LongevityHow to extend your healthy years.

Longevity does not mean "living as long as possible". It means "living healthy, capable and independent for as long as possible". Research distinguishes two measures here. Lifespan is the number of years lived. Healthspan is the number of years without chronic disease, without needing care, with physical and mental function intact. In most industrialised countries there is a gap of several years between the two, lived with chronic illness or limitations. Longevity in the true sense means closing that gap.

Lifestyle beats genetics

The idea that longevity is mostly inherited does not hold up against the data. Classic twin studies put the genetic share of lifespan at around 15 to 30 percent; an analysis by Ruby et al. (Genetics 2018) of family trees covering several hundred million people arrives at less than 10 percent once partner choice effects are accounted for. The rest is environment, behaviour and chance. Perhaps the most robust figure comes from the analysis by Li et al. (Circulation, 2018) of more than 120,000 participants over three decades: people who met five factors at age 50 (not smoking, regular exercise, a healthy diet, normal weight, moderate alcohol intake) had a remaining life expectancy 14 years (women) and 12 years (men) higher than people who met none of them. Every single factor counted; the combination counted most.

What longevity is not

Longevity is not a promise of 100 years, not an anti-ageing product and not a reversal of ageing. It is the sum of decisions that slow biological decline and lower the likelihood of chronic disease. Once you understand that, you also see why most longevity trends miss the point: they promise results without behaviour.

Ageing is not a single process but a bundle of damage mechanisms that reinforce each other: chronic inflammation, insulin resistance, loss of muscle mass, oxidative stress, impaired DNA repair. The factors that drive these mechanisms are well documented, and almost all of them can be influenced.

Two things stand out. First, none of these factors is exotic. Second, they do not add up, they multiply. Lack of sleep worsens the next day's food choices, lack of exercise worsens sleep, and stress drives both. Change one thing and you usually change several.

The evidence comes down to five levers. They are not new, but they are the only ones for which an effect on mortality and healthspan in humans has actually been shown.

1. Exercise. Endurance plus strength. The WHO recommends 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous aerobic activity per week, plus strength training for all major muscle groups on at least two days. Just 30 to 60 minutes of strength training per week lowers the risk of death by 10 to 20 % (Momma et al., BJSM 2022).

2. Nutrition. Mostly whole foods and mostly plants, with enough protein. The PREDIMED study, the largest randomised nutrition trial on cardiovascular prevention, found around 30 % fewer major cardiovascular events on a Mediterranean diet with olive oil or nuts compared with a reduced-fat control diet.

3. Sleep. Seven to nine hours, at consistent times. The relationship between sleep duration and mortality is U-shaped, with the lowest risk at around seven hours (Yin et al., JAHA 2017).

4. Stress regulation and mental health. Chronic stress is an independent risk factor for cardiovascular disease, depression and accelerated biological ageing. Breaks, nature, exercise, sleep and meaningful activity are the most effective regulators.

5. Social connection. The meta-analysis by Holt-Lunstad et al. of 148 studies with 308,849 people found that people with strong social relationships had a 50 % higher likelihood of survival, an effect on the scale of quitting smoking and well above that of excess weight.

The order is not a ranking. According to the data from Li et al., covering all five gets you most of the achievable gain. Working on just one still pays off: each factor showed its own dose-response relationship in the analysis.

Nutrition research argues about details, not about the basic pattern. Practically every diet with documented benefits (Mediterranean, Nordic, traditional Japanese, DASH) shares the same structure: plenty of vegetables, legumes, whole grains, nuts, fruit and high-quality fats, moderate amounts of fish or plant protein, little red and processed meat, little sugar, hardly any ultra-processed food. The label matters less; the pattern decides.

Protein: the underrated building block after 40

From midlife on, muscle responds less well to dietary protein. The standard recommendation of 0.8 g per kilogram of body weight is then no longer enough. The European PROT-AGE expert group recommends at least 1.0 to 1.2 g/kg per day for people over 65, 1.2 g/kg or more with regular training, and 1.2 to 1.5 g/kg during illness. For a person weighing 70 kg, that is 85 to 100 g of protein per day, best spread over three to four meals. It is the only nutritional factor where most people in later life take in too little rather than too much.

