Only 6% of Men Reach 70 in Good Health: What 40 Years of Harvard Research Shows

Only about 6% of men reach age 70 in all-round good health, according to a 2025 analysis of Harvard's Health Professionals Follow-Up Study (HPFS), the largest and longest-running study of men's health in the world. "Good health" here meant no major chronic disease, no memory complaints, no physical limitations and no depressive symptoms, all at the same time. Among women in the parallel Nurses' Health Study, 10.8% met the same bar. The men were not a random slice of the public. They were dentists, vets, pharmacists and other health professionals, arguably the best-informed men in the United States.

This month, HPFS marked its 40th anniversary. Forty years of questionnaires, blood samples and toenail clippings from more than 51,000 men have produced close to 1,500 scientific papers on diet, heart disease, prostate cancer and aging. This article explains where the 6% figure comes from, what the strict definition actually measured, what the men who made it did differently, and what the same cohort has to say about a signal most men ignore: their erections.

What the Health Professionals Follow-Up Study is

In 1986, researchers at what is now the Harvard T.H. Chan School of Public Health recruited 51,529 male health professionals aged 40 to 75. The idea was simple: build an all-male counterpart to the all-female Nurses' Health Study, which had started a decade earlier. Health professionals were chosen because they could report their own diagnoses and habits accurately, and because they tended to stick with a study once they had joined.

They did stick with it. Every two years since, participants have answered long questionnaires about what they eat, how much they move, what medications they take and what illnesses they have been diagnosed with. Follow-up rates have stayed above 90%. Around 18,000 men gave blood in the early 1990s, and a new round of blood collection is under way now, with participants in their 80s, 90s and beyond. The study also holds tumour tissue from about 7,500 men diagnosed with cancer, and one of the world's largest collections of toenail clippings, used to measure long-term exposure to trace elements.

On 10 September 2026, researchers and participants gathered in Boston to mark 40 years. Nearly 15,000 of the original men are still returning questionnaires. Some have passed 95 and 100. The study's top findings, as summarised at the event, include:

• Not all fats are harmful, but trans fats are very harmful. HPFS data helped get them removed from the US food supply.
• More than half of chronic disease is attributable to modifiable lifestyle factors.
• Men who have already been diagnosed with a chronic disease can still improve how they age by changing diet and lifestyle.
• Keeping muscle mass matters alongside aerobic activity, and even moderate amounts of activity deliver most of the benefit.

The main study grant is ending, but the co-principal investigators, Lorelei Mucci and Walter Willett, have said the work will continue through individual grants covering healthy aging, prostate cancer, heart disease and diet. As Willett put it at the anniversary, the most may still be to learn about how men stay healthy into very old age.

Where the 6% figure comes from

The headline statistic does not come from the anniversary itself. It comes from a paper published in Nature Medicine in March 2025 by Anne-Julie Tessier, Frank Hu, Marta Guasch-Ferré and colleagues, which used HPFS and Nurses' Health Study data to ask which diets best predict healthy aging.

To answer that, they first had to define healthy aging. They borrowed a strict, four-part definition used in earlier Harvard work. A participant counted as a "healthy ager" only if, at the 2016 assessment, they had:

1. Survived to at least 70. Anyone who died before 2016 was counted as a usual ager, not dropped from the analysis.
2. No diagnosis of 11 major chronic diseases: cancer (excluding non-melanoma skin cancer), diabetes, heart attack, coronary artery disease, heart failure, stroke, kidney failure, COPD (chronic lung disease), Parkinson's disease, multiple sclerosis or motor neurone disease (ALS).
3. Intact cognitive function: reporting one or fewer memory concerns on a validated six- or seven-item questionnaire.
4. Intact physical function and mental health: no limitation on everyday tasks like walking a mile, climbing a flight of stairs or bathing and dressing, and one or fewer depressive symptoms on a standard 15-item scale.

