2. Outline Why? Why do we age? How do we age? What can be done now? One example – folic acid
3. Why Why this talk? Why extend life? Why now? Why do we age?
4. Why this talk? Human life extension is untestable using double blind interventions Have to use epidemiological studies Animal models Probabilities, not certainties R is the only proven mechanism for slowing aging in mammals ....?
5. CR is the only proven mechanism for slowing aging in mammals ....? CR does extend maximum lifespan, but more effectively in laboratory bred rodents than wild ones. Decreased average lifespan in some wild strains Lab strains have been bred to live fast, grow obese and die young (Austad) Mortality due to increased frailty cancelled the average longevity (in Rhseus monkeys) Same may apply to reservatol (a CR mimic)
6. Why We Age by Steve Austad Critically reviews all the theories of aging Author has done research on testing calorie restriction on wild mice.
7. Why this talk?Some popular claims: CR is the only proven mechanism for slowing aging in mammals ....? No drug slows aging (true only if you exclude micronutrients) Supplements are a waste of time and money Maximum lifespan is immovable ...?
8. Maximum lifespan is immovable Leonard Hayflick (How and Why We Age, 1994), claimed that the maximum human lifespan was currently 115 years and that it would take 10,000 years to breach the 120 year barrier. He should have spoken to ....
10. Why extend life? Good health is good Bad health is expensive, especially in your last years Reaching the singularity alive is important ETA was c.2030 in 1980s, now it’s c.2045.... Reaching the singularity in relative youth and good health is important because....
12. Why now? Life extension becomes more popular as the singularity approaches and immortality becomes more credible Losing a chance at immortality is worse than losing the chance of a few more years. CR now seems worth the effort But are there easier options? First we have to understand why we age.
13. Why do we age? Necessary for species survival Without population turnover, no evolution. So evolution invented aging. “Species selection” is not a viable driver of evolution. Selfish genes (Dawkins) explain most things that superficially appear to be species-driven Popular view – make room for the kids, prevents stagnation etc, but not a scientific theory.
14. Why do we age? Rate of living Max Rubner and later Raymond Pearl, 1920s Small animals with high metabolic rates have short lives. Total number of heart beats over a lifetime is roughly the same. Unfortunately birds are a prominent exception. So only works for mammals? Unfortunately humans are also an exception. Not very credible
15. Why do we age?Wear and tear / repairs and errors Dr. August Weismann, a German biologist, 1882 Things go wrong and life grinds you down. Updated in 1963 Dr. Leslie Orge to include specifically errors in protein synthesis and DNA repair Related to the rate of living theory, but includes repair mechanisms. Credible
16. Why do we age?Developmental theories Aging changes are programmed We grow old in the same way as we grow up But not everyone grows up, but everyone grows old. Why would evolution bother? In the wild very few animals reach old age. Evolution doesn’t have to kill us, even if it “wanted” to – life will do that anyway.
17. Infantilism or Peter Pan syndrome Growing old but not growing up. Reverse is not seen – everyone ages, so it can’t be developmentally controlled, since any developmental process could abort.
18. Why do we age? Disposable soma Thomas Kirkwood, “Disposable soma”, 1977 Evolution has invested resources in genetic survival over personal survival., Genes (germline) survive Our bodies (soma) don’t Bodies degrade once past peak reproductive age Genes that aid reproduction but reduce personal survival are selected for – includes genes that are useful in youth but injurious in old age, which contribute to aging (antagonistic pleiotropy, George Williams, 1957) Highly credible – is mainstream. Makes successful predictions
19. Disposable somaPredictions Creatures without a germ-soma division won’t age. E.g. Hydra. High predation, unstable environment – “r-strategy”- rapid aging - opossums – subspecies on islands age more slowly (Austad) Low predation, stable environment – “K-strategy” – slower aging - Bowhead whales (150-200 years) - elephants, - Galapagos tortoises - bats and birds
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21. An immortal When food is abundant hydra reproduce by budding. No germline distinct from the soma. Total regeneration.