Fibre, fats, micronutrients

• Fibre: the German Nutrition Society (DGE) sets a guide value of at least 30 g per day; actual intake in Germany averages 18 to 19 g (DGE carbohydrate guideline). Legumes, oats, whole grains, vegetables and berries close the gap most easily.
• Fats: olive oil, nuts, seeds and oily fish instead of trans fats and excessive saturated fat. In PREDIMED, it was precisely the fat sources (olive oil, nuts) that made the difference.
• Micronutrients: in the DEGS study by the Robert Koch Institute, 61.6 % of adults were below 50 nmol/l of vitamin D, and in winter 25 % were even below 30 nmol/l. Omega-3, magnesium and, on a mostly plant-based diet, vitamin B12 are other realistic gaps. A blood test tells you more than any blanket recommendation.

Practical rules

• Plate model: half vegetables, a quarter protein, a quarter complex carbohydrates, plus a high-quality source of fat.
• Meal rhythm: three main meals, as little snacking as possible, last meal two to three hours before bed.
• Drinks: water, unsweetened tea, coffee in moderation. Sugary drinks and fruit juices are the easiest source of sugar to cut.
• Cut down on ultra-processed food: the BMJ umbrella review 2024, covering almost ten million participants, found consistent associations between high consumption and cardiovascular mortality, type 2 diabetes, depression and anxiety disorders.

Fasting and calorie restriction: an honest assessment

In animal models, calorie restriction reliably extends lifespan. In humans the data is newer and more cautious. The CALERIE study, so far the only two-year randomised trial, found clear improvements in LDL cholesterol, blood pressure, insulin sensitivity and inflammatory markers in healthy adults without excess weight who aimed for a 25 % reduction in calories. In practice, only around 12 % restriction was achieved, even with intensive support. That is the realistic limit in everyday life.

According to current data, intermittent fasting works mainly as a tool for eating less. In the randomised trial by Liu et al. (NEJM 2022), an 8-hour eating window over twelve months brought no significant added benefit over calorie reduction alone, neither for weight nor for metabolic markers. If an eating window makes it easier for you to eat less, it is a useful tool; it does not show an independent longevity effect. For older people, people with low body weight and people with a high training volume, fasting is less suitable because it competes with protein requirements.

If a drug lowered the risk of death by 20 to 30 %, prevented depression, diabetes, dementia and several types of cancer and cost almost nothing, it would be the most prescribed drug in the world. Exercise does exactly that and remains the most underrated intervention.

Why strength training after 40 is not optional

From midlife on, without countermeasures, the body steadily loses muscle mass and above all muscle strength; in later life this loss speeds up. Muscle strength is not a fitness topic but a survival marker: in the PURE study with almost 140,000 participants in 17 countries, grip strength predicted all-cause mortality more strongly than systolic blood pressure. Every 5 kg less grip strength meant 16 % higher mortality. Strength training is the only known way to stop or reverse this loss, at any age.

The good news: the dose is small. Momma et al. found the largest risk reduction (10 to 20 % for all-cause mortality, cardiovascular disease and cancer) at 30 to 60 minutes per week. More brought no additional benefit. Two sessions of 30 minutes with basic movements (squat, hip hinge, push, pull) are enough.

Everyday movement versus training

Both count, in different ways. The meta-analysis by Paluch et al. (Lancet Public Health 2022) of 15 cohorts showed that the risk of death falls with every additional step until it plateaus at 6,000 to 8,000 steps per day (over 60) or 8,000 to 10,000 steps (under 60). The often quoted 10,000 steps are not a scientific threshold; they come from a marketing campaign in the 1960s. Everyday movement does not replace training, though: only targeted load maintains strength and cardiorespiratory fitness (VO₂max), both of which are independently linked to life expectancy.

A concrete weekly plan

In total: about 150 minutes of endurance, 60 to 80 minutes of strength, daily steps. That meets the WHO recommendation and sits in the range where studies show the largest effect.

Adjusting for beginners and older adults

• Beginners: start with two sessions per week and build up volume over eight to twelve weeks. The dose-response curve is steepest at the start; the biggest gain lies in going from nothing to something.
• Over 65: the WHO additionally recommends balance and strength training on three days per week to prevent falls. At this age strength training matters more, not less.
• With existing conditions: for almost every chronic condition, exercise is part of the treatment, not its opposite. The intensity is agreed with a doctor; the volume is not simply dropped.

Sleep is the time in which the body repairs what the day has damaged: cell damage is fixed, the brain clears out metabolic waste, memories are consolidated, hormones such as growth hormone and testosterone are released, the immune system recalibrates. Cut back on sleep chronically and you cut back on all of this at once.

What lack of sleep does to the body

Just a few nights of under six hours measurably reduce insulin sensitivity, raise blood pressure and increase hunger hormones. Over the long term, prospective studies show a higher risk of high blood pressure, type 2 diabetes, cardiovascular disease and dementia. The meta-analysis by Cappuccio et al. of 1.3 million people found 12 % higher mortality with short sleep, and as much as 30 % with long sleep of more than nine hours, although the latter mostly reflects underlying illness. The optimum lies at seven to eight hours; quality and regularity count at least as much as duration.

