Jump to content

Search the Community

Showing results for tags 'SIRT1'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Forums
    • CR Science & Theory
    • CR Practice
    • Chitchat
    • General Health and Longevity
    • CR Recipes
    • Members-Only Area
  • Community

Blogs

  • Paul McGlothin's Blog
  • News
  • Calorie Restriction News Update

Categories

  • Supporting Members Only
  • Recipes
  • Research

Product Groups

  • CR IX
  • CRSI Membership
  • Conference DVDs

Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


Website URL

Found 1 result

  1. All, I'm usually reluctant to post studies that try to associate single nucleotide polymorphisms (SNPs) with health or longevity outcomes. There are several reasons to be skeptical of such gene studies, including: They often fail to replicate across different populations The effects of individual SNP variations are often quite small - since there are usually many genes and polymorphisms that contribute to any important health/longevity outcome Often it's not even clear from the study what the specific allele variation(s) the authors are evaluating You often can't even find out what variant of an allele you have - since only some of us have our own genetic data and even that is only partial coverage through 23andMe. There is nothing you can do about it anyway - your genes are your genes. These polymorphisms and their effects often have nothing to do with CR. But this new meta-analysis [1] posted by Al Pater (thanks Al!) seems to suffer from none of these shortcomings. It focuses on a SNP in the FoxO3 gene (rs2802292) which has been previously associated with longevity - is it overrepresented in centenarians [2], as discussed here, and summarized as: [T]he odds ratio for reaching 100 years of age for rs2802292(G;G) vs (T;T) carriers was 2.75 (p = 0.00009; adjusted p = 0.00135). One's odds of living to 100 with one copy of 'G' for rs2802292 (i.e. G:T), appears to be about 1.5-2 times greater than people with T:T. Those results were encouraging, but didn't address causality, and was limited to a homogeneous population of men. Plus it only seemed relevant for people without other 'gotchas' (genetic or otherwise) that might kill them off long before reaching 100. What about the rest of us mortals, who may not be destined to live that long? Does having copies of the 'G' allele for rs2802292 do the rest of us any good on the way to extreme longevity? Apparently - Yes! Study [1] followed three pretty large groups of Americans with Japanese (N ≈ 3600), Caucasian (N ≈ 1600), or African (N ≈ 1000) ancestory for 17 years to assess the association between SNP rs2802292 status and mortality. Interestingly, the frequency of being a lucky 'G' Allele Carrier (GAC) for this SNP varied between the three populations - 47% of Japanese, 58% of Caucasian and 92% of African ancestry folks were GACs. Across all three populations, being a GAC was associated with a 10% reduction in all-cause mortality over the 17 year follow-up, with virtually all of the benefit resulting from a 26% reduction in heart disease mortality. Here is the most important figure from the free full text: As you can see the effect was quite consistent across the three populations. The difference in the confidence interval for the three groups was a result of the different population sizes. The cool thing is that those of us with 23andMe data can find out our status for SNP rs2802292. Simply log in to 23andMe and follow this link. I'm fortunate to be in the ~60% of caucasian people who is a 'G' carrier for this allele (I've got one copy). But for anyone who isn't lucky enough to be a GAC for this allele, there is still hope. Why? Because FoxO3 gene activity is something we know quite a bit about, including ways of boosting its activity, like the G allele for rs2802292 apparently does. Curiously, cider vinegar appears to upregulate DAF-16, the C. Elegans equivalent of FoxO3, which in turn resulted in the worms living 25% longer, as discussed here. So maybe cider vinegar is worth including in one's diet. I do. But even more relevant, we know that both CR and cold exposure increase FoxO3 gene expression largely by upregulating SIRT1, as discussed recently here. So everybody wins! --Dean ------------------ [1] The FoxO3 gene and cause-specific