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  1. Thank you Dean. I enjoyed the graphic too. A very nice summary. Notwithstanding the somewhat disturbing data from ( Goodrick, 1990) presented by Michael above, I agree with Mattson 's interpretation of (Masoro, 1995) that "Although providing evidence that meal frequency does not alter the ability of caloric restriction to extend life span, that study did not allow a conclusion as to whether IF can increase life span independent of overall calorie intake. " [ Source:: Anson RM, Guo Z, de Cabo R, et al. Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proc Natl Acad Sci U S A. 2003;100(10):6216–6220. doi:10.1073/pnas.1035720100]. As for (Goodrick, 1990), and related work, as a matter of perspective, I think it is worth keeping in mind that the relative harshness of the fasting protocols examined for rodents in these studies - versus say OMAD or a narrow daily TRF in man - are quite different metabolically. Michael's points is well taken, and this data should certainly be considered in assessing the preponderance of the research findings across model organism and outcome measure, but I have concluded that at least as of right now, the jury is still out -regarding the question of a small or modest CR-independent LE dividend or not. Fortunately, whether or not there is a mild LE dividend is not the primary motivation for my own personal TRF routine. Rather, my focus has been on enjoying the lifestyle itself, along with a not unreasonable likelihood of compression of morbidity with correspondingly better quality of life over my lifetime that goes along with it. These benefits may be enhanced by coordination with other healthy lifestyle choices, and implementation of "best practices," such as earlier meal timing: Jamshed H, Beyl RA, Della Manna DL, Yang ES, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves 24-Hour Glucose Levels and Affects Markers of the Circadian Clock, Aging, and Autophagy in Humans. Nutrients. 2019;11(6):1234. Published 2019 May 30. doi:10.3390/nu11061234 We clearly have a lot to learn with forthcoming research which will take time, but I have been pleased by increasing emphasis on lifestyle medicine in mainstream healthcare, just over the last few years. This was published in the most prestigious U.S. journal only a few months ago: de Cabo R, Mattson MP. Effects of Intermittent Fasting on Health, Aging, and Disease [published correction appears in N Engl J Med. 2020 Jan 16;382(3):298]. N Engl J Med. 2019;381(26):2541–2551. doi:10.1056/NEJMra1905136 In particular I concur with Dr. Mattson's suggestion in this NEJM piece that doctors write fasting prescriptions as a new standard of care, and that this should be taught and incorporated in medical education, starting from medical school. The idea of an "exercise prescription" is not new, has been gaining momentum over the last several years, and expanding this more broadly across lifestyle medicine could - with fewer side effects and adverse events - rival the positive impact of our entire collective surgical and pharmacological armamentarium.
  2. Mitchell SJ, Bernier M, Mattison JA, et al. Daily Fasting Improves Health and Survival in Male Mice Independent of Diet Composition and Calories. Cell Metab. 2019;29(1):221–228.e3. doi:10.1016/j.cmet.2018.08.011 Link: https://www.sciencedirect.com/science/article/pii/S1550413118305126 PDF: https://reader.elsevier.com/reader/sd/pii/S1550413118305126?token=D538587D59D918F2D842E8731AEAC8370AFDE49194F934865C08F67E1CD23F0C6FCD41DB887D7CDB27220A66D2FF1F47
  3. Hi Ron indeed this is what Michael argues, that it is not possible for natural diets and is more the purview of synthetic diet to achieve true SAAR. As I stated, more realistic Is methionine moderation to RDAish levels ( and as Michael warms and I caution below-RDA levels are not without risk) rather than striving for research protocol level restriction with the full caveat on morbidity prevention associated with the former vs. potential life extension suggested in animal models for the latter. Indeed, RDA may be too low depending on your age, health, and circumstances. Everything posted is not medical advice, but only for information purposes - Consult with your health professional! 🙂 if there is any rule of thumb take away, it is simply that a balanced, moderated calorie, yet high nutrient whole foods based diet and sound lifestyle is more important than precise protein levels as long as you don’t overdo it. Vegetable protein quality is generally lower from most sources, which is good for most people and indeed fiber can reduce absorption though not tremendously. Getting down to RDA levels of methionine is definitely possible. Playing around with cronometer it is possible to isolate the highest and lowest sources of methionine which can be readily identified. For example, it is possible to consume up to 3000-4500 kcal with 100-150% total protein requirements yet with (Met+Cys) in the 50%-120% range. That also implies <50% range for moderated calorie or FMD-like semi-fasting days of similar dietary composition and Of course 0% with a complete water fast. Keep in mind this may be helpful or harmful in humans and the jury is still out there; the