When did the English and Americans realize that vegetables were healthy?

Question

I've recently come across two quotes in very unrelated sources implying that for centuries, the English and their colonial offspring did not appreciate the role of vegetables in a healthy diet.

From "Religion and the Decline of Magic: Studies in Popular Beliefs in Sixteenth and Seventeenth-Century England":

The well-known ‘green sickness’ in young women, to which contemporaries gave a sexual meaning, was chlorosis, anaemia produced by a lack of iron in the diet, stemming from upper-class disdain for fresh vegetables. The well-to-do ate too much meat and were frequently constipated . . . In the seventeenth century [the poor] may have escaped the gout and stone which plagued their betters, and may even have had better teeth from eating more vegetables.

From Jacksonian America: Society, Personality, and Politics:

During [the cholera epidemic of 1832], among the quaint notions that flourished was a belief in the the therapeutic qualities of beef and mutton and the evil effects of vegetables. Before and after the epidemic many people considered tomatoes taboo.

I was already aware of anti-potato prejudice, but now it seems to me like disdain for vegetables was even more widespread. Even some vegetarians did not think much of the health benefits of vegetables, according to an editorial in The Index to Good Health (Michigan, 1899):

Nothing short of confusion is produced when a vegetarian declares to his friends that he does not eat vegetables . . . Generally he does [eat vegetables] when he first becomes a vegetarian, but very often as he progresses in the knowledge of the value of foods, he comes to a point where he thinks it economy of labor to live on fruits and grains and nuts, discarding vegetables as not worth the trouble of consumption and digestion.

When did members of the English-speaking world begin eating vegetables by choice instead of out of poverty? When did it become conventional wisdom that vegetables were, in fact, healthy? Was this change attributable to any kind of research?

Answer 1

In his 1827 home medical group, the doctor Thomas J. Graham wrote that:

It is a common practice among Europeans in sultry climes to eat plentifully of either fresh or salt meat, at breakfast, tiffin, and dinner; this practice is followed day after day, and my only surprise is, that such a dangerous course of living does not produce a much greater mortality among our countrymen in tropical countries than what actually takes place. A diet of a vegetable and acescent nature, with a large proportion of condiment, such as we find used by the natives of those countries, is best suited to the preservation of health.

_{- Graham, Thomas John. Modern Domestic Medicine. London: 1826.}

This passage confirms that the English populace was still habitual meat eaters. However, despite arguing it is better to eat more meat in colder climates, Dr Graham strongly advocated a more vegetarian diet in tropical regions as well (and summer),

Graham's book was sufficiently popular to go through 11 editions. Missionaries and colonists carried it, and other books like it, to the far-flung dominions of the British Empire. Thus the early 19th century appears to be a period when new knowledge on the healthiness of vegetables was introduced to traditional eating habits.

Although nutritional science was in its infancy, attempts were being made to understand healthy eating habits. For example, Bernstein, Aaron David devoted a chapter explaining the "wise instinct" of housewives in serving vegetables and fruits, in his successful Popular Books on Natural Science: For Practical Use in Every Household, for Readers of All Classes. This was translated into English during the 1860s.

Answer 2

Looking into the other answers, it seems that weather and diet were closely linked in the minds of 19th century writers. Thomas Graham (see Semaphore's answer) may have been important in disseminating the belief that vegetables were most beneficial in hot climates, as this begins showing up elsewhere by the end of the century.

For example, in an 1864 trial in Illinois, there was debate over whether people who ate mostly vegetables would heal more slowly than people who ate mostly meat. The answer was "It depends on climate":

In 1888, "embarrassed housekeepers" struggled with setting a good table in hot weather. Mrs. S. T. Rorer published a book called "Hot Weather Dishes," which offered such sensible advice as:

Have some courses at every meal without meat, and learn to eat vegetables with bread. Most persons eat too much, and don't know that a good meal can be made of vegetables . . . To eat meat three times a day in Summer is barbarous.

This implies that by the late 19th century many housekeepers still served meat three times a day. Not knowing how to serve trendy vegetables, housekeepers were "embarrassed" in summer.

So by the late 19th century, conventional wisdom was beginning to catch up to the scientific advice of earlier decades. However, it seems that by the 20th century, professionals recognized the wisdom of eating vegetables year-round. For example, an English physician writing on health at boarding schools in 1905 notes that "as a rule, boys will not eat [vegetables] in the autumn and winter," and to this he attributes "autumnal eczema" and "constipation, which always occurs . . . on the advent of cold weather."

How long would it take for the idea that one should eat vegetables year-round to sink into the public consciousness? The motherly injunction to "eat your vegetables" only became commonplace around 1940, and really took off in the 1970s.

Answer 3

I am not sure if it is the first recognition of healthiness but about the end of age of discoveries, sailors started to realize if they bring sour cabbage with them, they can prevent various diseases. Or better to say some diseases are just don't show up on their ship for the long trip.

In those times they knew nothing about Vitamin C, and most of diseases were caused by serious lack of this vitamin.

I can provide this source about sour cabbage

Anson’s voyage brought scurvy to the public’s attention and after studying historical accounts of the disease, in 1753, Scottish naval surgeon James Lind noticed scurvy was invariably linked to those whose diet had been severely limited. He began testing various foods and noted that citrus fruits provided the quickest and most effective cure for the disease.

However, this brought about another problem. How do you keep fruit fresh on a sailing ship that could be at sea for months at a time? You don’t.

With no real cure available, the British crown outfitted four captains during the 1760s with various potential cures in an attempt to find a reliable method to prevent scurvy through trial and error.

Captain James Cook, one of these four captains, was given several different experimental foods to try aboard his ship the HM Bark Endeavor when he left England for the South Pacific in 1768. Among them, as noted in the victualing minutes — the log of provisions put aboard — was 7,860 pounds of sauerkraut.

So James Cook was one of the first captains who realized (without knowing the precise effect) of having consumable vegetables on his ship the health issues were way less serious on the long trips.

Answer 4

I conjecture that this was an empirical result deduced from experience with long distance sea voyages. Scurvy was a real disaster in many long expeditions. Seaman began the dietary experiments to fight scurvy in 18-th century (or maybe earlier, I just do not know the earlier records). At first they tried sauerkraut. The lemon juice was introduced to the sailor ration in 19-th century.

Answer 5

In the past there was a great diversity of opinions about what constituted a good diet and you can certainly find examples of people who deprecated, for example, vegetables. However, this was not typical. Overall, the most common recommendations were to eat a variety of food, and to eat less food. Many physicians going forward from Galen recommended the simple expedient of eating less, and eating a wide variety.

Just like today, there were many who recommended a vegetarian or vegetable diet, and cited the ancient Greeks or other supposed vegetarians, such as the "Hindoos" as their model, but once again these were in the minority. The average doctor typically prescribed the same thing doctors prescribe today: eat a variety of foods and reduce the amount you eat.