Curious Cook: How food talks

Although ultra-processed foods offer cause for health concerns, the reality is that these are often the cheapest foods available. — TYSON/Unsplash

The food we eat talks a lot, and at many levels, though we often do not realise it. The dishes we eat define cultures, emotions, memories and ultimately our bodies. Also, food has a remarkable way of bringing people together. Sharing a meal is a simple, universal act that can transcend language barriers and unite individuals from diverse backgrounds.

From family dinners to communal feasts, food can serve as a common language that builds social connections, strengthens relationships, and often nurture a sense of community. The act of eating together with others often conveys simple acceptance, warmth, and solidarity.

Food is also incredibly effective at evoking emotions and triggering memories. A familiar smell or taste can remind us of happy moments or special occasions spent with loved ones.

But food does not always communicate with your conscious mind so readily, and it takes a long time, often too long, to understand what the food you eat is really saying. And this is a convoluted story, supported by a significant number of sobering correlations with human diseases in modern times. At this point, it has to be pointed out that correlation is not always proof of causation, so you can make up your mind about the observable facts below. All I can suggest is, do not bet against the facts.

The new pandemic, revisited

Many doctors and researchers have suggested that the world is currently suffering a slow-burning pandemic called ‘metabolic syndrome’. This is already reviewed in an earlier column, titled ‘TOFI, FOFI and Metabolic Syndrome’ on The Star Online.

More evidence is emerging that metabolic syndrome is very probably the root cause of a curiously disproportionate increase in early-onset diseases in modern times. They are known as early-onset diseases because they are occurring in younger age groups below the older age ranges when such diseases statistically tended to appear in the past.

The link between early-onset diseases such as diabetes and certain cancers is heavily correlated with being overweight and obese. In 1950, less than 1% of the UK population was obese. Currently, it is 28% with another 32% classed as overweight, with both statistics rising in the UK. At the same time, incidence of colorectal cancers have increased 70% between the ages of 15-39 in industrialised countries between 1990 and 2019. The soaring diabetes rates have already been covered in the linked article above.

The human digestive system can detect poor nutrition, especially when consuming too much ultra-processed foods like cold cuts. — VLAD MELNIKOV/UnsplashThe human digestive system can detect poor nutrition, especially when consuming too much ultra-processed foods like cold cuts. — VLAD MELNIKOV/Unsplash

Therefore, one interesting question is: Have humans changed in the last half century or so? And the answer is clearly No, because evolution just does not work that quickly. But the food humans eat has changed tremendously over the last few decades due to modern industrial processing of food, using techniques, processes, and chemical additives unknown and unimaginable to our ancestors.

Half a century ago, most people generally were not eating every day, for example, synthetic additives (such as polysorbate-80, carboxymethylcellulose, sodium nitrite, sucralose, etc), or highly processed, extremely calorie-dense foods, packed with flavourings enhanced with sugars and salts.

And people now eat a lot of “funny” foods which confuse the digestive system. A packet of carbohydrate-based crisps may be flavoured with chicken or beef seasoning, thereby setting up the body to expect proteins. But crisps do not contain proteins so the body craves eating more crisps in a futile search for the protein content that it expects. This appears to be a standard tactic used to make people consume more, simply by introducing flavours that contrast with the underlying food characteristics, such as meat flavours added to carbohydrates and sugars to proteins. It works commercially because it makes people buy and eat more.

Risk factors

Regardless of the age of occurrence, risk factors for early-onset diseases today remain the same as fifty years ago, and they include smoking, alcohol, physical inactivity, genetics, and poor diet (which leads to obesity and/or metabolic syndrome).

Statistically, as rates of smoking, alcohol consumption, physical inactivity, and genetic causes have not gone up exponentially, at least not enough to drive rates of obesity up 28-fold since 1950 in the UK, one may therefore make the reasonable assumption that poor diet is the primary driver of the current increase of early-onset diseases.

There are now a lot of foods that confuse the digestive system, like crisps enhanced with chicken flavouring that trick the body into wanting to eat more protein. — JEFF SIEPMAN/UnsplashThere are now a lot of foods that confuse the digestive system, like crisps enhanced with chicken flavouring that trick the body into wanting to eat more protein. — JEFF SIEPMAN/Unsplash

And that is because human diets have changed very significantly over the last few decades due to the widespread availability of ultra-processed foods. Therefore, the current higher incidence of early-onset diseases would certainly be due to the prevalence of ultra-processed foods in modern diets. This is supported by curious facts such as 80% of the processed food sold in advanced countries such as the UK is considered unsafe for children by the WHO (World Health Organisation).

