As a lupus patient i have avoided foods like garlic and mushrooms (foods that improve immune system). is it advisable? on 1g mmf bd, 400mg plaquenil (hydroxychloroquine)

Eat what you like.: I would not recommend any supplement advertised as an immune booster. It is ok to eat any fresh foods or vegetables. There is no research evidence that any specific diet or food will cause significant worsening or omprovement in sle.

No: Diet has no influence on lupus activity. Eat what you want.

Eat what you wish: The "pop" claims that mushrooms and garlic "improve the immune system" are internet rubbish. Many, may be most, plants contain chemicals that in huge doses can interact with cell cultures to exert various effects one way or the other. However, diet isn't going to affect lupus. In fact, having your disease is tough enough without superstition or (as you've probably experienced) ill-informed advice.