10 minutes of sunlight: The science-backed brain boost you’re likely overlooking

As the pace of modern life speeds up, and high rises mushroom in Nairobi, many people spend more time indoors and under artificial lighting than ever before.

Yet, research continues to confirm what ancient traditions and simple intuition have long suggested: just 10 minutes of basking in natural sunlight can have powerful effects on the brain, sharpening memory, lifting mood, and enhancing mental clarity.

However, these simple, natural habits are becoming increasingly uncommon.

Children are often placed in front of screens while parents are caught up with work, digital distractions, or browsing social media.

As life moves indoors and online, the everyday ritual of stepping outside into the sun is slowly fading, yet its benefits remain as vital as ever.

The brain on sunlight

Sunlight plays a key role in regulating circadian rhythms, the body’s internal clock that governs sleep, hormone production, and cognitive function.

Morning exposure to natural light especially helps synchronise this rhythm, keeping the brain alert during the day and promoting restful sleep at night.

Which is also one of the reasons mothers are often advised to bask their babies in the early morning sun.

Not only does morning sunlight help set a healthy sleep-wake cycle in infants, but it also supports vitamin D production, which is vital for brain development, bone growth, and immune function. Plus, the early morning rays are gentle on the skin, making it the safest time for both children and adults to soak in the benefits of natural light.

In a 2023 study published in Neuroscience and Biobehavioral Reviews, researchers found that even brief sunlight exposure significantly improved attention and processing speed.

Participants who spent between 10 and 15 minutes in sunlight in the morning performed better on memory and reaction-time tests compared to those who remained indoors under artificial light.

Mood: Nature’s antidepressant

The sun’s rays stimulate the release of serotonin, a neurotransmitter associated with feelings of well-being, focus, and emotional stability.

In fact, according to the National Institute of Mental Health, serotonin levels tend to rise with increased exposure to sunlight, which explains why people often feel more cheerful and motivated on bright days.

“Just a few minutes of sunlight can act like a natural antidepressant,” says Dr Maria Odhiambo, a Nairobi-based clinical psychologist.

“It’s a simple, free way to reset your mood, especially for those struggling with low energy or seasonal depression.”

The link between low sunlight exposure and Seasonal Affective Disorder (SAD) is also well documented. Countries with limited daylight during winter months often report higher rates of mood-related issues, prompting the use of light therapy lamps to mimic natural sunlight.

Sunlight and vitamin D: The memory connection

Another major benefit of sunlight is its role in triggering vitamin D synthesis in the skin. Vitamin D is not just crucial for bone health, but it also plays a role in brain development, memory formation, and cognitive health.

A 2022 meta-analysis in Frontiers in Ageing Neuroscience found a strong correlation between adequate vitamin D levels and improved episodic memory and executive function.

Deficiency, on the other hand, has been linked to cognitive decline and increased risk of neurodegenerative diseases like Alzheimer’s.

Although vitamin D can be obtained through food and supplements, sunlight remains the most efficient and natural source.

Experts recommend 10–15 minutes of direct sun exposure on the arms, face, or legs, several times a week, ideally before 10:00 am or after 4:00 pm when UV risk is lower.

Incorporating a short daily “sun break” can be as simple as stepping out onto a balcony, walking around the block, or sitting near a sunny window with the glass open.

It is a micro-habit that costs nothing but delivers noticeable mental and emotional gains.

"Even when I'm busy working from home," says 29-year-old software developer Kirstern Njoroge.

"I take 10 minutes outside with my coffee. It clears my head and improves my focus for the rest of the day."

Of course, sunlight exposure should be balanced with skin safety.

Dermatologists consistently advise limiting unprotected exposure to direct sunlight during peak UV hours, typically between 10:00 am and 4:00 pm, when the sun’s rays are strongest and pose the highest risk for skin damage.

For those planning to spend longer periods outdoors, especially beyond 15–20 minutes, broad-spectrum sunscreen, protective clothing, and shade are strongly recommended to reduce the risk of premature ageing and skin cancer.

However, moderate morning sun exposure, particularly between 7:00 am and 9:30 am, remains not only safe for most people but highly beneficial. A 10-minute dose of gentle natural light at this time strikes an ideal balance: it is long enough to support mood regulation, brain function, and vitamin D synthesis, yet short enough to avoid skin harm.

In an age where daily life is saturated with screens, artificial light, digital pressure, and mental fatigue, stepping outside for a few moments of sun offers more than just warmth.

It is a natural reset, a chance to reconnect with your body’s natural rhythm, reduce stress hormones, and reclaim a sliver of mental clarity, without the need for a device, applications, or subscription.

The science is clear: the sun does not just light up the sky, it lights up the mind.

And sometimes, all it takes is 10 quiet minutes in the morning light to set the tone for a healthier, more focused, and emotionally balanced day.