8 ms·
The relationship between telomere length and diet (2016)
- marvel_boy 9y agoNewbie here. So now to eat red meat was good? Really confused.
- nabla9 9y agoNo. Almost all diets have some positive and some negative effects.. One diet is better than another if its overall effects are better. Has T/S ratio in peripheral blood mononuclear cells have positive effect for health or lifespan of humans, how large the effect is, is it smaller than negative effects of eating meat, ... , lots of questions before we get into a diet.
- loeg 9y agoThe study is inconclusive at this point.
- narrator 9y agoIt's a low sample size, and observastional, but it points in that direction. The effect is probably IGF-1 related as IGF-1 indirectly activates HTRT and telomere lengthening (http://www.sciencedirect.com/science/article/pii/S004763740900147X http://www.sciencedirect.com/science/article/pii/S0047637409...). IGF-1 is also what the non-meat eating lobby use to connect red meat eating with cancer. IGF causes cells to grow. Anything that causes cell growth, even if it generally manifests as bigger muscles, stronger bones or longevity also helps cancer cells grow and gets tagged as bad by association, even though preventing cancer is more about having a strong immune system, early detection and avoiding mutagenic chemical pollutants. There is a huge pro-vegetarian bias is nutrition studies. That's because there are a lot of people who want the world to switch to a vegetarian diet because it is more ecologically sustainable or they are intensely devoted to animal welfare and not necessarily because it is the most healthy.
- georgewsinger 9y ago> There is a huge pro-vegetarian bias is nutrition studies. That's because there are a lot of people who want the world to switch to a vegetarian diet because it is more ecologically sustainable or they are intensely devoted to animal welfare and not necessarily because it is the most healthy. This is the first time I've heard people charge nutrition studies are pro-vegetarian. Usually I hear people claiming food industry pressure causes the opposite bias.
- 1001101 9y agoFTS: "This study showed that diet rich with red meat can decrease leucocyte telomere length 10 years after receiving diet data." I'd steer (no pun intended) clear if you like your telomeres the length they are.
- asciimo 9y agoThere is such a tremendous amount of contradictory research on diet that I wouldn't be too easily swayed by one study or another. I would step back a bit and consider that red meat is definitely bad for our habitat (https://en.wikipedia.org/wiki/Environmental_impact_of_meat_production https://en.wikipedia.org/wiki/Environmental_impact_of_meat_p...), and it's definitely bad for animals (https://en.wikipedia.org/wiki/Death https://en.wikipedia.org/wiki/Death).
- veddox 9y agoThe study doesn't say whether red meat is "good" or "bad", just that eating red meat correlated (within their study group) with shorter telomere lengths. Telomeres are caps at the end of the chromosomes that serve as a protection against genetic damage. They decrease in length every time a cell divides until they are eventually used up altogether - at which point a healthy cell will initiate self-destruction. Some years back they were a much-hyped focus of aging research, as there was the hypothesis that if you could keep the telomeres long, your cells (and by extension, you) could live indefinitely. In that context, eating red meat would appear to be an unhealthy choice. However, said hypothesis is no longer current. Telomeres probably do play a role in the aging process, but the whole affair is much more complex than just "keep your telomeres long". So basically, never eating red meat again isn't going to make you immortal.
- deleted 9y ago[deleted]
- dvcrn 9y agoCan someone rephrase the conclusion and results? I read through it multiple times but can't figure out if a higher T/S ratio is a good thing or not.
- scriptproof 9y agoThey claim that eating more meat increase longevity, against popular belief. But it is contradicted by what we can see: people that eat less meat like those in blue zones have higher longevity in fact.
- voidlogic 9y ago>against popular belief. To be fair its amongst people who study diet, it is also common belief that a ketogenic diet (which while can have lots of plant matter is often high in meat) is almost as good for longevity as caloric restriction.. :)
- ggggtez 9y agoIt's possible on average red meat does improve it, but there is also a global optimum with 0 red meat when you get to be in your late ages.