most conservative approach would be to aim for 100% met+cys but not necessarily above that unless your background and circumstances indicate you would personally benefit from more. While leucine levels remain quite stable during fasts, Met drops like a rock and is one input for lower IIS signaling and mTOR inhibition with downstream autophagy - which in turn helps recycle AAs. Not advocating that example, just speaking from experience that it is possible for most people to get methionine down to RDA-ish levels provided that they are data-oriented with flexible preferences and permissive circumstances. As a rule of thumb, legume-heavy and vegan / near-vegan diets, and dilution by non-protein sources ( like healthy fats and/or carbs) tend to have lower methionine levels. For your interest, see the charts here on methionine levels by food ( through remember it is really C+M so not 100% accurate): https://www.brendadavisrd.com/methionine-restricted-diet/ Or really drill down with cronometer coupled with isolating low Met and Cys ratios with this nifty tool: https://tools.myfooddata.com/nutrient-ranking-tool.php Of course it depends in your dietary preferences. I personally enjoy giant whole foods based meals centered around diverse non-starchy vegetables and nuts. Remember, macadamia nuts are your friend! good luck, -Mechanism
  4. Glad it was helpful Clinton. I did some polishing and just added a couple new sections and sample calculations.
  5. Ron, I suggest as a starting point carefully reading sections 3 - 5 of the Lancet review I dubbed "magnificent" in my first reply above ( https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(19)30239-7/fulltext ). Though you are inquiring about BCAA ( ie leucine, isoleucine, and valine), rather than methionine, it is good to keep in mind Michael's perspective that MetR is neither realistically attainable on a natural-food diet (thus requiring a synthetic diet such as used in research protocols) nor desirable . For purposes of this thread, I am using MetR to designate restriction of Met AND Cys since Cys supplementation essentially abrogates the potential benefits of methionine restrictions. Some prefer calling this total sulfur AA (TSAA) restriction. In any case, Michael's objections that true MetR is neither possible with a natural diet, nor desirable in people ( he recommends 100% RDA but no more, which is not the same things as MetR) is well-summarized here: MetR is in some respects better characterized than BCAA restriction whereby per the National Academy of Sciences, the Met+Cys RDA is 19 mg/kg•d ( with an EAR of 15 mg/kg•d), and in mice most MetR studies have classically been in the 17% - 33% range; that is a 66-83% reduction in met+cys. Tables of NAS RDAs and EAR can be found here: https://www.nal.usda.gov/sites/default/files/fnic_uploads/DRIEssentialGuideNutReq.pdf Although these figures don't add up perfectly, the RDA corresponds to a Met recommendation of 10.4 mg/kg BW/day and a Cys recommendation of 4.1mg/kg BW/day. More explicitly at least for rodents "the range of dietary methionine restriction which elicits leanness without protein wasting and food aversion is 0.12 to 0.25 g per 100 g diet, as compared to the 0.43 to 0.86 g per 100 g in complete rodent diets [5,6]. However, most studies to date utilize methionine levels ranging between 0.12 to 0.17 g per 100 g diet with 0.17 g per 100 g diet the most well-studied restriction level " and "By restricting the methionine content from 0.86 to 0.17 g per 100 g diet(~80% reduction) throughout the adult lifespan of the animals, the authors observed an approximate 40% extension in average lifespan compared to unrestricted rats." [ Source: "Dietary Sulfur Amino Acid Restriction and the Integrated Stress Response: Mechanistic Insights" (2019): https://pubmed.ncbi.nlm.nih.gov/31208042-dietary-sulfur-amino-acid-restriction-and-the-integrated-stress-response-mechanistic-insights/ ]. This same review is helpful if you wish to learn more about some of the "robust physiological improvements with SAAR in rodent models" that are independent of CR since as they note SAAR tend to lose weight too. That in itself is interesting given that rodents lose weight despite feeding more: "the increased energy expenditure seen in SAA restricted animals has been well-delineated and found to be, at least in part, dependent on a number of mechanisms including β-adrenergic signaling." Among these CR-independent mechanisms that extend healthspan and lifespan that review focus on the "integrated stress response (ISR) [....] a lesser-understood candidate in mediating leanness and/or longevity by SAAR." This includes a variety of metabolic and other health measures with concomittant increase in FGF21 and other candidate mediators, though as with all interventions not without potentially concerning caveats such as the observation that "recent findings suggest that male mice subjected to SAAR display decreased bone tissue density in both trabecular and cortical bone, simultaneous with an observed induction in fat accumulation in bone marrow." A potential counter-argument regarding attainability of SAAR in humans is that at least one study found that mere 40% MetR - something more realistically