good foods that have bad effects

[Guest guest]

Hi,

One of the values of this support group is the ability to ask

questions and get informed answers about nutrition.

My current question is:

What foods, which generally have overwhelmingly good benefits, can

have some negative effects as well.

I have read about some of these situations:

1. green tea causes a reduction of folate acid

2. red wine (and alcohol, in general) also causes a reduction in

folate acid.

3. Cruciferous vegetables reduce the amount of iodine in the body

4. grapefruit can cause severe reactions on some individuals taking

some forms of medication (ie. some blood pressure medicine, viagra,

and a few other common medicines)

Are these situations true? And, how pronounced are the effects?

Are there other examples?

Rad