Nature’s Secret Immune Booster (It’s Not What You Think)
This week’s Better You, Backed by Science is about your immune system — and a surprising way to enhance it.
What’s the secret?
At risk of sounding overly simplistic — be kind.
I know that might sound too easy. But hear me out.
Researchers once asked volunteers to watch a one-hour video showing acts of compassion and kindness. Before and after, they measured levels of secretory Immunoglobulin A (s-IgA) — an antibody that lines our mucous membranes and serves as the immune system’s first line of defence against infection.
Amazingly, after just watching the video, s-IgA levels rose substantially. They hadn’t eaten, exercised, or taken any supplements — they simply witnessed kindness.
In another study at the HeartMath Institute in California, volunteers were asked to feel a sense of care and compassion for just five minutes. Again, s-IgA levels surged — and stayed elevated for hours afterwards.
How is this possible?
Kindness (and its forerunner, compassion) is physiologically the opposite of stress.
Stress suppresses immune function, while kindness supports it.
You might think of stress as tension on the nervous system. Kindness, by contrast, calms it — easing the pressure on your body’s systems, including the immune system, allowing them to work more effectively. The result: better immune function… and higher s-IgA levels.
But kindness also acts deeper — right down to your genes.
Kindness in the Blood
In a randomised controlled trial by researchers at Sewanee, the University of California, Riverside, and the HopeLab Foundation, 182 participants were assigned to one of three groups:
Group 1: Kind to others: three acts of kindness for others, one day each week, for four weeks.
Group 2: Kind to self: three kind acts for themselves, on one day each week.
Group 3: Control: simply listed daily activities.
Blood samples were taken before and after the four weeks.
The result?
Being kind to others changed the genetic activity of circulating immune cells (white blood cells), reducing inflammation and increasing antiviral defences.
That’s kindness affecting the immune system — at the genetic level.
Nature’s Reward
Why does kindness do this?
Because nature rewards kindness.
Our ancestors survived not by competing, but by cooperating — caring, sharing, and protecting one another. These pro-social behaviours were life-extending.
So nature “baked in” health benefits as rewards for kindness — like better immune function.
Nature’s Catch-22
There’s one important caveat, though.
Kindness only benefits your health when it’s genuine.
Why? The biological boost doesn’t come from the act itself but from how it feels — the internal experience of kindness, the warm, authentic sense of connection.
If you don’t mean it, you won’t feel it… so no reward.
That’s Nature’s Catch-22: only genuine kindness heals.
So if you want to strengthen your immune system — be kind, and mean it.
Try This
💡 1. The Kindness Challenge
Pick one day each week and do three kind things for others. Do it for four weeks — just like in the above study. You won’t measure your immune function, but you might feel the difference.
💡 2. The 21-Day Kindfulness Experiment
Last year, starting on World Kindness Day (which is November 13th!!), I ran the 21-Day Kindfulness Experiment — a short daily practice combining kindness and mindfulness.
Each day I sent a 2-minute video to over 3,000 people inviting them to reflect on a specific aspect of kindness, plus a 10-minute ‘kindfulness’ meditation (a blend of mindfulness and kind-focus).
In just 21 days, participants reported a greater than 30% boost in happiness, connection, and wellbeing.
You can try it yourself — or do it with friends or colleagues. You’ve still got time to get people involved! I’ve uploaded the full playlist of videos and meditations here:
👉 The 21-Day Kindfulness Experiment YouTube Playlist
A quick warning: you might just feel happier and more connected than you do right now. Just saying. 😉
Want to explore more?
🎥 Watch my new YouTube video where I explore this research and dive deeper into how kindness strengthens immunity.
References (if you’re curious)
- Watching kindness boosted s-IgA: J Health Psychol, 1988
- HeartMath compassion research: HeartMath Institute
- Kindness and gene expression: PubMed 35905861
- More on kindness and health: The Joy of Actually Giving a Fck
More
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