Apple has tightened its rules around the use of health data by developers making apps that connect to the HealthKit aggregation platform.

The company has changed its privacy policy to state explicitly that developers can’t draw data from Apple’s platform for their apps, then pass it on in some form to marketers.

The policy change comes just before Apple announces the first new phones running iOS 8, which will include a feature called Health that will present HealthKit data.

The HealthKit platform can be thought of as a big ball of APIs (application programming interfaces) in the cloud that allow it to collect data a multitude of connected devices from smartwatches to scales. All this data will be presented in the Health app in iOS 8.

App developers can also access HealthKit data and combine it in creative ways within their own apps. The privacy change prevents them from aggregating the HealthKit data then packaging up for data brokers or marketers.

This is a logical move for Apple. Its interest in the consumer health space is selling more devices, not selling health data.

And yet the market for consumer health data is big and thriving in the USA. One data broker, IMS Health, says it aggregates data from 100,000 companies, some of which make apps.

Health data privacy advocates like Dr. Deborah C. Peel have been writing and discussing this problem for a long time. And people on Capitol Hill are becoming increasingly interested.

“If Apple is really doing this, if they’re really saying to developers that you can only use the data for the specific purpose that app provides the user, and that they can not share the data with anyone else without informed consent, that is the victory of victories,” Peel told VentureBeat.

“That’s what we’re seeking from all of the 100,000 of the companies that are now selling health data,” Peel says.

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