A “Sleepless In Seattle” Anomaly

I was watching the movie “Sleepless In Seattle” the other day (for the umpteenth time) – and found myself caught up in the following exchange:

The Meg Ryan character, Annie Reed, was explaining to her mother how she met her fiancé Walter.

Seems there was a mix-up with their lunch orders.

Walter – who’s allergic to everything – had ordered a Tomato Sandwich on white bread.

Annie had ordered a Tomato Sandwich on whole wheat

According to Annie, here’s what happened:

“One day we both ordered sandwiches from the same place, and he got my Lettuce & Tomato on Whole Wheat – which, of course, he was allergic to – and I got his Lettuce & Tomato on White”

In other words, Walter was allergic to whole wheat bread, but not white bread.

I mean, is that even possible?

Aren’t they both made from wheat? The white bread simply contains less of the whole grain goodness, otherwise they’re basically the same.

Anyway, this had me thoroughly stumped.

If anyone knows differently and would like to set me straight, I’m all ears.