Walking and Eating – a Healthy Duo

Without wishing to sound like I am stating the obvious, these are two components of most people’s lives over which they have control. Therefore, they are elements embedded in the way we construct our daily decisions, both of which carry a power much misunderstood – albeit they are best not actioned simultaneously.

The June 2023 column by Erin Gibbons in the Journal Nature explores the benefits of meditative walks and adds credence to what is essentially an automatic deeply held experiential rationale – namely that being out in a different environment, preferably one rich with natural exposures, helps to reset thought patterns and emotions.

Cal Newport’s 2016 book, Deep Work explained that the goal is to take some time in which you’re physically occupied but not mentally engaged, such as walking, jogging, or swimming, and focus your attention on a single problem. As in typical mindfulness meditation, if you notice attention slipping away from the specified topic, gently bring it back. That is the key. Keep pulling your focus back to that one hard problem or concern you need to work through. He contends that focus is like a mental muscle: through deliberate training, you can strengthen your focus and expand your mental capacity and confer other health benefits including helping to resolve burnout and various non-communicable disease risks[1],[2]. Importantly, it does not matter where you are physically; it is where you are mentally during the walking that is important.

How to make it work

To make the most of the walks and limit distractions, establish a structure beforehand. Perhaps start by defining the intent of the walk and then set a clear objective by asking what it is you would like to achieve during this period of activity. Maybe prepare a short mental list of the elements you think may be associated, or are deeply connected, and let them fall into place – by starting with a plan, you are far less likely to find that you become distracted, or your focus becomes diluted. If loss of intent creeps in, try acknowledging the distraction, and place that concern to the bottom of the list. You can return to that nagging thought later, and repeat the aims that you started with. Once mastered, the mental boost is noticeable.

Evidence-Based

The benefits are not merely anecdotal. Studies have found that walking significantly enhances creativity, improves memory recall and promotes neural network plasticity (the growth and reorganisation of functional connections between brain cells)[3].

One study found that walking specifically enhances ‘divergent thinking’ which is the creative process of brainstorming original ideas and fresh possibilities, as opposed to the process of identifying familiar solutions to problems[4].

Shane O’Mara, Professor of Experimental Brain Research at Trinity College Dublin has written a book on the power of walking called In Praise of Walking where he explores in more detail the various benefits of this simple act. The book is peppered with insights about everything from 19th-century poets and flâneurs to modern-day experiments with subjects playing video games in fMRI scanners.

Choosing Food to Eat

Previous studies have shown that the relationship between foods, the human gut microbiome and numerous health concerns, are progressing from correlation to a more secure relationship of causation – yet much remains to be discovered[5].

One group of individuals who have had their microbiome analysed for several years are the Hadza Tribe who still follow a very traditional hunter-gatherer lifestyle in Tanzania. Comparisons between their microbiome and those people who eat a western-style diet have been explored in small groups. In the Journal Cell a June 2023 paper explored a far greater number and then compared their genetic sequencing from people in Nepal and California. The study has found not only that the Hadza tend to have more gut microorganisms than people in the other groups, but that a Western lifestyle seems to diminish the diversity of gut populations[6]. The Hadza had an average of 730 species of gut microbe per person. The average Californian gut microbiome contained just 277 species, and the Nepali microbiomes fell in between. The team also found species in the Hadza microbiomes that were not present in the Californian samples, such as the corkscrew-shaped bacterium Treponema succinifaciens. Only some of the Nepali microbiomes contained this microbe, suggesting that the bacterium is dying out as societies become more industrialised.

An adapting microbiome

Furthermore, the gut-microbe species commonly found in industrialised populations often contained genes associated with responding to oxidative damage. The progressive triggering of chronic inflammation in the gut from a Western lifestyle, and food selection, could trigger such damage, creating a selective pressure for those genes. If you have a state of chronic inflammation, your gut microbiome has to adapt. These genes were not detected in the Hadza microbiomes.