- mchannon 9y agoA lower T/S ratio is associated with advanced age (had to dig hard to find that one- check out page 9 of this paper: https://www.rug.nl/research/genetics/students/internships/anastassiablanter_bsc_thesis.pdf https://www.rug.nl/research/genetics/students/internships/an...). In other words, high T/S = good. As far as statistical correlation, the p-value of 0.02 (lower, and further away from 0.05, is better) is pretty strong. Where this article fails to convince me to start waving red meat in the faces of all the vegs I know is the limited sample size of a couple dozen people. Maybe there's some protective factor in red meat, or maybe their small sample size just overrepresented young carnivores and old vegetarians.
- patcheudor 9y agoThe small sample size is what most concerns me. Just from personal observation I have no doubt that genetics play a huge part in all of this, part that's hard to believe could be accounted for in a study of 28 people.
- marze 9y agoThis study should be replicated with n > 200.
- DangerousPie 9y agoI am extremely skeptical about the statistical analysis here. It sounds like they tested nine food types, eight beverages and then even tried out different types of comparisons for each food/beverage. And the best p-value they observed was p=0.02: "Among nine food types (cereal, fruits, vegetables, diary, red meat, poultry, fish, sweets and salty snacks) and eight beverages (juices, coffee, tea, mineral water, alcoholic- and sweetened carbonated beverages) only intake of red meat was related to T/S ratio. Individuals with increased consumption of red meat have had higher T/S ratio and the strongest significant differences were observed between consumer groups: “never” and “1–2 daily” (p = 0.02)." Nowhere in their methods do they mention adjusting for multiple testing. If we do that using the standard Bonferroni approach, the p-value would have to be multiplied by a factor of at least 17 x 2 to account for the number of options that they tried. So the adjusted p-value would be 0.02 x 17 x 2 = 0.68 and thus far from statistical significance. In other words, this seems to be a real-life example of this: https://xkcd.com/882/ https://xkcd.com/882/ Maybe I missed something, but if this is really the case then it's embarrassing that this made it through peer review.
- jbmorgado 9y ago> "And the best p-value they observed was p=0.02" A p-value of 0.02 is quite good in physics and absolutely outstanding in medical sciences or biology.
- BeetleB 9y agoYou didn't address anything the GP said. The more variables you test for, the more likely you'll get a low p-value by pure chance.
- highd 9y agoGreat catch. This is a super important factor. The real concern in science is how easy it can be to hide the fact that so many possibilities were tested, precluding this observation. As another example, there are GWAS studies where people take surveys and medical histories of large groups of people and then sequence their DNA to look for correlations across all possibilities. Those studies only report results with p values less than 1e-4 or 1e-5.
- tomrod 9y agoNote: as an observational study, this is not the final word on the subject. A p of 0.02 being the strongest evidence may also be the result of p-hacking. More research is needed. Causal studies should be performed to confirm. Further, the sample size is exceptionally low (n=28).
- heisenbit 9y agoIt is even worse, there were only 7 male participants. Imagine - of course totally theoretical - that men eat more red meat then the study may attribute the fact that men age faster to red meat.
- astrange 9y agoThat would make sense, for the same reason men's vitamins don't have iron in them.
- eeZah7Ux 9y agoHonest, slightly OT question: what motivates researchers to perform and publish studies with low N? Can it have a positive or negative impact on their career?
- JumpCrisscross 9y ago> what motivates researchers to perform and publish studies with low N? Consider the systemic perspective. There are problems where we have no idea what's going on. (The pool of possibilities is so big, relative to the budget, that it's practically infinite.) In these cases, lots of low-N studies could be better than a few high-N ones. It's a balance between the odds of your study giving a false result against the odds of picking the wrong hypothesis.
- wuschel 9y agoThat - or the results are based on one of those low quality medical research studies that is performed by medical students in order to get their MD in some countries.
- nhaehnle 9y agoPerforming studies with low N makes it more likely for spurious effects to pass the various statistical effects. Therefore, it makes it more likely to obtain a result that can be published (despite being wrong).
- criddell 9y agoI would think that a high n study finding no relationship between telomere length and diet would be very publishable.
- nhaehnle 9y agoTraditionally not really, unfortunately. The problem is that negative results usually don't allow you to tell a story. The solution to this is a publication process where you register studies before you do them, in exchange for guaranteed publication once you're done with them. Different fields are further along in establishing such processes. (I've never worked in an empirical field myself, just reporting what I hear from a psychologist friend.)
