No Pump + Insulin Resistant? Maybe It's Your Healthy Low Salt Diet. Low Sodium Induced Increase in Aldosterone Has Direct Negative Impact on GLUT4 Mediated Glucose Uptake
|A single Triple Whopper or about six whole steaks, what do you chose to get >75% of the 2g/sodium per day the feds are telling you you should maximally consume on a daily basis?|
If you also listen to the SuppVersity Science Round-Up on the Super Human Radio Network, you should be aware that very different rules apply with respect to salt consumption for athletes and physical culturists on a whole foods diet and the average sedentary inhabitant of the Western obesity belt (check out past episodes of the Science Round-Up).
|Suggested Read: On "Clean Eating" being a myth - "A Tale of Macro- & Micro-Nutrient Modifi-cations" | read more|
"Salt is bad, no matter what!"
In fact, Feldman & Schmidt were able to show that the provision of either normal or salt reduced diets to subjects aged 25 to 40 year.
All of the participants had normal blood glucose levels, and were free of other abnormalities on history and physical examination. They did not smoke and their blood pressures levels ranged from normotensive to high normal/borderline. So, what would happen to the poor wretches consuming the additional sodium chloride tablets? Common wisdom tells us, their blood pressure will increase and they will develop metabolic abnormalities. Truth is (I quote from the study; Feldmann. 1999, my emphases), almost the exact opposite happened:
"Subjects were given a standardized diet that contained 75 mmol/L sodium chloride, 60 mmol/L potassium, and 20 mmol/L calcium for 14 days. Diets contained 16% protein, 54% carbohydrate, and 35% fat. Caloric intake was 2800 kcal/day. Subjects were advised to drink approximately 2L of water/day.
Figure 1: Increased aldosterone levels during salt restriction will not only make you retain salt, but also reduce glucose uptake (Luther. 2011; my edits)
To assess the effects of dietary salt restriction independent of other dietary changes, subjects were randomized on a double blind cross-over basis to a daily supplement of 16 tablets of slow release sodium (Novartis, Mississauga, Ontario; 10 mmol/L sodium chloride/tablet) or matching placebo. Each were administered for 7 days." (Feldmann. 1999)
- Did you know? Aldosterone increases are caused by falling blood pressure, increased potassium levels, a higher blood acidity and decreased sodium concentrations in the blood trigger, decreases occur when your blood pressure drops, the potassium levels get low and/or the sodium levels are high.Dietary sodium restriction was associated with a significant decrease in 24-h urinary sodium excretion. However, blood pressure (based on the average 24-h automatic ambulatory measurements) was not significantly decreased with dietary salt restriction.
- Moderate salt restriction was associated with a significant increase in plasma norepinephrine concentrations. Dietary salt restriction was associated with a significant decrease in the glucose-to-insulin ratio, suggesting increased systemic insulin resistance. This decrease was primarily accounted for by an increase in plasma insulin concentration.
|Most of you will remember the recent post about the ability of salt to block the negative effects of high intensity exercise on the cellular integrity of your heart and kidneys don't you?|
Now it is important to point out that it is not clear whether these effects are transient and a response to the abrupt changes in dietary salt in take that are characteristic of these short term intervention studies.
I am certainly not recommending you copy the salt intake of the average junk-food fanatic!
But let's be realistic, here: How much salt do you actually consume on a daily basis if you follow my advice and leave as much of the processed pre-packaged junk as you can right in the supermarket!? This will leave you with actually having to put salt on your foods and there really is no good reason for the average physical culturist not to so in a way that it's tasty and supplies you with one of the most important minerals in your body.
Suggest figure: Only obese people have increased risk of CVD with increasing sodium consumption | check it out the SuppVersity Facebook Wall
- Egan BM, Lackland DT. Biochemical and metabolic effects of very-low-salt diets. Am J Med Sci. 2000 Oct;320(4):233-9. Review.
- Hornstra JM, Serné EH, Eringa EC, Wijnker MC, de Boer MP, Yudkin JS, Smulders YM. Insulin's microvascular vasodilatory effects are inversely related to peripheral vascular resistance in overweight, but insulin-sensitive subjects. Obesity (Silver Spring). 2013 Mar 20.
- Luther JM, Brown NJ. The renin-angiotensin-aldosterone system and glucose homeostasis. Trends Pharmacol Sci. 2011 Dec;32(12):734-9.
- Ruppert M, Diehl J, Kolloch R, Overlack A, Kraft K, Göbel B, Hittel N, Stumpe KO. Short-term dietary sodium restriction increases serum lipids and insulin in salt-sensitive and salt-resistant normotensive adults. Klin Wochenschr. 1991;69 Suppl 25:51-7.