New Zealand / Health

Do we need nature to be healthy?

18:52 pm on 16 November 2024

Looking at a natural landscape screensaver image for 90 seconds has been shown to lower blood pressure and heart rate variability. Photo: Bailey Zindel

Looking at a landscape screensaver lowers blood pressure, listening to birdsong decreases stress, and smelling lavender reduces anxiety.

It's common sense that interacting with the natural world makes us feel calmer, but what is actually happening in our bodies and minds?

Fifteen years ago, Oxford University biologist Kathy Willis - "quite a cynical scientist" - got interested in this question.

She takes a deep dive into how sensory connection with the natural world can help make us healthier and happier in her new book Good Nature.

Nature makes us healthier: Kathy Willis

Photo: Teddy Hall/Bloomsbury

In the last 50 years, a big body of scientific evidence has built up about how contact with nature can regulate heart rate variability, blood pressure, cortisol and adrenalin, Willis tells RNZ's Saturday Morning.

We can all self-prescribe nature as a calming medicine in our own lives, she said.

"If you're having a stressful incident the best thing you can do is actually look out the window or look to look at some vegetation because it really does induce calming.

"If you know that certain sorts of nature lower your blood pressure, reduce your stress and anxiety levels, that is enough [to be beneficial].

"Those are the things that then trigger strokes and cardiovascular diseases."

To really understand how to maximise the health benefits of nature we will need clinical studies, Willis said, but in the meantime, accessible green space should be a necessity in towns and cities, Willis said.

"We need to think of nature more like a part of infrastructure so we automatically think 'This is where the water goes, this is where the electricity goes, this is where the nature goes."

Spider plants have been shown to remove formaldehyde from the air. Photo: Public domain

How to harness the health benefits of nature

  • Get amongst it on the regular

A 20-minute walk in nature (ideally around scented plants) three or four times a week is beneficial for stress relief.

  • Seek out (real) plants and flowers

Plants with yellow and green leaves are particularly good at triggering brain activity, Willis said.

Spider plants - which reproduce easily and are really hard to kill - excel at air purification.

Yellow and white flowers are best for relaxation and calming.

  • Bask in nature sounds

The melodic up-and-down sound of birdsong on headphones has been shown to lower stress and pain scores during surgery, Willis said

Other sounds of nature, such as wind in trees and trickling streams, also have a proven calming effect.

  • Touch wood (and plants)

'Tree hugging' is kind of a derogatory term but stroking unvarnished wood lowers your heart rate, Willis said.

"We know that stroking animals can calm people down. Actually also touching plants seems to have similar triggers, similar reactions."

  • Soothe yourself with smells

The soothing benefits of lavender are not an old wives tale, Willis said.

"It makes you sleep. It makes you more relaxed because lavender molecules, once they're in your blood, they interact with that biochemical pathway to reduce anxiety."

The scents of cedar and cypress trees, especially Japanese hinoki, have been shown to significantly elevate the natural killer cells in our blood which attack cancers and viruses, she said.

In her diffuser at home, Willis burns hinoki essential oil in the mornings, rose oil to stay awake and lavender at night time.

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