- Mz 9y agoPhysical activity... was not related to telomere status. Other studies say the opposite: https://www.ucsf.edu/news/2013/09/108886/lifestyle-changes-may-lengthen-telomeres-measure-cell-aging https://www.ucsf.edu/news/2013/09/108886/lifestyle-changes-m... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2581416/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2581416/ http://www.edinformatics.com/news/exercise_and_aging.htm http://www.edinformatics.com/news/exercise_and_aging.htm
- JackFr 9y ago> Many factors can modify telomere length, among them are: nutrition and smoking habits, physical activities and socioeconomic status measured by education level. That seems especially poorly worded.
- veddox 9y agoI don't think the authors are native speakers, let's forgive them for that ;-)
- Nomentatus 9y agoAll speculative but... I've assumed since hearing about telomeres that they were a failsafe against cancer; X cell divisions allowed, then apoptosis. If so, maybe shorter telomeres are something you can afford if you have the energy (etc) to engage in a lot of DNA maintenance.
- oliwarner 9y ago> Study included 28 subjects Well beside the other process issues, 28 is a farcically small set to draw any conclusions, even future hypotheses from. Scale that to 2800 and we can talk.
- veddox 9y agoThis whole study strikes me as rather weak, I wouldn't give assign too much importance to the results. As mentioned below, the number of participants was rather low (though that is not uncommon in the life sciences and medicine). Also, the statistics appear to be sloppy, or at any rate not sufficiently documented to be verifiable. Thirdly, they tried to investigate too many things at once ("diet, smoking habit, physical activity and education"). And lastly, they base their whole study on the supposed link between telomere length and human longevity - a somewhat obsolete hypothesis.
- pavement 9y agoStudy included 28 subjects (seven male and 21 female, age 18–65 years) completed the questionnaire and gave blood for testing peripheral blood mononuclear cells telomere length. So, in other words anecdotal evidence, and an interesting sidebar, but really just some notes about one type of tissue sample across 28 people. If it were any other look at any other tissue sample, what would you say about the sample size and the reliability of voluntary answers from subjects based on memory?
- uuuiiiiooooppp 9y agoFunny how a shitty study about how butter is good for you funded by the meat and dairy industry is lavished with praise, but any study that says your bad habits are bad for you is met with "oh I am unconvinced. Probably p-hacked. Too small a sample size."
- Mz 9y agoActually, the thing I thought was funny is that some comments here interpret the study as saying "red meat is bad for you" and others interpret the study as saying "red meat is good for you." I actually couldn't quite figure out wtf it was saying about red meat's impact on you. And given the conflicting interpretations here, I feel like I am not the only one.
- tr1ck5t3r 9y agoThey didnt test for Vit D3 levels, and d3 has been shown to reduce the shrinkage of the telomeres during cell replication, but before you all go out and get some sun to raise your d3 or consume some d3 supplements, as Vitamin D Receptors (vdr's) also have a zinc finger as do Vitamin A receptors, make sure you increase your zinc intake otherwise the body will try to load balance the zinc between the different parts of the body which need zinc. Some enzymes have also been shown to increase the length of telomeres so it takes more time for the cell to reach the Hayflick limit. I also ask myself, does having cells with long telomeres benefit me? What if the genes have mutated in the cell, it could then be faulty like cancer cells, so then what? Is my immune system capable of spotting the faulty cell and killing it off (apoptosis). If it is, is the removed cell replaced with a stem cell mobilised to replace the removed cell? Melatonin increases the release of mesenchymal stem cells, but what if the wifi from my laptop is detroying or degrading the bone marrow in my femur so the stem cells are destroyed or reduced so theres a deficit whereby only essential cells are replaced with stem cells? As you can see, we are more complicated than a study of sorts which looks at one part of the body in relative isolation in order to draw a conclusion. Perhaps this study is being used to get people to eat less red meat as the planets ability to produce it en-masse is limited which could explain burgers grown in test tubes and the UN's call to start eating insects as a protein food source, whilst no one really wants to admit global human population is putting some resources at unsustainable levels.
- paulcole 9y agoPhew, I was worried this study of 28 people would make me reject the fad diet I read about in a magazine.