Although this is an old thread, and 2catlady is sadly no longer with us, it is definitely relevant. In fact grapefruit interferes with the absorption of a lot of medications so the advice is not to have it if you're on other meds such as blood pressure tablets, blood thinners etc. As bon has said other fruits should also be avoided - best check with your GP or oncologist.
I'm not on letrozole, I'm on exemestane, but I don't eat any colour of grapefruit, it's a no no when taking any aromatase inhibitor which both letrozole and exemestane are. Grapefruit interferes with your absorbtion of the drug in your gut. I also don't eat seville orange marmalade which is a shame because I used to make and eat bucket loads. I don't think you should eat pomegranates or starfruit ether.
Hi Helen, interesting q as I was just wondering the same... I'm on letrozole for the 2nd time having had 4 different chemos and several other treatments at various times.
As always, the mantra is, "ask your onc / BCN" but I hope it may be helpful to make some general comments (I worked on a food-science database before I retired).
There is a compound found in grapefruit, also in smaller amounts in Seville oranges (the bitter oranges used for making marmalade) which can interfere with the body's ability to process many drugs. This compound is NOT found in other types of orange / citrus, and I don't think it occurs in lemons or limes either. Citrus fruits in general have health benefits.
Hope this helps... and that you do well on letrozole. I tolerate it well, though I do have "letrozole-legs" - that heavy feeling on getting out of bed. A scan and blood tests are booked for later this month - see whether letrozole is still working for me.