[m_mueller]

I'm a meat eater, but we should acknowledge that iron from red meat, while easy to absorb, has been linked to a higher stomach cancer rate. There may be ways to mitigate it (e.g. yoghurt), but it's AFAIK so far unproven whether it's possible to get rid of that effect.

[pvaldes]

Yes, high intakes of iron, vitamin E and copper are linked with higher probability of developping canker in the digestive system. On the other hand, this risk is not exclusive of meat eaters; copper sulphate is a common treatment against plagues in vegetables. Unless you peel or clean thoroughly your vegetables, your diet could have a lot of copper achieving the same result.