attained -"decreases heart mitochondrial ROS production at complex I during forward electron flow, lowers oxidative damage to mitochondrial DNA and proteins, and decreases the degree of methylation of genomic DNA." ( that's from Gusavo Barja's work: https://link.springer.com/article/10.1007/s10863-011-9389-9 ). However it should be kept in minds that these are merely biomarkers for health and longevity and thus do not necessarily demonstrate life extension per se. Michael has not advised protein excess however as there is good data suggesting higher than RDA numbers may be deleterious, which is not the same thing as saying RDA numbers are life-extending, merely that RDA numbers prevent excess mortality seen when such thresholds are exceeded. " A word of caution against excessive protein intake (2019) provided a nice review of some of the problems with excessive protein, sorry it is behind a paywall: https://www.nature.com/articles/s41574-019-0274-7 . We can recall here that the RDI meeting the needs of 97.5% of the population is 0.8g/kg/day with some controversy for the geriatric population which may need up to 1.0-2.0 g/kg/day or more. This contrasts with an Estimated Average RequIrement (EAR) of only 0.6 g/kg/day. And in the UK the Reference Nutrient Intake (RNI) is set at 0.75 g/kg/bw This difference between the RDI and EAR underlies Mccoy’s periodic reminders on inter-subject variability in protein requirements. Here's an example to illustrate with nice round numbers: Let's say a 5 foot 8.5 inch tall healthy,( no absorption problem, no renal or hepatic disease, history of inflammatory bowel disease, free from chronic and inflammatory conditions with higher protein requirements such as status post a major burn, etc.) middle-aged ( ie., not geriatric) , active but not-an-athlete nor targeting any particular body composition goals individual practices "mild CR" is in the low end of normal body weight, a little above the underweight/normal weight demarcation. For some perspective, at 5 foot 8.5 inches, some milestones include 115 pounds = BMI 17.2 , 120 pounds = BMI 18.0, 125 pounds= BMI 18.7, and 130 pounds = BMI 19.5 . The cutoff between normal weight and underweight is a BMI of 18.5, which would about 123.15 pounds. I provide this for perspective. One quick note - A common question is whether to use actual or lean body mass. In theory estimates of lean body mass ( LBM) may be more accurate than using actual weight - however the difference between the two is likely not that great given the readers are presumably CR members. For a manuscript making the case LBM is superior, see "Inadequacy of Body Weight-Based Recommendations for Individual Protein Intake—Lessons from Body Composition Analysis" 2016: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5295067/pdf/nutrients-09-00023.pdf If you use this method , fat free mass can be determined by bioelectrical impedance (BIA), DEXA, or other methods. In either case let's say this individual practices "mild CR," and either weighs 121.25 pounds ( i.e., a BMI of exactly 18.5), or weighs a little more than that and prefers the FFM approach. This converts to a nice round number: 55 kilograms. So 55 kg *0.8 g/kg/d = 44 g/day total protein RDI - and this meets the needs of 97.5% of individuals at that FFM. What does the estimated average requirement ( EAR ) meeting 50% of the population needs look like for that FFM? 0.6 g/kg/day = only 33 g/day total protein. By comparison Valter Longo in his Longevity Diet, based on his own subjective assessment of risks/benefits for the average healthy individual, recommends 0.31 to 0.36 grams per pound protein per day . For 125.25 pounds, this corresponds to i the neighborhood of 38.8- 45.1 g/day Finally for Met+Cys ( ie, TSAA) with a DRI of 19 mg/kg/day this is 1,045 mg/day or around just over a gram a day. Two notes: Note 1: The values above represent only one paradigm, other guidelines are discussed and debated at : where mccoy cites a great piece going into the underlying molecular mechanisms including areas of knowledge: gaps: https://www.intechopen.com/books/muscle-cell-and-tissue/molecular-mechanisms-controlling-skeletal-muscle-mass . Sarcopenia yields significant morbidity such as from frailty and loss of independence as well as survival with aging, so preserving lean muscle mass warrants attention to be balanced with the benefits of not exceeding minimum requirements for maintaining muscle and molecular structure and function. For just a taste of the complexity and controversy over how best to estimate protein requirements, consider this passage: "Because the concept of protein requirement is predicated on an appropriate supply of the essential AAs and sufficient nonessential AAs and nitrogen, it is imperative the AA requirements are determined appropriately. To assess AA requirements properly, careful consideration must be given to the experimental design, statistical analyses, and interpretation of the results. Methods of assessing protein and AA requirements and availability have focused on outcome measures such as nitrogen balance, AA oxidation, growth, and blood concen- trations of urea nitrogen and plasma AAs in studies where animals were adapted to the diets over days or 1–2 