Your brain weighs about as much as a cantaloupe and burns roughly a fifth of your body’s energy. Much of the brain health advice on social media treats the brain like an organ in a jar. Do a puzzle. Take a supplement. Get more sleep. Some of that helps, but it misses something yoga has understood for centuries.

We are multidimensional beings, so brain health must be approached from a multidimensional perspective. Yoga philosophy offers a map that describes five koshas, or dimensions of being human. The koshas are interpenetrating and interdependent sheaths, or layers. Each one is a little more subtle than the last. The dimensions aren’t separate-a change in one ripples through the others. For example, a slow breath settles the mind and a worried mind braces the body. We can start anywhere on the kosha map to promote changes in the brain.

Annamaya kosha: the body you move

When a muscle works, it releases signalling molecules called myokines. Some of them reach the brain and stimulate production of BDNF, a protein that helps brain cells grow and connect. BDNF is made in the brain and muscle activation is one of several ways to turn it up.

Walking is enough. In a well-known 2011 study, older adults who walked regularly for a year (three days a week, starting with 10 minutes and gradually increasing to 40 minutes) grew their hippocampus, the brain’s memory center, by about two percent. The group that only stretched saw it shrink.

BDNF production is also affected by bones; they a hormone called osteocalcin when stimulated by weight-bearing. In mice it has been shown to affect memory and mood but the human trials, though still unclear, are promising.

Try this. Stand barefoot. Rock slowly from heels to toes and back. Then side to side. Feel the floor press up through your bones. Notice how many small adjustments your feet make without asking you.

Pranamaya kosha: breath and the autonomic tide

Breath is the one automatic function you can deliberately alter. Slow the exhale and the vagus nerve responds, slowing the heart rate and down-regulating the whole nervous system. This down regulation affects memory. The hippocampus is packed with receptors for cortisol, the stress hormone. Sustained high cortisol is linked to a smaller hippocampus so a regular breath and nervous system regulation practice can prevent or slow this shrinkage.

Sleep quality also affects pranic health. During deep sleep, fluid flows through the brain and clears metabolic waste, including the proteins linked to Alzheimer’s. Sleep is not just downtime; it is housecleaning of our brain.

Try this. Sit tall. Close your mouth and hum at an easy pitch for several breaths. You can plug your ears if you want. Notice where you feel the vibration. Count your natural breaths for a minute before and after to compare.

Manomaya kosha: sensing, filtering, feeling

“Manas”, the mind, is significantly affected by high chronic stress levels. Elevated cortisol levels can increase inflammation and affect memory, but also change the way the brain processes information. Prefrontal cortex functions like attention, decision-making and learning can be diminished. Threat sensitivity can be magnified, which can increase reactivity and defensive behaviours. Even our interoceptive and proprioceptive capacity can be altered in chronic stress, interfering with our capacity to feel. Chronic stress is the enemy of brain health.

Your brain is flooded with sensory signals every second but most never reach your awareness because the thalamus filters what is important. In the process of interoception, the insula records the inner sensations of your body: heartbeat, hunger, the tightness before a hard conversation.

This is why we practice pratyahara, one of the eight limbs of yoga. We deliberately disengage the senses from the outer world and focus them inside. We are not shutting the senses down but are choosing where attention goes and how much sensory input we allow ourselves to receive. This gives the brain some respite.

Try this. Close your eyes. Find one sensation you can name precisely-warmth in the palms, pressure under the sitting bones, or a pulse somewhere. Stay with it for three breaths, simply observing.

Vijnanamaya kosha: knowing, predicting, discerning

Your brain is a prediction machine. It builds models of the world, then checks them against what actually happens. Every pattern that you deliberately interrupt is a chance to update and stimulate neuroplasticity. This is how cognitive reserve gets built, through doing something that is challenging mentally or physically. It has to be hard though. In the Synapse Project, older adults spent three months learning digital photography or quilting. Their memory improved while the control group doing pleasant social activities or easy tasks at home did not improve. Difficulty was the special ingredient.

We can translate this into our yoga practice by doing familiar poses in nonhabitual ways, like changing tempo, direction, load, or adding additional elements like eye movements or a cognitive task. And really paying attention to the sensations.

The pause matters too. Learning consolidates in the rest after effort. Abhyasa also matters-steady practice over time.

Try this. Interlace your fingers. Now do it with the other thumb on top. Notice the strangeness. That flicker of “this is wrong” is your brain updating a model. Or stand on one leg, eyes on a fixed point. Then slowly move your gaze. Keep a wall within reach.

Anandamaya kosha: integration and rest

Our nervous systems continually read each other for safety and connection. A large analysis of more than 600,000 people found loneliness linked to an approximately 31 percent higher risk of dementia. The 2024 Lancet Commission lists social isolation among the risk factors we can change. So showing up to a yoga class is brain health.

Feeling connected to ourselves, others, nature, meaning and purpose, and that which is greater than ourselves, is brain health. Tapping into our innate wholeness is brain health. It’s very difficult to access this dimension when we are continually stressed, but trusting that wholeness is our essential nature can be a resource in difficult times. We can remind ourselves through practices like prayer, ritual, and gratitude.

Integration needs rest. The brain needs time when nothing is asked of it.

Try this. After practice, lie down for five minutes. No breath technique. No body scan. Nothing to achieve. Let it be enough. Know that you are already whole.

One brain, many doors

Brain health is not one thing. It is muscle and bone, breath and sleep, attention, company, challenge and rest. The koshas give us a framework to hold all of this at once.

You don’t need to work every layer at once. Pick one door this week. Walk barefoot. Lengthen your exhale. Call a friend. Learn something awkward.

With care, Leila