Phenylalanine Help Please

[pr0t31n]

Hi,

Can someone please help me here and explain the difference between the amino acid phenylalanine and the phenylalanine found in the artificial sweetener Aspartame? I understand that there are various studies saying that Aspartame is dangerous and that many people these days choose to have protein supplements not sweetened by Aspartame but don't all protein powders contain the amino acid phenylalanine anyways, so wouldn't that make them unsafe?

Please help me understand this. Thanks in advance.

[TheWaffleIron]

Hi,

Can someone please help me here and explain the difference between the amino acid phenylalanine and the phenylalanine found in the artificial sweetener Aspartame?

There is no difference.


I understand that there are various studies saying that Aspartame is dangerous

The toxicity of aspartame is dose-dependent. In moderate amounts (within the recommended daily intake), it poses no significant health risks.


and that many people these days choose to have protein supplements not sweetened by Aspartame but don't all protein powders contain the amino acid phenylalanine anyways, so wouldn't that make them unsafe?

Please help me understand this. Thanks in advance.

Not necessarily. Whereas both aspartame and protein powders contain phenylalanine, they are different substances - and thus exert different effects on the body. Unless an individual suffers from phenylketonuria, phenylalanine should not be avoided; in fact, phenylalanine is an essential amino acid.

Edit: For further reading,

http://en.wikipedia.org/wiki/Aspartame

http://en.wikipedia.org/wiki/Phenylalanine

[pr0t31n]

[QUOTE=TheWaffleIron;564798171]There is no difference.



The toxicity of aspartame is dose-dependent. In moderate amounts (within the recommended daily intake), it poses no significant health risks.



Not necessarily. Whereas both aspartame and protein powders contain phenylalanine, they are different substances - and thus exert different effects on the body. Unless an individual suffers from phenylketonuria, phenylalanine should not be avoided; in fact, phenylalanine is an essential amino acid.


Aspartame is made up of phenylalanine, aspartic acid and methanol. Protein powders contain phenylalanine and aspartic acid but not methanol, unless they contain Aspartame right? So is it the methanol in Aspartame that can make it toxic in large doses? I understand that methanol is in various foods like tomatoes, but ethanol is present to wo0rk as a protective barrier right? But such is not the case with Aspartame? So is that why Aspartame can be toxic yet protein powders without aspartame but containing the AAs Phenylalanine and Aspartic Acid are safe?

Thanks.

[TheWaffleIron]

Aspartame is made up of phenylalanine, aspartic acid and methanol.

More or less. Aspartame is the methyl ether of a dipeptide (that consists of phenylalanine and aspartic acid). Within the body, aspartame yields phenylalanine, aspartic acid and methanol.


Protein powders contain phenylalanine and aspartic acid but not methanol, unless they contain Aspartame right?

Phenylalanine and aspartic acid are amino acids, so yes.


So is it the methanol in Aspartame that can make it toxic in large doses? I understand that methanol is in various foods like tomatoes, but ethanol is present to wo0rk as a protective barrier right?

Both ethanol and methanol are substrates for the same enzyme: alcohol dehydrogenase. As they are "processed," more toxic byproducts (formaldehyde from methanol, for example) may be generated. So, if ethanol is present, those enzymes will act on ethanol, as well as methanol, and thus less toxic byproducts from methanol will be accumulate. That is why, for instance, if someone is taken to an ER for methanol poisoning, he or she will be given ethanol.


But such is not the case with Aspartame? So is that why Aspartame can be toxic yet protein powders without aspartame but containing the AAs Phenylalanine and Aspartic Acid are safe?

Thanks.

Aspartame is found in a variety of foods (protein powders, diet sodas, etc.). In any case, there is a certain (exorbitantly high) mega-dosage that may cause serious health effects.

[Naturalham4]

Phenylalanine is also a precursor to dopamine (l-isomer>tyrosine>dopamine) and phenylethylamine (d-isomer), two important neurotransmitters that affect mood and energy. This is why you can buy it in health food stores.

[BrandonKlodo]

This is true that phenylalanine is an essential amino acid, however just because something is essential does not mean you should supplement with high doses of it. Phenylalanine has been used in clinical trials for people who suffer from depression. Studies have shown that Phenylalanine levels are substantially higher if the subject carries the PKU gene. That being said, when Phenylalanine levels are too high, it can cause nerve cells to excite/depolarize until the cell dies.

So supplementing with Phenylalanine may not be such a good idea after all. Talk to your doctor or local pharmacist if you have any concerns about Phenylalanine. Just food for thought.

[msmartsmart]

Wow! I'm blown away by the amount of information in this thread! This is good stuff! (srs)

[bhffs]

Hi,

Can someone please help me here and explain the difference between the amino acid phenylalanine and the phenylalanine found in the artificial sweetener Aspartame? I understand that there are various studies saying that Aspartame is dangerous and that many people these days choose to have protein supplements not sweetened by Aspartame but don't all protein powders contain the amino acid phenylalanine anyways, so wouldn't that make them unsafe?

Please help me understand this. Thanks in advance.
You're probably referring to those labels, 'warning: contains phenylalanine".
Unless you have a condition known as phenylketonuria you don't need to worry about this. Also note it says Warning for phenylketonurics.
It's a rare genetic disorder in which the body can't process and break down phenylalanine, an amino acid. Aspartame has a lot of it so you'll often see this warning on products with aspartame.

You'll often hear people complain about aspartame but the simple fact is it's been used for decades and is perfectly safe. It's only dangerous if as one of the other posters mentioned you get an absurdly high amount of it. Pretty much impossible to do in any normal diet.
Perfectly safe if you don't have the condition :)

[asudean]

You're probably referring to those labels, 'warning: contains phenylalanine".
Unless you have a condition known as phenylketonuria you don't need to worry about this. Also note it says Warning for phenylketonurics.
It's a rare genetic disorder in which the body can't process and break down phenylalanine, an amino acid. Aspartame has a lot of it so you'll often see this warning on products with aspartame.

You'll often hear people complain about aspartame but the simple fact is it's been used for decades and is perfectly safe. It's only dangerous if as one of the other posters mentioned you get an absurdly high amount of it. Pretty much impossible to do in any normal diet.
Perfectly safe if you don't have the condition :)

I get extreme migraines when I eat foods sweetened with aspartame (within 30 minutes), but not when I eat foods with phenylalanine. I also eat protein powders on a daily basis that use splenda/sucralose as sweeteners with no problems.

If phenylalanine is found in aspartame, what could be the cause of my migraines after eating aspartame?

[GrokTheCube]

I get extreme migraines when I eat foods sweetened with aspartame (within 30 minutes), but not when I eat foods with phenylalanine. I also eat protein powders on a daily basis that use splenda/sucralose as sweeteners with no problems.

If phenylalanine is found in aspartame, what could be the cause of my migraines after eating aspartame?

It's likely that it's all in your head. The amount of methanol created in the breakdown of aspartame is less than the amount released during the digestion of some types of fruit. I'd add that everything I've read indicates that there isn't even a measureble increase in blood levels of aspartic acid or phenylalanine after consuming a can of diet soda. It's pretty close to being practically physiologically inert at sane doses.