Can I exclude /cache folders from my backup?

I regularly back up my WordPress sites, both database and files.

There are plenty of files within /cache folders, sometimes taking a fair bit of space, and slowing down the backups. These include not only the base WordPress cache folder /wp-content/cache, but also cache folders from plugins. Examples from my sites include the following.

• wp-content/cache
• wp-content/nfwlog/cache
• wp-includes/SimplePie/Cache

Question:
Can I safely omit /wp-content/cache? What about all other folders named /cache (whether uppercase or lowercase)? Or would this cause problems on restoring a site?

Thank you