40 Minutes That Could Add Years to Your Life

Siim highlighted that many self-trackers freak out over elevated creatinine, which is a normal byproduct of muscle metabolism. The standard eGFR equation uses creatinine and thus produces artificially low numbers for muscular people. Cystatin C, a protein produced by all nucleated cells at a constant rate, is freely filtered by the kidneys and reabsorbed, making it a more robust marker. He advises checking cystatin C and recalculating eGFR from it if kidney health is a concern, rather than restricting protein or stopping exercise based on a misleading creatinine reading.

Siim moves the protein debate from population-derived intake numbers to personalized biomarker monitoring. He explains that chronic disease states like diabetes can drive mTOR and IGF-1 far more than dietary protein alone, so blanket protein restriction may miss the point. He shares that his own IGF-1 sits around 100 ng/mL (slightly below his optimal range, but still normal) despite eating more protein than average and 300g of carbs daily, illustrating that diet composition doesn't map linearly to circulating IGF-1. He therefore advises people to test, observe, and adjust instead of dogmatically cutting protein.

Siim describes his own technique for balancing alertness and calm during fasted work: he will use caffeine and sometimes nicotine for focus, but the combination on an empty stomach can tip into anxiety. He noticed that a pinch of salt in water helps, hypothesizing that cortisol-driven natriuresis (salt excretion) creates a kind of subclinical hyponatremia that exacerbates the jitters. By restoring sodium, he feels more centred. He also notes that if he overshoots with stimulants, a small carb meal can dampen the effect.

Siim ranks nicotine as the second most common nootropic after caffeine. He advocates for low-dose, intermittent use to avoid tolerance and vascular side effects. He references a threshold of about 8 mg/day where vasoconstriction becomes a documented concern. His own approach is to use nicotine sparingly at 1-2 mg, treating it as an occasional tool rather than a daily habit. He acknowledges that not everyone tolerates it well.

Siim points out that organic certification does not mean chemical-free; organic pesticides are used. He therefore sees washing as a non-negotiable step for produce, especially thin-skinned fruits that you eat whole. He uses either baking soda or apple cider vinegar and soaks them briefly. This simple practice, in his view, offers meaningful reduction of potential contaminants at a minimal cost.

Siim identifies a class of overhyped, overpriced superfoods — sprouts, kombucha, sauerkraut — and argues that their true nutritional value does not justify their premium. He recommends growing sprouts at home (e.g., broccoli sprouts for sulforaphane) and home-fermenting foods and drinks. He ties this to a broader principle: you don't need huge quantities of expensive foods to meet nutrient needs. For example, a modest amount of meat covers B vitamins and iron, allowing the rest of the diet to be inexpensive staples like rice or potatoes.

In the nootropics discussion, Siim distinguished between the subjective feeling of productivity from caffeine and the objectively measurable output he gets from fasting. He structures his workdays to avoid high-carb meals early on. If he needs a stimulant boost, he layers caffeine or nicotine, but he finds that fasting forms the foundation of his cognitive performance. When the combination becomes too jittery, he adds salt or eats some carbs to dampen the overstimulation.

Siim has practiced intermittent fasting for ten years and started tracking blood markers only six years ago, so he cannot directly prove its effect on his early health. He acknowledges the published data but argues that the trials may not capture the subtle, long-term benefits he perceives. He speculates that a 5-10% advantage in biological aging could emerge over decades and cites his own stable blood work and vitality as indirect evidence. This view is a personal hypothesis, not supported by large-scale trials, but it reflects his willingness to integrate personal experience with scientific evidence.

Siim points to epidemiological data showing that the association between protein intake and mortality changes around age 65. Below 65, lower protein may be tolerable, but after 65, low protein predicts higher death rates. He attributes this to the accelerating risk of sarcopenia (muscle loss) and frailty. He doesn't prescribe a blanket gram-per-kilo target; instead he advises using biomarkers like IGF-1 to individualize intake. He notes that IGF-1 itself has a U-shaped relationship with mortality — both too low and too high are risky — so the goal is a sweet spot (115–130 ng/mL). He also highlights that many factors beyond protein (diabetes, high blood sugar) chronically activate mTOR, so personal metabolic context matters more than a single dietary rule.

Siim explains that physically active people often see elevated creatinine and are told their kidneys are impaired, when in reality the marker simply reflects their muscle metabolism. Because eGFR is calculated from creatinine, it too appears worse on paper. He advocates using cystatin C, a protein filtered by the kidneys that doesn't vary with muscle, diet, or creatine supplements. This test gives a more accurate picture of kidney health and prevents unnecessary dietary restrictions or anxiety. He deems creatinine tracking a red herring in the quantified-self community.

Siim acknowledges that some studies do correlate higher clock scores with mortality risk, but the field is riddled with noise. He cites findings that biological age can change throughout the day and jump dramatically after viral infections like COVID or the flu. A person who tests during an illness might get a terrifying result that normalizes weeks later. This variability undermines confidence in both single assessments and population-level correlations. He advises that anyone using these clocks should do repeated measures in stable health and understand their limitations before drawing conclusions.

Siim draws a distinction between interventions that improve healthspan and those that truly extend maximum lifespan. In the next five years, he expects wider use of existing regenerative tools like stem cells, exosomes, peptides, and hormones, which can rejuvenate joints, skin, and perhaps immune function but won't add decades. In 10 years, he foresees refined geroprotective drugs — better than rapamycin — and GLP-1 agonists repurposed beyond weight loss for inflammation, blood sugar, or other age-related dysfunctions. For lifespan beyond 150 years, he argues we will need gene editing or even whole-body replacement, which he puts at 15 years out. He also muses about using AI-driven simulations to accelerate human longevity trials.

Siim slept just four hours total per 24 hours for over three months. He could keep his cognitive function equal by using caffeine, and he experienced the lucid, semi-drunk feeling often reported with sleep deprivation (which might temporarily boost mood). However, his gym performance plateaued and he considered the long-term cardiovascular and metabolic cost as too high. He also experienced a frightening sleep paralysis episode. He now unequivocally states that the time gained is not worth the health trade-off, even if you feel productive in the short term.