Could looking at spinach be soothing?
A surgeon in 1904 thought so.
Harry Mitchell Sherman, a physician at a San Francisco hospital, realized how easily tired his eyes became while doing surgery in a bright white environment. The white rooms and white cloth popular back then reflected the bright lights of the operating room. So he decided to swap out white surgical drapes for black ones, reducing the glare and making it easier to focus on the surgical procedure.
He later decided to upgrade the black cloth to a different color. And he chose "the green of the spinach leaf," as he later wrote in an article published in the May 1914 issue of the California State Journal of Medicine. Sherman's reasoning was simple. And it was based on something you might remember from elementary school...
Complementary colors sit opposite from each other on the wheel. And staring at a very red incision area for a long time and then blinking can result in you seeing a complementary (green) afterimage. But that distracting "floater" disappears into a green background. Sherman also painted most of the operating room green, which made it easier to notice any traces of blood for cleanup.
With the help of other architects and industry consultants who chimed in over the next few decades, Sherman's favorite color really took off... Soothing greens and blues began to dominate hospitals... from the walls to the medical equipment to scrubs.
Plus, cool colors tend to have a relaxing effect – which is great for a doctor performing such a high-stress task and for antsy patients. For instance, some scientists have studied how looking at the color green can lower the heart rate.
And, of course, we associate greens and blues with nature...
Even just looking at photos of a lush green meadow, brilliant blue skies, or deep greenish-blue seas instantly makes us feel calmer, uplifts our moods, and instills in us a sense of awe.
But experiencing nature firsthand is best...
Research has shown how long-term exposure to the greens and blues of our natural surroundings – like the forest and the ocean – is associated with better mental health and lower mortality. And according to a December 2022 study published in JAMA Network Open, being around green and blue nature could benefit Americans suffering from the two most common neurodegenerative disorders, Alzheimer's and Parkinson's diseases...
Researchers looked at the number of first-time hospitalizations with a diagnosis of Alzheimer's or Parkinson's among nearly 62 million elderly Americans (aged 65 and up) on Medicare. From 2000 to 2016, roughly 1 million folks ended up in the hospital for Parkinson's and nearly 8 million folks were admitted for Alzheimer's.
The team also ran the zip codes of where these folks lived each year through a few different geological-survey databases to figure out just how much Mother Nature was present in the patients' environments. Specifically, the study included the percentage of land covered by parks or bodies of water.
As for measuring how dense the vegetation was in a certain area, or the "greenness," the researchers used satellite images that detected certain wavelengths of light – namely, near-infrared light – coming off the land. Chlorophyll molecules (which give plants their green color) happen to reflect near-infrared light pretty well, so the greenest areas on the maps meant the land was rich in plant life.
According to the results, seniors who lived in greener areas lowered their risk of hospitalization from both diseases. Also, folks who lived in areas with at least 1% of land covered by water had a 3% reduced risk of hospitalization for Parkinson's. That risk also dropped by 3% for every additional 16% of land covered by parks.
Previous studies have shown possible links between higher exposure to air pollution and a higher risk of developing and/or worsening symptoms of both diseases. And since it's already well known that plants can "clean" the air of common air pollutants, the researchers suggested being around more of nature's "air purifiers" could mean having better outcomes in both diseases. Also, other studies show older adults who live in greener neighborhoods tend to exercise more – a healthy habit that slows cognitive decline and lowers Alzheimer's risk. They've also shown that more greenery was linked to having better grip strength, which means better muscle strength and healthy aging.
Parks also give us physical and mental health boosts, too. They're places to exercise and socialize with others. And we know sounds of ocean waves or running water can calm and soothe us by activating the parasympathetic nervous system and relaxing our bodies. Less stress means less cortisol, and we know that having high cortisol levels for a long time can cause health problems like hypertension and Type 2 diabetes.
Even if you live in a busy city, you can still reap some of the benefits by carving out some of your free time and spending it at a local park, green space, lake, or reservoir. You can also bring nature to you by taking up gardening. Check out a nearby community garden, bring in some houseplants, or grow your own herbs indoors. (Here's a brief introduction to indoor gardening.)
Also, finding a green space in the city can be mightily rewarding for your mood, according to a small 2022 study on 40 middle-aged adults. It showed that walking for just 20 to 30 minutes in an urban green space with shade and plants can significantly lower stress and boost your mood, compared with walking in a less-green urban area.
Personally, I try to walk outside every day. If I happen to take my daily walking break in a city, I try to focus on the hints of nature around me – like observing any small trees, bushes, or potted flowers that pepper the block, feeling the wind and sun on my face, and taking note of any squirrels or birds that cross my path. (Did you know our avian city dwellers, or pigeons, naturally love hard surfaces?)
And the more time you spend in nature, the better... A 2019 study on nearly 20,000 folks suggests that spending at least two hours in nature a week reported better health and well-being. And a study published earlier this year on people in three of Finland's biggest cities found a link between frequent weekly pilgrimages to a nearby green space and less pill-popping. Researchers saw making three to four trips per week to a park, forest, or meadow was associated with lower odds of having to take prescription medications for common health issues... 26% lower odds for asthma drugs, 36% lower odds for blood-pressure drugs, and 33% lower odds for anxiety, depression, and sleep-disorder drugs.
If you live in an area without a lick of green or blue nearby, plan a weekend trip to visit a national park. You can use this search engine to find some nearby. If you're lucky enough to live near the coast, head over to the beach. For the landlocked folks, seek out streams or lakes which typically have hiking trails.
And one more thing... a major threat lurks amid all that greenery. It might be tiny, but it can wreak havoc on your body if you aren't careful. So before you head off to get your weekly dose of nature, don't forget to check out my latest issue of Retirement Millionaire. (If you're not an existing subscriber, feel free to give it a trial run by going here.)
What We're Reading...
- Did you miss it? A different (and tasty) kind of green space.
- Something different: Ten facts you probably didn't know about Belize's Great Blue Hole.
Here's to our health, wealth, and a great retirement,
Dr. David Eifrig and the Health & Wealth Bulletin Research Team
May 25, 2023