Even if ultra-processed foods are conclusively determined to be the primary risk factor in the increases in early-onset diseases, it would likely make little difference to the consumption patterns of billions of people around the world. That is because of the cost of living crisis now affecting practically the entire world.

Whatever serious health disadvantages ultra-processed foods have, the underlying facts are they are almost always the cheapest, most convenient foods available, and usually also with the longest storage life. Additionally, they are very tasty and addictive, as they are specially engineered to exploit human weaknesses in how we perceive “tasty” food.


The nutrition of the food people eat is significantly determined by the Human Gut Microbiome (HGM) residing in the human intestines. The HGM is of such importance that many medical researchers now consider this community of roughly 100 trillion bacteria (10 times the number of human cells) to be a specialised organ in its own right. And there is indisputable evidence that consuming too much ultra-processed foods can disrupt or wreck the HGM within a short period.

The HGM connects to the brain via the vagus nerve (also known as the Gut-Brain Axis) and communications to the brain are done via neurotransmitters, hormones, and special compounds generated by the HGM. The signals from the HGM are important, but also subtle and weak, and are thus easy to ignore or misinterpret.

The neurotransmitters identified as emanating from the HGM are GABA (Gamma-aminobutyric acid), serotonin, dopamine, and acetylcholine, with probably the most important being GABA and serotonin, both used for regulating mood, anxiety and sleep. The other neurotransmitters help invoke the sensation of bodily and mental well-being or general discomfort.

The hormones generated by the HGM include Interleukin-1 beta, Interleukin-6, Tumor necrosis factor-alpha, and Interferon-y. They interact in a complex manner with the body and have either pro- or anti-inflammatory effects. In a balanced HGM, they augment the body’s immune system.

Other specialist compounds produced by the HGM include Short-chain fatty acids (SCFAs), Lipopolysaccharides (LPS), and Trimethylamine N-oxide (TMAO), of which SCFAs are probably the most beneficial to humans, as LPS is associated with inflammation and gut damage, and TMAO is linked to heart disease and inflammation.

The most interesting aspects of SCFAs are how they promote and improve health in humans. The known effects are (1) protection of the gut lining by promoting the production of mucus and sealing the joints between groups of cells in the gut lining, thus preventing infiltration damage by harmful bacteria or toxins; (2) anti-inflammatory effects, which reduces the risk of inflammatory bowel diseases and other gut disorders; (3) promoting growth of beneficial bacteria in the gut, such as Bifidobacterium and Lactobacillus; and (4) increasing absorption of water within the fecal mass in the intestines, which prevents constipation.

SCFAs have also been linked to improved insulin sensitivity which helps to reduce blood sugar levels, general lowering of cholesterol levels, easier weight loss, and protection against certain cancers. To improve the levels of SCFAs, eat more fibre and foods containing pre- and pro-biotics.


It should be recognised that the human digestive system can detect poor nutrition. However, the pain receptors in the intestines (called ‘nociceptors’) are activated only by mechanical, chemical, or pathogenic (disease) stimuli. Until such stimuli are present, people seldom notice the much more subtle signals of poor nutrition from the HGM, which have no pain receptors at all.

Therefore people tend to ignore messages from the HGM because they usually lack urgency, unlike an important email. Problems with the human gut are a little like global climate change. Nothing much seems to happen for a long time, even when eating poor diets, and then some symptoms appear which people can ignore until they cannot ignore them any longer.

The other issue is inconsistency and variability amongst humans. Some people react quickly and strongly to an HGM imbalance (perhaps due to more sensitive nociceptors), while others can tolerate significant HGM damage for many years.

Poor nutrition is communicated from the HGM to the brain by very tangential signals such as (1) mood changes, (2) loss of hunger, insatiable eating or other appetite anomalies, (3) fatigue or hyperactivity, and (4) changes in sleep patterns. These signals are often also physically associated with abnormal bowel movements.

Research consistently shows that the eventual result of a poor HGM for people is generally a (much) higher incidence of metabolic diseases and cancers, leading to shorter lifespans and/or inferior quality of life. In short, there are no good outcomes of having a problematic HGM.

So it is helpful to be aware of the above subtle messages from the HGM about the food one has been eating. If the messages are persistent, it is probably a signal to cut down on ultra-processed foods and improve the diet immediately.

The views expressed here are entirely the writer’s own.

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