The most shocking diet myths slideshow

GrammyWhammy

This was in my mailbox this morning. The source is a popular diet program I'm not sure I'm allowed to write on this site (the initials are WW), but the footnotes below list the names of researchers and studies that support this thinking.

"More than saturated fat, obesity and dietary cholesterol, high blood pressure is the most critical risk factor for heart disease.1 The evidence is clear that the higher the intake of salt and other sodium-containing foods, the higher the blood pressure.

Current health recommendations generally call for a reduction to about half of today’s average intake, which is still several times higher than the amount needed for human health.2

If you already have high blood pressure
In a meta-analysis published in 2002, the authors showed that lowering salt intake in people with hypertension produced significant improvements in both systolic and diastolic blood pressure. In addition, the greater the reduction, the greater the improvement.3

If your blood pressure is normal
While the reduction in blood pressure for those without existing hypertension who cut back on salt is only about half of those seen among those with the disease, the result is still significant.4

Cutting back
Leaving the salt shaker in the cupboard is an obvious strategy but is a relatively small help because more than 75% of the salt that is consumed comes from processed foods. Focusing food choices on more wholesome, less processed food can help. In addition, food manufacturers are increasing being asked to progressively reduce the salt used in their products. There is evidence that preferred levels of salt for taste are reduced following a sustained reduction in intake.5

In addition to eating less salt, blood pressure can be lowered by losing excess weight, increasing the intake of potassium (sources include fruits, vegetables and dairy products) and consuming alcohol in moderation (if at all).6

Exercise also has a positive effect. A 2002 meta-analysis of studies done this area found that aerobic exercise was linked to a significant lowering of mean systolic and diastolic blood pressure. This held true for both those with high blood pressure and normal blood pressure. It also was consistently found for both overweight and normal-weight participants.7"

FOOTNOTES

1 He FJ, MacGregor, GA How far should salt intake be reduced? Hypertension 42: 1093, 2003.

2 Institute of Medicine. Dietary Reference Intakes: Water, Potassium, Sodium Chloride, and Sulfate. 1st ed. Washington, DC: National Academy Press; 2004.

3 He FJ, MacGregor GA. Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials: implications for public health. J Hum Hypertens 16: 761 2002.

4 Mattes RD, Donnelly D. Relative contributions of dietary sodium sources. J Am Coll Nutr 10:383, 1991.

5 Bertino M, Beaucamp GK and Engelman K. Long-term reduction in dietary sodium alters the taste of salt . Am J Clin Nutr 36: 1134, 1982.

6 Appel LJ et al. Dietary approaches to prevent and treat hypertension. Hypertension 47: 296, 2006.

7 Whelton SP et al. Effect of aerobic exercise on blood pressure: a meta-analysis of randomized, controlled trials . Ann Int Med 136: 493, 2002.

chrisdavey

GrammyWhammy: are you saying you had blood pressure issues during your pregnancy? I don't think the article is saying that you should aim to exceed the RDA sodium intake on purpose just that unless you actually have a blood pressure issue it isn't something you need to focus on. It seems a lot of people get really stuck up on it around here.

Another take on it.
http://www.t-nation.com/strength-training-topics/469

Sedentary people require less sodium than those who exercise hard reguarly.

chrisdavey

bimp

LilMissFoodie

I do agree that there is reasonable evidence that suggests lowering sodium intake is beneficial for people with normal blood pressure rather than just those with high blood pressure. I think the difficulty there is always going to be in the debate for this is that it is only certain people that are 'salt sensitive' ie there are some people whose blood pressure will never be effected by their sodium and nobody really has any idea as to why except that some people really do seem to be exempt.

The second thing 'against' the reduced sodium diet is the recommendations that have been set vs the research. Most of the actual clinical studies use ridiculously low sodium counts (less than 1000mg per day) to show that sodium makes a difference, it has been shown to have no difference at all when cut to 2300mg (100mmol) - so why are our recommendations more than twice the amount that is shown to have benefit? It's generally to do with sustainability but it does make you wonder what the point is.

Just for fun - the low sodium research began after someone did a study on a rice only diet and found that it lowered blood pressure! Not something you would get away with these days