24. How we age(some) mechanisms of aging Acidification Autoimmune Excess Calorics Cross-Linking Developmental theories, including the Death Hormone DNA and Genetic Theories Errors and Repairs Free Radicals Glycation The Hayflick Limit Membrane Theory of Aging Methylation Mitochondrial Decline Neuroendocrine Redundant DNA Theory Telomeres Thymic-Stimulating Theory "Wear and Tear“
25. How we age Telomeres Ends of chromosomes lost with cell division Eventually cell division ceases Unfortunately rodents regenerate telomeres, yet age as we do More likely that telomeres are a defence mechanism against cancer, which large, long-lived organisms (us) need more than small, short-lived organisms (e.g. mice)
26. How we age Free-radicals / oxidation Denham Harman, 1956 Free-radicals produced by mitochondria Reactive molecules with available links Form cross links with other molecules DNA damage Very popular model: Good vs evil Anti-oxidants mop up free-radicals Little evidence (vitamin E does not extend lifespan)
29. How we age Glycation Free glucose acts as a free radical Diabetics age more quickly Can’t eliminate glucose, but can control diabetes I & II
30. Thymus Master gland for immune system (makes T cells) Decreases in relative size from birth to puberty Decreases in absolute size from puberty onwards (35 grams to 5 grams at 70) Shrinkage regarded as irreversible
32. Thymus Reversibility of the thymic involution and of age-related peripheral immune dysfunctions by zinc supplementation in old mice. Mocchegiani E, Santarelli L, Muzzioli M, Fabris N in Int J Immunopharmacol. 1995 Sep;17(9):703-18. PMID: 8582782 “These findings clearly pin-point for relevance of zinc for immune efficiency and suggest that the age-related thymic involution and peripheral immunological dysfunctions are not intrinsic and irreversible events but are largely dependent on the altered zinc pool.” The mice received 22mg /L/d of zinc sulphate in their water. Restoration of the thymus in aging mice by in vivo zinc supplementation. Dardenne M, Boukaiba N, Gagnerault MC, Homo-Delarche F, Chappuis P, Lemonnier D, Savino W in ClinImmunolImmunopathol. 1993 Feb;66(2):127-35. PMID: 8453784
33. How we age Death clock Dr Donner Denckla, endocrologist, 1974 Death clock – we switch off at some predetermined time, controlled by release of a “death hormone” Same evolutionary objections as developmental theories in general; why would evolution bother? In the wild very few animals reach old age. Occurs in plants and animals that make a huge one-off seasonal investment in reproduction. E.g. salmon, some fruiting plants, cacti. Not applicable for other organisms.
34. Methylation Transfer of methyl groups -CH3 Mediated by a coenzyme, SAMe Decreases with age Responds to supplementation with zinc, B5 , B6, folate (B9), vitamin B12
35. Coenzymes Coenzymes are molecules that an enzyme needs to complete a reaction An enzyme may require many different coenzymes to function. Some attach permanently, some are co-substrates and detach afterwards. A coenzyme may be used by many different enzymes for the same function. Many-to-many relationship Either synthesized or sourced from diet Modular or even object-orientated. Suspiciously well “designed”. But evolution will suborn processes for other uses.
37. Methylation Transfer of methyl groups -CH3 Mediated by a coenzyme, SAMe Decreases with age Responds to supplementation with zinc, B5 , B6, folate (B9), vitamin B12 What about all the other groups transferred?
38. Entropy All the mechanisms are partial causes Biology is complex We don’t know how we age Entropy is a measure of disorder and ignorance Entropy = loss of information Aging is a form of biological entropy
39. Entropy True information loss is irreversible Aging is reversible only by injection of information Current therapies are information poor Supplements are information poor Aging can’t be reversed (this side of the singularity) “War on aging” cf Nixon’s “war on cancer”, 1970
40. Rejuvenation vs retardation True information loss is irreversible Have to reduce the rate of information loss Retard aging, not reverse it Prevention versus treatment
41. Entropy All the mechanisms are partial causes Biology is complex We don’t know how we age Entropy is a measure of disorder and ignorance Entropy = loss of information Aging is a form of biological entropy
42. Entropy Information loss is irreversible Aging is reversible only by injection of information Current therapies are information poor Supplements are information poor Aging can’t be reversed (this side of the singularity) “War on aging” cf Nixon’s “war on cancer”, 1970, failed through underestimating the complexity of problem Rejuvenation, regeneration is a pipe dream – not before the singularity
43. Rejuvenation vs retardation True information loss is irreversible Have to reduce the rate of information loss Retard aging, not reverse it. Rejuvenation or regeneration is a pipe dream – not before singularity Is there any evidence that we can slow aging? Let’s examine just one coenzyme, folic acid.
