Yes it's bad, keep away from grapefruit when eating meals that have iron in them, the vitamin C will increase the absorption of iron. Vit C has it's greatest effect when in the stomach with another food that contains iron. Likewise many fruits e.g. strawberries (vit A) but to a lesser degree than vit C. Generally your body should absorb fruits quite quickly so you can eat meat quite soon afterwards (eg 30mins) but I've seen 2hrs wait recommended before eating fruit after a eating meat etc.

But you should eat grapefruit, oranges, kiwi fruit etc as they have beneficial antioxidants etc that should help protect us. Though it should be noted that having high levels of vit c in your body will also increase iron absorption slightly, the beneficial effects of fruit are considered to be of more importance.

Here are just a few foods

Iron Absorption Enhancers
Meat/fish/chicken (will increase absorption of iron from plant sources)
Fruits: Orange, Orange Juice, cantaloupe, strawberries, grapefruit etc
Vegetables: Broccoli, brussels sprouts, tomato, tomato juice, potato, green & red peppers
White wine

Iron Absorption Inhibitors
Coffee & Tea
some Red Wines (but don't use it specifically to inhibit absorption)
Vegetables: Spinach, chard, beet greens, rhubarb and sweet potato
Whole grains and bran
Soy products
calcium (cheese/milk), phosphates

THANKS, FERAFERR: I HAD FORGOTTEN THE VIT C FACTOR. I ALSO HADN'T CONSIDERED EATING GRAPEFRUIT PRIOR TO OR AFTER EATING MEAT. I HAVE PRETTY MUCH QUIT RED MEAT. WHAT LITTLE I HAVE HAD SINCE MY DIAGNOSIS, IS HAMBURGER, WHICH I BOIL AND RIINSE. AND I ONLY CONSUME A VERY SMALL AMOUNT. I EAT CHICKEN AND FISH AND PORK, NOT IN MASS QUANTITIES. I QUIT BOOZE, LOST 45 POUNDS, TRYING TO LEARN HOW TO LIVE WITH THIS. IT SURE IS NICE OF YOU FOLKS TO SHARE YOUR EXPERIENCES AND KNOWLEDGE. I HAVE THREE CHILDREN, AND THEY DON'T UNDERSTAND HOW IMPORTANT IT IS FOR THEM TO GET TESTED!! THEY ARE ALL ALOT SMARTER AND BETTER EDUCATED THAN I AM. JUST STUBBORN AND YOUNG... THANKS AGAIN.