When many think about factors influencing our metabolic health, the first and usually the only thing ever spoken about is food. This is not wrong, per se. Nutrition does seem to be an overwhelming driver and controller of our metabolism and nutritional hormones. But sometimes this blinkered approach to metabolic health, and I’d argue health in general, fails to acknowledge the broader intricacies of life and what it is to be a healthy individual.
You may know someone, or you may have cleaned up your diet and yet still hit health or fitness walls. These can be frustrating times. But I’d encourage you to see this as a blessing. Life has told you to look for answers elsewhere. Broaden your knowledge. Get curious.
Food is vital for survival, but don’t forget that there are other equally important components of life needed by most organisms on this planet. These includes sunlight, water, and
and oxygen (or air quality). You and I are not really different from the humble house plant or mountain goat in this regard. And I’d urge that the answers to better personal health lie more in our similarities than in our differences.
What we all share is an overwhelming proportion of DNA dedicated to just existing on this rocky green and blue planet whirling around the centre of our galaxy at some 490,000 miles per hour. We are genetically hardwired to work optimally in environments that birthed and moulded us. Our ancestors span all the way back to single cell organisms that were estimated to have been formed 4 billion years ago.
If you’re talking about human evolution, then the earliest ‘human’ (origin of the genus Homo) is thought to have originated in eastern Africa between 2.0 and 3.0 million years ago. The earliest representatives of our species—people that looked like us, Homo sapiens—are thought to have originated some 315,000 years ago.
“What’s all this got to do with metabolic health?”, I hear you asking. Well, your body and mind are models made some three hundred thousand years ago using ancient technology that has been continuously updated over billions of years. We were hunter-gatherers for most of that time and farmers for the rest. For most of human history, the line between us and the outer world remained fairly thin. Up until very recently.
In the middle of the 18th century, we kicked off the Industrial Revolution, and since then, this gap between us and nature, i.e., the environment best suited for us, has widened. Don’t take me as a technophobic Ebenezer Scrooge shouting “Bah Humbug” every time I walk past an Apple store, however. No, I understand and appreciate the ease, connectivity, and positive transformative abilities that technology has brought into our lives. In a way, too, it was only inevitable that our prefrontal cortex, wired to tool making and problem solving, would take us to where we are now. I get all that. But if you dare look, you will notice the downfall of living in a world where our genetic software and the outer technological software are at war with each other. If you truly understand this, you will understand health.
I’ll give you a general trick I use when I try to unpick health walls or plateaus. I use Lindy’s Law’. Lindy’s Law is a theorised phenomenon popularised by Nassim Taleb - the famous mathematical statistician and author, and states that the future life expectancy of some non-perishable things, like a technology or an idea, is proportional to their current age. In simpler words, the longer something has existed in the past, the longer it will likely survive in the future.
I’ve morphed it for health, specifically evolutionary health, whereby the longer a certain factor has existed and contributed to our wellbeing, the more likely it is to play a greater role in our health. Thus (most of the time, as exceptions exist), disruptions in more Lindy factors disproportionately affect health negatively than other factors. And you can’t get more Lindy than sunlight, air, water, and food.
Though seemingly basic, these components of life are not only vital for our survival but also control various hormones and biochemical reactions that are happening in us at all times. Take vitamin D, the hormone activated by sunlight, for example. Did you know that vitamin D deficiency has been shown to impair insulin synthesis and secretion in humans and in animal models of diabetes? We talk about food when it comes to metabolism, but are we focusing on sunlight or other areas of health?
To really boil it down, one could go as far as saying that ‘we are what we are subjected to’. Optimise your surroundings to optimise your health. This is no more important than in current times, where modern technology, phoney capitalism, and poor public health policies have disrupted our natural habitat and thus our health.
Improving our wellbeing and thus our metabolic health relies on three steps. First, we have to understand our evolutionary needs. Secondly, we have to understand the disruption caused by modern living. And third, we have to ameliorate the damage caused to us. We’ve got to learn to use technology rather than be used by it.
This can all sound slightly obscure. But believe me when I say that I am not wearing a tin foil hat while I am writing this. And you don’t have to believe me; just believe the science.
Sunlight
Let’s focus on sunlight first, the most Lindy component of life of them all. Formed about 4.6 billion years ago, and without it we wouldn’t have our beautiful Earth or life as we know it. Thanks to the sun and the Earth’s spin, most organisms, including mammals, have developed a circadian system under the earth’s natural 24‐hour rhythm that is adapted to the regular alternation of light and dark phases.
But instead of basking in the sunlight during the day and sleeping in pitch-black darkness at night, like during most of our history, our modern society has turned this upside down. Artificial street lighting uninvitedly forces its way into our bedroom at night. If that isn’t enough, our faces are illuminated by our smartphones right before bed,and we work indoors all day away from the sunshine. Others of you may even be in a more compromised position by shift working for a living. And all this light imbalance is looking like it has a significant impact on our metabolic health.
