Subluxation of Atlas vertebra is becoming a very common problem and will lead to multitude health issues ( One of them being high BP).
Hanging upside down can help naturally align the C1.
Doesn't it make sense to align our spines before we reach out for any supplement ?
In Yoga, a headstand is considered a "king of all asanas". Yogis say, if you have no time to do other asanas, at least do a headstand. Although the spine is still compressed in headstand, thats why inverting using the table or boots is better for spinal decompression.
First thing first. Start with a healthy spine and a healthy diet.