An evening routine that works

• Fixed times, weekends included. The circadian rhythm rewards regularity more than any other measure.
• Manage light: daylight within the first hour of the morning; in the evening dimmed, warm light and screens away one hour before bed.
• Cool, dark, quiet: a room temperature of 17 to 19 °C, blackout, earplugs if needed.
• Caffeine until midday, alcohol ideally not at all: alcohol helps you fall asleep faster but wrecks the second half of the night.
• Last meal two to three hours before, no intense exercise in the last two hours.
• A wind-down ritual: ten minutes of reading, journaling or breathing exercises signal the end of the day to the nervous system.

Stress: the underrated longevity factor

Acute stress is harmless; chronic stress is not. Persistently raised cortisol promotes visceral fat, insulin resistance, inflammation and sleep problems, and worsens practically every health decision of the day. The tools with the best evidence are unspectacular: regular exercise, enough sleep, time in nature, deliberate breaks, social contact and activities that feel meaningful. In meta-analyses, mindfulness-based approaches show moderate but consistent effects on stress, anxiety and blood pressure.

When to seek professional help

Persistent trouble falling or staying asleep for more than three months, loud snoring with pauses in breathing, daytime tiredness despite enough sleep, or stress that affects work, relationships or health should be assessed by a doctor or psychotherapist. Sleep apnoea is underdiagnosed and an independent cardiovascular risk factor; it is treatable.

Most longevity articles cover lifestyle and leave out medicine. That is a mistake. The diseases that most often shorten healthspan (heart attack, stroke, type 2 diabetes, dementia, several types of cancer) announce themselves for years through measurable values. If you know these values and act early, you prevent disease instead of treating it later.

The numbers worth knowing

Screening by age

The following reflects the benefits catalogue of statutory health insurance in Germany, as set by the Federal Joint Committee (G-BA) in its health check guideline and its cancer screening guideline; the vaccination recommendations come from the Standing Committee on Vaccination (STIKO). Austria and Switzerland have their own programmes with a similar logic.

• 18 to 34: a one-off health check.
• From 35: a health check every three years with blood pressure, blood sugar, cholesterol and urine; skin cancer screening every two years; a one-off hepatitis B/C screening.
• From 45 (men): annual screening for prostate and genital cancer.
• From 50: bowel cancer screening (stool test or two colonoscopies ten years apart); mammography screening for women every two years up to 75.
• From 60: additionally an annual flu vaccination, a one-off pneumococcal and shingles vaccination; from 75 a one-off RSV vaccination. From 65, a one-off ultrasound screening for abdominal aortic aneurysm for men.

Eye and hearing tests are not covered by statutory insurance in the strict sense, but they are worthwhile: in dementia research, untreated hearing loss counts as one of the largest modifiable risk factors.

Act early

Warning signs such as chest pain on exertion, sudden vision problems or paralysis, unintended weight loss, blood in the stool or persistent exhaustion are not longevity questions but medical ones. Longevity also means keeping the threshold for seeing a doctor low. The screening programmes above exist because the diseases they cover can be detected early and are then much easier to treat.

The "Blue Zones" (Okinawa, Sardinia, Ikaria, Nicoya, Loma Linda) are the most popular longevity narrative of the past 20 years. They deserve a critical look.

The data is shakier than the narrative

The demographer Saul Justin Newman (UCL) has shown that regions with unusually many centenarians are disproportionately found where birth registers are incomplete, incomes are low and pension fraud is common. Only 18 % of "validated" supercentenarians worldwide have a birth certificate; the Blue Zone regions of Sardinia, Okinawa and Ikaria have lower life expectancy and weaker socio-economic indicators than their national averages. When Japan cleaned up its registers in 2010, tens of thousands of "living" centenarians disappeared. Blue Zone researchers disagree and point to extensive age validation in the core regions; the debate is open. What is certain: the number of centenarians is no proof of a lifestyle recipe.

What still holds true

The Blue Zone principles are not wrong; they are simply neither new nor regional. Each of them is supported, independently of the Blue Zones, by the studies cited in this article:

• Natural, daily movement instead of sitting: Paluch et al., WHO guidelines.
• Mostly plant-based, minimally processed food: PREDIMED, BMJ umbrella review.
• Strong social ties and community: Holt-Lunstad et al.
• Meaning and purpose ("Ikigai", "Plan de Vida"): consistent with research on meaning in life and mortality.
• Stress reduction and rhythm: sleep research, stress physiology.