There have been many animal studies looking at the effects of light on metabolism. All-in-all light disruption wasn't doing them any favours and will not do us any favours. Here are a handful of findings from some studies:
- “exposure to light at night has acute adverse effects on glucose metabolism in a time-, intensity- and wavelength-dependent manner.”
- “suppression of blue light at night effectively maintains circadian rhythms and metabolism.”
- “1‐hour of blue artificial light at night exposure induced a higher glucose response in the oral glucose tolerance test accompanied by a significant decrease in plasma insulin.”
- “We demonstrated in rats that exposure to artificial light at night causes changes in energy expenditure, respiratory exchange ratio, and clock and metabolic gene expression in the liver”
- “In conclusion, the present study demonstrates that continuous light exposure, an important environmental factor, contributes to the occurrence and developmental progress of polycystic ovary syndrome and changes in microbial component and structure.”
Human studies have not been so promising either. One review noted that “exposure to artificial light at night has been shown to impact glucose homeostasis also in humans and to be associated with an increased incidence of overweight, obesity, and atherosclerosis.”. Another study of 43,722 women found that those who slept in light rooms had higher body weights compared with women sleeping in dark rooms. A study of 103 Brazilian individuals showed that greater exposure to light during the day and a lower exposure to light at night were associated with a reduced risk of metabolic syndrome. Reducing light exposure, especially blue light exposure before bed, has also been shown to improve insulin sensitivity.
With an established 99% of the population of the European Union and the United States living in areas where nighttime illumination is above the threshold for light pollution. And many of us use our smartphones and watch TV at night. It might now make a little more sense why rates of obesity are rising. For sure, our food type and quality matter, but does your dietician recommend you buy blackout curtains or get outside and get as much sunlight as possible?
Air quality
“Air pollution is the leading environmental cause of premature reversible death and disability in the world today”. Not the most promising start to a scientific study. But it doesn’t get much better. “A large body of evidence implicates the component of air pollution containing particulate matter smaller than 2.5 μm (PM2.5) in size in the development of cardiovascular disease risk factors such as hypertension, insulin resistance (IR), and type 2 diabetes mellitus”. Great, so the air is contributing to disease too? It seems so.
In fact, if you look at this graph, you begin to appreciate the size of this problem.
With regards to metabolic issues, one population study of 1110 Korean adults showed a strong association between elevation in diabetes-related parameters and exposure to air pollution. This was markedly seen in men over the age of 65 years old.
In a meta-analysis of cohort studies involving a total of 2,371,907 participants, the relative risk for diabetes increased by 39% per 10 mg/m3 of PM2.5. Or as the study puts it ”Long-term exposure to high levels of main air pollutants is significantly associated with elevated risk of type 2 diabetes mellitus.”.
It seems like breathing in pollutants day in and day out isn’t good for us. Who'd thought? (Note the sarcasm.) It seems like PM2.5 is associated with inflammation and specific changes to genes related to inflammation, vessel wall dysfunction, and the production of inflammatory immune mediators. And all of these seem to impact blood glucose levels.
I hope you can appreciate that poor air quality is a public health crisis, but how many of us are warned about the implications of this for our metabolism?
Water quality
Water has seemingly shaped human history. The earliest known permanent settlement, Jericho, dates from 8000-7000 B.C. and was located near springs and other bodies of water. Traces of wells have been found in ancient Egypt and stone rainwater channels in Mesopotamia from 3000 B.C.
The quality of water back then was vital to keeping populations, cattle, and farmland healthy. It was regarded as so essential that water has become part of our culture. To this very day, various religions use water to symbolise cleanliness and vitality.
Alcmaeon of Croton (470 B.C.) was the first Greek doctor to state that the quality of water may influence people's health. The ancient Romans and Greeks were quite aware of the dangers of water coming from hills and mountains where mining was practised, as well as avoiding water from marshy areas. Like Alcmaeon, I’m going to reinstate the fact that water quality may influence people's health. And there is some evidence that water quality may impact one’s metabolism.
In one study, rats were either fed fructose (a type of sugar) in natural mineral water or fed fructose in tap water. The natural mineral-rich water tested high in total mineralization content, being mainly rich in sodium and bicarbonate and having higher potassium, calcium, and magnesium content than tap water. As you’ve guessed, rats fed fructose with mineral water seemed to be more protected against weight gain and metabolic dysfunction compared to the tap water group. The study goes on to suggest that this may be due to the mineral water’s high magnesium content.
It seems like human studies on this subject are lacking. One study I did find, this time of 18 postmenopausal women, showed that drinking bicarbonate mineral waters with a standard meal improved insulin sensitivity. Remember, too, that the benefit of good quality mineral water may also be due to the fact that it is not tap water.
