The harm is indirect, because they are mixing real medicine wit pseudoscience. There are a lot of miracle "cures" that appear every month. Many of them steal the patients or the family money, other steal just time and hope. And in some cases, people following the alternative cures avoid following the standard treatment that is better ot at leas reduces the suffering.
He's been curing patients for past 20 years with diet changes alone. So, I am impressed with his results and shared his idea. Doing a study on it and not using it until you study is your problem. In other words, I sense your worry of how your medicine will react since it's posion (full of unnatural chemicals) compared to a natural food item in it's unaltered form which is being used in daily food consumption in many cultures. Are you suggesting people taking medicine to stop eating food on a daily basis? I never suggested to stop any medication.
I am more than willing to contact him, will you be able to fund the study?
From your other comment:
> He claims to have cured them in 6 months.
I'm not sure how long it takes to transform a 6 month treatment to a paper. I guess 1 year before for designing, filling all the forms and preparations. And I guess 1 year after to process all the statistics, write the results in a nice form, fighting with the referee/editor. So in 2.5 years it could be published. Let's round it to 3 years because it's not my field of study. [1]
So in 20 years he has enough time to publish a serious paper on a cure an a popular illness that has a lot of people working on it. (Perhaps if the evil Big Pharma is blocking his study, he can replace the pre-registration to a single big announcement in a blog post an a hash of the post in the bitcoin blockchain. It's not official, but any good registration is enough. Most of the other steps, like double-blind, can be made anyway.)
[1] In Physics the typical time is 3 month, but there are very few paperwork because the study doesn't use humans. In Math the typical time is more than 1 year, perhaps 2, because math is forever and the review is proportional.
A nutritionist with Ph.d with good credibility claims that he got good results with using black sesame seeds. The way he used it is - roast 2 spoons of black sesame seeds and eat once a week for 6 months (no need/should not take every day). He claims to have cured them in 6 months. If I have someone I know I would try as there is no harm in having a regular food item taken once a week. Don't know how it works or if any studies already done to back it up.