Are nature and biodiversity essential to health and happiness?

There is no prize for guessing the answer given by Susan Prescott and Alan Logan in The Secret Life of your Microbiome: Why nature and biodiversity are essential to health and happiness.

This recently published book is written for a popular audience, but the authors have expert knowledge of the microbiome – the microbes and their genetic material found in the human gut and skin. Susan Prescott is an immunologist and paediatrician. Alan Logan’s background is in research relating to naturopathic medicine. It is obvious that the authors have spent a lot of time sifting through scientific evidence in writing the book.

Some of the evidence suggesting that nature and biodiversity are essential to health and happiness is derived from inspection of the stools of our Paleolithic ancestors. Evidence from archaeological sites suggests that our hunter and gatherer ancestors ate a wide variety of plant food and had a greater diversity of micro-biota than most people living modern lifestyles. The same is true today of people who are still living traditional lifestyles close to nature.

The authors accept that modern medicine and hygiene have brought great benefits, but they point to evidence that a diet with a great deal of sugar, ultra-processed food and drinks – as well as excessive use of antibiotics, stress and physical exhaustion – can lead to gut permeability, an increase in blood endotoxins, and an increase in central nervous system inflammatory chemicals. Intestinal permeability is apparently associated with a range of chronic conditions including autism, asthma, allergies, chronic fatigue, depression, fibromyalgia, heart disease, irritable bowel, obesity, type 2 diabetes, psoriasis and schizophrenia.

Prescott and Logan argue that we have a symbiotic relationship with the human microbiome, which co-evolved with our ancestors. The microbiome provides functional benefits such as nutrient extraction, protection against harmful microbes, regulation of metabolism and production of important biochemicals. Researchers don’t yet understand what microbes would comprise an ideal microbiome, but the key seems to be diversity, which is encouraged by dietary diversity. The authors suggest that the human immune system has evolved to expect a kaleidoscope of biodiversity.

The authors view commercially available probiotics and prebiotics as a useful supplement that can help defend against dysbiotic forces in the modern environment, rather than as a substitute for the adoption of a healthy lifestyle. They emphasize the importance of dietary choices, physical activity, sleep and experience of natural environments.

There is substantial evidence, some previously discussed on this blog, that experience of natural environments has a positive impact on health and happiness. Prescott and Logan provide an interesting account of Japanese research relating to shinrin-yoku – the absorption of the forest into the body and mind:

“Remarkable studies have demonstrated that, individually, the sounds of nature, the sights of nature, the invisible chemicals secreted from trees (phytoncides, or phytochemicals), and the touch of natural products like wood (compared to synthetic resin), can positively influence stress physiology and our parasympathetic nervous system, the “rest and digest” branch of the nervous system that cools the jets of over-stimulation. The sum of research shows that our sensory system understands nature like an old friend.”

One of the authors’ aims seems to be to promote nature relatedness – fascination with nature and a desire for contact with it. They note evidence that nature relatedness is associated with high levels of psychological wellbeing, lower anxiety and greater meaning and purpose in life. Experience in nature tends to lift nature relatedness scores. Practicing mindfulness while walking in nature has additional emotional benefits. Moreover, the combination of nature relatedness, mindfulness and meaningfulness of life promotes pro-environmental behaviours.

Prescott and Logan leave readers in no doubt that they view pro-environmental behaviours to be desirable. I agree with them.

However, I strongly disagree with authors about economics and politics. They argue:

“It’s up to governments, insulated against lobbyists, to help curb the wild west that is fueling the dysbiosphere. Time and time again industry has shown it just can’t stop itself from pushing dysbiotic choices on our children.”

They oppose the view that “an individual can assume responsibility for personal health problems by simply adopting what biomedicine has to offer”. They suggest that view is deficient because it “doesn’t consider that a broken socio-ecological system might be the driving force for the need of biomedicine in the first place”.

