Re: Blood pressure and sodium

[Guest guest]

> PS You also have to consider that with the studies we do, and the

one McDougall did and the ones the Rice Diet did, that not only were

those drops in SBP seen, there was also the reduction in or

elimination of, HTN medicine during the study. So, the original

numbers were while on HTN meds and the final numbers were without

them. So the actual drops were much more.

>

> We get around 80% of our patients off their HTN meds in 14-21 days.

The rice diet has similar stats.

>

> Jeff

>

------------------------

Well, Jeff, I stand corrected in terms of very low sodium diets.

Certainly the rice diet as originally construed did manage to control

very severe hypertension, and I'm sure that very low sodium diets will

lower BP. But I don't think the diets you're talking about are this

type of super-low sodium diet.

Apart from the very low sodium diets (which are not used clinically in

my experience, due to difficulty in adherence), the change in BP due

to modest reductions in sodium (to about 1500 mg/day, is much lower.

You have to factor in the fact that whenever you put people on a

study, their BP goes down. So I was referring to the drop in systolic

BP compared to placebo.

For example, when you do such a study, the systolic BP may go down, by

say an average of 13 mm Hg, with a typical study, but it may well drop

by an average of 8 mm Hg in the placebo control group, so the actual

fall in BP due to the actual change in diet, is much less.

Here is what a structured analysis of a great number of studies in

this area shows:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=15266549 & query_hl=45 & itool=pubmed_DocSum

Cochrane Database Syst Rev. 2004;(3):CD004937.

Effect of longer-term modest salt reduction on blood pressure.

He FJ, MacGregor GA.

You can click on the link to read the whole abstract, but-

{{Now read this part carefully:}}

In individuals with elevated blood pressure the median reduction in

24-h urinary sodium excretion was 78 mmol (4.6 g/day of salt), the

mean reduction in systolic blood pressure was -4.97 mmHg (95%CI:-5.76

to -4.18), and the mean reduction in diastolic blood pressure was

-2.74 mmHg (95% CI:-3.22 to -2.26).

{{So 5 mm Hg systolic and 2.7 mm Hg diastolic - very similar to what I

said.}}

In individuals with normal blood pressure the median reduction in 24-h

urinary sodium excretion was 74 mmol (4.4 g/day of salt), the mean

reduction in systolic blood pressure was -2.03 mmHg (95% CI: -2.56 to

-1.50) mmHg, and the mean reduction in diastolic blood pressure was

-0.99 mmHg (-1.40 to -0.57).

{{So in normotensives, only 2 mm systolic and 1 mm Hg diastolic.}}

----------------------------

This is peripheral to the discussion about vitamin D and blood

pressure. I of course believe we should be following a dietary sodium

intake, ideally, in the 1-2 g/day range, and I agree that as you get

older, or if you are African American (or maybe Hispanic, also), or

have kidney disease, you should be closer to 1 g/day than 2 g/day.

I didn't know what the Pritikin diet recommended, so I looked on their

website. They say you can eat up to 1.5 g/day sodium. This is my own

recommendation as well (well, 1.5-2.0, but leaning towards the lower

end), so again, I think any disagreements between us are less than

they appear, unless you are advocating going lower than what the

Pritikin website recommends. 1.5 mg/day is a modest sodium intake,

and not really a low sodium intake.

This is far above what the original rice diet used. Which rice diet

are you talking about? The original Kempner rice diet had only 15-25

g/day of protein, and ONLY 100-150 mg/day of sodium, one-tenth the

sodium of what the Pritikin, DASH, and other diets recommend. Blood

pressure reductions with this diet were huge, I agree, but no one uses

this.

For a ref, see:

http://www.ajcn.org/cgi/reprint/4/3/254.pdf

I presume you're talking about the Rice Diet program run out of Duke

and championed by ti?

If so, I could find only one article by ti using this diet:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=11152083 & query_hl=50 & itool=pubmed_docsum

Here is what they say about change in blood pressure:

" systolic and diastolic blood pressure decreased by 4.3 mmHg (p <

0.01) and 2.4 mmHg (p < 0.05), respectively. "

I guess my own approach to all of this has been to avoid very radical

diets; I've tried to follow a very low sodium diet, and i've actually

liked it - but I have found it to be too hard to follow in the context

of family and socializing and practicality. Even patients who really

need such a diet - those with congestive heart failure, kidney

disease, etc. almost never follow such diets. Otherwise our

pharmaceutical company stocks would have a lot less value.

But maybe the CR crowd is an intrepid lot. Has anyone surveyed the

range of sodium intakes that people follow? It would be interesting

to find this out.