A population study of 26,166 residents in Taiwan showed that environmental quality, including nitrite, sulphate, and calcium carbonate in drinking water, was significantly associated with an increase in metabolic syndrome. And a smaller study of 160 people indicated that mean concentrations of heavy metals - vanadium, manganese, nickel, arsenic, cadmium, and strontium—in drinking water of the people suffering from metabolic syndrome were higher than in those who didn’t.
Be like water, my friend.
Location
If you want to protect yourself from metabolic disease, then moving to the mountains may be an option. In a long term study of over six thousand participants, subjects who lived at higher altitudes exhibited a reduced risk of developing metabolic syndrome compared to those at the lowest altitude. Between people living at different altitudes, no significant differences were found in baseline sedentary behaviour, smoking status, alcohol consumption, adherence to the Mediterranean dietary pattern, special diets or sleeping time. Or in other words, it wasn’t like the people living at higher altitudes were living any different from those lower down.
This isn’t the first study to note this association between higher altitudes and better health. In a US cross-sectional study, after controlling for urbanisation, temperature,behavioural, and demographic factors, obesity was found to be significantly higher at lower altitudes. Another study found the mortality rate from coronary heart disease was reduced in men living above 1220m.
Higher altitudes may be beneficial for a lot of reasons. The thinner air and lower available oxygen may play a part. Increased metabolic rates and the production of the hunger-preventive hormone leptin have also been shown at higher altitudes.
If you are looking to move to the mountains, it might be more beneficial to avoid food deserts. Food deserts are neighbourhoods defined as low-income areas with low access to healthy food. And as expected, they are linked to worse health outcomes. One study of over fourteen hundred participants in the Atlanta metropolitan area noted that those who lived in food deserts were more likely to have higher blood pressure, BMI, fasting glucose levels, blood inflammatory markers, and a 10-year risk of cardiovascular disease. Interestingly, though, this study did note that although living in food deserts was associated with a higher burden of cardiovascular risk factors, these associations were mainly driven by area income and individual income rather than access to healthy food.
As always, having money is a great and usually overlooked health supplement.
Politics
For most of human history, including much of the 20th century, not enough food was the greatest nutritional challenge. To combat this, governments aimed to boost the production and distribution of as much low-cost food as possible, particularly starchy (high carbohydrate) staples and their shelf-stable processed counterparts. Too much of anything is bad for you, and like that, though unthinkable at the time, a colossal rise in obesity and chronic diseases ensued, partly to be blamed on the broad availability of cheap, subsidised foods.
As one study notes, “Among US adults, higher consumption of calories from subsidized food commodities was associated with a greater probability of some cardiometabolic risks.”.
But why?
Well, approximately 80% of the calories eaten in the United States are grown domestically. The current US federal agricultural subsidies focus on financing the production of corn, soybeans, wheat, rice, sorghum, dairy, and livestock. And though only 5% of the corn produced in the US is converted into high-fructose corn syrup (HFCS), the average American consumed approximately 22.1 lb (10.0 kg) of HFCS in 2018.
I bring up HFCS specifically because intake of beverages and food products containing HFCS has been associated with obesity, non-alcoholic fatty liver disease (NAFLD), cardiovascular diseases, type 2 diabetes mellitus (T2DM), reproductive system diseases, and even cancer.
In a way, you could say that our taxes are indirectly harming us.
Chronic disease
Other than external toxins causing dysregulation, certain diseases and conditions can themselves increase the risk of metabolic issues. When we think of someone with metabolic problems, we commonly think of them having diabetes, being obese, or both, but like everything else we have learned so far, I want you to broaden your thinking.
Obese asthmatics are at higher risk of metabolic syndrome as opposed to obese individuals who do not suffer from asthma, suggesting that asthma per se can increase the risk of developing metabolic syndrome.
Likely due to antipsychotic medication, the implications of poor mental health, and genetic alterations, metabolic syndrome is highly prevalent in individuals with schizophrenia.
And patients with rheumatoid arthritis have a significantly higher prevalence of metabolic syndrome compared to the general population.
I picked a chronic lung, mental health, and rheumatological condition to make a point.
What can you do about it all?
I am sorry if you've read this and left with a feeling of helpless despair. As you can see, there are other causes of metabolic upset other than certain foods and drinks. There are a lot more than the three I have mentioned, and the list continues to grow every day. Though a growing problem, we hardly ever hear about the health impacts of the pollutants caused by this rapidly expanding consumerist society that we currently live in. Or about the metabolic dangers of watching a harmless YouTube video just before bed. Or about the risk of other diseases on top of the one you may have now. Well, now you know.
The first step to combating these issues is to understand the problems. And the way to tackle them is to get back to a cleaner, more natural way of living. Think of a houseplant. What things do you need to do to grow healthy and strong?