Editing Human nutrition (section)

=== 18th and 19th century: Lind, Lavoisier and modern science ===
[[File:James lind.jpg|thumb|right|upright|alt=Waist high portrait drawn in pen and ink of a man balancing three books|[[James Lind]] conducted in 1747 the first controlled [[clinical trial]] in modern times, and in 1753 published ''Treatise on Scurvy''.<ref>{{cite journal | journal=Perspectives in Clinical Research | date=January–March 2010 | pages=6–10 | author=Bhatt, Arun | title=Evolution of Clinical Research: A History Before and Beyond James Lind | pmc=3149409 | pmid=21829774 | volume=1 | issue=1 | doi=10.4103/2229-3485.71839 | doi-access=free}}</ref>]]
Sometimes forgotten during his life, [[James Lind]], a physician in the British navy, performed the first [[science|scientific]] nutrition experiment in 1747. Lind discovered that [[Lime (fruit)|lime]] juice saved sailors that had been at sea for years from [[scurvy]], a deadly and painful bleeding disorder. Between 1500 and 1800, an estimated two million sailors had died of scurvy.<ref name=Willett-scurvy>{{cite book | author1=Willett, Walter C. | author2=Skerrett, Patrick J. | title=Eat, Drink, and be Healthy: The Harvard Medical School Guide To Healthy Eating | year=2005 | orig-year=2001 | isbn=978-0-684-86337-5 | publisher=Free Press (Simon & Schuster) | page=[https://archive.org/details/eatdrinkbehealth00will/page/183 183] | url-access=registration | url=https://archive.org/details/eatdrinkbehealth00will/page/183}}</ref> The discovery was ignored for forty years, but after about 1850, British sailors became known as "limeys" due to the carrying and consumption of limes aboard ship.<ref>Gratzer 2005, pp. 21–24, 32.</ref> The essential [[vitamin C]] within citrus fruits would not be identified by scientists until 1932.<ref name=Willett-scurvy />

[[File:Lavoisier humanexp.jpg|alt=Black and white engraving of Lavoisier's laboratory, man seated at left with a tube attached to his mouth, man at center conducting experiment, woman seated at right drawing, other people visible|thumb|left|By containing his assistant, [[Armand Seguin]], inside a rubber suit fitted with a tube sealed to his mouth with putty, [[Antoine Lavoisier]] first measured [[basal metabolic rate]].<ref>Gratzer 2005, p. 60.</ref> Drawing by [[Marie-Anne Pierrette Paulze|Madame Lavoisier]] (seated at right).]]
Around 1770, [[Antoine Lavoisier]] discovered the details of metabolism, demonstrating that the [[oxidation]] of food is the source of body heat. Called the most fundamental chemical discovery of the 18th century,<ref>{{cite book | author=Silberberg, Martin S. | year=2009 | title=Chemistry: The Molecular Nature of Matter and Change | publisher=McGraw-Hill | isbn=978-0-07-304859-8 | edition=5 | page=44}}</ref> Lavoisier discovered the principle of [[conservation of mass]]. His ideas made the [[phlogiston theory]] of [[combustion]] obsolete.<ref>Gratzer 2005, p. 56.</ref>

In 1790, [[George Fordyce]] recognized [[calcium]] as necessary for the survival of fowl. In the early 19th century, the elements [[carbon]], [[nitrogen]], [[hydrogen]], and [[oxygen]] were recognized{{by whom|date=November 2014}} as the primary components of food, and methods to measure their proportions were developed.<ref name="Paul Muljadi">{{cite book | url=https://books.google.com/books?id=dpNGTccTTbEC&pg=PA42 | title=Health | publisher=Paul Muljadi | author=Muljadi, Paul | pages=42}}{{dead link|date=May 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

In 1816, [[François Magendie]] discovered that dogs fed only [[carbohydrate]]s (sugar), [[fat]] (olive oil), and [[water]] died evidently of starvation, but dogs also fed protein survived&nbsp;– identifying [[protein]] as an essential dietary component.<ref>Gratzer 2005, pp. 73–74.</ref> [[William Prout]] in 1827 was the first person to divide foods into carbohydrates, fat, and protein.<ref>{{cite journal | journal=The Journal of Nutrition | title=William Prout (1785–1850): A Biographical Sketch | author=Ahrens, Richard | date=1 January 1977 | volume=107 | issue=1 | pages=17–23 | url=http://jn.nutrition.org/content/107/1/15.full.pdf+html | format=PDF | doi=10.1093/jn/107.1.15 | pmid=319206 | access-date=3 January 2020 | archive-date=17 October 2015 | archive-url=https://web.archive.org/web/20151017082420/http://jn.nutrition.org/content/107/1/15.full.pdf+html | url-status=live}}</ref> In 1840, [[Justus von Liebig]] discovered the chemical makeup of carbohydrates ([[sugar]]s), fats ([[fatty acid]]s) and proteins ([[amino acid]]s). During the 19th century, [[Jean-Baptiste Dumas]] and von Liebig quarrelled over their shared belief that animals get their protein directly from plants (animal and plant protein are the same and that humans do not create organic compounds).<ref>Gratzer 2005, p. 82.</ref> With a reputation as the leading [[organic chemistry|organic chemist]] of his day but with no credentials in [[Physiology|animal physiology]],<ref>Carpenter 1994, p. 224.</ref> von Liebig grew rich making food [[extract]]s like beef [[Liebig's Extract of Meat Company|bouillon]] and [[infant formula]] that were later found to be of questionable nutritious value.<ref>Gratzer 2005, pp. 86, 92, 95, 115.</ref>
[[File:Takaki Kanehiro.jpg|thumb|right|upright|alt=Neck high portrait of middle aged man wearing a military uniform|[[Takaki Kanehiro]] surmised that [[beriberi]] was a nutritional deficiency not an infectious disease.]]
In the early 1880s, [[Kanehiro Takaki]] observed that Japanese sailors (whose diets consisted almost entirely of white rice) developed [[beriberi]] (or endemic neuritis, a disease causing heart problems and paralysis), but British sailors and Japanese naval officers did not. Adding various types of vegetables and meats to the diets of Japanese sailors prevented the disease. (This was not because of the increased protein as Takaki supposed, but because it introduced a few parts per million of [[thiamine]] to the diet.)<ref>Carpenter 1994, p. 220.</ref>).
In the 1860s, [[Claude Bernard]] discovered that body fat can be synthesized from carbohydrate and protein, showing that the energy in blood [[glucose]] can be stored as fat or as [[glycogen]].<ref>Gratzer 2005, pp. 98–99.</ref>

In 1896, [[Eugen Baumann]] observed [[iodine]] in thyroid glands. In 1897, [[Christiaan Eijkman]] worked with natives of [[Java (island)|Java]], who also had beriberi. Eijkman observed that chickens fed the native diet of white rice developed the symptoms of beriberi but remained healthy when fed unprocessed brown rice with the outer bran intact. His assistant, [[Gerrit Grijns]] correctly identified and described the anti-beriberi substance in rice. Eijkman cured the natives by feeding them brown rice, discovering that food can cure disease. Over two decades later, nutritionists learned that the outer rice bran contains vitamin B1, also known as [[thiamine]].{{medical citation needed|date=July 2015}}