Deep Dives

The research behind the years.

Each article ranks what actually matters for a topic, names the studies, and gives you one concrete action per factor. Read one, test yourself, then check your own numbers.

Energizing drinks, by the numbers

3–5 cups

of coffee a day is where mortality risk bottoms out across 402,260 US adults followed for 14 years (NEJM 2012). Zero is fine too. More is not better.

Risk of dying during study follow-up

Versus people who drink none of that drink

Green tea, 5+ cups a day−16%
Coffee, 4 to 5 cups a day−12%
Black tea, 2+ cups a day−11%
Freedman NEJM 2012; Kuriyama JAMA 2006; Inoue-Choi Ann Intern Med 2022

Latest deep dive

The 7 things to know about coffee, tea, and energy drinks

Few daily habits have been studied as hard as what you drink to wake up. The verdict is unusually consistent and unusually kind: plain coffee and tea are two of the only pleasures in the longevity literature that keep coming back associated with longer life, cohort after cohort, country after country. But the pattern has edges. It flattens past a handful of cups, it reverses when the drink is mostly sugar, it does not extend to energy drinks, and it quietly sabotages the sleep that matters more than any of it when the timing is wrong. Here are the 7 findings worth knowing, ranked by evidence.

The short version

  • Coffee drinkers at 3 to 5 cups a day had 10 to 15% lower mortality across 402,260 adults over 14 years (Freedman, NEJM 2012). The curve is U-shaped: zero is fine, a dozen cups is not.
  • It is not just the caffeine. An umbrella review of over 200 meta-analyses found the same benefit in decaf drinkers (Poole, BMJ 2017), so the polyphenols are doing real work.
  • Tea shows the same pattern: 16% lower mortality at 5+ daily cups of green tea in 40,530 Japanese adults (Kuriyama, JAMA 2006), and 9 to 13% lower at 2+ cups of black tea in half a million UK adults, milk and sugar added or not (Inoue-Choi, Ann Intern Med 2022).
  • Energy drinks are not coffee, and going sugar-free does not make them coffee. The QT and blood-pressure effects appeared against caffeine-matched controls (Shah, JAHA 2019), implicating the additive stack rather than the sugar, and the longevity benefit tracks compounds energy drinks do not contain.
  • Timing decides whether coffee costs you sleep: caffeine taken even 6 hours before bed cut measured sleep by over an hour (Drake, JCSM 2013). Keep the last dose 8+ hours out.

7 factors · personal risk check · updated 2026-09-03

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Deep dive

The 10 things that matter most for your heart

Cardiovascular health is the strongest lever on how long you live, worth about 9 extra years. The 10 factors with the best evidence, ranked, each with one concrete action.

10 factors · personal risk check · updated 2026-08-10

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Deep dive

The 8 things that matter most for your sleep

Sleep is when the body repairs itself, and how regularly you do it predicts lifespan even better than how long. The 8 factors with the best evidence, ranked, each with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The 8 things that matter most for connection and purpose

Strong relationships predict survival about as well as quitting smoking, and a sense of purpose is worth years. The 8 social and psychological factors with the best evidence, ranked, each with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The 8 things that matter most for your metabolism

Diabetes at 50 costs about six years of life, and the road there is silent but usually reversible. The 8 metabolic factors with the best evidence, ranked, each with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The 7 things to know about alcohol

Above about 7 drinks a week, alcohol starts costing measurable lifespan, and the protective glass of red wine has not survived better research. The 7 findings with the best evidence, each with one concrete action.

7 factors · personal risk check · updated 2026-08-17

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Deep dive

The 8 things that matter most in exercise

The first 15 minutes a day buy the most years, fitness out-predicts every classic risk factor, and it is never too late to start. The 8 exercise findings with the best evidence, ranked, each with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The sports that add the most years, ranked

Tennis players outlived sedentary people by nearly a decade in the Copenhagen study, and the social sports beat the solo ones across the board. What the evidence says about picking a sport, each finding with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The 7 things worth knowing about hydration

Chronic underhydration tracks with faster aging in a 25-year NIH study, but most hydration advice is overblown. What the evidence actually supports, each finding with one concrete action.

7 factors · personal risk check · updated 2026-08-17

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Deep dive

The 8 things that matter most on your plate

Poor diet is tied to 11 million deaths a year, yet the fixes with the strongest evidence are additions, not restrictions. The 8 nutrition findings with the best evidence, ranked, each with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The 9 things that matter most for your colon

Colorectal cancer is the second-deadliest cancer and one of the most preventable: screening cuts deaths roughly in half, and fiber, meat, alcohol, and movement each move the risk. The 9 factors with the best evidence, ranked, each with one concrete action.

9 factors · personal risk check · updated 2026-08-23

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Deep dive

The 9 things that matter most for your blood pressure

High blood pressure at 50 costs about five years of life, and roughly half the people who have it do not know. The 9 factors with the best evidence for assessing and lowering it, ranked, each with one concrete action.

