Evolutionary Association, Chapter 5: Does Size Matter?
The Dietary Change
Our eating habits have changed massively over roughly the last 100 years - and with them the foods we use, the way we treat them, and the constant availability of sufficient calories - though at the same time with a reduced nutrient density. Carbohydrates now make up the bulk of our energy intake, and foods are available not just seasonally and locally, but constantly and globally.
The usual dietary guidelines occasionally mention such conditions, but really they ignore aspects like locality, seasonality, and often the degree of processing as well.
For many of the recommended foods, the necessary preparation steps are not part of the recommendation, which can easily mean that nutrients actually present in the food are not available to the body. Sourdough fermentation of wholegrain cereals is a good example: without it, many of the nutrients in the grain are almost entirely unavailable - on the contrary, many anti-nutrients remain, which also bind the nutrients in other foods eaten at the same time.
The next chapter of this series will contain a closer look at sourdough.
More about fermentation and sourdough
Evolutionary Association, Chapter 6: Sourdough
Why modern turbo-bread burdens the body - and why the lockdown sourdough craze accidentally got it right: long fermentation pre-digests what the gut cannot.
Read more →We’ll also have a look at milk and dairy products, now available everywhere all the time, kept fresh through suitable processing and refrigeration - which, by their improved shelf life alone, are far more readily available than they ever used to be.
The Phenomenon
When we look at various biological traits of humans across the past, we find some striking things. Over the very long term (which this series largely sets aside, but which matters here for context) we can see that people before the agricultural revolution were considerably taller than afterwards, and had a far higher bone density. As body height fell, the human brain shrank as well. The change followed almost immediately on the change in diet, with the advent of agriculture.
Over the last 100-150 years, by contrast, we can observe that people grew taller again. That height correlates at the same time with ever-earlier puberty in children, and with a raised susceptibility to cancer.
The Biochemical Association
The Growth Command
The increase in height seems to have different causes than its decrease at the dawn of agriculture. One sign of this is the lower bone density - despite the larger body. As the obvious driver of today’s growth in height, one factor in particular has been identified: IGF-1. The name stands for “Insulin-like Growth Factor 1"(1).
“Insulin-like” already tells us that this name simply has to be covered on butterbei.de. It is a growth factor that depends on insulin levels: IGF-1 is produced by the liver - when insulin is present in excess, the liver’s receptors for growth hormone become more sensitive. Plenty of available carbohydrates lead to high insulin levels, the liver becomes receptive to growth hormone, and more IGF-1 is produced.
IGF-1 activates an important switch for cell growth: mTOR(2).
Our dietary guidelines recommend that we take the bulk of our energy from carbohydrates - and whichever kind of carbohydrate we look at, that is a guarantee of a more or less permanently raised insulin level, and with it the processes documented here that depend on it. The simulator also shows this clearly.
Milk brings its own mechanisms on top of that. Milk is a food whose actual purpose is to spur young creatures to grow especially fast (and it contains the corresponding hormones and signalling molecules). Despite its low sugar content, milk has a measurable effect on insulin levels - through the protein it contains(3), and thus again on the IGF-1 -> mTOR cascade…
Around 10% of milk protein is leucine(4), an essential amino acid that is itself a direct activator of mTOR.
When the human body now receives permanently elevated growth stimuli, and follows them, the result - in the right phases of life (in youth) - is increased growth in height. Ergo: people become taller than under other dietary scenarios. Food supply - especially in the Western world, and thanks to the dietary guidelines particularly the large helping of carbohydrates - is largely assured, and all year round at that. The growth impulses can thus be kept up very easily and efficiently; people get taller.
Growing Taller
The dimension of growth in height is open above all in the first phase of life - and is the real occasion for this article: children and adolescents grow upward, and we touched on some of the mechanisms for that above. Their absence - along with a lack of suitable building materials - has the opposite, inhibiting effect on growth. Since we established above that people have for some time been growing taller again than at the start of the agricultural revolution, the growth factors appear to be winning for now.
In the case of surprisingly little growth, though, I would certainly also look at the availability of the building materials - the quality of the food consumed. The bioavailability of the nutrients is what matters here in particular. And that
- even if it runs entirely against the current trend - is highest in animal foods.
At the latest once the body has finished growing in height, but keeps receiving plenty of growth signals, there are other directions and dimensions that have to stand in for the growth (and that are plausible from the metabolism’s point of view):
Growing Wider
One of them is growth in width - or, expressed in another dimension: weight. Sooner or later, excess weight likes to come along with this growth-promoting diet too.
Growing Wild
The other, though, is tumour growth. What fascinated me most here is the way cancer in the body is sometimes detected: a contrast agent is injected (labelled glucose), and imaging techniques(5) then show where this glucose is processed especially intensively. As a rule, those are the tumours, and any metastases - which, in many kinds of cancer, are particularly dependent on glucose for their energy, and so positively attract the sugar. (6)
Low Carb as a Worthwhile Measure
Going without sugar or carbohydrates is certainly no cure-all, but the biochemical mechanisms behind it are so convincing that considering a low-carb diet - both for cancer prevention and alongside treatment - looks in any case like a worthwhile measure with no negative side-effects.
I list these options here because many patients wish to contribute to their own treatment as well. And even if (or in case?) a low-carb diet does not help against cancer: my personal experience with it is so good that I would choose it for the positive effect on how I feel, and on the focus I can reach, alone.
Even if diet does not help against illness: for me it would be worth it, to improve quality of life as markedly as I have experienced myself (even without any acutely life-threatening illness on the horizon).
To many, giving up carbohydrates often feels like a deprivation. From my own experience I can say: I no longer want to “give up that deprivation”. Yes, there are delicious things made with carbohydrates. But when you trade 2 minutes of flavour for 24 to 48 hours of well-being and focus (that is my personal experience with a really good croissant), the decision becomes enormously easy. Once you have seen how life can also feel.
