Comment To actually conclude this (Score 1) 88
To actually make a study conclusion that is truly solid, you would need a RCT (Randomized Control Trial) - this is impossible for such a hypothesis.
A confounding issue issue such as the amount of sunlight a person gets per day has been shown to affect mitochondrial health - 15 minutes per days makes a big difference. If you work inside, there is an observed difference in health outcomes based on the spectrum of the artificial light (full-spectrum being healthier). Did they control for these affects? How could they possibly do so. Did they control for percentage of processed food fiber intake, serum Vit D levels, glucose and sodium sensitivity, liver and kidney function, ad infinitum. We don't even have an accepted gold standard for measuring sodium sensitivity (that I am aware of).
I'm not saying researchers were dishonest, I'm saying that observational studies are very difficult to be coerced into truly clinical significance, much less something that would be considered proved in other areas of science. Human behavior and biology is very complex and messy. A shame considering how nice it would be to develop reliable answers.