A groundbreaking Finnish study shows how smoking, drinking, and being inactive accumulate to impact both mental and physical health over decades—with a critical turning point at age 36
We all know that smoking, heavy drinking, and not exercising are bad for our health. But new research reveals something crucial that many of us overlook: these habits don’t just affect us in the moment—their impacts accumulate over our entire adult lives, creating a snowball effect on both our physical and mental well-being that becomes measurable by the surprisingly young age of 36.
A remarkable 30-year study from Finland, following the same group of people from their late 20s into their early 60s, provides unprecedented insights into how our lifestyle choices in early adulthood can shape our health decades later.
The Long View of Health
The research team from the University of Jyväskylä tracked 369 Finns born in 1959, checking in with them at ages 27, 36, 42, 50, and 61. At each checkpoint, they assessed three key risky behaviors:
- Current smoking (including occasional smoking)
- Heavy alcohol consumption (more than 8 drinks per week for women, 15 for men)
- Physical inactivity (exercising less than once a week)
What makes this study unique is its focus on accumulation. The researchers didn’t just look at whether someone smoked at age 50—they tracked whether they smoked at 27, 36, 42, and 50, creating a cumulative risk score that captured the total burden of unhealthy behaviors over time.
The Age 36 Wake-Up Call
Perhaps the study’s most sobering finding is when these accumulated effects become apparent. While the researchers tracked behaviors from age 27, they began measuring health outcomes at age 36, and the damage was already evident.
At just 36 years old, those who had maintained risky behaviors since their late twenties already showed:
- Measurable differences in mental well-being
- Lower self-rated health
- Early signs of metabolic problems
Think about that: 36 is hardly “old.” Many people at this age are building careers, raising young children, and feeling in their prime. Yet beneath the surface, a decade of poor health habits has already left its mark.
“This finding challenges the common assumption that we can live recklessly in our 20s and 30s without consequences,” the research suggests. By 36—an age when many still feel invincible—the cumulative burden of unhealthy behaviors is already affecting both body and mind.
The Compound Interest of Bad Habits
The study found that these effects only intensified with time. People who maintained multiple risky behaviors from their 20s through their 60s showed:
- Increased depressive symptoms and lower psychological well-being
- Poorer self-rated health
- More metabolic risk factors (high blood pressure, large waist circumference, abnormal cholesterol, and blood sugar issues)
Crucially, the accumulated effects were significantly more potent than simply examining current behaviors. For example, someone who smoked throughout their adult life faced greater mental health challenges than someone who only recently started smoking.
Different Habits, Different Impacts
The study revealed that not all risky behaviors affect us in the same ways:
Smoking primarily impacted mental well-being, with long-term smokers showing both more depressive symptoms and lower psychological well-being. This aligns with the complex relationship between smoking and mental health—while some people smoke to cope with stress, the addiction itself may worsen mental health over time.
Heavy alcohol consumption affected nearly everything—mental well-being, self-rated health, and metabolic health. Long-term heavy drinkers showed more depressive symptoms and significantly more metabolic risk factors.
Physical inactivity primarily affected physical health measures, with sedentary individuals exhibiting poorer self-rated health and a higher prevalence of metabolic risk factors. However, it had a lesser impact on mental well-being.
Why Age 36 Matters for You
If you’re in your 20s or early 30s, age 36 might seem far away. If you’re past it, you might wonder if it’s too late. The study offers important insights for both groups:
For those under 36: You’re in a critical window. The habits you’re forming now are actively shaping your health at 36 and beyond. This isn’t about scaring you—it’s about empowering you to make changes while the accumulated burden is still relatively low.
For those over 36: While the study shows health impacts are already measurable by this age, it also demonstrates that continuing risky behaviors only compounds the problem. Starting healthy habits at 40, 50, or even 60 can still prevent further accumulation of health risks.
Dr. Tiia Kekäläinen, the study’s lead author, emphasizes: “Preventing these behaviors early in adulthood and midlife is crucial to avoid their accumulation and subsequent health risks.”
The Good News
While the study focused on risks, its findings also point to opportunities. Since health behaviors tend to be relatively stable once established, making positive changes early can have compounding benefits over the course of decades. The earlier you quit smoking, reduce alcohol consumption, or start exercising regularly, the more you can minimize the accumulated burden on your health.
The age 36 milestone shouldn’t be seen as a deadline but as a checkpoint—a reminder that our bodies are keeping score even when we feel fine.
Practical Takeaways
- The 36-year reality check: If you’re approaching or past 36, consider getting a comprehensive health assessment. The effects of lifestyle choices may already be measurable.
- Think long-term: Your current habits aren’t just affecting you today—they’re shaping your health at 36 and beyond.
- Start where you are: While starting healthy habits at a young age is ideal, the study shows benefits at any age. The key is to prevent further accumulation of risk.
- Consider comprehensive change: Since these behaviors often cluster together, addressing multiple habits simultaneously (though perhaps focusing on one at a time) may be beneficial.
- Seek support: Given the strong associations with mental health, don’t hesitate to seek professional help when making lifestyle changes, especially if you’re dealing with depression or anxiety.
Looking Forward
This research underscores a fundamental truth about human health: our bodies keep score, and the bill starts coming due earlier than we think. Age 36 isn’t middle age, but it’s when the consequences of our choices become undeniably real.
Every cigarette, every week of inactivity, every period of heavy drinking adds to a cumulative burden that becomes increasingly difficult to reverse. But knowledge is power. Understanding that the choices we make at 27 will be reflected in our bodies and minds by 36 can motivate us to make changes today that our future selves will appreciate.
Whether you’re 27 or 57, the best time to invest in your health is now—because when it comes to healthy behaviors, time is either your greatest ally or your silent enemy. The choice, as always, is yours.
