Does artificial sweeteners are really that bad?

[KennyR]

Aspartame poisoning is one of those big, groundless paranoid hoaxes. Aspartame (and its metabolite, phenylalanine) are found in nature and the human body possesses many enzymes to break it down. We also need phenylalanine, since its an essential amino acid. The only bad part is that its digestion creates very small quantities of methanol, a poison which damages proteins and attacks the nervous system. We also have enzymes to deal with that, however, since our diet consists of many peptides which liberate methanol on digestion.

Among the documented symptoms caused by aspartame >according to them were headaches, dizziness, seizures, >nausea, numbness, muscle spasms, weight gain,
>rashes, depression, fatigue, irritability, tachycardia, >insomnia, vision problems, hearing loss, heart >palpitations, breathing difficulties, anxiety
>attacks, slurred speech, loss of taste, tinitus, vertigo, >memory loss, and joint pain.

These are not caused by aspartame in ordinary people, but on people who have a genetic disease called PKU. This disease prevents them metabolising phenylalanine which then builds up and can cause many health problems, including retardation. The PKU test is done shortly after birth. If you don't know you have PKU, you don't have it.

That's not to say you couldn't get poisoned if you ate too much of aspartame (just like anything else) - but man, you'd really need to eat a LOT before the buildup of methanol became an issue. Something like 10 kilograms of the stuff - and the ordinary aspartame sweetener is only about 2% aspartame. It's probably physically impossible.

And the key argument of using phenylalanine - and other sweeteners - they may have some toxic element to them, but they're a LOT safer than real sugar. These "phenylalanine is evil!!" people should just look at the deaths connected to diabetes and obesity alone.

[KennyR]

Wain wrote:
I remember reading that the big problem with phenylalanine and aspartame was about depression that could be caused by microscopic amounts...does this fall into the above categories too??

Actual research into this has come back with inconclusive results. While there is no evidence (and no particular medical reason) that aspartame affects ordinary people, evidence does seem to hint that it can have an effect upon people who already have mood disorders. So basically, aspartame will only make you more depressed if you're already a depressive, or if a jar of it falls off a shelf and kills someone you know.

Much more important was the finding that those patients given high doses of aspartame sometimes developed eye problems. This is probably related to methanol. Again, nobody gets these kind of doses anyway, but those with eye problems already should avoid it just in case.

(If you want real eye problems, become diabetic. Eating lots of sugar instead would be better for that than aspartame.)

[KennyR]

Karlos wrote:
However, (and this mostly depends which -OH groups have been substituted) is it metabolised by any other processes in the body, I wonder? I can't imagine a build up of chlorinated polysaccherides that aren't (as) easily processed normal ones.

Nope, Splenda/Surcralose goes straight through the body. Those big chlorine groups make it as unreactive as hell (stearic hindrance), although it still has the hydroxyl kick it needs to make it taste sweet. When we studied sweeteners at uni and how they work, sucralose hadn't been approved yet. That's not because it's nasty, but because the FDA are understandably anal about what goes into food.

You're quite right to be wary of chlorine radicals. I really don't like the idea of filling myself full of organochlorides. Tests on sucralose said in theory it could be changed to chlorofructose in the body or in the sewers later by bacteria, quite a nasty chemical. I wouldn't opt for Splenda. The environment has enough alien chlorine based horrors floating around.

[KennyR]

Karlos wrote:
Same basic overall shape and dipole presumably helps fool the taste receptors. The chlorine, however, shouldn't tightly bond to the active sites in enzymes that would metabolise (IIRC hydrogen bonding plays an important role in the keying of sugars to the appropriate enzymes) it.

Sweet taste receptors aren't all that sophisticated. All you basically need is an active hydroxyl group to trigger the sweet taste. Anything that looks like sugar, will taste like sugar. (Acesulfame-K has no OH group but H O and H groups are close enough that can interact.) Most alcohols and ketones will taste sweet to the human tongue.

Does sucralose hydrolyse into chlorinated glucose in the same way as ordinary sucrose?

Not to my knowledge. The stearic hindrance of the huge chlorine atoms prevents easy hydrolysation.

Do (if they occur) the chlorinated glucose molecules still exist as open chain form in solution?

I'm not sure, but my guess is they only exist as open chain. Sucralose doesn't denature with cooking, which seems to indicate it doesn't change chemically. It probably doesn't even caramelise. So the ring form of glucose may be impossible to form (once again, those big chlorines blocking everything off). This is a guess, however.

[KennyR]

Karlos wrote:
Hmm, if they only exist in the open chain form, I wonder what the crystal form is like?

There's always the possibility that it doesn't crystalise. For covalent compounds you need hydrogen bonding for that, and as you know chlorine is quite electronegative and likes to repel. Chlorine compounds are almost always non-polar. Put it this way, have you ever seen an organochloride in crystal form? I've only ever seen liquids and waxes.

