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Life Sciences => Physiology & Medicine => Topic started by: DoctorBeaver on 09/05/2008 21:43:37

Title: Could humans thrive on a single food source?
Post by: DoctorBeaver on 09/05/2008 21:43:37
Is there a single type of food that we could eat and get all the nourishment we need?

I remember a Vegan once telling me that brown rice would fit the bill (she was waffling on about macrobiotics & I didn't really understand it).
Title: Could humans thrive on a single food source?
Post by: iko on 09/05/2008 22:47:41
Hi DocBeaver!

It is a risky experiment indeed...a sort of bungee-jumping between cofactor deficiency and umbalanced diet:

do we actually need vitamin suppliments? you see in boots for instance, a whole range of suppliments with a lot aimed at children.

do children need suppliments?

I can see a case for them in more deprived countries where a balanced diet may not be possible.

Hi paul.fr,

It is just a matter of knowledge, culture, information or family tradition if you like.
We may not be what we eat, but certainly we have to eat to survive, even if we tend not to live only to eat, fortunately.
If the combination of foodstuff we eat from time to time is correct, thanks to our family traditions and culture, for example, we probably won't have any deficiency problem from the cradle to the end of our life.  Even if we have to face a period of starvation or a polar expedition, our information, culture, tradition will help.
Over the years, many children had to be reminded: have your orange juice plus scrambled eggs, get your fresh veggies each meal, eat fruits, drink your milk and go play outside, take your 'cod'...
Ignoring the basic priciples of our survival on this Planet might lead to dreadful consequences.
At least one young man became irreversibly blind for a badly managed diet.
Here is the story:

Blindness in a Strict Vegan

Vegetarians are at risk for nutritional deficiency if they do not receive vitamin supplementation. We report a case of severe bilateral optic neuropathy in a patient who had been a vegan for many years and who did not take vitamin supplements.
The patient, a 33-year-old man who had started a strict vegetarian diet at the age of 20 years, was referred for evaluation of progressive visual loss. "Improved health" was the reason for the diet, which contained no eggs, dairy products, fish, or other sources of animal proteins. He did not smoke or use alcohol, and his medical history was unremarkable.

Examination showed severe bilateral optic neuropathy with very poor vision (less than 20/400 in both eyes), central scotomata, dyschromatopsia, and atrophy of the optic disks. We found no evidence of a compression of the visual pathway or of a toxic, infectious, or inflammatory cause of the blindness. Mitochondrial-DNA analysis showed no mutation for Leber's hereditary optic neuropathy. On neurologic examination, there was a sensory peripheral neuropathy, confirmed by electrophysiologic studies. The cerebrospinal fluid was normal, including the opening pressure. The remainder of the general examination showed no abnormalities.

The plasma level of folate was low (5.4 nmol per liter; normal range, 7.5 to 28), as were the levels of vitamin B1 (4 nmol per liter; normal range, 6 to 40) and vitamin B12 (114 pmol per liter; normal range, 150 to 720). There were also deficiencies of vitamins A, C, D, and E and zinc and selenium, but plasma levels of iron, ferritin, vitamin B6, and nicotinamide were normal. The patient had megaloblastic anemia (hemoglobin level, 10.5 g per liter; mean corpuscular volume, 110 µm3), which was not due to pernicious anemia (there were no anti–parietal-cell or anti–intrinsic-factor antibodies, upper gastrointestinal endoscopy showed normal findings, and multiple biopsies showed no gastric atrophy) or other causes of malabsorption. After treatment with intramuscular vitamin B12 (1000 µg daily for one week) and oral multivitamin supplementation, the hemoglobin level was normal and the sensory neuropathy had disappeared, but there was no recovery of vision.

Vitamin B12 deficiency in vegetarians may cause neurologic disturbances.  Moreover, deficiencies of vitamins B12 and B1 may be responsible for optic neuropathy associated with nutritional factors.   Amblyopia and painful neuropathy have been reported in cases of dietary deprivation in prisoners during World War II, and more recently, dietary factors were noted in the Cuban epidemic of optic neuropathy.4 The optic neuropathy in our patient was apparently related to deficiencies of vitamins B12 and B1, but other associated deficiencies may have had a role. Vitamin supplementation is essential in persons who adhere to a strict vegetarian diet, especially because vitamin deficiencies may cause severe, irreversible optic neuropathy.


Dan Milea, M.D.
Nathalie Cassoux, M.D.
Phuc LeHoang, M.D., Ph.D.
Groupe Hospitalier Pitié–Salpêtrière
75651 Paris CEDEX 13, France

New England Journal of Medicine  342:897-898  March 23, 2000.

Title: Could humans thrive on a single food source?
Post by: DoctorBeaver on 09/05/2008 22:59:04
Hmmm - that's a bit dodgy. So the short answer is "no"?
Title: Could humans thrive on a single food source?
Post by: iko on 09/05/2008 23:24:04
Hmmm - that's a bit dodgy. So the short answer is "no"?

