| does it take 7 years to digest through your system? |
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| Total Votes : 9 |
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| geoffo
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| 33578. Tue Nov 22, 2005 7:46 pm |
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fact or fiction
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geoffo |
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| Kevino7
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| 33580. Tue Nov 22, 2005 7:52 pm |
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| According to Snopes.com its false. |
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| geoffo
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| 33690. Wed Nov 23, 2005 11:01 am |
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| well spotted kev! |
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| Amie
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| 33787. Wed Nov 23, 2005 5:41 pm |
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| I heard it takes that long for sweetcorn to digest in the stomach... will have to do some research! |
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| Jenny
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| 33795. Wed Nov 23, 2005 6:23 pm |
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| According to the F plan diet book, you can find out the fate of the sweetcorn you eat by looking carefully at the contents of the toilet... certainly used to work when my children were still in nappies, the last time I looked at excrement at a close range. |
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| geoffo
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| 34646. Sat Nov 26, 2005 10:38 am |
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| Jenny, what a strange hobby! |
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| Jenny
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| 35074. Sat Nov 26, 2005 9:01 pm |
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| I didn't look at it out of choice geoff - somebody had to change the poor little buggers. |
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| Tas
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| 40833. Tue Dec 20, 2005 3:15 pm |
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Chewing gum:
"Contains a source of Phenylalanine. Excessive consumption may cause laxative effects"
How much would be needed???
| Quote: | Phenylalanine uses the same active transport channel as tryptophan to cross the blood-brain barrier, and in large quantities interferes with the production of serotonin. Too much Phenylalanine is a neurotoxin and can excite neurons in the brain to the point of cellular death. ADD/ADHD, emotional and behavioral disorders can all be triggered by too much Phenylalanine in the daily diet.
Courtesy of Wikipedia.
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:-)
Tas |
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| Mr Grue
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| 40842. Tue Dec 20, 2005 4:12 pm |
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A dietician of an old friend of mine told him that phenylalanine also impaired the body's ability to turn fat into energy, but I don't know how true that is. I don't see many thin people drinking diet drinks, though.
Regardless of that, phenylalanine is a fun word to say. Phenylalanine.
Elbow.
Ellllbow...
sorry. |
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| Mostly Harmless
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| 40843. Tue Dec 20, 2005 4:18 pm |
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| ..
Last edited by Mostly Harmless on Sun Jan 08, 2006 11:24 pm; edited 1 time in total
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| Celebaelin
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| 41007. Wed Dec 21, 2005 4:55 am |
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| Tas wrote: | Chewing gum:
"Contains a source of Phenylalanine. Excessive consumption may cause laxative effects"
How much would be needed??? |
| Quote: | Aspartame is the artificial sweetner used in most diet drinks and other low calorie products. It is 200 times as sweet as table sugar (sucrose) but contains only 4 calories per gram
Quotation taken from the Third Edition of Organic Chemistry-Structure and Function by K. Peter C Vollhardt and Neil E. Schore.
The acceptable daily intake is 40mg/kg |
http://www.chm.bris.ac.uk/webprojects2000/srogers/sarah.html
The 'laxative effect' is osmotic I think. The sweetener Aspartame contains phenylalanine and aspartic acid but amino acids would not naturally be linked in this manner. The compound contains a bond not seen in nature and this is the key to its severely reduced energy provision whilst exhibiting its very sweet taste. It's not that the body flatly cannot break the bond but that it is not a naturally encountered ‘ask’. I’m being as careful as I can as there is a lot of alarmist stuff on the web about Aspartame and whilst there is an element of truth in what is said I think that the amount of phenylalanine that has been found to be released by Aspartame (data generated as a result of concerns over phenylketonuria) does not indicate that levels of assimilation/breakdown are high. Thus, logically, the osmotic laxative effect.
| Quote: | Definition
Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration.
The definition contains three important statements:
Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration.
It does not matter too much which order you put these statements in. Nor does it matter if you write the definition as one sentence or three sentences. All that matters in your exam is that you make all three points when you explain what osmosis is. |
http://www.purchon.com/biology/osmosis.htm
| Quote: | | Stegink et al. (1989) tested the effect of aspartame (N-L-alpha-aspartyl-L-phenylalanine methyl ester--a widely used dipeptide sweetener) on phenylalanine concentrations in persons heterozygous for PKU. They found moderate elevations in phenylalanine levels above baseline for heterozygotes for PKU (2.3-4.7 micromoles, 30-45 minutes after ingestion of a 12-ounce beverage). |
http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=261600
This not recommended for sufferers or certain other groups with allergies of unspecified varieties but OK for the ‘average’ person.
Aspartame is VERY sweet, so you don’t need much to act perfectly well as a sweetener and as such concerns over the release of, eg methanol, as a breakdown product are overstated and the levels of consumption required to generate a ‘significant’ laxative effect would be high.
None of the above constitutes a medical opinion of course as that would depend on individual circumstances and perforce there would be an imperative towards a most cautious examination of all aspects and potential consequences.
<Edit>Modification of weird osmosis definition which slipped past me the first time
Last edited by Celebaelin on Wed Dec 21, 2005 10:37 am; edited 1 time in total
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| Tas
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| 41022. Wed Dec 21, 2005 10:17 am |
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Maybe it is not the Pheny-wotsit-name that is the laxative then.
My question is though, how much gum would need to be chewed or consumed for the onset of laxitivity to be noted?
