The World’s Longest Study Reveals the Secret to Living a Long and Healthy Life

It seems like every couple of months or so, an article about the secret to living a long, healthy life starts making the rounds.

And it makes sense––we’re naturally drawn to information that we feel can give us a better life, and since lifespans on the whole are increasing, of course we want to know how we can set ourselves up for healthy years ahead.

As engaging as all the advice out there on living a happy, fulfilling life can be, much of it is often based purely on anecdotal evidence, meaning that what worked for one person or small group of people might not be all that representative of what works for people in general.

There’s a good reason for this; to figure out what works for people in general, you would need to do a massive study compiling years and years of data, rigorously maintain the integrity of the study structure, and of course, get continuous funding over decades, something that’s just not that common in the academic world.

But that’s just what researcher Robert Waldinger and his team of researchers from Harvard have been doing for nearly 8 decades, and they started with this simple question:

What Keeps Us Happiest and Healthiest Over Time?

To find out the answer, they started following two groups of men in 1938, asking them questions about their health and happiness, studying their medical data, and considering all kinds of factors, from marriage and accidents to smoking habits and number of children.

And after decades of research, they found some very compelling data about what actually keeps us vital over time. It turns out that the answer isn’t a good diet, exercise, or even access to healthcare. It’s relationships.

These riveting studies show that having at least a few strong connections in your life is found to be a greater predictor of healthy longevity than any other factor you could think of. In fact, the study found that people who are more closely connected to people, whether that’s through their family, their friends, or simply their community, are far more likely to be happier, healthier, and longer-lived than people who aren’t––and that loneliness has the opposite (almost toxic-like) effect.

And while you might think to your bunches and bunches of Facebook friends as being the key to fulfillment and longer life, it’s the quality of the relationships that counts, not the quantity. Waldinger found that people who had a lot of superficial relationships didn’t see nearly the numbers of benefits as those with closer bonds, and people who were in unhappy or isolating relationships (like marriages with a lot of conflict) actually experienced negative health effects.

But what is the positive, physiological change that happens when you do have those meaningful relationships? Among a myriad of benefits, a feeling of unity with others around you actually appears to have a buffering effect on some of the more common health conditions that affect us as we age, both in terms of mental and physical health.

Frankly, We’re Not Surprised––Your Gut Loves Good Relationships, Too.

Research shows that the health of your gut microbiome, which essentially runs the show when it comes to your overall health, is also positively impacted by good relationships.

Being in a relationship supports your immune response by increasing levels of Immunoglobulin A (IgA), an antibody found in mucous membranes that fights antigens within the body—such as in the membrane lining the gastrointestinal tract. It basically gives your immune system the benefit of the upper hand when it comes to invaders (and the majority of the immune system lives within the gut). What's more, healthy relationships can lower stress levels, which is associated with a healthy microbiome.1

And just as in the case of kids being able to enrich the diversity of their gut bacteria through socializing, adults in a relationship also naturally trade bacteria back and forth through their physical contact.2 Everyone’s microbiome is unique, meaning that they have an individualized mix of bacterial strains. Kissing and skin-to-skin touch allow different strains of bacteria to spread from body to body, naturally diversifying the microbiome.

3 Ways to Find More Connection in Your Relationships

While some relationships naturally develop and stay healthy over time, it can be increasingly challenging to feel connected in today’s world, especially when it’s so much easier to zone out in front of a screen. But since caring relationships are such an important factor in your well-being, here are some tips for enjoying the relationships you have and nurturing the flames of new friendships.

When it comes to loving partnerships...

Whether you’re ready for someone new in your life or you want to rekindle an existing relationship, one of the easiest ways to get sparks flying is to try something new together. Whether you’re making a delicious chocolate cake, spending some time in the great outdoors, or exploring a new place together, the novelty of making new memories together will have your brain firing the hormones dopamine and norepinephrine, which mimic the feeling of first being in love.3

When it comes to your neighbors and community...

Take a walk sans headphones (trust me, it makes a difference) to explore your surroundings with new eyes; you might find yourself naturally connecting more with the people around you when you are in receptive mode. Another great idea is to try out a local event like a farmer’s market. (You can try picking up some tomatoes, dandelion greens, or asparagus while you’re there, they’re great prebiotic foods!) If you have a pet, then look for local playgroups. It’s so much easier to connect with people when you have a common interest, and spending time around animals is great for your health in so many ways.4

If you’re just not sure where to start with new relationships...

What would you do if you had millions of dollars in the bank? Find other people who are interested in doing *that* too and plan a meet-up. There are many sites that facilitate this kind of interaction, as well as local business groups and networking clubs you can join. With so many niche groups of people seeking connection, you might just find your perfect mix of eclectic friends who share a similar interest or passion.

Or, try looking for ways that you can give back! Giving of your time and energy to a cause that you really care about can be a great way to connect with like-minded people in a way that lays the foundation for those deep relationships that are so very important for your health. You really can’t lose with this one: even if you don’t end up connecting with anyone, doing something charitable is also highly correlated with personal happiness.5

No matter what you choose to do to deepen your relationships, from calling your grandmother just a little more often to getting more deeply involved in your community, just make sure you actually do it. It’s easier and easier to become isolated in our modern Western lifestyle, which not only cuts us off from the things that keep us feeling good––it takes us away from the things that really make life worth living, like our families, our friends, and the memories we make with them.


1. Dinan, T. G., & Cryan, J. F. (2012). Regulation of the stress response by the gut microbiota: Implications for psychoneuroendocrinology. Psychoneuroendocrinology, 37(9), 1369-1378.

2. Kort, R., Caspers, M., Graaf, A. V., Egmond, W. V., Keijser, B., & Roeselers, G. (2014). Shaping the oral microbiota through intimate kissing. Microbiome, 2(1), 41. doi:10.1186/2049-2618-2-41

3. Sternberg, R.J., Weis, K. (2006). The New Psychology of Love. New Haven, CT: Yale University Press.

4. Azad, M.B. Konya, T., Maughan, H., Guttman, D.S., Field, C.J. . . . Kozyrskyj, A.L. (2013) Infant Gut Microbiota and the Hygiene Hypothesis of Allergic Disease: Impact of Household Pets and Siblings on Microbiota Composition and Diversity. Allergy, Asthma & Clinical Immunology 9(15) doi: 10.1186/1710-1492-9-15

5. Grimm, R., Spring, K., Dietz, N. (2007). The Health Benefits of Volunteering: A Review of Recent Research. Washington, DC: Corporation for National and Community Service, Office of Research and Policy Development.


Rachel Allen is a writer at Hyperbiotics who's absolutely obsessed with learning about how our bodies work. She's fascinated by the latest research on bacteria and the role they play in health, and loves to help others learn about how probiotics can help the body get back in balance. For more ideas on how you can benefit from the power of probiotics and live healthier days, be sure to subscribe to our newsletter. To learn more about how a healthy microbiome can enrich your life, subscribe to our newsletter.


Posted in Gut Brain Connection, Gut Health, Lifestyle, Top Articles