9 factors · personal risk check · updated 2026-08-17

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Deep dive

The 10 things that matter most for your dementia risk

Nearly half of dementia cases are linked to 14 factors you can act on, and the biggest ones are not what most people guess: hearing, blood pressure, and staying connected. The 10 with the best evidence, ranked, each with one concrete action.

10 factors · personal risk check · updated 2026-08-17

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Deep dive

The 8 things to know about Alzheimer’s risk

Alzheimer’s is the most common dementia, genes load the dice but do not throw them, and sleep is when the brain clears the protein at the center of it. The 8 findings with the best evidence, each with one concrete action.

8 factors · personal risk check · updated 2026-08-17

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Deep dive

The 9 factors that decide your type 2 diabetes risk

One in three adults has prediabetes and most have no idea. The 9 factors that predict who develops type 2 diabetes, ranked, each with one concrete action, so you can assess your own risk honestly.

9 factors · personal risk check · updated 2026-08-17

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Deep dive

The 9 things that matter most for surviving the road

Crashes are a leading killer before old age gets a vote, and your risk is mostly a handful of habits: belt, speed, phone, sleep, and what you ride. The 9 factors with the best evidence, ranked, each with one concrete action.

9 factors · personal risk check · updated 2026-08-17

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Deep dive

The 9 things balding is actually telling you about your health

Going bald will not shorten your life, but early balding is a surprisingly useful health signal: it correlates with heart and metabolic risk, and a bare scalp changes your sun math. What the evidence says, what is myth, and what is worth acting on.

9 factors · personal risk check · updated 2026-08-18

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Deep dive

What you inherit from your family, and what you don’t

Lifespan itself is barely heritable, but specific diseases do run in families. What your family tree actually predicts, what it doesn’t, and how to use it — ranked by the evidence.

8 factors · personal risk check · updated 2026-08-20

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Deep dive

The 8 things that matter most for staying calm

Centenarians share a personality profile: low stress, high resilience. Chronic distress raises death risk in a dose-response curve, and calm is trainable. The 8 factors with the best evidence, ranked, each with one concrete action.

8 factors · personal risk check · updated 2026-08-25

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Deep dive

The mental health conditions that cost the most years, ranked

Every major mental health condition ranked by the years it takes off a life: substance use disorders and schizophrenia at the severe end, anxiety at the mild end, and depression appearing twice — roughly 7 to 11 years lost untreated, close to baseline when treated.

9 factors · personal risk check · updated 2026-08-30

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Deep dive

What depression does to a lifespan, treated and untreated

Untreated recurrent depression costs an estimated 7 to 11 years, mostly through heart disease, diabetes, and stroke rather than suicide. Actively treated, death rates fall to near those of people without depression. How the damage happens, and how treatment interrupts it.

9 factors · personal risk check · updated 2026-08-30

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Deep dive

The 9 things that matter most for taming inflammation

Aging researchers call it "inflammaging": the chronic low-grade inflammation that accumulates with age and drives heart disease, dementia, diabetes, and frailty. A landmark trial proved lowering it prevents disease on its own. The 9 levers with the best evidence, ranked, each with one concrete action.

9 factors · personal risk check · updated 2026-09-01

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Deep dive

Why doctors will not shut up about fiber

The largest fiber review ever conducted found 15% lower all-cause mortality and up to 31% lower heart disease death at 25–29 grams a day. Beans, oats, vegetables, fruit with skin — not powders. The 8 things the research actually shows, ranked.

8 factors · personal risk check · updated 2026-09-01

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Deep dive

What your skin is actually telling you about how long you live

Skin is a scoreboard for smoking, sunburns, sugar, and inflammation. Wrinkles are photoaging. Shade and clothing beat sunscreen. The evidence on what matters, and what does not.

8 factors · personal risk check · updated 2026-09-01

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Deep dive

Vegan, vegetarian, omnivore, carnivore: what the labels actually buy you

Vegetarians cut heart-disease deaths by about a quarter, yet health-conscious omnivores live just as long. Vegans do well only if they manage B12 and bone health. Carnivore has zero long-term evidence, and its nearest studied cousin raises mortality. What the diet-camp studies really show, and the checklist that matters more than the label.

8 factors · personal risk check · updated 2026-09-01

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Deep dive

What your eyebags are actually telling you about your health

Most eyebags are inherited anatomy, not illness: eyelid sagging is 61% genetic. But the timing of the puffiness, and the company it keeps, can point at sleep debt, sleep apnea, thyroid, kidneys, or heart risk. The evidence on which is which.

10 factors · personal risk check · updated 2026-09-02

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Essay

The years we already cite

The year figures YapSpan already cites, next to the checks that already exist. Cited facts from named studies, not a countdown.

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