me to be a donor. I think it’s important to help people out, but I didn’t like the idea of anyone sticking a needle in my bones, general anesthesia or not. To forestall any suspense, I was “released from the donation” — which is, I suppose, official terminology for “we don’t need you, after all.” Before I was released, however, I learned that my idea of donation was really outdated.
…Both procedures, bone marrow donation and PBSC, do essentially the same thing: harvest stem cells. The only difference is the degree of complication. So if you’re interested in being a donor, but scared of the pain or complication of a traditional bone marrow transplant, things have changed. Odds are the whole procedure doesn’t involve anything more complicated than sitting in a chair waving goodbye to your extra stem cells.
There is some undisclosed blood thinner used in the PBSC method. I’ve only found one source stating that being on blood thinner would likely require you to stop taking the medication, which is to be expected. I’m interested to see if I can be a donor in 2015, though it’s likely to be the same story as blood donation 😦