Natürliche Ernährung des Menschen: Kulturelle Omnivore, aber biologische Frugivore?

Die moderne omnivore Ernährung passt nicht zu unserer Biologie

Die meisten Menschen ernähren sich heute omnivor. Aufgrund der lokalen Lebensmittelvielfalt und Kochkultur gibt es verschiedene – mehr oder weniger gesunde – Ernährungsweisen. Die meisten Kulturen enthalten Getreide, Fleisch und/oder Milchprodukte, Eier, Gemüse und Obst… und verarbeitete Lebensmittel. Eine moderne omnivore Ernährung!

Unsere Anatomie und Physiologie deutet jedoch darauf hin, dass der Mensch ein biologischer Frugivore (spezialisierter Fruchtfresser) ist, wenn wir einen Vergleich mit unserem nächsten Verwandten, dem Schimpansen, anstellen!

Was bedeutet das für den Menschen? Der Mensch hat eine extrem ähnliche Ernährungsbiologie wie der Schimpanse! Würden wir in der Natur leben, hätten wir sehr ähnliche Nahrungsvorlieben und könnten – wenig überraschend – nur in tropischen Lebensräumen mit ihrem Reichtum an tropischen Früchten, Nüssen und anderen Nahrungsquellen überleben. Die biologisch angemessene Ernährung des Menschen ist eine fruchtbasierte, tropische Ernährung – also frugivor!

https://www.youtube.com/watch?v=kqIMN5DsV78Dieses schöne Video von Menschen und Schimpansen, die gemeinsam essen, könnte Sie von unserer genügsamen Natur überzeugen!

Doch wie kam es dazu, dass wir heute in der modernen Gesellschaft ein so unterschiedliches Ernährungsverhalten an den Tag legen? Hier kommen die Geschichte, der natürliche Lebensraum und die kulturellen Anpassungen unserer Spezies ins Spiel!

Die Biologie legt nahe, dass Menschen Frugivoren sind!

Was darauf hindeutet, dass der Mensch in hohem Maße frugivor ist (nicht ausschließlich Früchte):

• Humans are well adapted to a fruit diet (read full article): Humans have remarkable biological adaptations that they share with other high-fruit-eating primates. Examples are dental structure, optimized hands for fruit handling, specialized color vision, loss of Vitamin C genes, and relatively high tolerance to seed toxins compared to other mammals. Unlike typical omnivores or carnivores, we do not possess distinct biological features for hunting, meat consumption, or digestion. Instead, we need tools like Speers, knives, and fire to substitute for the «missing» claws, teeth, sprinting skills, etc. 
• Our closest relatives eat a diet very high in fruits: Learning from chimpanzees gives us great insights, as separation from our original tropical niche has confused us about our true human diet. We share many biological traits with our frugivorous closest relatives, the chimpanzees. Chimps specialize in ripe tropical fruit and do not regularly consume meat. To be precise, chimpanzees are frugivorous omnivores: they are able to digest both, animal foods and plant foods. Their preferred and primary food source however is ripe tropical fruits. Around 70% generally, and sometimes exclusively fruit! Chimpanzees do eat small amounts of other foods, including animal foods, with little to no meat, depending on the individual and social groups. 
• Our instincts know what is appealing straight from nature – ripe, sweet, colorful fruits: Kids love raw, ripe fruits, but won’t eat raw meat, grains or broccoli – nor would we ever feed them those foods raw. we know they would get in troubles. Our common sense and instinctual knowledge can answer the simple, but the relevant question to define a species› natural diet: what foods taste good when eating it unaltered straight from nature? Our smell and taste receptors is a reliable guide, if we don’t confuse them: only what is edible and tasty when raw, unprocessed, or unseasoned is suitable human food. Anything else is somewhat survival food. This does not mean we cannot eat other foods, as we clearly survive on different foods. We are, in a sense, «generalists» with our survival foods, but biologically we are still specialized fruit-eaters.

Why do humans eat an omnivorous diet today? 

We are, biologically, specialized fruit-eaters, which have become cultural omnivores. In short: we have adopted a diet with less fruits and more other type of foods instead, because we had to! 

«As a result of this cultural propensity to migrate to new areas, humans have adapted to differences in climate, altitude, and resource availability. Some of these adaptations to new environments are themselves cultural practices: for example, clothing and foot coverings that are suited to the climate, as well as novel tools and techniques for food acquisition and cultivation.»Creanza & Feldman, 2016

Despite some local genetic adaptations have occurred, humans are still best-adapted to live in their original tropical habitat and to the food sources in the tropics!

We left paradise… and cooked to survive

Humans are primates and our biology is that of a tropical frugivore (like our closest relatives, the chimpanzees). But humans moved out of their original climatic zones. Migrating into colder climate zones forced humans to find new food sources, which included making non-foods edible by processing them through cooking.

Cooking turns «non-foods into «food»

Cooking often makes nutrients in inedible foods available, while reducing the amount of toxins. Together with seasoning it also turns the otherwise unappealing foods tasty. Most foods we eat today are actually toxic in their raw natural state! Most of them grow in temperate climates and have not evolved as foods with humans. Examples are grains, legumes, but also temperate vegetables and fruits before they were hybridized and selectively bred for edibility (read more here about food groups).

