Dairy causes major dandruff for me, is that weird? Specifically, cheese!
I just wanted to share in case anyone might benefit. I cut dairy from my diet for 30 days to see if I would notice anything. I did not. Upon reintroducing it (full fat greek yogurt, half and half in coffee, cheese), I noticed my scalp would flake up. It made me think, "hmm, I didn't have any dandruff or scalp irritation whatsoever that last month."
I've found I can eat butter and have heavy cream in my coffee. I haven't experimented with other things too much, but I know the instant I eat cheese (as little as an ounce or so), the next day the flakes start. And then it takes about a week for it to go away.
Interesting that there's a way to keep the flakes away, but darn, I love love cheese, especially blue cheese on my salads, which are my go-to when eating out!