Many here know more than me, but I've read that in Russia and surrounding northern-lying areas the tendency toward lactose reactions (intolerance, allergy, etc.) is somewhere near 1% - which is close enough to nonexistent to think people/vendors/hotels/etc maybe won't make a big effort for that small fraction.
Well if you count Scandinavia as "surrounding northern-lying areas", actually lactose intolerance is really common. Every supermarket has lactose free milk, yogurt, kefir, cream etc, as well as milk free substitutes.

Allergies are a relatively "modern" phenomenon and there have been some differences in lifestyle, although I am not quite sure on exactly what sorts of factors make the big difference. But Russians clearly suffer less from allergies.

The study that I was referring to was saying that certain cleaning products are to blame. British people are more allergic in general, than Scandinavians - asthma is really common in the UK. They use modern cleaning products even more frequently, and there is more pollution. But it comes down to lots of factors that affect people in childhood. I think that Russians use more or less the same products as peope in Western Europe now, so they will probably affected just as much. Pollution and eating habits also come into it.

This said, there are some seriously polluted places in Russia. It is quite possible that people in such places suffer more from health problems, like asthma, allergies, cancers etc.