mortality. Willcox BJ, Tranah GJ, Chen R, Morris BJ, Masaki KH, He Q, Willcox DC, Allsopp RC, Moisyadi S, Poon LW, Rodriguez B, Newman AB, Harris TB, Cummings SR, Liu Y, Parimi N, Evans DS, Davy P, Gerschenson M, Donlon TA. Aging Cell. 2016 Apr 13. doi: 10.1111/acel.12452. [Epub ahead of print] Free Article http://onlinelibrary.wiley.com/doi/10.1111/acel.12452/full http://onlinelibrary.wiley.com/doi/10.1111/acel.12452/pdf Abstract The G allele of the FOXO3 single nucleotide polymorphism (SNP) rs2802292 exhibits a consistently replicated genetic association with longevity in multiple populations worldwide. The aims of this study were to quantify the mortality risk for the longevity-associated genotype and to discover the particular cause(s) of death associated with this allele in older Americans of diverse ancestry. It involved a 17-year prospective cohort study of 3584 older American men of Japanese ancestry from the Honolulu Heart Program cohort, followed by a 17-year prospective replication study of 1595 white and 1056 black elderly individuals from the Health Aging and Body Composition cohort. The relation between FOXO3 genotype and cause-specific mortality was ascertained for major causes of death including coronary heart disease (CHD), cancer, and stroke. Age-adjusted and multivariable Cox proportional hazards models were used to compute hazard ratios (HRs) for all-cause and cause-specific mortality. We found G allele carriers had a combined (Japanese, white, and black populations) risk reduction of 10% for total (all-cause) mortality (HR = 0.90; 95% CI, 0.84-0.95; P = 0.001). This effect size was consistent across populations and mostly contributed by 26% lower risk for CHD death (HR = 0.74; 95% CI, 0.64-0.86; P = 0.00004). No other causes of death made a significant contribution to the survival advantage for G allele carriers. In conclusion, at older age, there is a large risk reduction in mortality for G allele carriers, mostly due to lower CHD mortality. The findings support further research on FOXO3 and FoxO3 protein as potential targets for therapeutic intervention in aging-related diseases, particularly cardiovascular disease. KEYWORDS: FOXO3; heart disease; longevity; mortality PMID: 27071935 -------------- [2] Proc Natl Acad Sci U S A. 2008 Sep 16;105(37):13987-92. doi: 10.1073/pnas.0801030105. Epub 2008 Sep 2. FOXO3A genotype is strongly associated with human longevity. Willcox BJ(1), Donlon TA, He Q, Chen R, Grove JS, Yano K, Masaki KH, Willcox DC, Rodriguez B, Curb JD. Author information: (1)Pacific Health Research Institute, 846 South Hotel Street, Honolulu, HI 96813, USA. bjwillcox@phrihawaii.org Human longevity is a complex phenotype with a significant familial component, yet little is known about its genetic antecedents. Increasing evidence from animal models suggests that the insulin/IGF-1 signaling (IIS) pathway is an important, evolutionarily conserved biological pathway that influences aging and longevity. However, to date human data have been scarce. Studies have been hampered by small sample sizes, lack of precise phenotyping, and population stratification, among other challenges. Therefore, to more precisely assess potential genetic contributions to human longevity from genes linked to IIS signaling, we chose a large, homogeneous, long-lived population of men well-characterized for aging phenotypes, and we performed a nested-case control study of 5 candidate longevity genes. Genetic variation within the FOXO3A gene was strongly associated with human longevity. The OR for homozygous minor vs. homozygous major alleles between the cases and controls was 2.75 (P = 0.00009; adjusted P = 0.00135). Long-lived men also presented several additional phenotypes linked to healthy aging, including lower prevalence of cancer and cardiovascular disease, better self-reported health, and high physical and cognitive function, despite significantly older ages than controls. Several of these aging phenotypes were associated with FOXO3A genotype. Long-lived men also exhibited several biological markers indicative of greater insulin sensitivity and this was associated with homozygosity for the FOXO3A GG genotype. Further exploration of the FOXO3A gene, human longevity and other aging phenotypes is warranted in other populations. PMCID: PMC2544566 PMID: 18765803
×