Can ZigBee CAN? (Controller Area Network)

I would also like to know that!

Zigbee is not designed to send/receive at a high-rate.

I found this on Amazon:

http://www.amazon.com/Controller-Network-Gateway-Proposition-Architecture/dp/3836428156

Zigbee is good at control area network but not send/receive data at high rate. If you can specify your application, I can try to give you my suggests.

I am looking for a concept to connect a network of components of an implanted medical device with components outside of the human body.

Do you need to support mesh network? If not, I would suggest BLE instead of Zigbee. 

2.4 GHz is not an option, because it is strongly damped by the human body.

Both Zigbee and BLE run on 2.4G. If you don't prefer using 2.4G, you have to consider other solution such as SubG RF.

I've read, that zigbee has also channels around 868 MHz. But you are right, commercial SOCs usually employ the 2.4GHz band.

SubG RF would be perfect. But is there a solution for CAN <-> SubG-RF <-> CAN ?

You can try to refer to SimpliciTI.

Thank you YiKai Chen!