Of course the answer is no.
That's what 'nutrition' science is all about (did I say it right?)
Me english is getting clumsy indeeeeed  [:o]



bits and pieces you might have read:
Title: Could humans thrive on a single food source?
Post by: Bored chemist on 10/05/2008 17:48:07
The short answer might be "no" but, as a mammal, I'm not sure it's the right answer. Ithink there's strong evidence that we can thrive one one single foodstuff, at least for quite a long while.
It's difficult to get by on a vegan diet because of the shortage of vitamin B 12 in most plants (animals cheat and get their gut bacteria to make it or get it from other animals).
Title: Could humans thrive on a single food source?
Post by: iko on 10/05/2008 18:32:52
The short answer might be "no" but, as a mammal, I'm not sure it's the right answer. Ithink there's strong evidence that we can thrive one one single foodstuff, at least for quite a long while.It's difficult to get by on a vegan diet because of the shortage of vitamin B 12 in most plants (animals cheat and get their gut bacteria to make it or get it from other animals).

Hi B.C.,

indeed we have to define better which 'one single foodstuff' and 'quite a long while'!
Being all different inside, with different biochemical 'machinery', tiny defects here and there, enzymes that work 50% and so on...it surely is a risky experiment.
We could play with it.  Too many people HAVE to deal with these problems for lack of food and 'subhuman' conditions.
As far as vitamin B12 is concerned, we seem to have a storage good enough for a six months deficient diet. B1(thiamine) has little storage and could go in 3-4 weeks.
When a cofactor deficiency hits 'only' the nervous system, diagnosis is difficult, treatment delayed and damage too often irreversible (to be soft, call them "sequelae").
In the old days sailors were eating more or less the same foodstuff for months...but only 10-20% of them had symptoms of scurvy and had to be abandoned to die in the nearest harbour.
Let's enjoy our diets as far as they are available  [;)]


Talking about foodstuff, thiamine and things: did you read the 'Nardoo' story about western explorers in Australia?  It is a neat example of how only experience and traditions allow survival in critical environments.
Title: Could humans thrive on a single food source?
Post by: Bored chemist on 10/05/2008 20:58:57
Very interesting point- what is a single food and what is a typical person? I heard that you can live on beans on toast (and water, of course) for a long while.

I still maintain that people can- and most of us did, live on milk and only milk for some time- generally 6 months or more. During that time we put on so much weight that it seems very unlikely that we were using stores of any nutrient.
For those unfamiliar with Australian ferns here's a tale I pinched from a website.
"Legend has it, and so does Moorehead's book Cooper's Creek (1963), that a couple of Australian explorers, Robert Burke and Willliam Wills, died in 1861 from thiaminase poisoning. They were wandering around the Australian continent, doing what explorers do, and their supply of pork which was their main source of thiamin ran out. So what did these guys start feasting on? Nardoo, of course. Now, if they had watched the Aborigines they would have known that one does not eat nardoo without cooking it first. But, being typical explorers, and thus thinking that they were smarter than the indigenous people that had lived on the continent for thousands of years, Burke and Wills ate their nardoo raw. They began complaining in their journals of increasing weakness and starvation, but "not so much from absulute want of food" because, Wills wrote, "I have a good appetite and relish the nardoo much but it seems to give us no nutriment." What they were suffering from then, was thiamin deficiency. Coupling a low-thiamin diet with a large intake of thiaminases from the nardoo, Burke and Wills developed beri-beri. They complained not only of weakness, but of edema too, and sensitivity to cold. They died. "
Title: Could humans thrive on a single food source?
Post by: iko on 10/05/2008 21:57:01

Very interesting point- what is a single food and what is a typical person? I heard that you can live on beans on toast (and water, of course) for a long while.



How long? One year? Five years? [???]
Not to mention the high risk of dying of boredom!
Go ahead, me won't be in the number.
I couldn't live on cod liver only...[;D]


(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fscience.uniserve.edu.au%2Fschool%2Fcurric%2Fstage4_5%2Fnativeplants%2Fgallery%2Fnardoo%2Fnardoo.jpg&hash=49e13dc65e28c55c109fd2c8b13da15d)
http://science.uniserve.edu.au/school/curric/stage4_5/nativeplants/gallery/nardoo/nardoo.jpg


BTW I read that it was simpler than to cook or not to cook...just soaking!

Quote
...
The Aborigines also gave them nardoo(Marsilea), a fern whose spores can be ground into an edible flour. The Aborigines had learned in thousands of years of trial and error that ground nardoo must be soaked in water before being eaten. The water leaches out an enzyme called thiaminase which destroys thiamine (vitamin B1). The result of ingesting thiaminase is thiamine deficiency, which undoubtedly contributed to the deaths of Burke and Wills.

http://victoria.slv.vic.gov.au/print/burkeandwills/expedition/food.html

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