(5 mins) Transcript. Dr Greger explains that those on a high salt diet have far worse asthma attacks — lung function drops significantly. Moreover, the development of various autoimmune diseases involves "activation of Th17 cells"; one trigger for this activation is salt. In particular, Multiple Sclerosis (MS) patients on a high salt diet have exhibit 3x-4x the 'exacerbation rate' after a few years and 3x more likely to develop new MS lesions in their brains, and on average, had many more brain lesions as compared to low salt group. See video for details.

(5 mins) Tanscript. Dr Greger mentions that in 1960s and 1970s, it was observed that childhood asthma rates in the developed world were between 2% and 5%, but in the developing world as low as 0.007%. Also, when they moved from a low-risk area to a high-risk area, their risk went up! Turns out that there is an association of asthma with salt intake! Experiments have shown that reducing salt intake from 3 tsp → 1 tsp improves lung function considerably! The same effects cannot be seen by merely reducing salt intake by only half a teaspoon a day. The reduction in salt needs to be significant for effects to be noticeable.