Dr. Weston A. Price claims in his Nutrition and Physical Degeneration that a plant-based diet never sustained any traditional culture.
As yet I have not found a single group of primitive racial stock which was building and maintaining excellent bodies by living entirely on plant foods. (Chapter 15)
Is this true?
Okinawa Japanese is one of the populations with the longest life span. Their average life span is 77 for men and 86 for women. They eat to 80% fullness and rely very heavily on whole unrefined plants. 70% of their total calories comes from sweet potatoes. They eat essentially no meat, eggs, dairy, no sugar, no oil, but they do have very small amounts of fish. They are almost purely plant-based (98%), but not 100% pure.
There is a population which lives longer than the Okinawa Japanese and that's the California Adventists. Their average life span is 83 for men and 86 for women. The average life span for California Adventists who exercise and don't smoke is 87 for men and 90 for women. And they eat a 100% pure plant-based diet. (1)
Eskimos, on the other hand, have an average life span of 68 years. They have excessive mortality due to cerebrovascular strokes and their overall mortality is twice that of non-Eskimo populations. They eat an all-meat or a mostly meat diet. So Eskimos are living proof that humans can survive on meat, but the more humans tend to eat a whole food plant based diet the more they prosper. (2)
I wouldn't be very surprised if it was. In the history of mankind, the ability to sustain something as big as a culture by purely plant-based means would not be the easiest way of doing things and unless there exist strong outside pressures (such as ethical ones that can be seen nowadays) then plant-based diet would be overshadowed by more diversified sources of nutrients. From the very beginning, human species sustained on a combination of animal (hunters) and plant (gatherers) food. Generally, for a change to happen, there needs to be a reason for the change. As it happens, there just never was a sufficiently big one for cultures to do differently.
It is also good to note that plant-based diet has some specific requirements such as cobalamin (B12) which are hard/nearly impossible to get from plant-based diet alone and need to be supplemented. While this fact would be unknown to the civilizations that we are talking about, the simple correlations would probably be apparent over time, where people eating only plant-based diet would suffer from B12 defficiency symptoms (fatigue, depression, reduced mental capabilities, even psychosis).
The only real source of outside pressure for most of our history as species would be probably religion or a supreme ruler with plant-based agenda in mind. No religion with impact that spans cultures that I am aware of requires people to follow plant-based diet and I have not heard of an authoritarian figure who would require this either. In the case of the supreme ruler, the diet would be hard to control anyways and it would be probably overruled as soon as they die so we are talking about a horizon of one human lifetime at most.
Plant-based diet is a viable diet for a great number of people in today's world and can theoretically be means of sustaining a culture. This has, however, not been true for most of our history and so I think the claim that you refer to is true. I would be happy to be proved otherwise if someone can offer a counter example.
Some Neanderthals in Spain have been found to have consumed zero animal products.
The theory is that since they lived inside forests there was plently of roots, mushrooms, nuts and fruits thus no reason to chase giant animals.
"Neanderthals from El Sidrón showed no evidence of meat eating – instead they appear to have survived on a mixture of forest moss, pine nuts and a mushroom known as split gill."
Source: Neanderthal dental tartar reveals plant-based diet – and drugs (The Guardian)
If you combine roots, mushrooms, fruits and nuts you get all the nutrients needed to sustain a human being; in fact, Neanderthals were the bulkier and most naturally muscular hominids ever existed with muscles too strong for their own bones to bear.
It is definitely not true "that a plant-based diet never sustained any traditional culture."
St. Jerome gives numerous examples of cultures in antiquity who abstained from eating flesh in Against Jovinianus bk. 2:
Dicæarchus in his book of Antiquities, describing Greece, relates that under Saturn, that is in the Golden Age, when the ground brought forth all things abundantly, no one ate flesh, but every one lived on field produce and fruits which the earth bore of itself. Xenophon in eight books narrates the life of Cyrus, King of the Persians, and asserts that they supported life on barley, cress, salt, and black bread. Both the aforesaid Xenophon, Theophrastus, and almost all the Greek writers testify to the frugal diet of the Spartans. Chæremon the Stoic, a man of great eloquence, has a treatise on the life of the ancient priests of Egypt, who, he says, laid aside all worldly business and cares, and were ever in the temple, studying nature and the regulating causes of the heavenly bodies; they never had intercourse with women; they never from the time they began to devote themselves to the divine service set eyes on their kindred and relations, nor even saw their children; they always abstained from flesh and wine, on account of the light-headedness and dizziness which a small quantity of food caused, and especially to avoid the stimulation of the lustful appetite engendered by this meat and drink. They seldom ate bread, that they might not load the stomach. And whenever they ate it, they mixed pounded hyssop with all that they took, so that the action of its warmth might diminish the weight of the heavier food. They used no oil except with vegetables, and then only in small quantities, to mitigate the unpalatable taste. What need, he says, to speak of birds, when they avoided even eggs and milk as flesh. The one, they said, was liquid flesh, the other was blood with the color changed? Their bed was made of palm-leaves, called by them baiæ: a sloping footstool laid upon the ground served for a pillow, and they could go without food for two or three days. The humours of the body which arise from sedentary habits were dried up by reducing their diet to an extreme point.
Josephus in the second book of the history of the Jewish captivity, and in the eighteenth book of the Antiquities, and the two treatises against Apion, describes three sects of the Jews, the Pharisees, Sadducees, and Essenes. On the last of these he bestows wondrous praise because they practised perpetual abstinence from wives, wine, and flesh, and made a second nature of their daily fast. Philo, too, a man of great learning, published a treatise of his own on their mode of life. Neanthes of Cizycus, and Asclepiades of Cyprus, at the time when Pygmalion ruled over the East, relate that the eating of flesh was unknown. Eubulus, also, who wrote the history of Mithras in many volumes, relates that among the Persians there are three kinds of Magi, the first of whom, those of greatest learning and eloquence, take no food except meal and vegetables. At Eleusis it is customary to abstain from fowls and fish and certain fruits. Bardesanes, a Babylonian, divides the Gymnosophists of India into two classes, the one called Brahmans, the other Samaneans, who are so rigidly self-restrained that they support themselves either with the fruit of trees which grow on the banks of the Ganges, or with common food of rice or flour, and when the king visits them, he is wont to adore them, and thinks the peace of his country depends upon their prayers. Euripides relates that the prophets of Jupiter in Crete abstained not only from flesh, but also from cooked food. Xenocrates the philosopher writes that at Athens out of all the laws of Triptolemus only three precepts remain in the temple of Ceres: respect to parents, reverence for the gods, and abstinence from flesh. Orpheus in his song utterly denounces the eating of flesh. […]
(Jovinian thought there was no difference between fasting and taking food in thanksgiving, and St. Jerome refuted him.)
Some Hindus have a plant based diet apart from using ghee. They seem to be doing pretty well after a few thousand years.
Gherunda Samhita a Classical text on Hatha Yoga (a branch of Hinduism) which gives instructions to Yogis gives following dietary instructions.
- A Yogi should eat rice badey (bread), or wheaten bread. He may eat Mudga beans, Phaseolus Mungo), Máha beans (Phaseolues Radiatus), gram, &c. These should be clean, white and free from chaff.
18 - 19. A Yogi may eat patola (a kind of cucumber, jack. fruit, niánakachu (Arumn Colocaia), kakkola (a kind of berry), the jujube, the bondue nut (Bonducella guilandina), cucumber, plantain, fig; the unripe plantain, the small plantain, the plantain stem, and roots, brnja1, and medicinal roots and fruits (e.g., riddhi &c.)
