Hi Tom, I have been treated for GH since 1998 after suffering severe symptoms for 9 years, which led to my hips breaking up because my blood was so thick with iron, it blocked the fine capillaries which fed the bone.
I am homozygous C282Y, my husband (also Tom) is homozygous H63D, and our son is compound heterozygous C282Y/H63D so I have had a lot of experience reading medical research, talking personally to researchers, attending conferences, running a support group, talking to many drs, (and educating them, making them aware of this disorder at least), medical students, and people with GH.
It is not recommended to try to control your GH with diet - you will only affect your haemoglobin, and you need good Hb to enable you to have venesections. Not eating red meat will only have a minuscule affect on your ferritin levels. A venesection will eliminate the iron of 50 steaks. Just don't eat it 3 times a day, as one young fellow I know did (he lived on a cattle property where they killed their own meat) and ended up with a ferritin level of >4000 at age 22. And don't forget, this was before he was diagnosed and had treatment.
You can have as much spinach and green veggies as you like. Liver and clams have the highest heme iron, so best to avoid. Sounds contradictory I know, but everything in moderation as they say. You can eat whole oranges and other fruits which have Vit C, but not fruit juices made with Vit C fruits as you are drinking many pieces of fruit at once without the fibre which is beneficial.
Tea, coffee with meals are said to reduce the uptake of iron, and calcium is proven to reduce the uptake of iron. Eg, have yoghurt, cheese, etc as dessert. To read up on this, try to get hold of a book called Haemochromatosis Cookbook (published by Irondisorders Institute in the US). It will explain why you can eat all these foods. Ask for it at your local library. I bought mine from Amazon.
Eliminate sugars and starchy carbohydrates to prevent or reduce fatty liver to which we are prone.
We have one small glass (100mls) of red wine with dinner as the polyphenols also help reduce the uptake of iron. But if you have liver problems - don't, until that issue is mended. Turmeric is an anti-inflammatory. It helps reduce inflammation which causes a higher ferritin. It, in itself, does not reduce the uptake of iron, but may be effective if you have inflammation. I expect you have to consume a lot of it. It also gives make your teeth yellow, so if you feel you must take it, capsules may be better (but more expensive). But - GH researchers vehemently say it does not reduce ferritin. Only pseudo medics push this and other myths (e.g. cabbage, aubergine skins) in order to get you to buy their products.
As you are having frequent venesections, it will benefit you to have Vit B12 injections (more effective than tablets) and folate (which is plentiful in green veggies. Vit B12 is in proteins, especially red meat. Also have your Vit D checked as a deficiency in this worsens the side effects of having GH.
Other vitamins recommended by GH researchers is CoQ10 and Vit E. But don't waste your money on cheap products for CoQ10, look for a practitioners brand.
Be aware that drs do not read up on GH, they often only become aware of the basics and the myths. Haemotologists know how to read blood levels and know when to change the frequency of venesections. Overall, though, current research says you must be de-ironed to <50 to get all the stored iron out of your organs, and an international program yet to be published advises it best to keep to same. My ferritin level is currently 21 and my TS% has finally come down to <45%. I will continue to have venesections every 3 months to keep this happening. A low ferritin level is not harmful, but a low Hb is.
I was constantly searching for a dr who knew a lot about GH in order to get treatment of damaged organs according to having GH. I got the best advice from a heart specialist. He said "even if they found deposits of iron in my heart, they cannot cut it out, drain it out, etc., just keep having venesections". So any health problems that may have arisen from having GH should be treated same as those who don't have GH - just keep having those venesections.
Good health.