Longevity: what actually adds healthy years, and what’s still hype

Aim for healthspan, not only lifespan

Lifespan is how long you live. Healthspan is how long you live in good health. The gap is years of chronic disease, pain, frailty, or memory loss.

The World Health Organization estimates people spend their last 9 to 10 years in less-than-good health, on average. Good habits shrink that gap.

Your genes matter less than you think

Older studies estimated lifespan is 20 to 30% heritable. A 2018 analysis of family trees covering hundreds of millions of people corrected for spouses sharing lifestyles. The corrected heritability was likely below 10%.

Long-lived families mostly pass down habits and circumstances, not a longevity gene.

Aging is a set of processes you can influence

Scientists group aging biology into “hallmarks” that drift with age and drive disease:

• DNA errors, shorter telomeres (chromosome caps), and misfolded proteins build up.
• The epigenome (chemical tags that switch genes on and off) drifts.
• Mitochondria (the cell’s power plants) weaken, and nutrient sensors like insulin and mTOR favor growth over repair.
• Senescent cells stop dividing but don’t die, and they release inflammatory signals.
• Low-grade chronic inflammation (“inflammaging”) rises, feeding heart disease, diabetes, dementia, and frailty.
• Stem cells become fewer and less active, and the gut microbiome loses diversity.

Exercise, sleep, food, and stress all act on these pathways.

Habits with strong evidence

A study followed more than 120,000 U.S. adults for up to 34 years. It tracked five habits: not smoking, 30+ minutes of activity a day, a high-quality diet, a healthy weight, and limited alcohol. At age 50, women with all five could expect about 14 more years of life than women with none. Men could expect about 12 more. The data are observational, but trials of each habit agree.

1. Don’t smoke, or quit at any age. In the 50-year British Doctors Study, smokers died about 10 years earlier on average. Quitting at 30 avoided almost all of that risk; quitting at 60 still gained about 3 years.
2. Build fitness and strength. Heart-and-lung fitness and muscle strength are among the strongest predictors of lifespan.
3. Sleep 7 to 9 hours a night. In a meta-analysis of 1.3 million people, short sleepers had about 12% higher risk of death. Long sleep was also linked to higher risk, often because of existing illness.
4. Eat mostly vegetables, fruit, legumes, whole grains, nuts, and fish. Limit ultra-processed food, sugary drinks, and processed meat. Variety and fiber matter.
5. Keep blood pressure, blood sugar, and cholesterol in range; they drive the top causes of death. In the SPRINT trial of adults at high heart risk, a systolic (top number) target under 120 instead of 140 cut deaths from any cause by about a quarter.
6. Stay connected and manage stress. Strong relationships are linked to about 50% better odds of survival, on par with quitting smoking. Chronic stress works through the same biology as inflammation.
7. Limit alcohol. Studies that correct for “sick quitters” (people who quit because they were already ill) find little to no benefit from light drinking. Less is better; none is fine.
8. Get recommended screenings and vaccines. Finding cancer, heart disease, and diabetes early protects healthspan.

Psoriasis raises heart and metabolic risk

Psoriasis is linked to higher rates of heart disease, diabetes, and metabolic syndrome (a cluster that includes high blood pressure and high blood sugar). Joint guidelines from the American Academy of Dermatology and National Psoriasis Foundation recommend screening for these.

Skin inflammation can affect blood vessels too, so movement, sleep, food quality, blood pressure, and blood sugar matter more if you have psoriasis. Ask your clinician to check those numbers regularly.

Promising, but not proven in humans

No trial shows these extend healthy human life.

• Rapamycin extended lifespan in mice, even when started late. In people, it suppresses the immune system, has real side effects, and lacks long-term longevity trials.
• Metformin, a diabetes drug, looked promising in observational data but lacks large trials in people without diabetes. It may blunt some benefits of exercise.
• NAD+ boosters (NR, NMN) raise blood NAD+ levels, but human trials show small or inconsistent health effects.
• Senolytics, drugs that clear senescent cells, show promise in animals. Human research is early.
• Calorie restriction and fasting extend life in many animals. In people, modest restriction improves heart and metabolic markers but is hard to sustain and can cost muscle. Skip it if you’ve had disordered eating.

What’s mostly hype

• Biological-age tests. Results vary between tests and labs and don’t tell you what to change. Blood pressure, fitness, and blood sugar tell you more for less.
• Megadose supplement stacks. Fix deficiencies you’ve measured and skip the rest. Iron and vitamin A, for example, are harmful in excess.
• IV vitamin drips for healthy people. No good evidence shows they add years, and they carry infection and overload risks.
• Anything promising to “reverse aging.” Nothing reliably does yet.

Numbers worth knowing

These predict healthy years, and you can change them:

• Blood pressure: check at home or a pharmacy, and ask your clinician what target fits you
• Blood sugar: HbA1c or fasting glucose
• Cholesterol: LDL or ApoB, plus triglycerides
• Waist size: a rough gauge of deep belly fat, which is linked to metabolic disease
• Fitness: how far you can walk briskly in 6 to 12 minutes
• Strength: whether you can get up from the floor or carry heavy groceries easily

Where to start this week

1. Check your blood pressure on two different days.
2. Walk daily and do two short strength sessions (simple plan here).
3. Wake at the same time every day to anchor your sleep.
4. Swap one daily ultra-processed snack or drink for fruit, nuts, yogurt, or water.
5. Call a friend or family member.
6. Book any screenings you’re overdue for.

Track your habits for two weeks

Each day, note movement minutes, sleep hours and quality, stress (0 to 10), mood, time with people, and how you feel (energy, skin, gut). Effects often lag: better sleep this week can mean more energy next week. A short daily check-in makes those delayed patterns visible.

When to see a clinician

• You don’t know your blood pressure, blood sugar, or cholesterol
• You’re considering longevity drugs like rapamycin or metformin (these need medical supervision)
• You have a chronic inflammatory condition and haven’t been screened for heart and metabolic disease
• You have unexplained weight loss, fatigue, or memory changes
• Low mood or anxiety lasts for weeks (in the U.S., call or text 988 in a crisis)