My main question arising with regard to zeolite is: Can this product be damaging or have a negative long term side effect, especially if used in combination with other cancer medications and alternative homeopathic remedies? 

Someone who is a close member of my family is starting treatment with Zeolite against Glioblastoma Multiform brain cancer on the premise that zeolite will produce a neutral PH (PH 7) in her blood, which will prevent the growth of the cancerous cells, which require an acid environment, eventually eliminating all the cancer. She and her direct family members have deep faith in the product, which they are using in addition to multiple other therapies- both conventional and alternative. So, unless there is a risk to her health for taking this Zeolite, I don’t want to raise doubts about this part of the therapy lest they may start questioning the validity of many of the other therapies they are trying as well.

I may ultimately mention in passing the reservations/queries against Zeolite and its efficacy, so she can make a decision on this. However, if taking Zeolite on a permanent basis may entail any risk/side effect to her health, I would have to take a much proactive stance in making sure she stops the zeolite treatment. By the way, she is a close member of my direct family.

Thanks for any info on side effects/health hazard risks resulting from Zeolite intake.