weeks, depending on the outcome measures. [...] The majority of AA requirements have been mea- sured using short adaptation periods, usually anywhere from 2 to 14 days. This short duration fails to account for physiological adaptations over longer time periods. Indeed, the potential effects of PR or Met restriction (MetR) are likely repercussions of much longer feeding periods and are there- fore associated with protein accommodation rather than adaptation. Scrimshaw and Young19 eloquently described how accommodation to lower protein intakes results in loss of lean body mass and reduced rates of protein and AA turnover, and that these are related to survival.19 We are only starting to under- stand how both indispensable and dispensable AA intakes contribute to mammalian health and well- being. In contrast to the PR and MetR literature, human nutritionists generally seek to supply adequate protein and AAs to promote lean body mass, especially when combined with adequate physical activity.15 Under these conditions, nutritionists seek to then understand how other dietary variables and the environment may affect these requirements." [ source: Lessons from animal nutritionists: dietary amino acid requirement studies and considerations for healthy aging studies" https://www.researchgate.net/publication/322687412_Lessons_from_animal_nutritionists_Dietary_amino_acid_requirement_studies_and_considerations_for_healthy_aging_studies ] This review, presenting data of variable quality makes a case for higher-than RDA requirements in a variety of settings: "Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults" ( 2018) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872778/pdf/nutrients-10-00360.pdf In contrast, this recent high quality RCT published in JAMA internal medicine found that "changes in lean body mass, muscle strength and power, and physical function did not differ between men who consumed controlled diets containing the recommended dietary allowance and men who consumed a higher amount of protein (1.3 g/kg/d) for 6 months." Source: "Effect of Protein Intake on Lean Body Mass in Functionally Limited Older Men A Randomized Clinical Trial" ( 2018): https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2673735 And then, finally, there research - primarily basic and translational on the impact of sub-RDA levels of protein and certain AAa such as Met+Cys or BCAA’s ( as well as tryptophan, which I do not discuss in this thread) - and more on this can be found below and in the references provided in this post throughout. Among the most comprehensive is the Lancet piece I keep referencing: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(19)30239-7/fulltext Though ““methionine restriction extended lifespan in mice by nearly 7% [267], rats by 44% [268], and Drosophila by 36% [269]” [ Source “Amino acids in the regulation of aging and aging-related diseases” https://www.sciencedirect.com/science/article/pii/S2468501119300082 ], it is worth considering how much of the benefits of PR are explained by CR. Speakman’s analysis of rodent data concluded that “Our analysis of multiple manipulation experiments in rodents over the past 80 years shows that the food restriction effect on lifespan is due to reduced calories and not reduced protein intake (or sucrose intake, and possibly also fat intake), and hence is correctly called ‘caloric restriction’ or CR. Nev- ertheless, it is also clear that there is an independent impact of dietary protein reduction on lifespan, but it operates over a different range of restriction (50 to 85%: relative to a reference intake of 18–26% protein in the diet) than that over which CR is effective (10–65% relative to ad libitum intake), and has a much smaller impact. Hence, reducing protein levels by 80% (from 20% to 4%) increases median lifespan by about 15%, while reducing calories by half this amount (40%) increases median lifespan by on average twice as much (30%).” [ Source: “Calories or protein? The effect of dietary restriction on lifespan in rodents is explained by calories alone ( 2016) https://www.abdn.ac.uk/energetics-research/publications/pdf_docs/457.pdf ]. The overlap and relative magnitude of CR vs PR continues to be hotly debated and will be the subject of further research teasing this apart. Less controversial is the CR-independent metabolic and cancer risk reduction benefits of PR/BCAA/MetR, etc, as highlighted in multiple reviews cited in this post. Hence, debates in the scientific community abound, both regarding what is the optimal research protocol to capture our true protein/AA demand, the interpretation of these protocols and methods, and over the fine art and subjective assessment based on limited human data on what might comprise the best balance between (a) avoiding excess AA ( or Met in particular for example) and (b) avoiding deficiency/malnutrition that at a certain level may outweigh the benefits of AA/Met moderation/restriction. The sample calculation above was provided for illustration purposes only and is not medical advice. Individuals requirements vary by age, health status and physical activity level and other individual and environmental factors that can effect protein requirements; for example, for