#sodium consumption

[foodsciencedaily]

Children’s Preferences for Sweeter and Saltier Tastes Are Linked to Each Other and to Measures of Growth

Scientists from the Monell Chemical Senses Center have found that children who most prefer high levels of sweet tastes also most prefer high levels of salt taste and that, in general, children prefer sweeter and saltier tastes than do adults. These preferences relate not only to food intake...

Read more Children Prefer Sweeter And Saltier Tastes Than Adults

[tymkrs]

Ham Radio vs Tasty Ham Part IV

So the second half of my hypothesis was that for those who had hypertension, diabetes, heart failure, kidney disease- salt consumption would either make or break you (mostly break). 

The basic reason is this: Excessive salt keeps the circulatory volume higher than it should be, exerting excess fluid pressure on blood vessel walls. These walls react to this stress by thickening and narrowing, leaving less space for the fluid already cramped in the blood compartment, raising “resistance” and requiring higher pressure to move blood to the organs. The heart has to pump against this high pressure system. This 24/7 activity can cause the heart to enlarge dramatically, and dangerously. The kidney contains around one million tiny, delicate filters comprised of blood vessels. The increase in pressure transmitted to the kidneys damages its vascular system leading to a disorder known as “hypertensive nephrosclerosis,” a major cause of kidney disease.

So for those who have dialysis - the main issue people have that requires dialysis is that they can't get rid of wastes and fluids.  So their weight goes up in between dialysis days just because of fluid weight.  The last thing you want is to have a high-salt diet because then that's just exacerbating the issue.

For those who have hypertension - the main issue is that your heart's already working hard to get what volume you have blood-wise through your system.  If you tax it by adding on fluids that follow your salt intake, the heart becomes stressed out and overtime that leads to stretching of the heart and heart failure.

For those who have heart failure - the main issue is that their heart can't pump enough fluids through at a given time.  When that happens, there's low perfusion to the kidneys which makes the kidneys think that there isn't enough volume.  The kidneys then spring into action producing hormones that make the body retain salt which then induces storage of water.  So now you've got way too much fluid in your body which the heart can't pump effectively enough.  Where does it go?  Into the lungs, into the arms, into the legs, essentially everywhere but your bladder.  So a lot of patients who deal with disease complain of puffiness and shortness of breath.  The main way we treat it is diuretics and encourage minimal salt intake.

Interestingly - when trying to look for articles to back what I've said up - most are review/commentary articles that say "Yes, we encourage low salt intake" without data to back up its efficacy.  Below are some quick sentences found in articles that I won't cite:

Stress is unlikely to be a major contributor to salt intake though it might induce snacking.

Mean systolic and diastolic blood pressure increased as the ratio of urinary sodium to creatinine increased (as estimated from a casual urine sample), with differences of 7.2 mm Hg for systolic blood pressure and 3.0 mm Hg for diastolic blood pressure.

24h sodium excretion was positively and significantly associated with systolic blood pressure (SBP) and with diastolic blood pressure (DBP) in post-menopausal women. Pooled regression coefficients of sodium-BP association were not significant in pre-menopausal women.

Sodium (adjusted for calories) and sodium/calorie ratio as continuous variables had independent inverse associations with CVD mortality. The inverse association of sodium to CVD mortality seen here raises questions regarding the likelihood of a survival advantage accompanying a lower sodium diet.  (Ie a low sodium diet was associated with a higher likeliness of death in the 13 years the scientists studied them)

Myocardial infarction and urinary excretion of sodium were inversely associated in the total population and in men but not in women. In men, age- and race-adjusted myocardial infarction incidence in the lowest versus highest urinary excretion of sodium quartile was 11.5 versus 2.5.  (Ie those who were had low sodium levels in their urine were more likely to have heart attacks and those who had high sodium levels in their urine were more likely to not have heart attacks.)

TONE (Trial of Nonpharmacologic Interventions in the Elderly) randomized 975 elderly men and women on hypertension treatment to weight loss or sodium reduction, with the attempted withdrawal from antihypertensive medication after 3 months of intervention. After 29 months, a 31% reduction in hypertension or cardiovascular event was observed in the sodium-reduction group, and they had a 50% decrease in the return to antihypertensive medication compared with those on usual care.

I hate to say it, but these studies straddle the fence.  Some say it works, some say it doesn't and in fact is opposite what we'd expect.  I might just have to find someone who specializes in this to answer this question!  My take on it, moderation.  If you're eating in moderation, you're golden.

EDIT: For bullet points 4 and 5 I think another feasible explanation is that the patients who died first may have had kidneys that were unwilling/unable to excrete sodium in the urine.  This would give a false reading for sodium in the urine and perhaps still mean that those particular individuals had higher sodium levels in their blood causing more damage? Maybe!

@atdiy/@tymkrs

[mousemedia-blog]

New U.S. Dietary Guidelines Recommend Limiting Excess Salt, Fat, Sugar

The U.S. Department of Health and Human Services and the Department of Agriculture have updated their nutritional guidelines, taking aim at sodium, refined sugars, fats, and refined grains.

Among the 23 recommendations:

·       Limit daily sodium consumption to less than 2300 mg. High-risk groups (e.g., those who are over 50, are black, or who have hypertension, diabetes, or chronic kidney diseases) should consume less than 1500 mg.

·       Restrict the percentage of calories coming from saturated fats to less than 10%.

·       Consume less than 300 mg of dietary cholesterol daily.

·       Replace refined grains with whole grains.

·       Restrict consumption of solid fats and added sugars.

·       Limit alcohol to one drink per day for women and two for men.

·       Eat a variety of fruits and vegetables and more of them.

·       Replace some meat and poultry with seafood.

The guidelines also offer specific recommendations for people ages 50 and up and women who may become pregnant or who are pregnant or breast-feeding.

January 31, 2011