Low Sodium Diet Increases CVD / Death Regardless Of Person's Blood Pressure

Another big point in favor of salt and this time the scientists actually provide salient explanation for why the low salt diet was detrimental - i.e. it increases renin, aldosterone and adrenaline. Pretty much what Peat wrote...about 30 years before this study.
It also matches well another study that I posted almost some time ago that showed serotonin starts to increase when sodium intake drops below 5g a day. This matches well the 4g daily sodium listed in the study below as a cutoff for activation of the renin and catecholamine system. The 4g - 5g elemental sodium a day corresponds to about 12g salt, which is about 1 tablespoon and again matches Ray's recommendations.


http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)30467-6/fulltext?rss=yes
https://www.sciencedaily.com/releases/2016/05/160521071410.htm

"...The researchers showed that regardless of whether people have high blood pressure, low-sodium intake is associated with more heart attacks, strokes, and deaths compared to average intake. "These are extremely important findings for those who are suffering from high blood pressure," said Andrew Mente, lead author of the study, a principal investigator of PHRI and an associate professor of clinical epidemiology and biostatistics at McMaster's Michael G. DeGroote School of Medicine."

"...Current intake of sodium in Canada is typically between 3.5 and 4 grams per day and some guidelines have recommended that the entire population lower sodium intake to below 2.3 grams per day, a level that fewer than five per cent of Canadians and people around the world consume. Previous studies have shown that low-sodium, compared to average sodium intake, is related to increased cardiovascular risk and mortality, even though low sodium intake is associated with lower blood pressure. This new study shows that the risks associated with low-sodium intake -- less than three grams per day -- are consistent regardless of a patient's hypertension status."

"...Low sodium intake reduces blood pressure modestly, compared to average intake, but low sodium intake also has other effects, including adverse elevations of certain hormones which may outweigh any benefits. The key question is not whether blood pressure is lower with very low salt intake, instead it is whether it improves health," Mente said."

From the actual study above:
"...This suggests that the eff ect of a given level of sodium intake on clinical outcomes is only partly mediated through its eff ects on blood pressure and that other mechanisms might also be at play. This is supported by observations of activation of the renin system and of catecholamines with low sodium intake. High renin concentrations have been reported in studies of the Yanomamo Indians who reportedly consume very little sodium. Several studies have shown that increases of renin, aldosterone, and catecholamines are all associated with increased cardiovascular disease events and mortality. Therefore, predicting the net clinical effect based on only considering the eff ects of sodium on blood pressure might not provide a comprehensive understanding of its effects on cardiovascular disease and mortality, especially within the range of sodium intake that affects the renin system (<4 g/day)."

 

Wouldn't the sodium intake of our ancestors have been lower than 5 grams a day ?
Our species survived a long time taking in less than 5 grams a day.

I guess if your not hypothyroid and the environment is low stress, your body can go with a lot less dietary sodium since it will hold onto it better.

 

That's a valid point. The proper sodium intake depends on many variables, so I don't know if a study has been done to see if ingesting less than 4g sodium daily also activates the renin system in non-stressed people. Things like sweating, infections and even the production of gastric acid depend on salt, so those would be factors to consider regardless of stress.

 

I think one can increase sodium intake without taking salt ? i.e baking soda (sodium bicarbonate).

So you increase sodium + co2 at once.

 

You did not mention a second important finding of the study: In patients with hypertension a salt intake of around 6.5g sodium per day and higher is also associated with a consistent increase in CVD death and events. So while salt restriction is problematic on the one hand, liberate salt intake in patients with hypertension is also of concern on the other. People with hypertension should be aware of this.

 

True, the study said that in people who already have BP above 140/90 eating more than6.5g sodium daily increases risk. So, loading up on salt if you have high BP is risky as is also lowering sodium intake below 4g. So, for people with established BP above 140/90 optimal salt intake seems to be between 12g and 18g daily, which is still quite a bit of salt.

 

Going back to the early 1800s, people were generally consuming twice as much salt as today.
I also found it interesting that the group with the lowest sodium consumption was know for being aggressive and violent, along with have a short life expectancy.

Salt and our Health - Weston A Price

"The lowest consumption population in this group was the primitive Yanomami Indians, who live in the Brazilian rain forest. "

"The Yanomami are described in the ethnographic literature as an aggressive and violence-prone people. The stress associated with this character along with the continual exposure to environmental stresses does not appear to influence the BP of the Yanomami as they would other population groups. While their abnormal BP profile has been attributed to reduced salt consumption, a far more likely reason appears to be the almost complete absence of a D/D genotype—a genetic trait shared with other Amerindians such as the Xingu Indians of the Amazonian rainforest, one of the other four outlier points. Notwithstanding their lack of an age-related rise in blood pressure, the Yanomami are characterized as a small stature, high mortality and high fertility population with a low life expectancy. It is also interesting to note that despite their long history of evolution in a salt-limited rainforest environment, they have never acclimatized to low sodium intake and have chronically high levels of plasma renin. Nevertheless, the inclusion of the Yanomami data in the formal Intersalt analysis, however misguided, initiated the latest round of salt-restriction efforts."

"MYTH 1:

We eat more salt today than ever before.

FACT: Our current salt consumption (1.5 to 1.75 teaspoons per day, 8-9 grams) is about one half of the amount consumed between the War of 1812 and the end of World War II, which was about three to 3.3 teaspoons (16-17 grams) of salt per day."

"It is of great interest that available data suggest Western societies consumed between three and 3.3 teaspoons (15-17 grams) of salt per day from the early 1800s until the end of World War II, based on military archives for prisoner-of-war and soldier rations around the world. During the Anglo-American War of 1812, despite its high cost, salt rations amounted to three teaspoons (15 grams) per day. American prisoners of war, incarcerated in Britain’s Dartmoor prison, bitterly complained that the 1.5 teaspoons (8 grams) of salt per day they received was part of “…scanty and meager diet for men brought up in the land of liberty, and ever used to feast on the luscious fruits of plenty…” Declassified World War II documents regarding rations fed to American prisoners of war show a ration of one hundred forty grams per week or 3.3 teaspoons (17 grams) per day."

 

That's so interesting! And I've heard people say things like "the Yanomami don't eat salt and they are doing great!". Yeah, low life-expectancy and agressiveness don't really indicate that they are doing fine. They are probably dumping a lot of calcium in the urine as well to hold onto sodium, which explains their short stature.