|Beans from Nepal. Crop of photo by Gaurav Dhwaj Khadka on Wikimedia. CC BY 4.0.|
Anatomy books describe kidneys as bean shaped, but the converse does not apply. This is because beans, multitudinous in their species, come in different shapes and sizes. Many look like small kidneys, but only one is called a kidney bean.1,2 Like their cousins lentils and peas, beans are the dried seeds of the flowering plants of the Fabaceae family, technically classified as legumes rather than as vegetables, also called pulses and growing in non-edible pods. The most common varieties are Black, Black-Eyed, and Cannellini Beans, Chickpeas (Garbanzo Beans), Kidney or Broad Beans, and Great Northern, Lima, and Pinto Beans. There are also others—all featured differently in regional and national cuisines.
The therapeutic value of beans is extolled in the 1880 edition of Dr. Chase’s household “receipt book for the million” in a letter to the New York Evening Post:
“About 20 years ago, a daughter of mine – then about 6 years old – was given up to die by her family physician, who said she had Bright’s disease, which has never been known to be cured. He told the mother to give the girl anything she wanted and make her as comfortable as possible while she lived. As the girl cried constantly for beans, the mother cooked some quickly and gave them to her to eat. The girl went to sleep and from that time began to improve. She became mother of two children, and has not been troubled with the disease unless she takes a severe cold; and when that happens she at once uses her old remedy, and it is always effective”3
Yet Pythagoras of Samos (died c. 495 BC) enjoined his pupils to abstain from beans, meaning perhaps to stay out of politics, as beans were used to count votes. More likely he worried about favism, a hereditary deficiency of the enzyme G6PD (glucose-6-phosphate dehydrogenase) especially common along the Mediterranean littoral, in the Middle East, and in Southeast Asia. The problem is that Fava (or broad) beans contain two substances, vicine and convicine, which when eaten may disrupt the wall of blood red cells and thus cause an acute hemolytic anemia. This is usually mild and self-limited, but can be severe, requiring blood transfusion or hospitalization.4
Beans, especially red beans, contain a tasteless but toxic phytohaemagglutinin called lectin. This must be inactivated by cooking, for otherwise even as few as four beans can cause a severe stomachache with vomiting and diarrhea. Beans need to be boiled for at least ten minutes to avoid this rare complication, which is not well recognized and may be misdiagnosed.
Linguists know that the word “bean” itself, just as its Germanic cognate Bohne, has been in common use in West Germanic languages since before the 12th century. In English slang it has acquired sexual connotations too indelicate to discuss here, as well as referring to head size and levels of intelligence. Accountants are often referred to as bean counters, as are administrators who cannot see beyond their spreadsheets.1,2
Beans contain goodly amounts of protein (1 cup = about 16 g) as well as unsaturated fats, vitamins, and minerals, and are low in cholesterol. They are a good source of dietary fiber and are commercially advertised on television as being for diabetes, hypercholesterolemia, Parkinson’s disease, constipation, weight loss, preventing birth defects, improving the immune system and bone health, lowering blood pressure, preventing fatty liver, supplying enough folic acid, and preventing colon cancer. An apocryphal story tells of a legendary prince who deflowered numerous virgins in a single night while eating only chickpeas, suggesting that beans are also a source of unusual vigor.1,2
Beans provide vegetarians with much of their required protein intake. According to the dour but once venerated Scottish physician Sir Robert Hutchison (1871–1960) it also fills them with righteousness and wind. “It is universally known,” wrote Benjamin Franklin, “that that in digesting our common food there is produced in the bowels of human creatures a great quantity of wind.” Regrettably the bacteria inhabiting the human gut cannot break down the oligosaccharides originating from milk products, bread, fruits, and vegetables. They instead produce odorless hydrogen, carbon dioxide, and methane, but also about 1% foul smelling ammonia, skatole, and hydrogen sulfide.1,2
A human being generates about a liter of gas per day, far less than an elephant, and even less so than what a dinosaur may have contributed to climate change. In modern times, dramatic explosions have been reported during electrocautery of the colon, when the ratio of methane to hydrogen reached an incendiary range, causing a frightening blast.
No non-inflammable or “low flatulence” bean has ever been produced, nor does soaking beans in water leach out the oligosaccharides. Benjamin Franklin wished one would discover a drug that “shall render the natural discharges of wind from our bodies, not only inoffensive, but agreeable as perfumes.” But an Italian courtesan reportedly solved the problem by surreptitiously crushing a vial of perfume in the company of her paramours when making an audible sound.1,2
Hippocrates, Petronius, Montaigne, and Sir Thomas More believed that holding back gas was harmful. In AD 41, the emperor Claudius planned to legitimize passing wind at banquets. More recently a gastroenterologist proposed that retaining flatus caused diverticular disease and recommended pedaling on a bicycle. A scientist has classified emissions into explosive, thunderous, repetitive, and musical. The impolite word itself comes from the Indo-European root “pert,” said to be more offensive to Protestant than to Catholic ears. Labelled “not in decent use” in the early Oxford English Dictionary, it was omitted by Webster’s in 1909, but reinstated in 1961.1,2 For many it remains what Edward Gibbon would have called “an indelicate subject of conversation.”
- Dunea, G. “Beans.” BMJ 2005;331:973 (22 October).
- Dunea, G. “The gas we pass.” BMJ 2004;329:925 (16 October).
- Chase’s Home Recipes: Treatment of Diseases (1870).
- Luzzatto, L. and Arese, P. “Favism and glucose-6-phosphate dehydrogenase deficiency.” New England Journal of Medicine 2018;378:60.
, MD, Editor-in-Chief