The analysis included only people who were healthy in 1986 and young enough to reach 70 by 2016, so between 39 and 69 at baseline. That left 34,924 men and 70,091 women. After up to 30 years of follow-up, 2,169 men (6.2%) and 7,602 women (10.8%) met all four criteria. Pooled together, 9.3% of participants achieved healthy aging.

You can read the full open-access paper in Nature Medicine. The 6% is a real, published figure, but it is worth being precise about what it describes: healthy men aged 39 to 69 in 1986, assessed once in 2016, against a very demanding definition.

Why the number is so low

The first reaction most men have to "6%" is disbelief. Surely more than one in sixteen 70-year-olds are basically fine? The answer lies in the word "and". The definition demanded four things at once, and each one on its own removed a large share of the cohort.

In the pooled data, only 37.9% of participants had reached 70 by 2016 at all, because many were still in their sixties when the assessment was made and others had died. Of the whole group, 22.8% had avoided all 11 chronic diseases. Around a third (33.9%) reported intact memory, 28.1% had no physical limitations, and 26.5% had no meaningful depressive symptoms. Clear all four hurdles, and you are left with 9.3%.

Two things stand out. First, disease and death are not the only ways to fall out of the healthy group. Losing the ability to carry groceries up the stairs, or developing low mood, each took out roughly as many people as chronic disease did. Physical function and mental health are not soft extras. They are half the definition.

Second, men did worse than women on the same test. The paper reports the gap but was not designed to explain it. What we do know from the wider literature is that men in high-income countries die younger and develop cardiovascular disease, diabetes and several cancers earlier, which removes them from the "healthy ager" pool sooner. We have written in more detail about why men die younger and live fewer healthy years, and the HPFS figure fits that pattern.

What separated the men who made it

The good news is that the same cohort tells us a great deal about what the 6% did differently, because the researchers have been tracking habits for four decades.

Diet quality

In the Nature Medicine analysis, every one of eight healthy dietary patterns was linked to greater odds of healthy aging. The strongest was the Alternative Healthy Eating Index (AHEI), a score built from foods and nutrients that predict chronic disease: more fruit, vegetables, whole grains, nuts, legumes and unsaturated fats; less red and processed meat, sugary drinks, sodium and trans fat. People in the top fifth for AHEI had 86% greater odds of healthy aging than the bottom fifth. Eating a lot of ultra-processed food pointed the other way: the top fifth for ultra-processed intake had 32% lower odds of aging healthily.

The five habits

A 2020 paper in the BMJ, also from HPFS and the Nurses' Health Study, looked at five low-risk lifestyle factors: never smoking, a body mass index between 18.5 and 24.9, at least 30 minutes a day of moderate-to-vigorous physical activity, moderate alcohol intake, and a diet quality score in the top 40%. It then estimated how many years a 50-year-old could expect to live free of cancer, cardiovascular disease and type 2 diabetes.

Men at age 50	Disease-free years expected
None of the five habits	23.5 years
Four or five of the habits	31.1 years

That is a difference of roughly 7.6 disease-free years for men. Heavy smokers and obese men had the worst ratio of healthy years to total years lived. You can read the abstract on PubMed. An earlier 2018 paper from the same team in Circulation had already shown that these five habits were linked to longer overall life expectancy; the 2020 work showed the extra years were largely healthy ones.

One caveat: the alcohol item is the most debated of the five, and nobody should start drinking for their health. The other four are not in dispute. Nor is the anniversary's message about muscle: keeping strength alongside aerobic fitness, with even moderate activity giving most of the benefit.

What the same men taught us about erections

In 2000, HPFS added a set of questions about sexual function. The result, published in the Annals of Internal Medicine in 2003, remains one of the largest studies of erectile function in men over 50 ever conducted. It found that erectile dysfunction rose steeply with age, and that the same lifestyle factors that predict chronic disease also predicted it. Men in the most physically active group had about 30% lower risk of erectile dysfunction than the least active. Obesity, smoking and hours spent watching television were each linked to higher risk. The details are on PubMed.

