Your mind is not separate from your physiology, and changing your mindset in various ways can lead to a happier, healthier life. When we open our minds to this idea of mind-body unity, new possibilities for controlling our health become real.

In one mind-blowing study, Harvard researcher Ellen Langer had people with type 2 diabetes play video games while checking a clock every 15 minutes. Unbeknownst to the participants, some clocks ran on time, while others ran either twice as fast or twice as slow.

Based on blood readings, those whose clocks ran faster (who believed more time had passed) had lower blood sugar levels than any other participants—meaning, they were using up energy faster than people in groups with slower clocks. The participants’ perception of time affected their energy consumption more than the actual time that had passed!

Despite these kinds of findings, the effects of our minds on our bodies are often called a “placebo effect” in research and dismissed as irrelevant, says Langer. In fact, she argues, many studies find that a placebo is as effective or outperforms a drug, but those studies are rarely published. This makes it hard to understand and harness a placebo’s potential for healing. “What we should be learning from these studies is not that a particular drug is ineffective but rather how effective the placebo may have been,” she writes.

In other words, expectations matter.

What all this means for our lives is a bit tricky. Langer isn’t suggesting we abandon all medical research and start healing ourselves with our minds alone. But she does think we can use the power of our minds to change our health and well-being in ways that are mostly untapped.

 Langer also cautions us to be more mindful of our everyday experiences. She doesn’t mean meditate more—she wants us to notice variations in our state of being. If we pay attention to how we feel, moment to moment, we can break out of rigid, fixed beliefs that we are sick or damaged and notice the moments when we feel happy, healthy, or pain-free.

How to Harness the Power of Your Mind

How can you use your mind to help yourself? To start, she suggests adhering to a few basic principles:

1. Question authority
2. Recognize that what counts as “risky” is different from person to person.
3. Approach predictions with skepticism.
4. Understand how our choices are never completely “right” or “wrong.”
5. Avoid social comparisons or ranking yourself. This is never good for our health or happiness.

As Langer notes, “When we make these shifts in our thinking, our relationships with others and ourselves improve, and our stress lessens, all in the service of improving our health.”

“Once we recognize that mindless decisions from the past are limiting us, there is little stopping us from redesigning the world to better fit our current needs rather than using yesterday to determine today and tomorrow,” she writes.