Editing Chlorella (section)

== As a food source ==

When first harvested, ''Chlorella'' was suggested as an inexpensive protein supplement to the human diet. According to the [[American Cancer Society]], "available scientific studies do not support its effectiveness for preventing or treating cancer or any other disease in humans".<ref>{{cite web
|url=http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/herbsvitaminsandminerals/chlorella
|publisher=[[American Cancer Society]]
|date=29 April 2011
|access-date=23 August 2013
|title=Chlorella
|url-status=dead
|archive-url=https://web.archive.org/web/20130905235019/http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/herbsvitaminsandminerals/chlorella
|archive-date=5 September 2013}}</ref>

Under certain growing conditions, ''Chlorella'' yields oils that are high in [[polyunsaturated fat]]s—''Chlorella minutissima'' has yielded [[eicosapentaenoic acid]] at 39.9% of total lipids.<ref name=Yongmanitchai>{{cite journal |pmid=2014989 |year=1991 |last1=Yongmanitchai |first1=W |last2=Ward |first2=OP |title=Growth of and omega-3 fatty acid production by Phaeodactylum tricornutum under different culture conditions |volume=57 |issue=2 |pages=419–25 |pmc=182726 |journal=Applied and Environmental Microbiology|doi=10.1128/AEM.57.2.419-425.1991 |bibcode=1991ApEnM..57..419Y }}</ref>

=== History ===
Following global fears of an uncontrollable human population boom during the late 1940s and the early 1950s, ''Chlorella'' was seen as a new and promising primary food source and as a possible solution to the then-current world hunger crisis. Many people during this time thought hunger would be an overwhelming problem and saw ''Chlorella'' as a way to end this crisis by providing large amounts of high-quality food for a relatively low cost.<ref name= "belasco">{{cite journal |first1=Warren |last1=Belasco |date=July 1997 |title=Algae Burgers for a Hungry World? The Rise and Fall of Chlorella Cuisine |journal=Technology and Culture |volume=38 |issue=3 |pages=608–34 |jstor=3106856 |doi=10.2307/3106856|s2cid=109494408 }}</ref>

Many institutions began to research the algae, including the [[Carnegie Institution of Washington|Carnegie Institution]], the [[Rockefeller Foundation]], the [[National Institutes of Health|NIH]], [[University of California, Berkeley|UC Berkeley]], the [[United States Atomic Energy Commission|Atomic Energy Commission]], and [[Stanford University]]. Following [[World War II]], many Europeans were starving, and many [[Malthusianism|Malthusians]] attributed this not only to the war, but also to the inability of the world to produce enough food to support the increasing population. According to a 1946 [[FAO]] report, the world would need to produce 25 to 35% more food in 1960 than in 1939 to keep up with the increasing population, while health improvements would require a 90 to 100% increase.<ref name= "belasco"/> Because meat was costly and energy-intensive to produce, protein shortages were also an issue. Increasing cultivated area alone would go only so far in providing adequate nutrition to the population. The [[United States Department of Agriculture|USDA]] calculated that, to feed the U.S. population by 1975, it would have to add 200 million acres (800,000&nbsp;km<sup>2</sup>) of land, but only 45 million were available. One way to combat national food shortages was to increase the land available for farmers, yet the American frontier and farm land had long since been extinguished in trade for expansion and urban life. Hopes rested solely on new agricultural techniques and technologies. Because of these circumstances, an alternative solution was needed.