Colder climates: not our home, not our foods, not the best health

The natural habitat of a species is where it can survive within environmental conditions such as climate and food availability. If manipulation of an environment (heating, clothing, growing crops, or processing local foods) is necessary to survive, then it is not the natural habitat of that species. This indicates, that the physiology and anatomy has not evolved and adapted to the local conditions. 

Humans had no choice other than turning to suboptimal foods to survive in colder climates: more meat, insects, tubers and greens and later dairy and grains. We still do today – and it is not the best for our body’s integrity and health!

Turning to fallback foods is just what species do when their preferred food is not available! Frugivorous apes and monkeys turn to second-best foods when fruit (preferred food) is not abundant. However, unlike humans, animals cannot manipulate foods to an extent to turn inedible foods edible, and thus migration into another climatic zones is not an option. This also mean their survival foods do not deviate as much over time and thus are still species-appropriate:

«Across the range of the anthropoids, fruit is the major resource; in adapting to local conditions different species will extend that frugivorous preference in any number of directions – seeds and grasses (gelada), leaves (colobines and mountain gorillas), meat (chimpanzees, baboons), shellfish (chacma baboons), nuts (orangs, chimpanzees, uakari), and insects (chimpanzees, capuchins, squirrel monkeys) (Smuts et al. 1987). Such extensions might be in the direction of either lower quality or higher quality resources. However, the key element is that primates on the whole have a preference for relatively high quality resources.» (Craig Britton Stanford, Henry T. Bunn; Meat-Eating and Human Evolution; Oxford University Press, 2001, p.308). 

We are eating fallback diets today!

As we can see, there are survival foods and optimal foods for humans, too. This distinction certainly is not always a clear cut, however, it is obvious that foods, which must be processed to turn palatable or edible are «survival foods.» Those foods were important for humans to survive outside the tropics but are not optimal for health.

So what are fallback foods for humans? Everything that cannot be eaten raw and taste good is fallback food. If we start to think, this is about 80 % of what we eat today! Thus a cooked omnivore diet is a fallback diet – meaning most foods are not optimal for our biology! The further away we go from the tropics, the less we find optimal human foods in the diet. Read more about biological suitability of foods here.

Living and eating outside our original ecological niche come at a cost in health. Changes in environmental conditions (or migration into new areas) create selective pressure, which usually means decreased health!

But haven’t humans adapted biologically to colder climates and their new food sources? 

Cultural vs. biological adaptation

Humans have managed to live in cold areas mainly due to cultural adaptations – not biological evolution!

Human diet changed with their migration out of the tropics. In colder, harsher areas, humans had to learn to survive outside their natural habitat, where food was more abundant and temperatures cozy. The migration out of those «optimal» habitats forced humans to live in environments to which their biology was (and still is) not well-adapted: humans have no major biological adaptations to cold climate nor cooked foods!

Consequently, humans were forced to manipulate the environment, by building infrastructure (housing, heating, clothing) and turn inedible foods into edible, nutritious and tasty foods (cooking, seasoning etc.). Our ancestors› intelligence has enabled survival in areas outside the tropics. However, this is behavioral (or cultural) adaptation to an unsuitable habitat, not an evolutionary response to cold stress through selection and changes in biological traits:

Unlike animals with particular cold adaptations (fur, hibernation) living in temperate and cold climatic zones, the human body is biologically not viable in that type of condition. Undoubtedly, some physical local adaptations in cold-indigenous people (such as skin color) have manifested, but the human biology unmistakably shows that we are primarily adapted to warm climates and their food sources.

The human body can only survive in a warm environment with an abundance of nutritious, easy-to-forage foods because our bodies are still mainly adapted to tropical habitats. Most of us feel so good in the tropics, that we call the Caribbean “paradise -like”, as we walk with little clothing and enjoy beautiful local plants and also, improved health.

Where would you chose to live (or survive) without clothes, heating, and crops – I am guessing the answer is “near the tropics” for most of us.

Humans have developed cultural adaptation, that overcome limitations set by our biology within cold habitats.
Intelligence enables humans to manipulate their environment into more suitable, tropical conditions (i.e. warm housing, clothing and growing nutritious foods)

Eating foods that are not species-appropriate has health consequences

Humans have developed cultural adaptation, which allows overcoming the boundaries set by our biology. However, living in a habitat, which is not optimal, comes at the price of health. Today, humans grow up within a certain culture and local ecological conditions, and thus learn how to prepare and eat local foods and dishes without questioning, «what am I actually eating?”. 

This is the reason why most people eat a diet that does not suit human biology for the most part. We eat many foods, that are not edible straight from nature in its raw state. Some foods are even poisonous raw, and have to be prepared properly to be save (read more here and here).

Conclusion

There are many signs and indications in comparative anatomy and evolution, that the human biology strikingly resembles that of tropical high-fruit eating primates. After all, they are our closest relatives. If «a frugivore» is defined as an individual or species, that is well-adapted to eating a diet very high in ripe fruits, then humans match that category impressively well! Also, we cannot neglect instinctual knowledge of our own species and define our human diet by what we would actually eat in the wild!

Todays omnivorous diets found in most cultures around the world, are our survival fallback diet – not an optimal diet. Our biologically suitable diet resembles much more a Chimpanzee’s diet and is thus is highly frugivorous including high proportions of tropical fruits! For health reasons we should re-discover and strive towards our species-appropriate diet.

Learn more about the frugivore diet here:

Go to How to do the Frugivore Diet