Obviously, we are not able to follow a hunter-gatherer lifestyle, other than some base elements – most of us would not survive! However, there are some key takeaway messages, that whilst meaningful engagement with the natural world, a daily process for the Hadza, contributes to health generation, their remarkable bacterial redundancy capacity also does. Redundancy implies flexibility and the potential for multiple solutions to a given problem, which can greatly impact the outcome of evolutionary processes. Whilst functional redundancy, a key component of our survivability, permits gene transfers in the human gut to occur horizontally, the flexibility also requires an abundance of diversity.

Those of us born into Western lifestyles see a generational loss of microbiota and related metabolic loss of redundancy, in effect, our guts are no longer homes to ‘bacteria Dodos’ they are being rendered extinct – which leaves us open to a reduced capacity to adapt to change.

Natural herbs and functional foods contain bioactive molecules capable of augmenting the immune system and mediating anti-viral functions. Functional foods, such as prebiotics, probiotics, and dietary fibres, have been shown to have positive effects on gut microbiota diversity and immune function. These should be part of any gastrointestinal bacterial modulation program[7].

The new Hygge

Standing back from the technical presentation, there exists a simpler message. That consuming foods that are as unprocessed as possible, rich in fibre and antioxidants, mediate health in part through the generational support of the GI microbiota and their related outputs. In turn, using natural environments with the act of walking, or even sitting in a space that brings you a change in exposure are powerful allies when utilised.

Coined in an essay by the 14th-century Japanese monk Kenko, aramahoshi translates literally as a “desirable ideal”, but is perhaps better described as moving from a state of need to one of contentment. He cherished the precarious: “The most precious thing in life is its uncertainty.” He also proposed a civilised aesthetic: “Leaving something incomplete makes it interesting and gives one the feeling that there is room for growth.” Perfection is banal. Better asymmetry and irregularity.

Nature is perfect because of its transient nature and asymmetry, raw unprocessed foods also confer a benefit over those that are processed.

The desirable ideal is to blend the two to ensure metabolic, immunological and psychological contentment.

References

[1] Kavanaugh J, Hardison ME, Rogers HH, White C, Gross J. Assessing the Impact of a Shinrin-Yoku (Forest Bathing) Intervention on Physician/Healthcare Professional Burnout: A Randomized, Controlled Trial. Int J Environ Res Public Health. 2022 Nov 4;19(21):14505.

[2] Li Q. Effects of forest environment (Shinrin-yoku/Forest bathing) on health promotion and disease prevention -the Establishment of “Forest Medicine”. Environ Health Prev Med. 2022;27:43.

[3] Voss MW, Prakash RS, Erickson KI, Basak C, Chaddock L, Kim JS, Alves H, Heo S, Szabo AN, White SM, Wójcicki TR, Mailey EL, Gothe N, Olson EA, McAuley E, Kramer AF. Plasticity of brain networks in a randomized intervention trial of exercise training in older adults. Front Aging Neurosci. 2010 Aug 26;2:32.

[4] Oppezzo, M., & Schwartz, D. L. (2014). Give your ideas some legs: The positive effect of walking on creative thinking. Journal of Experimental Psychology: Learning, Memory, and Cognition, 40(4), 1142–1152.

[5] Lv BM, Quan Y, Zhang HY. Causal Inference in Microbiome Medicine: Principles and Applications. Trends Microbiol. 2021 Aug;29(8):736-746.

[6] Carter MM, Olm MR, Merrill BD, Dahan D, Tripathi S, Spencer SP, Yu FB, Jain S, Neff N, Jha AR, Sonnenburg ED, Sonnenburg JL. Ultra-deep sequencing of Hadza hunter-gatherers recovers vanishing gut microbes. Cell. 2023 Jun 15:S0092-8674(23)00597-4.

[7] Banerjee A, Somasundaram I, Das D, Jain Manoj S, Banu H, Mitta Suresh P, Paul S, Bisgin A, Zhang H, Sun XF, Duttaroy AK, Pathak S. Functional Foods: A Promising Strategy for Restoring Gut Microbiota Diversity Impacted by SARS-CoV-2 Variants. Nutrients. 2023 Jun 5;15(11):2631.