To cope with the upcoming postwar population boom in the United States and elsewhere, researchers decided to tap into the unexploited sea resources. Initial testing by the [[SRI International|Stanford Research Institute]] showed ''Chlorella'' (when growing in warm, sunny, shallow conditions) could convert 20% of solar energy into a plant that, when dried, contains 50% protein.<ref name= "belasco"/> In addition, ''Chlorella'' contains fat and vitamins. The plant's photosynthetic efficiency allows it to yield more protein per unit area than any plant—one scientist predicted 10,000 tons of protein a year could be produced with just 20 workers staffing a 1000-acre (4-km<sup>2</sup>) ''Chlorella'' farm.<ref name= "belasco"/> The pilot research performed at Stanford and elsewhere led to immense press from journalists and newspapers, yet did not lead to large-scale algae production. ''Chlorella'' seemed like a viable option because of the technological advances in agriculture at the time and the widespread acclaim it got from experts and scientists who studied it. Algae researchers had even hoped to add a neutralized ''Chlorella'' powder to conventional food products, as a way to fortify them with vitamins and minerals.<ref name= "belasco"/>

When the preliminary laboratory results were published, the scientific community at first backed the possibilities of ''Chlorella''. ''[[Science News Letter]]'' praised the optimistic results in an article entitled "Algae to Feed the Starving". John Burlew, the editor of the [[Carnegie Institution of Washington]] book ''Algal Culture-from Laboratory to Pilot Plant'', stated, "the algae culture may fill a very real need",<ref name="Algal Culture">{{cite book |title=Algal Culture-from Laboratory to Pilot Plant |publisher=Carnegie Institution of Washington |editor1-first=John |editor1-last=Burlew |year=1953 |page=6 |isbn=978-0-87279-611-9}}</ref> which ''Science News Letter'' turned into "future populations of the world will be kept from starving by the production of improved or educated algae related to the green scum on ponds". The cover of the magazine also featured [[Arthur D. Little]]'s Cambridge laboratory, which was a supposed future food factory. A few years later, the magazine published an article entitled "Tomorrow's Dinner", which stated, "There is no doubt in the mind of scientists that the farms of the future will actually be factories." ''[[Science Digest]]'' also reported, "common pond scum would soon become the world's most important agricultural crop." However, in the decades since those claims were made, algae have not been cultivated on that large of a scale.

=== Current status ===
Since the growing world food problem of the 1940s was solved by better crop efficiency and other advances in traditional agriculture, ''Chlorella'' has not seen the kind of public and scientific interest that it had in the 1940s. ''Chlorella'' has only a niche market for companies promoting it as a dietary supplement.<ref name= "belasco"/>

==== Production difficulties ====
[[File:L'Eclosarium 07.jpg|thumb|upright|Chlorella culture, L'Eclosarium, [[Houat]].]]
The experimental research was carried out in laboratories, rather than in the field, and
scientists discovered that ''Chlorella'' would be much more difficult to produce than previously thought. To be practical, the algae grown would have to be placed either in [[artificial light]] or in shade to produce at its maximum photosynthetic efficiency. In addition, for the ''Chlorella'' to be as productive as the world would require, it would have to be grown in [[carbonated water]], which would have added millions to the production cost. A sophisticated process, and additional cost, was required to harvest the crop and for ''Chlorella'' to be a viable food source, its cell walls would have to be pulverized. The plant could reach its nutritional potential only in highly modified artificial situations. Another problem was developing sufficiently palatable food products from ''Chlorella.''<ref name="becker" />

Although the production of ''Chlorella'' looked promising and involved creative technology, it has not to date been cultivated on the scale some had predicted. It has not been sold on the scale of ''[[Spirulina (dietary supplement)|Spirulina]]'', [[soybean]] products, or whole grains. Costs have remained high, and ''Chlorella'' has for the most part been sold as a health food, for cosmetics, or as [[animal feed]].<ref name="becker">{{cite journal |doi=10.1016/j.biotechadv.2006.11.002 |title=Micro-algae as a source of protein |year=2007 |last1=Becker |first1=E.W. |journal=Biotechnology Advances |volume=25 |issue=2 |pages=207–10 |pmid=17196357}}</ref> After a decade of experimentation, studies showed that following exposure to sunlight, ''Chlorella'' captured just 2.5% of the solar energy, not much better than conventional crops.<ref name= "belasco"/> ''Chlorella'', too, was found by scientists in the 1960s to be impossible for humans and other animals to digest in its natural state due to the tough cell walls encapsulating the nutrients, which presented further problems for its use in American food production.<ref name= "belasco"/>