As an open chain is a very high entropy system (so many conformations are possible with a similar energy), I can't imagine it would crystalise too readily so maybe it does exist in ring confromation?

Maybe.

[KennyR]

Quite odd that water itself is taseless, eh ? :-D

Not really Karlos, you know that water dissociates into polar hydronium and hydroxide ions, don't you?

[KennyR]

We know, evil conservative.

[KennyR]

Karlos wrote:
Structurally however, there is nothing immediately obvious (to my eye) that prevents that molecule dissosiating into a seperate chlorinated glucose / fructose pair - the centeral linkage is not protected by anything close enough to block dissosiation by acid catalysed hydrolysis.

After a little research, I found that sucralose WILL hydrolyse, but only under "conditions of high temperature and extreme acidity". Apparently the human digestive system does not qualify. It passes right through the body and doesn't trigger insulin, carbohydrate metabolism, digestion, or glucose-sensitive mechanisms. Apparently, its almost totally inert inside us.

If that inertness isn't caused by stearic hindrance then I'm lost for an explanation. Organic chemistry was never my prime forte.

[KennyR]

Of course sweeteners are never as nice as sugar. But I consider it worth it to not spend the last 30 years of my life pricking my fingers every four hours to draw blood and test my blood sugar, and stabbing myself with a five inch needle containing insulin after every meal, just to avoid going into shock and dying. And even doing that doesn't mean you wont go blind, lose limbs, or die of kidney or liver damage.

No...I prefer my pancreas actually working. Less sugar means less wear and tear on the insulin cells. That's a good enough reason for me to prefer a bad tasting sugar substitute.

[KennyR]

Odin wrote:
Now if your were my father, then I'd suggest using sweeteners. He eats so much sugar it's a miracle he doesn't insuline shots yet.

Mine almost does, and it depresses me like you wouldn't imagine. I'm next in line, it runs in my family. Even if I avoid sugar totally, chances are I'll still become diabetic.

Even if it doesn't run in the family, most 25+ people who eat too much sugar will probably already be living in a state of insulin resistance, and aren't more than a decade or two away from full blown Type II diabetes.

It would be great if there wasn't such a culture of over indulgence in the West. But since there is, I'll accept sweeteners as a practical godsend. (Even if they do taste like crap. ;-) )

[KennyR]

FluffyMcDeath wrote:
Which sugars were you thinking of avoiding. If only sucrose, there isn't much point.

Carbs?

Starches, carageenans, polyols and other carbohydrates are the slow burners. They are invaluable for diabetics because of their slow, constant release rate. Without carbohydrates and sugars, I wouldn't die of diabetes complications, I'd die of starvation, or would end up being forced to overeat to deal with the hypoglycemia caused by lack of available blood glucose. That would trigger hyperglycemia.

Current medical advice is: carbs are good for diabetics. Quick burn sugars are bad. Fats are especially bad, since high cholesterol is a very common side effect of diabetes.

When methanol is metabolized, the first step is methanol to formaldehyde, and that is the end of the line.

Not true, formaldehyde is metabolised very quickly by the body, into formic acid and paraformaldehyde, and either flushed out or changed into something else. Formaldehyde and methanol is being created in your body right now in fairly large quantities by digestion, and not of aspartame. The actual amount added by aspartame is trivial.

[KennyR]

FluffyMcDeath wrote:
Eat a plate of pasta and say carbs are slow burners!! Starches are partly lysed to glucose etc before you even finish chewing.

Nobody denies that the body turns these into sugar, but it does it slowly enough for low to medium 'grade' diabetics to produce enough insulin over time. Denied fat, carbs, and sugar, what do people actually have to eat? You can't survive on protein alone, considering that you're supposed to do a lot of exercise to get the tired out insulin glands running at all. And even if you could, the ketone biproducts of continuous protein digestion are almost as nasty as methanol.

As for formic acid, like any poisons it depends where it is and how much of it there is. Formic acid produced by digestion doesn't seem to be a problem, or we'd soon die. Drinking alcohol in large quantities produces similar quantities of acetaldehyde and acetic acid, chemically similar products. Possibly formic acid and formaldehyde produced in the liver never gets to the blood, where it can attack the CNS and small blood vessels.

[KennyR]

Fluffy wrote:
Generally, in nature, where you find meth you find eth, so safe up that diet coke and add a little rum! (Rum and diet coke is even more disgusting than rum and regular coke IMHO)

Or just drink regular coke. Rum is full of sugar anyway, so it sort of defeats the point.

[KennyR]

Actually it depends on the rum. Some kinds have virtually no sugar in them at all.

Anyway, what's the point on going on a diet if you're going to drink? Alcohol has a lot of calories too. (Indeed, it technically *is* a carb.)