That's an interesting issue. When Gwyneth Paltrow is making strange statements about efficiency of certain procedures or aspects of human health, a lot of what she says is untrue. However, by your definition, she is not lying as she (most probably...) believes what she says.
Many people are repeating lies in good faith. The fact they believe them doesn't magically make what they say true.
I think that is commonly shared definition. We distinguish lying from just being wrong. Saying untrue things in good faith, as Gwyneth Paltrow in your example, is not lying.
> 2
> : to create a false or misleading impression
> Statistics sometimes lie.
> The mirror never lies.
For me it sounds like lying and telling lies is not necessarily the same thing.
Another way to think of being delusional is “lying to yourself”…
> If you say something untrue that you believe is true, are you lying?
Personally I’d argue yes. I’m lying to myself and then by proxy to everyone around me.
I could say “I don’t know” instead, but I didn’t.
But that’s just this human’s opinion.
There's no intention to deceive or any possibility for you to know that your information might be untrue.