What matters is the mechanism: in these regions, the behaviours arise from the environment. People walk, eat together, know their neighbours. If you live in Zurich or Stuttgart, you have to build that environment deliberately. That is the lesson that transfers: not a food, but an architecture of everyday life in which the healthy choice is the easy one.

What does not transfer

Individual "miracle foods" (sweet potato, beans, red wine), the exact diet of a region, or the idea that copying a village will get you to 100. Blue Zones are observations of populations, not guarantees for individuals, and the observations themselves are partly disputed.

Most longevity substances are at the same point: the biology is plausible, the data from cell and animal models is often impressive, and the human studies are newer, smaller and shorter. That is no criticism of the substances; it is the normal state of a field that has only been working with humans for a few years. Anyone making a decision here should know which level of evidence they are standing on. The table sorts the best-known approaches by the state of the human evidence.

How to read a longevity study

Five questions put any study in context, whether it speaks for or against a substance:

• Which species? Mouse data shows mechanisms, not effects in humans. It is the start of a chain of evidence, not its end.
• Which endpoint? A changed biomarker (such as a higher NAD⁺ level) is a necessary but not a sufficient condition for a benefit.
• How long and how large? Twelve weeks with 40 people show tolerability and direction of the signal, not a long-term effect.
• Who paid? Manufacturer-funded studies are the rule in supplement research; what matters is whether independent replications follow.
• How large is the effect compared with exercise? Training reliably delivers a 20 to 30 % risk reduction. That is the bar every substance has to be measured against.

These questions are not an argument against supplementation. They are the tool for making an informed decision, in either direction.

Two views on supplementation

Whether and when supplementation makes sense is currently answered from two fundamentally different perspectives. Both can be argued scientifically.

The classic view: a balanced diet covers the needs of a healthy person; supplementation is indicated where there is a deficiency or where adequate intake is not realistically achievable. This position relies on reference values such as those of the DGE or the D-A-CH societies of Germany, Austria and Switzerland. It is worth looking at how these values came about: historically they were set to prevent deficiency diseases, not to achieve optimal function in later life. Accordingly, they differ considerably between countries and institutions. For vitamin D, the D-A-CH societies give 20 µg per day in the absence of the body's own synthesis, while the European nutrient reference value on labels is 5 µg. For protein, experts have already raised the recommendation for older adults from 0.8 to 1.0 to 1.2 g/kg, because the earlier value did not reflect muscle maintenance.

The longevity view: evolution optimised humans for reproduction, not for health at 70 or 80. There was never any selection pressure for the body to absorb or produce everything in optimal amounts at every age. Several observations fit this: the body's own NAD⁺ production declines with age, muscle responds less well to dietary protein, nutrient absorption in the gut decreases. From this perspective, supplementation can make sense even without a measurable deficiency, namely for substances the body makes itself, but less of as it ages. Those who follow this logic decide on the basis of mechanism, animal data and early human data, knowing that final proof in humans is still outstanding. Prominent researchers such as the Harvard geneticist David Sinclair explicitly describe their own supplementation as a personal judgement of this kind. Dosages in this area are accordingly not settled, because the long-term studies that could establish them are missing.

What follows from this: for substances without completed proof of efficacy, manufacturers in the EU may not make health claims. That protects against exaggerated promises, but it also means the decision lies with each individual and cannot be handed off to the text on a package. Anyone who decides in favour pays attention to verified quality (independent certificates of analysis, batch traceability, EU manufacturing), to interactions with medication, to a blood test before and after taking it, and to a conversation with a doctor. And whichever view you take: no supplement replaces sleep, exercise or nutrition. At most it can add to them.

Knowledge changes nothing; habits do. The plan deliberately sticks to what applies regardless of any decision about supplements: measures that, according to current evidence, have the largest effect and initially cost nothing. It builds up the five levers over four weeks, one change per week, while the earlier ones continue. The goal is not perfection but routines that no longer take willpower after 30 days.

What you measure

• Behaviour: steps per day, training sessions per week, hours of sleep, alcohol-free days.
• Body: resting heart rate (in the morning before getting up), blood pressure, waist circumference, grip strength or number of squats in 60 seconds.
• Wellbeing: energy during the day, mood, sleep quality, each on a scale of 1 to 10, noted daily.

After 30 days, resting heart rate and sleep quality should be measurably better; blood pressure and waist circumference respond over weeks to months. The routines from weeks 1 to 3 are the foundation for everything that comes after.