This matters for healthy aging because an erection is a vascular event. It depends on the small arteries of the penis relaxing and filling with blood, driven by nitric oxide (a molecule the lining of your blood vessels releases to make them widen). Those arteries are narrower than the ones supplying your heart, so when the vessel lining starts to fail, erections are often affected first.

The numbers back this up. A 2013 meta-analysis (a study that pools the results of many earlier studies) of 14 cohorts covering 92,757 men found that those with erectile dysfunction had 44% higher risk of cardiovascular events, 62% higher risk of heart attack, 39% higher risk of stroke and 25% higher all-cause mortality than men without. The relative risk was highest in younger men and in those at intermediate cardiovascular risk, exactly the group who most need an early warning.

That is why we pay so much attention to night-time erections. Every man has three to five during sleep, driven by the same nitric oxide system, with no performance pressure involved. If they are strong and regular, the vascular plumbing is working. If they are fading, something upstream is changing, often years before a doctor would diagnose anything. Whether morning wood is a reliable sign of healthy erections is a question we get asked a lot, and the short answer is that it is one of the best signals you have.

Reading this at 40: what the data suggests you do

The HPFS men were between 40 and 75 when they joined. The healthy-aging analysis started the clock at 39. So if you are reading this in your 40s, you are at exactly the point where these men's choices started to diverge. The study does not prove that changing habits causes healthy aging, but it is about as strong as observational evidence gets, and the direction is consistent across every analysis.

Move every day, and lift something

The 30-minutes-a-day threshold in the BMJ paper is moderate-to-vigorous, but the anniversary summary was clear that even moderate activity gives most of the benefit. Walking counts. We have made the case before that daily walking may be the most powerful habit in men's health, and the HPFS erectile function data points the same way. Add resistance work to hold onto muscle, which the study's researchers singled out as important.

Eat towards the AHEI

You do not need to follow a named diet. The foods that scored well across all eight patterns are the same: fruit, vegetables, whole grains, nuts, legumes, unsaturated fats such as olive oil, and modest amounts of dairy. The foods that scored badly are trans fats, sodium, sugary drinks and red or processed meat. Ultra-processed food was linked to lower odds of healthy aging on its own.

Protect your sleep

Sleep is where night-time erections happen, where muscle repairs and where much of the mental-health domain is decided. HPFS itself has added sleep questions in recent years. We cover the evidence in Sleep: the foundation of men's health.

Measure something

The HPFS men aged well or badly while filling in questionnaires that only researchers saw. You have a chance they did not: to track your own signals in real time. Blood pressure, waist size, resting heart rate and night-time erection quality are all cheap to measure and all move when habits change.

What the study can't tell you

A statistic this quotable deserves honest limits, and the researchers themselves are careful to state them.

It is observational. HPFS did not assign men to diets or exercise programmes. It watched what they did and what happened. The strong, consistent associations make a causal story plausible, but they do not prove it. People who eat well also tend to earn more, smoke less and exercise more, and although the analysis adjusted for all of these, some residual confounding is likely.

It is self-reported. Diet, activity and even the healthy-aging domains came from questionnaires, not lab tests or fitness assessments. Diagnoses were confirmed against medical records, but memory complaints and physical limitations were the men's own accounts.

It is health professionals. This cuts both ways. The 6% figure probably overstates how well the average man does, because these men had good jobs, good access to care and good health literacy. On the other hand, it means the gap cannot be blamed on ignorance.

The men-versus-women comparison is not perfectly like-for-like. Both groups were restricted to ages 39 to 69 in 1986, and the analysis adjusted for age, but the two cohorts differ in profession, age distribution and how long they had already been followed. The paper also found that healthy diets were linked to healthy aging in both sexes, with stronger associations in women. Why that is remains an open question.

It measured one moment. Healthy aging was assessed in 2016, when the youngest men had only just turned 70. It says nothing directly about what happens at 80 or 90, though the study continues to follow the men who are getting there.

None of this weakens the practical message. If anything, it sharpens it. The things that moved the odds in the HPFS men are the things you can measure and change in your own life, starting now.