:-)
Tas |
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| QI Individual
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| 41041. Wed Dec 21, 2005 11:40 am |
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| Tas wrote: | | Maybe it is not the Pheny-wotsit-name that is the laxative then. |
It isn't. Non-nutritive sweeteners (no calories) like aspartame and acesulfame are both absorbed by the body. Aspartame is broken down into its components and acesulfame is excreted by the kidneys unchanged.
These are often used in combination with sugar replacers called polyols. These are nutritive sweeteners (with calories) of which the most commonly used are sorbitol, xylitol, mannitol, maltitol, lactitol and isomalt. These can have a laxative effect because they are not (significantly) absorbed by the body. They remain in the digestive tract and because of their osmotic effect 'attract' water. This is a passive effect and not an active pharmacological effect on the intestine. Simply more water remains in the colon where it otherwise would be eliminated from the intestinal contents into the body. As a result the volume of the intestinal contents is (remains) increased causing osmotic diarrhea.
Now isn't that a nice appetising subject for the breakfast table when you drop your sugar substitute into your cup of tea.
_________________
Ahh... You gentlemen must be from the Spanish Inquisition.
I've been expecting you. |
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| Celebaelin
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| 41050. Wed Dec 21, 2005 12:34 pm |
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That said what then do you think might be the origins of a laxative effect warning in combination with the 'contains a source of phenylalanine' warning? A combination of artificial sweeteners perhaps?
I assumed that they would only use one type of artificial sweetener in any one product and were covering themselves against lawsuits in the event of excessive consumption.
Stereo-isomer sweeteners, L sugars, can only be absorbed/utilised* if the cyclic hexose is linearised; which can happen but doesn't often - that's why it is not claimed that they have zero calories.
*I’m fudging slightly here because some level of absorption will occur by passive diffusion and pinocytosis.
I have to say I didn’t realise that the presence of an -OH group rather than a =O would be such a barrier to passage through the intestinal wall, the ‘energy’ value is only 65% of normal sugar implying that 35% of the sweetener is not absorbed for metabolisation. I suppose the active transport enzyme mechanisms are better suited to more common substrates. There may also be a small energy requirement in dealing with the additional OH group.
http://en.wikipedia.org/wiki/Sorbitol
http://www.scientificpsychic.com/fitness/carbohydrates.html
| Quote: | | Aspartame is broken down into its components |
Whilst the acknowledgement of the elevated phenylalanine levels implies that this must be true I couldn’t find a source that explicitly dealt with this; could you post yours as I would like to read it.
| Quote: | L-sugar laxatives , United States Patent 5219573
The present invention relates to novel monosaccharide sweeteners which are capable of acting as laxatives when administered in dose-effective amounts. The present invention also contemplates monosaccharides with laxative properties which have a natural carbohydrate structure. More specifically, the present invention contemplates monosaccharide substances capable of producing laxative effects in humans and having the advantages of being only minimally absorbed from the intestine; and having osmotic laxative effects on the small bowel and colon. The present invention allows for improved laxative formulations with increased palatability and better dosing for all age groups. The present invention can be used to induce mild laxation six to ten hours after ingestion. |
http://www.freepatentsonline.com/5219573.html
| Quote: | Drugs may cross a biologic barrier by passive diffusion, facilitated passive diffusion, active transport, or pinocytosis.
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Passive diffusion: In this process, transport across a cell membrane depends on the concentration gradient of the solute. Most drug molecules are transported across a membrane by simple diffusion from a region of high concentration (eg, GI fluids) to one of low concentration (eg, blood). Because drug molecules are rapidly removed by the systemic circulation and distributed into a large volume of body fluids and tissues, drug concentration in blood is initially low compared with that at the administration site, producing a large gradient. The diffusion rate is directly proportional to the gradient but also depends on the molecule's lipid solubility, degree of ionization, and size and on the area of the absorptive surface. Because the cell membrane is lipoid, lipid-soluble drugs diffuse more rapidly than relatively lipid-insoluble drugs. Small molecules tend to penetrate membranes more rapidly than large ones.
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Pinocytosis: Fluid or particles are engulfed by a cell. The cell membrane invaginates, encloses the fluid or particles, then fuses again, forming a vesicle that later detaches and moves to the cell interior. This mechanism also requires energy expenditure. Pinocytosis probably plays a minor role in drug transport, except for protein drugs. |
http://www.merck.com/mrkshared/mmanual/section22/chapter298/298b.jsp
<E> After some reflection prompted by the discussion of stereoisomerism in the E Forum Enzymes thread I have come to the realisation that I am mistaken here, it would not be possible for conversion from one stereoisomer to another to occur via the linearised form.
Last edited by Celebaelin on Thu Jun 15, 2006 1:39 pm; edited 2 times in total
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| QI Individual
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| 41064. Wed Dec 21, 2005 1:49 pm |
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| Celebaelin wrote: | | That said what then do you think might be the origins of a laxative effect warning in combination with the 'contains a source of phenylalanine' warning? A combination of artificial sweeteners perhaps? |
That's what I said. Mentioned in this FAQ for instance.
More info on the metabolism of aspartame:
Multiple Sclerosis Foundation debunking the myths.
Greenfacts.org
Aspartame.info
And many more if you want them from Google.
_________________
Ahh... You gentlemen must be from the Spanish Inquisition.
I've been expecting you. |
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