Because the enzymes in Grapefruit increase efects of the supps… doesn’t that mean that they have a shorter effect? Like they’re being used in a very intense burst?
Wouldn’t it be better to have the effect of something like Carbolin 19 spread out?[/quote]
no, that is not how it works.
cytochrome p450 is responsible for deactivating what is known as “reactive oxygen species” (ROS for short). ROS are usually chemical intermediates or molecular oxygen which has not been fully reduced via electron transport before being released. These chemicals are highly reactive, and thus if left unchecked in the body can go on to start any number of harmful chain reactions (you might be familiar with the term free-radical damage). Cyt P450 basically renders these ROS harmless, preventing cellular damage through unwanted side reactions.
You might be wondering how this all ties in with supps. Well, ingested chemicals are metabolized via p450 to render them “harmless” before allowing them to be absorbed into the body. Thus, Cyt p450 metabolizes the supplements ingested, lowering the amount of active ingredient passed through into the circulatory system during digestion. By using grapefruit juice to effectively “shut-down” p450, you are allowing more of the active ingredient into your body via digestion. This does not shorten the active life of the compound, or cause it to react quicker in any way. In effect, you are just taking more of it.
My problem with this is that p450 is responsible for preventing cellular damage. Inhibiting its function may have very negative side effects if done frequently (I have no clue how long this deactivation lasts). Keep in mind that polyunsaturated fats (those touted as “healthy”) go rancid rapidly if not properly refrigerated, forming free-radicals and leading to increased cellular degredation. If your diet is high in potentially rancid PUFA’s, i’d stay clear of the grapefruit.