Why Your Brain Needs a Garden

August 21, 2014

Story at-a-glance

  • Garden use leads to decreased levels of agitation or anxiety among dementia patients
  • Gardening is one of the most potent stress-relieving activities there is and leads to lower levels of the stress hormone cortisol than other activities, including reading
  • Mycobacterium vaccae, a type of bacteria commonly found in soil, has been found to “mirror the effect on neurons that drugs like Prozac provide”
  • The microbes help to stimulate serotonin production, helping to make you feel happier and more relaxed.
  • In one animal study, mice that ingested mycobacterium vaccae had a demonstrated reduction in anxiety and improved learning

By Dr. Mercola

Mirabel Osler, an English writer and garden designer, famously said: "There can be no other occupation like gardening in which, if you were to creep behind someone at their work, you would find them smiling."

Indeed, gardening, a pastime taken up by 72 percent of US households,1 awakens a primal urge that many of us have to connect with the earth. By putting your hands in the soil, you are able to physically unite with nature on an elemental level.

At the same time, gardening gets you outdoors in the fresh air and sunshine, helping your body produce much-needed vitamin D. It gets you moving, providing important exercise, and allows you to connect socially with other gardeners.

When you garden, you're adding beauty to the landscape and habitat for birds, bees, frogs, worms, and so much more. Depending on what you garden, you can reap a harvest of fruits and vegetables to feed your family. You can also indirectly feed your brain for better mood and emotional health, and to satisfy your curiosity for knowledge.

In fact, learning is the fourth top reason why people say they garden -- after to grow safe, healthy food, get exercise, and add beauty to their yard.2 Perhaps it's no coincidence that people garden, in part, to stimulate their brains, as gardening has been shown to impact brain health considerably.

Spending Time in a Garden May Help Calm Dementia Patients

A new systematic review examined the impact of gardens and outdoor spaces on the mental and physical well-being of people with dementia. The research suggested that garden use, whether it be watering plants, walking through a garden or sitting in one, led to decreased levels of agitation or anxiety among the patients.3

As for why the garden may help induce calm, Dr. Mark Stecker, chairman of neurosciences at Winthrop-University Hospital, who was not involved with the study, said:4

"When your brain is impaired, you go back to your basic instincts. Many people have always enjoyed the outdoors. They may not have an explicit memory of that, but it's an implicit memory. And they find it comforting to be outside."

This makes sense, especially considering researchers in the Netherlands have found that gardening is one of the most potent stress-relieving activities there is.5 In their trial, two groups of people were asked to complete a stressful task; one group was then instructed to garden for half an hour while the other group was asked to read indoors for the same length of time.

Afterward, the gardening group reported a greater improvement in mood. Tests also revealed they had lower levels of the stress hormone cortisol, compared to those who tried to relax by quiet reading.

Interestingly, while spending time in a garden may help relieve some dementia symptoms, it may also help to reduce your risk of developing dementia in the first place. As reported by CNN:6

"Two separate studies that followed people in their 60s and 70s for up to 16 years found, respectively, that those who gardened regularly had a 36 percent and 47 percent lower risk of dementia than non-gardeners, even when a range of other health factors were taken into account.

These findings are hardly definitive, but they suggest that the combination of physical and mental activity involved in gardening may have a positive influence on the mind."

Gardening May Make You Happy Via Antidepressant Microbes in the Soil

According to a survey by Gardeners' World magazine, 80 percent of gardeners reported being "happy" and satisfied with their lives, compared to 67 percent of non-gardeners.7 Perhaps it's no coincidence that gardeners are happier…

Mycobacterium vaccae is a type of bacteria commonly found in soil, which people may ingest or inhale when they garden.8 Remarkably, this microbe has been found to "mirror the effect on neurons that drugs like Prozac provide."9 It helps to stimulate serotonin production, helping to make you feel happier and more relaxed. No wonder so many people describe their garden as their "happy place."

