Hacker News Reader

Comment by niels_olson | Hacker News Reader

Phenylalanine is one of the 20 amino acids required for life as we know it. You are exposed to many times more phenylalanine when you eat high-protein foods compared to an entire 12 pack of diet soda.

Phenylketonurics have to track their phenylalanine consumption, so there are several easy-to-use look-up tables for the amount of phenylalanine in various foods (1).

Diet soda (2) is a rounding error compared to soy, legumes, and meats. Show me a healthy diet without soy, cheese, whole grains, eggs, or legumes and I'll show you someone who's trying too hard to show me something.

(1) https://www.healthaliciousness.com/articles/high-phenylalani...

(2) http://static.diabetesselfmanagement.com/pdfs/DSM0310_012.pd...

View on HN

Arent amino acids metabolised very differently when taken in isolation from other amino acids? I recall reading that Arginine and Lysine compete for metabolic resources in some way- which is why Lysine capsules are often prescribed for cold sores- for example.

The article just states that the researchers suspected a mechanism of action that involves phenylalanine, but the experiment doesn't actually say anything about what the actual mechanism is. Anyway, aspartame isn't even phenylalanine or anything else that can be found in nature.

Aspartame is composed of aspartate, phenylalanine (two amino acids) and a methyl group.

After you ingest it, it's easily broken down. What your body actually absorbs are the component parts, all of which are ubiquitous in nature.

Forgive my ignorance, but it's not like that methyl group just becomes a free radical, right? Does it stick to either the aspartate or the phenylalanine, and if so, wouldn't that potentially change the body's reaction?

From a quick google search, it appears the methyl group gets converted to methanol.

Which we all know has no ill effects whatsoever.

In very high quantities, yeah, it's bad. Just like everything, including water and oxygen.

In small amounts, your body can handle methanol just fine. Which is fortunate, because it's present in many foods at much higher levels than what you'd get from drinking a can of Diet Coke.

The methyl ester is converted to the free acid and methanol, which you further metabolize into formic acid.

Methyl esters can be readily hydrolyzed (split by water) in an acidic environment. The stomach would be ideal.

Reply on news.ycombinator.com