Does Drinking jersy cow milk hazardous to health?

Now a days, lot of people are affected with serious diseases, reasons are mainly attributed to milk and food we eat/drink. There is a book written by a leaned western author ’ Davil in the milk ',it  has been proved scientifically that jersy cows milk is dangerous for health. A2  milk of desi cow is much safe and healthy to drink instead of Jersy cow having A1 milk. If so ,why people are still running after having jersy cow,i understand commercial profit for owner,but at what cost ?
I invite knowledgeable forum members to comment on the topic.

worldguernseys.org/PageMill_ … odford.pdf

There’s a devil in the milk, says agricultural scientist Keith Woodford, and it has little to do with
production methods. Woodford’s startling thesis, backed up by a pile of research, is that a mutation
many years ago created an aberrant protein in some European cows, called A1 cows to set them
aside from all other cows, which are called A2. As a result, the milk from these cows has been linked
to a host of maladies, including Type 1 diabetes, autism and heart disease.
Still virtually unknown in this country, the A1-A2 question is prominent enough in New
Zealand, where Woodford lives and works, to have spurred public controversy and the creation
of a successful company that markets only A2 milk, the a2 Corporation. For growing numbers of
Americans who have noticed that milk seems to attack their systems even though they are lactosetolerant,
Woodford’s work, collected in his book, Devil in the Milk, offers vital illumination.