When I read such views I have to remind myself that in writing about supporters of socialism Friedrich Hayek insisted “that it is neither selfish interests nor evil intentions but mostly honest convictions and good intentions which determine the intellectual's views”. (Quote from ‘The Intellectuals and Socialism’). It is not necessarily a waste of time to try to correct the errors of well-intentioned people.

Some of the errors made by Prescott and Logan are as follows:

1.       The view that government can be insulated against lobbyists is contrary to everything that is known about government and human nature.

2.       The phrase “pushing dysbiotic choices on our children” refers to advertising and selling products that are only harmful to human health when consumed inappropriately. There is nothing in our legal or economic system that requires parents to buy such products for their children or to allow them to over-indulge. Firms already offer foods for sale that are beneficial to health and will have a greater incentive to do so as consumers become more aware of the health implications of the choices they make on behalf of their children.

3.       The widespread human misery (and environmental catastrophes) caused by socialist economic experiments during the 20^th century should make us wary of claims that the socio-ecological system is broken. In what respects is it broken? What precise interventions are proposed to fix it? And, are we sure, beyond reasonable doubt, that those interventions will produce better overall outcomes?

Susan Prescott and Alan Logan were unwise to include ill-informed rants on economics and politics in this book. It seems to me that those rants detract from their efforts to promote a revolution in attitudes toward the micro-biome and the environment.

In my view this book is nevertheless worth reading because of the substantial body of scientific evidence it provides that many aspects of human health and happiness depend on the microbiome.

Where is the best place to live?

The pathway above Orion beach, Vincentia, NSW, Australia

Over the last few months I have had personal reasons to ponder this question. My wife and I decided that the time had come for us to move closer to family and downsize.

I can’t claim that I reviewed research relating to the question in a systematic way before we decided where we should live. However, I have been reading and writing about happiness research for over a decade, so that probably had some influence.

Since we made our decision I have read some of the more recent literature on the impact of happiness of location. Perhaps my recent reading could be explained in terms of seeking additional evidence to support the decision we have made, but I do find the topic intrinsically interesting.

My intention here is to discuss research findings on the impact of location on happiness rather than to attempt to justify our decision.  Relocation decisions made by different individuals and families obviously need to reflect their differing values and changing priorities at different stages of life.

If you do an internet search on “happiness best place to live” one of the first items to come up is likely to be an article telling you that according to a major Gallup poll, Hawaii is the U.S. state with the highest well-being ranking, with the top score in the physical, financial and community categories. If you search for the cities that are the best places to live, you are likely to find articles based on Gallup polls which suggest that the cities that score highest are near the ocean. When you read on you find that there is more involved than just beachside living. Research by Andrew Oswald has shown that average life satisfaction levels in different places closely correlate with objective measures of the quality of life – as measured sunshine hours, congestion, air quality etc.

Survey data on the happiness of people in different federal electorates in Australia suggests that many of the happiest electorates in Australia are not close to the coast (although the New South Wales south coast electorate of Gilmore, where we have lived for the last 12 years, is among the top five). Some of the unhappiest electorates in the country are in suburban Sydney. Some headlines claiming that major cities create unhappy Australians prompted me to write sceptically on this topic a couple of years ago. I suggested that current life satisfaction is not the only important consideration in making location decisions. Many families face trade-offs between current and future life satisfaction.

I recommend that people considering a move should also read an article by Brad Waters in Psychology Today which draws upon the insights of Daniel Kahneman to make the point that life satisfaction is influenced by many factors other than location. He suggests that people considering relocation should ask themselves: “Does a move satisfy those factors or does it temporarily distract us from satisfying them?”

There is evidence of substantial benefits from living in a location where it is possible to see family and friends frequently. For example, research by Nick Powdthavee, undertaken about a decade ago, suggested that the benefits of seeing relatives and friends “most days” rather than “less than once a month” was greater than the benefit of getting married and was sufficient to compensate for about two-thirds of the happiness loss from such events as unemployment or going through a separation.

