Salt Restriction Lowers Metabolic Rate And Increases Fat

[ecstatichamster]

Dietary sodium restriction exacerbates age-related changes in rat adipose tissue and liver lipogenesis - ScienceDirect

To investigate the effects of prolonged dietary sodiumrestriction on lipid metabolism, male rats weighing 35 to 40 g (just weaned) were fed either a low-salt (LSD) or a normal salt diet (NSD) and used in metabolic experiments after 1, 2, or 3 months of diet consumption. After 2 and 3 months on the diet, LSD rats showed increased amounts of lipid in carcass and retroperitoneal tissue.

In both LSD and NSD, extending the feeding period from 2 to 3 months resulted in a marked reduction in the in vivo rates of adipose tissue fatty acid synthesis that was accompanied by increases in liver lipogenesis and in the activity of adipose tissue lipoprotein lipase (LPL).

However, these increases were more marked in LSD rats.

Thus, in vivo rates of liver fatty synthesis and LPL activity in LSD rats, which were already higher (by about 35% and 20%, respectively) than in controls after 2 months, attained levels 50% higher than those in NSD animals after another month on the diet.

Brown adipose tissue (BAT) thermogenic capacity, estimated after 2 and 3 months by the tissue temperature response to norepinephrine (NE) injection and by guanosine diphosphate (GDP) binding to BAT mitochondria, did not change in controls, but was significantly reduced in LSD rats.

This raises the possibility that a decrease in overall energy expenditure, together with an LPL-induced increased uptake of preformed fatty acids from the circulation, may account for the excessive lipid accumulation in LSD rats. Taken together, the data indicate that prolonged dietary sodium restriction exacerbates normal, age-related changes in white and BAT metabolism.

 

[yerrag]

I believe salt restriction leads to lower blood volume, and lower blood volume would lead to lower rates of delivery of substrates oxygen and glucose to body tissues, and this would lower metabolic rate. With lower usage of glucose, blood glucose levels would increase, and cause an insulin response that leads to the liver converting glucose to fat. Not only does this increase fat generation, it also leads to low blood sugar, which triggers hunger, and leads to increased food intake. This increased intake of food leads to more fat generation.

 

[Tristan Loscha]

Could it be the equivalent to the impressive 50-percent reduction of Lipid-Peroxidation measured as F2-Isoprostanes seen in prescribed Low salt diets occuring in the context of Post Heart-Attack-Care.studies? I thought being fatter with aging is en vogue!