44. Folic acid (vitamin B9) Needed for cell replication, specifically to synthesize thymine for incorporation into the new DNA. Cell division induces DNA damage (mutation), and hence breast cancer, colon cancer etc Low levels of folate result in DNA damage (misincorporation of uraecil into the DNA leading to chromosome breaks) High levels of folate reduce the cancer rate
45. Folate and colon cancer Multivitamin use, folate, and colon cancer in women in the Nurses' Health Study. Giovannucci E, Stampfer MJ, Colditz GA, Hunter DJ, Fuchs C, Rosner BA, Speizer FE, Willett WC in Ann Intern Med 1998 Oct 1;129(7):517-24 PMID: 9758570 Long-term use (>15 years) of folate-containing multivitamin supplements produced an almost 5-fold reduction in the incidence of colon cancer. Other cancers not analysed. The protective effect (relative to age-matched controls) increased with the duration of supplementation. The relative risk of colon cancer over the period 1980-1994 (against folate intake in 1980, without adjusting for other vitamins) was: 1.0 (<= 200 ug/d), 0.92 (201-300 ug/d), 0.79 (301-400 ug/d) & 0.69 (>400 ug/d). This risk declined with time: comparing the >400 with the <=200 folate ug/d group the risk declined from 0.85 (1980-mid1988) to 0.56 (mid1988-1994). Amongst multivitamin users (pooling all folate categories) the risk declined with duration of use: 1.02 (4 years use), 0.83 (5-9yrs), 0.80 (10-14 yrs) & 0.25 (15+ yrs). Women who had 15+ years of multivitamin use and >300 ug/d energy-adjusted folate (in 1980) had a RR of only 0.22[CI: 0.05-0.88] compared with users with <15 years multivitamin use and 201-300 ug/d (>RDA) of energy-adjusted folate. FDA regulations forbad the use of 400ug of folate in multivitamin supplements prior to 1973, which limited the ability for a longer -term follow-up. The study abstract concludes: “Long-term use of multivitamins may substantially reduce risk for colon cancer. This effect may be related to the folic acid contained in multivitamins.”
46. Nurses' Health Study Epidemiological longitudinal study Initially cancer rate rose slightly (2%) Fell with long term use (5 years+) By 15 years the relative risk was reduced by 78% In absolute terms, no increase in the cancer rate with age, i.e. total genomic protection against the Gompertz curve (exponential mortality growth between ages of 30-80 years)
47. Folate and Alzheimer’s Intervention trial: Improvement of cognitive functions after cobalamin/folate supplementation in elderly patients with dementia and elevated plasma homocysteine. Nilsson K, Gustafson L, Hultberg B in Int J Geriatr Psychiatry 2001 Jun;16(6):609-14 PMID: 11424170 Epidemiological study: low folate plasma levels correlated with Alzheimer’s risk
48. Folate and longevity (in rodents) 18% mean lifespan extension. No extension of maximum lifespan.
49. Animal models Rodents display the same signs of aging as humans (greying of fur, reduced ambulation, frailty, sensory decline....) Age more quickly Share the same genes with us, although different variants. We are not longest lived mammal – bowhead whales live 2 or perhaps 3 times as long Metabolic pathways almost identical (exception: ascorbic acid where one of the steps is sourced endogenously in primates)
54. Of mice and men and rubber eels (an amphibian) Perhaps we are sufficiently closely related to rodents
55. Animal models A silicon-based life-form might think rodents and humans almost identical At the cellular level we are almost identical If aging is universal to all mammals then the differences in how our cells coordinate aren’t relevant
56. Folate Increases means lifespan Decreases risk of Alzheimer’s Protects the genome, stopping the age-associated increase of some cancers But there’s nothing special about folate; it’s just one coenzyme amongst many. Coenzymes are either synthesized endogenously (egSAMe, CoQ10 or CoA) or sourced from B-vitamins in our diet. Coenzymes are examples of metabolic cofactors. Minerals are also cofactors. They, of course, only come from our diet.
57. Other vitamins known to prevent cancer Niacin B3 (UV induced skin cancer) Thiamine B1 Vitamin D (all cancers)
59. Micronutrients and Lifespan Percentage increases comparable between insects and rodents - should therefore extrapolate to humans Coenzymes increase average lifespan Minerals increase maximum lifespan (extending the survival curve), as well as average lifespan (squaring the survival curve) Combinations are approximately additive Most metabolic factors are untested CR extends maximum lifespan in mammals and insects by the same order of magnitude
60. Additive? Coenzymes have distinctive metabolic actions B1 (thiamine) – carbonyl+C –CC=O- B2 (riboflavin) – one or two electron transfers B2 (niacin) – two electron transfers B5 (pantothenate) – acyl groups –C=O-R B6 (pyridoxine) – amino acid transfers (protein synthesis) B7 (biotin) – carbonyl transfers –C=O- B8 (inositol) – intracellular calcium signalling B9 (folate) – a number of one carbon groups B12 (cobalamin) – carbon side chain switching with adjacent hydrogen B12 (methylcobalamin) – re-methylation of THFolate The deficiency disease of one vitamin can’t be corrected by taking another. Likewise we would expect their benefits to be additive. Minerals have distinct roles – one element can’t substitute for another
61. Dietary RNA During digestion RNA is broken down into, and absorbed as, nucleotides and nucleosides. Nucleotides and nucleosides have a direct metabolic action, independent of their role in RNA, being the precursors to a number of coenzymes. ATP is a nucleotide based coenzyme as are UDP, CTP (required for biosynthesis of glycosaminoglycans, lipids and glycogen) NAD and CoA are also nucleotide coenzymes, involved in the Krebs cycle and elsewhere, but are not derived from dietary nucleic acids, rather dietary B3 and B5 respectively, Ribozymes are enzymes constructed from nucleotides instead of amino acids. Very ancient.