A couple of years ago when I wrote about the link between happiness and nature connectedness I speculated that some part of the correlation between nature connectedness and happiness is associated with “feeling connected”. Feeling connected to nature might be similar in that respect to feeling connected with family, friends or community.

Evidence continues to accumulate that actual contact with the natural environment has positive benefits for health and happiness. For example, a study conducted by Simone Kuhn (and others) for the Max Planck Institute for Human Development (discussed in this Forbes article) found that city dwellers who live near forests were more likely to have healthy amygdalas and thus better able to manage stress, anxiety and depression. A study by Chris Neale (and others) using mobile EEG has found that when walking in urban green space old people had a higher level of engagement and lower levels of excitement than when walking in both busy urban commercial streets and quiet urban space. The authors concluded that the urban green space seemed to have a restorative effect on brain activity.

An article by Ming Kuo has identified 21 plausible pathways linking nature to human health and has postulated that one pathway, enhanced immune functioning, may be of central importance.

Thoughts along those line prompted me to begin reading The Secret Life of Your Microbiome, why nature and biodiversity are essential to health and happiness, by Susan Prescott and Alan Logan. Perhaps I will write more about that later.

Meanwhile, my bottom line is that, other things equal, it might be a good idea to find a place to live where you can spend a fair amount of time in the natural environment with family and friends. Unfortunately, many people in this world do not currently have the luxury of making that choice.

Why might economic development influence how unhappy people feel when they don't get the love they desire?

There is evidence that a discrepancy between the amount of self-transcending emotion (e.g. love, trust) that people want to feel and what they actually feel has an adverse impact on their happiness.  Researchers have observed that this adverse impact is greater for people in countries with relatively high levels of economic development.

What is it about economic development that could explain this?

Before canvassing possible explanations I need to provide some background information. The evidence referred to above is in a recent article entitled ‘The Secret to Happiness: Feeling Good or Feeling Right?’  by Maya Tamir, Shalom H. Schwartz, Shige Oishi, and Min Y. Kim. The study was based on a cross-cultural sample of 2,324 participants from 8 countries around the world.  I wrote about the main findings of the article on this blog in my last post entitled: What was Aristotle’s secret of happiness?

As indicated in the diagram reproduced above, the authors found that the absolute discrepancy between desired and experienced self-transcending emotions had a larger impact on life satisfaction and depressive symptoms of people in countries with relatively high ratings on the Human Development Index (HDI).

Evidence that economic development influences the impact of emotional discrepancy on happiness was only observed in respect of self-transcending emotions. The findings of the study suggest that economic development has no influence on the way discrepancies between desired and experienced anger, excitement and calmness impact on life satisfaction and depressive symptoms.

So, what is it about economic development that could explain why it seems to make happiness levels more sensitive to feeling the right amount of love? The authors suggest that perhaps “for people who struggle to meet their basic needs the amount of love they actually feel matters more for their happiness than whether this amount feels right or not”. They suggest that this would not apply to other emotions because love is “linked to social connectedness”, which “is presumably a basic human need and a key determinant of well-being”.

I’m not sure I understand what the authors mean. Anger might also be linked to social connectedness. Angry people might find it harder to maintain strong social connections.

A distinguishing feature of love, relative to emotions such as anger, is that when people are asked how much love they feel they could think of either how much they feel loved by others, or how much love they feel toward others.

If we think in terms of Maslow’s hierarchy of needs, it might be reasonable to speculate that people whose basic physiological and safety needs are satisfied might place higher priority on obtaining love than those who are struggling to meet their basic needs. In economic terms this could be thought of as an upward shift in the marginal utility of love as incomes rise. That could explain why a shortfall in love obtained relative to the desired level seems to have a larger impact on happiness of people in countries with relatively high HDI ratings.

That is just speculation. The authors suggest future research should explore further “when, why, and how” the links between emotion discrepancies and well-being vary across countries. It will be interesting to see what eventuates.