In one animal study, mice that ingested Mycobacterium vaccae had a demonstrated reduction in anxiety and improved learning. The researchers noted that natural exposure to microbes may be important for emotional health and behavior: 10

"Recent studies show that contact with tolerogenic microbes is important for the proper functioning of immunoregulatory circuits affecting behavior, emotionality and health…

Collectively, our results suggest a beneficial effect of naturally delivered, live M. vaccae on anxiety-related behaviors… supporting a positive role for ambient microbes in the immunomodulation of animal behavior."

A Free Way to Drastically Improve the Health of Your Soil

Nurturing the health of your soil may benefit you on multiple levels, not only by exposure to mood-boosting microbes but also because healthy soil is what allows your food, the vegetables and fruits, to grow nutrient-dense foods.

Nature is self-sustaining, and when left alone the ground will get covered with leaves and organic materials that then turn into lush compost, adding nutrients back to the soil. This top layer of organic material also shields the soil and helps retain moisture.

Imitating nature by covering your garden with wood chips will result in less watering and improved yield. The most cost-effective solution is to contact your local tree service, where you can get large amounts of wood chips (tree branches that have gone through a wood chipper) for free, rather than purchasing mulch from a garden center.

It is important to distribute all the chips within 1-2 days though, otherwise they tend to decompose and you will breathe in some nasty dust as you move them. You can see my recent article for more information on wood chips. Besides wood chips, I strongly encourage you to consider adding biochar to your garden, to optimize the health of your soil. This soil amendment can truly transform your garden, in terms of dramatically boosting yields.

One of the keys to a truly successful garden is to improve the microbiology of the soil. It is this diverse collection of bacteria, fungi, and parasites that actually transfer the nutrients from the soil into the plant. While synthetic fertilizers like Miracle Grow will supply some nutrients, these salts actually kill the soil microbes! As a result, your garden will not become "self-sustaining" and it will worsen over time.

To thrive and multiply, these soil microbes need a home to hang out in, or else they simply die shortly after application. Biochar serves this function perfectly as do wood chips as, over time, they are converted to carbon stable humates. I've applied about eight tons of biochar on my property, and I'm now noticing major improvements. Biochar is not free, but wood chips typically are. I have applied 30 tons of chips and hope to double or triple that amount soon. Nitrogen sources like human urine can be a helpful approach to balance the mixture.

Gardening Helps You Get Grounded

There's another way that gardening may help your mood and brain health, and that is grounding. As detailed in the documentary film Grounded, the surface of the earth holds subtle health-boosting energy, and all you have to do to harness it is touch it. Walking barefoot on the earth transfers free electrons from the earth's surface into your body that then spread throughout your tissues.

Grounding has been shown to relieve pain, reduce inflammation, improve sleep, and enhance your well-being. Monty Don, a TV presenter and garden writer, attributes the wellbeing of gardeners to the "recharging" you get from sticking your hands in the soil and spending time outdoors in nature.11 To maximize grounding while you're gardening, try doing so barefoot.

Are You Ready to Try Out Your Green Thumb?

Aside from increasing your sense of well-being and calm, keeping a garden can also improve your health by providing you with fresher, uncontaminated food; nutrient-dense food that is simply unavailable in your grocery store. It will also help you reduce your grocery bill. You don't need vast amounts of space either.

Even apartment dwellers can create a well-stocked edible garden. You can use virtually every square foot of your space to grow food, including your lateral space. Hanging baskets are ideal for a wide variety of crops, such as strawberries, leafy greens, runner beans, pea shoots, tomatoes, and a variety of herbs. You can also grow sprouts like sunflower seeds and reap a harvest in 7-10 days.

And instead of flowers, window boxes can hold herbs, greens, radishes, scallions, bush beans, strawberries, chard, and chilies, for example. Just start small, and as you get the hang of it, add another container of something else. To learn more, please see my previous article on creating edible gardens in small spaces. Before you know it, large portions of your meals could come straight from your own edible garden. I recommend getting your feet wet by growing sprouts, which can be grown at any time of year. And with fall nearly upon us in the US, you can even create a winter garden.

Copyright 1997- 2014 Dr. Joseph Mercola. All Rights Reserved.

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