It's all connected. Health is affected by all of these topics. It's hard to have a decent diet when you are being targeted by all kinds of things. People need to be aware of dangers lurking so they can take steps to reduce all risks.
If it was only diet that contributed to health our world would be much simpler and healthier.
Like another poster mentioned there are many forums here. Each one delves into another aspect, each that contributes to the entire picture. Just explore the ones you resonate with and leave the rest.