Our fast-paced, and increasingly indoor-bound lives are leading us to experience abnormally high levels of chronic stress, anxiety, depression, physical ailments, and disease. Because humans have been adapting to the natural environment for millions of years, the artificial urban environment in which so many of us operate today is an unfamiliar habitat that threatens the well-being of our organism and our species. Thus, while a return to the lifestyles of our ancestors is a far-off notion, itâ€™s imperative that we continue to evolve the ways in which we harness all that nature has to offer.
Beginning as hunter-gatherers and then settled farmers, humans were regularly exposed to the great outdoors. Touching, breathing, and even swallowing a variety of microbes and phytoncides from dirt and plants was a normal part of everyday life, and came to play a significant role in regulating our immune system.
Exposure to microorganisms found in dirt has been shown to strengthen our immune systems, improve cognitive functioning, and trigger the release of serotonin, the neurochemical implicated in elevating mood and lowering anxiety. Spending time outside also allows us to come into contact with phytoncides, anti-microbial organic compounds produced by plants, which have been shown to significantly increase the numbers of natural killer cells and cancer-killing proteins in the human body, while also decreasing blood pressure and the stress hormone cortisol.
The more varied our exposure to the outdoors, the more varied the benefits. Unfortunately, the sterile urban environments in which many of us operate today, reduce or perhaps even eliminate our exposure to the natural properties that previous generations of humans have evolved in. This poses a great threat to our health and many immunologists speculate that it is the reason behind the increased incidence of allergies, asthma, and other serious illnesses. In support of this hypothesis, a recent study in Finland showed that teenagers who lived near forests and farms exhibited higher levels of immune-system robustness and lower incidence of allergies than those living in more developed areas.
Research findings show that physical activity is effective in the treatment of clinical depression, can reduce anxiety, decrease stress, improve mood states, enhance sleep, improve cardiovascular health and result in the formation of versatile new brain cells and the connections between them.
Just as muscles and organs experience physical atrophy with increasing age, so too does the brain. In contrast to chimpanzees and other primates, the human brain is subject to shrinkage and a host of neurodegenerative diseases. As it ages, the human brain can shrink up to 15%, and beginning in our early twenties, the average human begins losing about 1% of hippocampal volume per year. As the hippocampus is the area of the brain implicated in memory and particular types of learning, it plays an important role in our physical and mental well-being.
Until the 1990s, the predominant notion among neuroscientists was that we are born with a certain number of brain cells and are unable to generate new ones. Advancements in technology, however, have allowed researchers to observe neurogenesis, or the creation of new brain cells in the adult human brain. Consequent studies have found that physical activity is the best way by which to create new neurons and the connections that link them to the existing neural network, and studies show that walking for just 3 hours a week is enough to halt and even reverse the process of age-associated brain atrophy.
Having evolved alongside each other for over 14,000 years, humans and dogs have a deeply rooted, social symbiotic relationship, which when viewed in terms of health benefits, mimics that of the human-human interaction model and results in significant reductions on scales of loneliness. Social interactions, characterized by the exchange of physical and emotional energy combined with stimuli such as touch, warmth, and/or odor, which trigger the release of the hormone oxytocin, have long been touted for their varied benefits on human health.
Human-dog interactions have the potential to regulate the stress response, decrease cardiovascular reactivity, enhance brain function, decrease anxiety, and alleviate symptoms of depression. In triggering the release of oxytocin, these interactions result in calm mental states that promote relaxation, digestion, metabolism, growth, and healing, while also facilitating tolerance to monotony. In addition, studies have shown that spending time with your dog increases levels of dopamine and serotonin, chemicals which are noticeably depleted in patients with depression and which are implicated in the experience of pleasure.
Aside from providing direct physiological benefits through social interaction, dogs inevitably also come in contact with nature. Touching plants, fungi, and dirt allows the dogâ€™s coat to amass micro-organisms and bacteria, which can greatly benefit the immune system of the human body, increasing our own exposure to natureâ€™s bounty long after weâ€™ve arrived indoors.
Dagmara MachÂ is a traveler, yogi, freelance writer, and content contributor on behalf of fitness equipment retailer Fitness Blowout. Currently based in Breckenridge, Colorado, Dagmara is passionate about gaining new perspectives, building meaningful relationships, and exploring the mountains. Combining her education in psychology, statistics, and marketing, she strives to promote rationalism, education, and healthy lifestyles.