an overview of some factors affecting individuals over 40 years old, see: "Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults," 2018 @ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872778/pdf/nutrients-10-00360.pdf for more). Given such variation, mccoy has advocated in the past for individualized testing of protein requirements in the past, but regardless, where you stand on this, consultation with a knowledgeable and competent nutritionist, dietitian, or medical doctor specializing in this area would be best for significant nutritional interventions. Another metric is that moderated protein diet tend to average only around 7-9% calories from protein ( Dr. Fontana tends to use these numbers) , while in the U.S. the interquartile range ( IQR) is more like 10%-20% with most in the 1.0-1.5 mg/kg/day of protein [ Source: "A word of caution against excessive protein intake" 2019: https://www.nature.com/articles/s41574-019-0274-7. Again, requirements vary greatly, and these numbers are not set in stone: For example, Fontana examined a little less than 0.8g/kg/day ( ie 0.76 g/kg/day) total protein in humans relative to 1.73 g/kg/day and found a reduction in serum IGF-1 from 194 ng mL −1 to 152 ng mL with a concomittant elevation in IGFBP3 ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673798/ ) which we have reliably reproduced in follow-up studies ( esp. the rise in IGFBP3). Refer to my link in this paragraph for a review of some of the problems with excess protein - the data is based on various study designs and variable in quality - everything from epidemiological studies in man, to short-term RCTs focusing on surrogate markers of health and longevity, to well-controlled animal model . Something Michael emphasized in his long, well-documented thread above is that “based on data from both the Nurses’ Health Study (followed up from 1980 to June 1, 2012) and the all-male Health Professionals Follow-up Study (followup 1986 to January 31, 2012)” - and here Michael quotes the review: "The median protein intake, as assessed by percentage of energy, was 14%for animal protein (5th-95th percentile, 9%-22%) and 4%for plant protein (5th-95th percentile, 2%-6%). After adjusting for major lifestyle and dietary risk factors, animal protein intake was weakly associated with higher mortality, particularly cardiovascular mortality (HR, 1.08 per 10% energy increment; 95%CI, 1.01-1.16; P for trend = .04), whereas plant protein was associated with lower mortality (HR, 0.90 per 3% energy increment; 95%CI, 0.86-0.95; P for trend < .001). These associations were confined to participants with at least 1 unhealthy lifestyle factor based on smoking, heavy alcohol intake, overweight or obesity, and physical inactivity, but not evident among those without any of these risk factors." So that's the background, but how about BCAA ( leucine, isoleucine, valine) specifically? Just as we have seen for total protein - where definitions vary in intake threshold, organism, outcome of interest, and theoretical grounding ( e.g. g/kg vs. % calories vs. carbohydrate to protein ratio [ e.g., nutritional geometry framework ] vs. percentile of RDA or RDI, vs. percentile of measures observed in in the ad libitum population ), BCAA data is also all over the map. So the answer depends on what outcome you care most about, and how you feel about their methodology as well as the suitability extrapolating your goals in that domain. From the review I directed your attention to at the very top of this post, references 10, 12, and 75-84 focus most on this issue and you can read section 5.1 of the review to follow along depending on what benefits and protocols interest and suit you the most. In particular, you may find Fontana's work - whereby reducing total protein to only ~ 7-9% calories ( vs. ~50% more in the ad libitum controls) in humans improves metabolic markers, while in mice reducing BCAA's in particular by about 2/3 ( ie from 21% to 7%) recapitulated most of the metabolic benefits observed via 2/3 overall total protein reduction - pertinent : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4947548/pdf/nihms-800719.pdf ( "Decreased consumption of branched chain amino acids improves metabolic health"). For comparison, recall that the traditional Okinawan diet has ~9% kcal from protein with a C:P ratio of around 10:1, dubbed as the "Okinawan Ratio" by Simpson et. al. using their yet-controversial nutritional geometry framework: https://academic.oup.com/ageing/article/45/4/443/1680839 Having said that, why is there a relative dearth of BCAA standardized geroscience protocols compared to MetR despite the comparatively robust literature on BCAA and its anabolic effects of muscle hypertrophy? Partly because MetR - in contrast with BCAA - at least for synthetic diets with dramatically lower met+cys (ie MetR) protocols empirically have been observed to have a fairly consistent and robust impact on life extension. So BCAA work has focused more on moderating rather than restricting, and disease prevention rather than true life extension per se. There is lots more to it ( e.g., adding back Met specifically to CR diet abrogating the benefit of CR in at least one model), these are some of the highlights.