62. Minerals Vitamins are substances that we can’t synthesise Have to source vitamins from our diet Elemental minerals - selenium, chromium, zinc, magnesium,.... - can’t be synthesised – similar role to vitamins Components not only of enzymes (eg SOD) but also of proteins, directly (eg zinc fingers), and indirectly (the 21st amino acid is seleno-methionine) Perhaps this is why they have a more powerful anti-aging action than coenzymes and extend maximum lifespan, as well as mean lifespan.
63. Zinc finger No model of aging or detailed mechanism (like continental drift before plate tectonics, or inflation in cosmology today)
64. Micronutrients and LifespanDifferent starting ages The prolongation of survival in mice by dietary antioxidants depends on their age by the start of feeding this diet. Bezlepkin VG, Sirota NP, Gaziev AI by Mech Ageing Dev 1996 Dec 20;92(2-3):227-34 PMID: 9080401 Combination of beta carotene, alpha tocopherol, ascorbic acid, rutin, selenium, and zinc on the survival of male C57BL/6 (a long lived strain) Age in monthssupplementationstarted with human Remainingequivalent years lifespan extendedin ()s Median %LE Max %LE by (approx) 2 (6 yr) 16.4 11.4 18 9 (27 yr) 13.1 9.5 21 16 (49 yr) 4.2 2.7 14 23 (70?) 1.9 0 n/a This is how we would expect an anti-aging intervention to behave
65. Other (untested) candidates All the remaining B vitamins Carnitine Vitamin D Vitamin K Garlic Magnesium Vanadium Strontium Lycopene Fish oil
67. Mainstream neglect No model of aging or detailed mechanism (like continental drift before plate tectonics, or inflation in cosmology today) Unpatentable nutrients are unprofitable compared to patentable drugs Life extension experiments are time consuming (too long for a PhD) and expensive Preventative strategies are not as “sexy” as rejuvenation, attracts less funding The negative studies don’t get published Positive LE effects are artefacts of poor experimental design (eg reduced lifespan of the controls) Biological systems have complex feedback loops. Your metabolism will adjust to the higher intakes, and dump the excess, causing a rebound if you later cut back Counter-evolutionary. If aging is so easy to retard, why hasn’t evolution already done it?
68. No model The complexity of our metabolic paths means that we don’t have a simple one-to-one cause and effect scenario; it is many-to-many and much is currently unknown. (Known unknowns and all that.) Problem X isn’t treatable by nutrient Y alone. The reductionist model doesn’t easily handle the multifactorial nature of biological systems. Mindset is still vitamins just cure deficiency diseases; if you’re not suffering from a clinical deficiency disease you don’t need the vitamin. Not pregnant – you don’t need folic acid Not got rickets – you don’t need vitamin D (until recently)
69. Reduced lifespan of controls Chromium and selenium extended maximum lifespan past the species maximum. Therefore at least some of the lifespan extension can’t have been due to poor environment and reduced lifespan of the controls.
70. Tolerance and rebound Claim is that our metabolism has feedback mechanisms so that it excretes or neutralises megadose levels of micronutrients. Therefore benefits are lost after an initial period of adjustment. Called “tolerance”. Generates a “rebound” effect if intake levels are later reduced. Another explanation (Pearson and Shaw) is that the increased resources are diverted for employment elsewhere. This produces the increase in demand that we think of as tolerance. Increased consumption of a range of B-vitamins will induce deficiencies in the unsupplemented B-vitamins in line with the Pearson-Shaw hypothesis.
