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How Much Sodium Should You Consume Per Day?
Begin by asking yourself the question:
“Do I have high blood pressure (hypertension)?”
Normal blood pressure is 120/80 (mmHg, systolic/diastolic). Your blood pressure is considered high when it is above 140/90. If you do not have hypertension, consume 3g to 6g of sodium per day. If you do have hypertension, consider reducing your sodium intake to the lower end of that range around 3 g per day and consult with a medical professional. (Sodium reduction is often recommended for those with hypertension because it produces a small decrease in blood pressure, but as we will see it is possible to reduce sodium too much). One (1) teaspoon of salt contains 2.3 grams of sodium.
“If you do not have hypertension, consume 3 to 6 grams of sodium per day.”
Please note: Processed, packaged foods are often high in refined salt. Do not consume these foods, and do not get your sodium from these sources. Seek out sodium from foods that contain it naturally and use an unrefined salt like pink Himalayan sea salt. Do not consume refined table salt as your main source of sodium. Refined table salt is processed in such a way that removes most of the trace minerals, whereas an unrefined sea salt contains dozens of these trace minerals.
Refined table salt is fortified with iodine. You do not need fortified salt to obtain iodine; iodine can be obtained by eating a healthy diet that includes plenty of organic fruits and vegetables, wild-caught seafood and seaweed (nori – the green “paper” they wrap sushi rolls with), and dairy products such as cheese from grass-fed cows.
What the Research Says
In a study from 2016 that included 133,118 individuals (about half of them having hypertension), from 49 countries with a medium age of 55 years, researchers looked at sodium excretion levels (an indicator of sodium consumption) and compared that to risk of death and cardiovascular disease. They found the following conclusions:
1) In individuals with hypertension, sodium excretions of greater than 7 grams per day OR lower than 3 grams per day were both associated with increased risk.
2) In individuals without hypertension, sodium excretion of greater than 7 grams per day was not associated with increased risk, whereas sodium excretion of less than 3 grams per day was associated with a significantly increased risk.
3) Compared to moderate sodium intake, high intake is associated with cardiovascular events and death in hypertensive populations, but not in non-hypertensive populations.
4) Low sodium intake is associated with an increased risk of cardiovascular events and death in those with OR without hypertension.
In another study from 2014 that included 101,945 people in 17 countries, researchers concluded that:
1) An estimated sodium intake between 3 grams per day and 6 grams per day was associated with a lower risk of death and cardiovascular events than was either a higher or lower estimated level of intake. Sodium intake above 7 grams per day was associated with an increased risk with the strongest association in those with hypertension.
In a 1996 meta-analysis, a total of 56 trials were considered by researchers and after analyzing the data, they concluded: “Dietary sodium restriction for older hypertensive individuals might be considered, but the evidence in the normotensive population does not support current recommendations for universal dietary sodium restriction.”
What Do the Current Guidelines Say?
It is interested to note that the American Heart Association (AHA) recommends consuming “no more than 2.3 grams of sodium per day (about 1 teaspoon of salt) and moving towards an ideal limit of no more than 1.5 grams per day for most adults.” The DASH Diet, which is promoted by the US Department of Agriculture (the publisher of the food pyramid) and the National Institutes of Health, recommends similar guidelines for sodium consumption levels. These guidelines are in conflict with the research and following them by consuming less than 3 grams of sodium per day is associated with an increased risk of death and cardiovascular events in all populations. A reduction in sodium consumption can be beneficial in populations who are already consuming large amounts of sodium and have hypertension, but do not take that advice to the extreme and consume an ultra-low sodium diet. Moderation is important here. Do not follow the ultra-low sodium recommendations of the American Heart Association or the sodium-related guidelines of the DASH diet as a general practice. Have a valid, medically-justified reason before considering dropping below 3 grams per day.
The takeaway here is relatively simple. Just follow these rules:
1) Do not consume more than 7 grams of sodium per day.
2) Do not consume less than 3 grams of sodium per day.
3) If you have hypertension, consider staying at the lower end of that range and consult with you doctor.
4) Do not follow ultra-low sodium recommendations.
5) If you are active, especially in hot weather, you probably require higher levels of sodium (and other electrolyte) intake. Consult with a sports nutritionist or other medical professional to determine your required sodium intake based on activity levels if you are concerned.
EDIT: Some specifics on the study that led to the low-sodium DASH diet recommendation:
-Used 412 participants
-Conducted in the late nineties
-Used short studies: two week introductory period and 30 day intervention phase where the diets were controlled by researchers.
-Participants had hypertension or prehypertension. 60% were African-American and 59% were women.
-Compared DASH diet to a control diet. The researchers tried to make the control diet mimic a typical American diet and was designed to be low in key nutrients like potassium, magnesium and calcium.
-Sodium was varied in each group at the following levels: 3g, 2.4g and 1.5g.
-The outcomes they measured were diastolic and systolic blood pressure.
-The DASH diet led to better reductions in blood pressure than the control diet.
-The ultra-low sodium diet (1.5g) led to an average reduction in blood pressure of 8.9/4.5 mm Hg (systolic/diastolic) relative to 3g/day. Furthermore, since 60% of the study participants were African American and African Americans on average are more hypersensitive to salt relative to white populations, these blood pressure reductions are likely to be skewed higher than what would be observed in the average US population (e.g. 13% black and 73% white).
-This led researchers to propose these low sodium recommendations along with the DASH diet.
-The problem with these recommendations is that they were solely based on blood pressure reductions, not actual outcomes like cardiovascular events or increased risk of death.
-Had the researchers taken into account the studies mentioned above, which includes hundreds of thousands of people and looked at more meaningful outcomes, they would have come to a different conclusion.
-The conclusion the reader should come to is that ultra-low sodium diets will only slightly reduce blood pressure and will increase the risk of cardiovascular events and death (compared to the 3 gram per day safe minimum).
-Link to DASH-Sodium Study: Link