Good move to keep this as a selling point; if I were selling to folks who have any reason to distrust the medical establishment, though, I'd put it higher up on the page:

You are in charge of your data.

The Health app lets you keep all your health and fitness information under your control and in one place on your device. You decide which information is placed in Health and which apps can access your data through the Health app. When your phone is locked with a passcode, Touch ID, or Face ID, all of your health and fitness data in the Health app — other than your Medical ID — is encrypted. Your health data stays up to date across all your devices automatically using iCloud, where it is encrypted while in transit and at rest. Apps that access HealthKit are required to have a privacy policy, so be sure to review these policies before providing apps with access to your health and fitness data