Re: and this says they're both no good....

 >>We see this all the time when people are trying to outsmart Nature. They are called pharmaceuticals and look at how dangerous they are compared to the natural counterparts.

Cleverly put.

You've discussed this in the past but suddenly has me thinking about grapefruit juice. Surely you're aware that grapefruit juice can increase the "potency" (absorbability?) of various pharmals, yet also can have the opposite effect on others.

Would you happen to know whether this might also be the case if one drinks grapefruit juice with particular herbs, minerals, vitamins, etc.?

It is not just grapefruit.  Certain other related fruits, such as pummelos and certain oranges, can also have this effect.  The problem is that they interfere with the cytochrome p450 system involved in the metabolism and detoxification of the drugs.  This makes the drugs stay in the system longer than normal, which can lead to toxicity.

As for herbs yes, the same thing can happen.  But there are very few herbs that I would worry about. The reason is because unlike pharmaceutical drugs, which are often based on isolated extracts of herbs, herbs tend to have a balance making them less likely to have dangerous side effects.  Alfalfa contains blood thinning coumarins and blood clotting vitamin K.  Ephedra leaves are stimulant while the root is sedative.  Green tea contains stimulatory caffeine and relaxing theanine.  The coffee bean is a stimulant while the fleshy coating removed is a sedative.........  Again we are not going to outsmart Nature.