  6. Hi Saul, leucine besides being highly anabolic via multiple mechanisms including IGF-1 signaling ( along with other BCAA, etc.), it is a particularly potent mTORC1 stimulator: https://www.cell.com/cell-metabolism/pdfExtended/S1550-4131(18)30514-X Earlier mechanistic work was pioneered and continued in large part by David Sabatini’s lab at the Whitehead Institute and others; simple video follows or heard as an informal narrative on Peter Attia’s interviews on The Drive podcast Podcastnotes provides a summary of the interview on “The Drive” and link to the audio: https://podcastnotes.org/2018/08/14/mtor/
  7. For the motivated and/or lovers of Kripalu: https://kripalu.org/presenters-programs/wim-hof-method-weekend-fundamentals-nature-and-power-mind
  8. Beautiful find Dean. This highlights that you neither need to restrict protein ( nor methionine) to dangerous nor to an unrealistic degree to benefit from moderately limiting this macronutrient. Limiting protein ( or methionine in particular) further has been one of my cornerstone healthspan interventions over recent years. If you have the time and inclination this was a magnificent review on the subject you may enjoy: https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(19)30239-7/fulltext ( “The impact of dietary protein intake on longevity and metabolic health”)
  9. Mechanism

    "The CR Way" vs "The Longevity Diet" tips

    https://www.gwern.net/docs/longevity/2019-decabo.pdf
  10. Mechanism

    London meetup

    Hello Londoner. These days there are a limited number of active posters on the forum so I am not sure about other CR members in your area. Organizing and attending events takes energy so to open it up as much as possible you may consider organizing a virtual online meeting. Myself, I am in the U.S. EST (ie NYC / Boston). I don't know much about the technology, but you could piggyback off of established conferencing. For example the reddit on Longevity has the following channel available for either text or voice conferencing: https://discord.gg/ftSbffu Getting together periodically comes up but usually not a lot comes of it or maybe a meetup of 2-3 people. Perhaps if you set a default regular time for a walk-in / voice-in meeting ( e.g., every Friday 6pm EST @ " https://discord.gg/ftSbffu " on the voice channel ) it could provide a space for virtual meetings. Or, you can on an as needed basis announce availabilities.... or both ! Just a few thoughts for you. Please don't take the few responses here as a lack of interest, its great you like many of here have made efforts to incorporate evidence-based lifestyle practices towards optimal health. Good luck! - Mechanism
  11. Hi Ron, See the follow up Leiden Longevity Study publication, Association analysis of insulin-like growth factor-1 axis parameters with survival and functional status in nonagenarians of the Leiden Longevity Study (1). There they found that "lower IGF-1/IGFBP3 molar ratios conferred a survival benefit at the age of ninety years or older [and] Secondly, lower IGF-1/IGFBP3 molar ratios were associated with better functional status at the age of ninety years or older." To reconcile these findings with the earlier work you cited they speculate: This is within the context of an overall literature whereby a " large number of studies have reported an association between reduced IIS activity and longevity in various model organisms as well as in human studies showing life extending effects of reduced IGF-1 signaling." For more on this literature see ROLE of IGF-1 System in the Modulation of Longevity: Controversies and New Insights From a Centenarians' Perspective (2). The references in this brief piece cite some of the classic studies to unpack further. With regard to targets, I agree with Michael that provided nutritional adequacy and no other pertinent contraindications or individual and medical condition exceptions, that simulating IGF-1/IGFBP3 ratios more closely approximating the "low protein" group than the "low calorie" and "standard American diet" groups is likely generally better: See the first page of this thread where Sibiriak helpfully provided the link-out to the earlier thread. Consistent with the bar chart that Michael reproduced from the Aging Cell paper is data from (1). A ratio of ~ 0.09-0.15 may be optimal. References (1). van der Spoel E, Rozing MP, Houwing-Duistermaat JJ, Slagboom PE, Beekman M, de Craen AJ, Westendorp RG, van Heemst D. Association analysis of insulin-like growth factor-1 axis parameters with survival and functional status in nonagenarians of the Leiden Longevity Study. Aging (Albany NY). 2015 Nov;7(11):956-63. doi: 10.18632/aging.100841. PubMed PMID: 26568155; PubMed Central PMCID: PMC4694065. (2) Vitale G, Pellegrino G, Vollery M, Hofland LJ. ROLE of IGF-1 System in the Modulation of Longevity: Controversies and New Insights From a Centenarians' Perspective. Front Endocrinol (Lausanne). 2019 Feb 1;10:27. doi: 10.3389/fendo.2019.00027. PubMed PMID: 30774624; PubMed Central PMCID: PMC6367275.