[Guest guest]

> PS You also have to consider that with the studies we do, and the

one McDougall did and the ones the Rice Diet did, that not only were

those drops in SBP seen, there was also the reduction in or

elimination of, HTN medicine during the study. So, the original

numbers were while on HTN meds and the final numbers were without

them. So the actual drops were much more.

>

> We get around 80% of our patients off their HTN meds in 14-21 days.

The rice diet has similar stats.

>

> Jeff

>

------------------------

Well, Jeff, I stand corrected in terms of very low sodium diets.

Certainly the rice diet as originally construed did manage to control

very severe hypertension, and I'm sure that very low sodium diets will

lower BP. But I don't think the diets you're talking about are this

type of super-low sodium diet.

Apart from the very low sodium diets (which are not used clinically in

my experience, due to difficulty in adherence), the change in BP due

to modest reductions in sodium (to about 1500 mg/day, is much lower.

You have to factor in the fact that whenever you put people on a

study, their BP goes down. So I was referring to the drop in systolic

BP compared to placebo.

For example, when you do such a study, the systolic BP may go down, by

say an average of 13 mm Hg, with a typical study, but it may well drop

by an average of 8 mm Hg in the placebo control group, so the actual

fall in BP due to the actual change in diet, is much less.

Here is what a structured analysis of a great number of studies in

this area shows:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=15266549 & query_hl=45 & itool=pubmed_DocSum

Cochrane Database Syst Rev. 2004;(3):CD004937.

Effect of longer-term modest salt reduction on blood pressure.

He FJ, MacGregor GA.

You can click on the link to read the whole abstract, but-

{{Now read this part carefully:}}

In individuals with elevated blood pressure the median reduction in

24-h urinary sodium excretion was 78 mmol (4.6 g/day of salt), the

mean reduction in systolic blood pressure was -4.97 mmHg (95%CI:-5.76

to -4.18), and the mean reduction in diastolic blood pressure was

-2.74 mmHg (95% CI:-3.22 to -2.26).

{{So 5 mm Hg systolic and 2.7 mm Hg diastolic - very similar to what I

said.}}

In individuals with normal blood pressure the median reduction in 24-h

urinary sodium excretion was 74 mmol (4.4 g/day of salt), the mean

reduction in systolic blood pressure was -2.03 mmHg (95% CI: -2.56 to

-1.50) mmHg, and the mean reduction in diastolic blood pressure was

-0.99 mmHg (-1.40 to -0.57).

{{So in normotensives, only 2 mm systolic and 1 mm Hg diastolic.}}

----------------------------

This is peripheral to the discussion about vitamin D and blood

pressure. I of course believe we should be following a dietary sodium

intake, ideally, in the 1-2 g/day range, and I agree that as you get

older, or if you are African American (or maybe Hispanic, also), or

have kidney disease, you should be closer to 1 g/day than 2 g/day.

I didn't know what the Pritikin diet recommended, so I looked on their

website. They say you can eat up to 1.5 g/day sodium. This is my own

recommendation as well (well, 1.5-2.0, but leaning towards the lower

end), so again, I think any disagreements between us are less than

they appear, unless you are advocating going lower than what the

Pritikin website recommends. 1.5 mg/day is a modest sodium intake,

and not really a low sodium intake.

This is far above what the original rice diet used. Which rice diet

are you talking about? The original Kempner rice diet had only 15-25

g/day of protein, and ONLY 100-150 mg/day of sodium, one-tenth the

sodium of what the Pritikin, DASH, and other diets recommend. Blood

pressure reductions with this diet were huge, I agree, but no one uses

this.

For a ref, see:

http://www.ajcn.org/cgi/reprint/4/3/254.pdf

I presume you're talking about the Rice Diet program run out of Duke

and championed by ti?

If so, I could find only one article by ti using this diet:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=11152083 & query_hl=50 & itool=pubmed_docsum

Here is what they say about change in blood pressure:

" systolic and diastolic blood pressure decreased by 4.3 mmHg (p <

0.01) and 2.4 mmHg (p < 0.05), respectively. "

I guess my own approach to all of this has been to avoid very radical

diets; I've tried to follow a very low sodium diet, and i've actually

liked it - but I have found it to be too hard to follow in the context

of family and socializing and practicality. Even patients who really

need such a diet - those with congestive heart failure, kidney

disease, etc. almost never follow such diets. Otherwise our

pharmaceutical company stocks would have a lot less value.

But maybe the CR crowd is an intrepid lot. Has anyone surveyed the

range of sodium intakes that people follow? It would be interesting

to find this out.