71. If aging is so easy to retard, why hasn’t evolution already done it? This objection is the most common amongst biologists, and is the equivalent of the popular “it ain’t natural” objection. Although intuitively compelling, it is a logical fallacy Evolution has optimised our metabolism to cope with out diets, not to make our diets optimal. Assumes eating has zero cost, whereas it is highly risky for both prey and predators
72. Things I avoid Hormones (DHEA, HGH) treat the symptoms of aging, not the causes. Xenobotics / drugs (including modifications of natural substances). Most drugs have serious side effects, which their natural forms don’t because of billions of years of coevolution BHT Melatonin: prefer to let my body synthesise it (methylated serotonin) since timed release is critical CoQ10: poorly absorbed. Prefer to let my body synthesise it
73. Things I take B-vitamins: Thiamine (B1), 825 mg Riboflavin (B2), 400 mg Niacin (B3), 1575 mg Choline (B4), 545 mg Inositol (B8), 2000 mg Inositolhexanicotinate, 2480mg niacin (B3), 400mg inositol(B8) Pantothenate (B5), 7.6 gm Pyridoxine (B6), 625 mg Biotin (B7), 4.8 mg Folate (B9), 8 mg PABA (Para Amino Benzoic Acid) (B10), 900 mg Cyano-cobalamin (B12), 7 mg Methyl-cobalamin (B12), 6 mg TriMethylGlycine, 450 mg Other co-enzyme precursors: Acetyl-L-carnitine, 1000mg Alpha-lipoic acid, 500mg RNA, 1000 mg Minerals: Boron, 9 mg Chromium, 1200ug Copper, 6 mg Magnesium, 2000 mg Manganese, 48 mg Molybdenum, 750ug Selenium, 800 ug, in various organic and inorganic forms Vanadium, 6 mg Zinc, 95mg Miscellaneous: Aspirin, 150 mg Beta-carotene, 150,000 IU Glucosamine, 1000 mg Lycopene, 40 mg + other carotenoids Fish oil/Omega 3 4g Saw palmetto, 1240 mg Vitamin C, 3 gm Vitamin D3, 6000 IU Vitamin E, 600 IU Vitamin K (18mg K1, 2mg K2)
74. Summary We know why we age Very little idea of how we age Reversing aging is impossible Slowing aging is possible, perhaps a doubling of lifespan
75. Food for thought Most LE supplements also function as cognitive enhancers. A rare combination experiment, which got an 11% LE in normal mice, not only halted age related cognitive decline but actually reversed it (the mice got smarter as they aged) A dietary supplement abolishes age-related cognitive decline in transgenic mice expressing elevated free radical processes. Lemon JA, Boreham DR, Rollo CD in Exp Biol Med (Maywood). 2003 Jul;228(7):800-10. PMID: 12876299 Supplement probably consisted of:Vitamins B1, C, D, E, Acetylsalicylic Acid, Beta Carotene, Folic Acid, Garlic, Ginger Root, Ginkgo Biloba, Ginseng, Green Tea Extract, Magnesium, Melatonin, Potassium, Cod Liver Oil, and Flax Seed Oil
76. Food for thought A dietary supplement abolishes age-related cognitive decline in transgenic mice expressing elevated free radical processes. Lemon JA, Boreham DR, Rollo CD in Exp Biol Med (Maywood). 2003 Jul;228(7):800-10. PMID: 12876299 Abstract: “We previously found that transgenic mice over expressing growth hormone (TGM) have elevated and progressively increasing free radical processes in brain that strongly correlates with reduced survivorship. Young mature TGM, however, displayed vastly enhanced learning of an eight-choice cued maze and qualitatively different learning curves than normal controls. Here we document the age-related patterns in learning ability of TGM and normal mice. Learning appeared inferior in both genotypes of very young mice but TGM were confirmed to be superior to normal mice upon maturity. Older TGM, however, showed rapid age-related loss of their exceptional learning, whereas normal mice at 1 year of age showed little change. The cognitive decline of TGM was abolished by a complex "anti-aging" dietary supplement formulated to promote membrane and mitochondrial integrity, increase insulin sensitivity, reduce reactive oxygen and nitrogen species, and ameliorate inflammation. Results are discussed in the context of reactive oxygen and nitrogen species, long-term potentiation, learning, aging and neuropathology, based on known impacts of the growth hormone axis on the brain, and characteristics of TGM.” Note: the title seriously understates the result: not only was cognitive decline halted by the supplements, it actually increased cognitive performance; the older supplemented animals had a greater cognitive performance than the younger controls. The performance of normal, untransgenic mice was also dramatically improved, although the small sample size precluded any statistical conclusions.
77. Where will it end? The mice were sacrificed. Suppose they hadn’t been.