Now I know why the Galaxy 8 Watch antioxidant sensor doesn't use your wrist – and it's so obvious

One of the most innovative, if least understood updates in Samsung's new Galaxy Watch 8 is the new antioxidant index metric, which uses Samsung's latest BioActive sensor. Unlike sensors that look under the skin for, say, blood oxygenation or heartbeats, these new yellow, blue, and violet sensors focus on the surface and measure your level of antioxidants.

According to Samsung executives who walked us through Galaxy Watch 8's latest health capabilities shortly after unveiling the new wearables at Samsung Galaxy Unpacked on July 9, measuring antioxidant levels on the skin relates directly, though not immediately, to your eating and drinking habits. Certain foods, for instance, like fruits and vegetables, might raise the antioxidant levels in your skin. Having higher antioxidant levels might help stave off illness.

We were shown what looked like a direct correlation between, for instance, drinking alcohol during the holidays and ...