  12. 💥 Dang autocorrect! Gets me every time....
  13. The thermonuclear housing debate - current standing in 4 Links Forgive me Dean for any redundancy, but a recent commentary strung together very nicely the current standing of the research landscape. I think including them here, in sequence, as a shortcut for those new to the issue to quickly get up to speed on the controversy and state of the science may be helpful. And fortunately the debate is narrowing with increased consensus that indeed ( as #4 concludes): “mice should be housed slightly below thermoneutrality to best mimic humans thermal conditions.” 1) Here is Speakman’s original 2013 paper and argument that thermonuclear housing is adequate ( discussed previously along with critiques and reposted here to recapitulate the story line ). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3757658/?report=reader#__ffn_sectitle 2) 2018 experimental data - with a very elegant design - from Jan Nedergaard investigating Speakman’s hypothesis and calling into question his conclusion https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5784327/?report=reader#__ffn_sectitle 3) Speakman’s 2019 follow up experiment and response to Nedergaard — despite the tone, please observe on a close read that the conclusions have more commonalities than differences with the Nedergaard study. Indeed they revise upward their estimate optimal temperature from the original first publication. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6599456/?report=reader#__ffn_sectitle 4) Hot off the press now: Nedergaard’s response. For CRONIES looking for a quick bottom line, if you read nothing else, start here and work your way back to the other links provided to fill in details and examine the raw data for yourself Here the authors summarize their own work cited above from 2018 evaluating Speakman’s hypothesis, and cite the 2019 by Keijer / Speakman work emphasizing that both publications found that for mice the daily metabolic rate at 30 °C is about 1.7-1.8 times higher than their BMR — approximately the same ratio as found in free dwelling persons. This makes the case for their conclusion that: “thermoneutrality is the optimal housing temperature for mouse metabolic studies directed to being translatable into humans.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6667698/#__ffn_sectitle Of course much more work remains to establish the extent of impact, for what medical conditions, interventions, and populations, so there is a lot more detail to fill in here I have found much of the utility of this thread pertains not only to this but moreover, on a practice level, to incrementally address and better characterize who benefits, by how much, and for what magnitude ( dose/duration/frequency) of different CE exposures along a multitude of potential health-related dependent variables of interest.
  14. Great summary Dean, I thought you would appreciate it too. And Sibiriak - I love your irreverent humor. True enough while I favor “natural” approaches over drugs whenever possible at multiple levels and for many reasons ( though they are usually not mutually exclusive) - when technology advances to intervene with greater efficacy and safety, I would not hesitate either - even the “D” word. The challenge is that evolution has had a head start of hundreds of millions of years coupled with massive parallel statistical reshuffling for both safety and efficacy - for most lifestyle conditions and most of the time nature is still much smarter than us!
  15. Very interesting: Though I practice some “convenience CE” I more formally maintain low dietary BCAA and (M+C). So this new publication piqued my interest. It is testimony to the mounting documented crosstalk between CE and geroprotective nutrient sensing metabolic pathways. https://www.nature.com/articles/s41586-019-1503-x
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