The difference between cured and uncured bacon lies in the ingredients used in the curing process. Uncured bacon is actually cured, but it is cured using naturally-occurring nitrates rather than the sodium nitrates used in cured bacon. Uncured bacon is cured by using celery powder, its juice or sea salt.
The sodium nitrates used in cured bacon are potentially harmful to people and may be carcinogenic, so uncured bacon may be the safer choice. Both forms of bacon have the same calorie and fat content, but the uncured bacon may have more sodium added to replace the sodium in the nitrates not used for curing.