I found local honey helped my symptoms last year.
I find that first article a bit iffy. Citrus is very histamine-promoting - this outweighs the effect of vitamin C. That's why it's used as a traditional cold remedy, to get the mucous flowing. Berries are also histamine promoting. Red wine is extremely high in histamine.
Pineapple's a good one to try. It's one of the few fruits I ever eat. Also garlic, and the onion family in general.
Red onions are the only food I know of that contain significant amounts of quercetin to have a noticable anti-histamine effect. Coffee and green tea are also quite powerful anti-histamines. Black tea is high in histamine because it's fermented.
Any fermented foods, sardines, mackeral, smoked fish, hard cheeses are all high in histamine. Fresh salmon is quite beneficial as an antihistamine due to its high omega 3 content. But make sure it is fresh.
Spinach and tomato are histamine-promoting.
That's a distillation of my knowledge and experience.
I find I have much more energy eating a low histamine diet as it helps stabilise my blood pressure, which can dip quite low during a histamine attack. Before I started this, I had chronic non-allergic rhinitis all year round, peaking at 3pm each day, and hayfever in the early spring only, i.e. I only react to tree pollen.
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.