This is my history... hope it may be helpful for you...

After to drink milk all over my life, then few years ago I discovered I have allergy to milk and dairy products.

Then recently I tried a spread of butter and, after one or two weeks having such butter every day, some strange syntoms started, including trembling, some strange feelings and some clear brain problem. Days later I identified as Alzheimer synthoms.

As the brain is essencially made of fat, when ingested seems the butter is used in the brain, but its chemical characteristics are not suitable for the brain.

Stopped the butter and everything came back to normal after one month.