Dietary restriction of salt has been found to be as effective as single drug therapies for hypertension. Reducing salt intake by 8.5 g/day lowers BP by 7/3 mm Hg in type 1 and type 2 diabetes.

It is known that our current consumption of salt is a major factor in increasing BP. Salt sensitivity is particularly high in diabetic patients. Public health guidelines recommend reducing dietary salt intake to less than 5-6 g/day. A modest reduction in salt intake lowers BP, irrespective of levels of blood pressure being normal or raised. However the current knowledge of the role of salt in regulating BP and its impact on DKD is limited to small studies. There are no standard criteria for high and low salt diets.
A study was done to evaluate the effects of salt restriction on the prevention and progression of DKD. A meta-analysis of Randomised Control Trials (RCTs) of salt reduction was performed. It included 13 studies including 254 patients with type 1 and type 2 diabetes. The results were published in Cochrane Reviews, a reliable source of evidence-based health care.
It was found that reducing salt intake by 8.5 g/day lowers BP by 7/3 mm Hg in type 1 and type 2 diabetes. This effect is equivalent to that produced by a single drug therapy. Tight control of BP in diabetics slows the progression of diabetic kidney disease. All diabetics should consider reducing salt intake at least to less than 5-6 g/day. The recommendation of 5-6 g/day is actually meant for the general population. Diabetics may consider lowering salt intake to still lower levels.
The number of patients studied are not large but the results have significant implications owing to the fact that it is often difficult in clinical practice to control BP to the levels now recommended by guidelines. If a modest dietary restriction can be as effective as drug therapy - the fact has significant preventive implications to countries such as India and China that have seen rising incidence of both diabetes and hypertension.
Reference:
Source: Cochrane
Source-Medindia