The overriding theme of this blog is to provide you, my dear readers, with applicable and cool information about health, fitness, and nutrition. I usually refrain from splitting hairs and will continue to do so. However, this take on salt may be a bit more detailed than what many are comfortable with. However, I feel that salt is a huge health issue that affects all of our lives. If not the health aspect of it, it’s the ability to liberate yourself from a lack of knowledge. Armed with the information here, you can decide for yourself whether you should agonize about including salt in your diet or not.
Asides from L O V E, it’s another four letter word that evokes all sorts of emotions, especially to those in the nutrition field. Not a day passes by that I don’t get sucked into a conversation about salt.
“Oh, you put salt on your food? That’s bad for your health!”
“But won’t salt raise your blood pressure?”
“Salt hurts your kidneys!”
Along with fat, salt is one of those things that seems to get looked at through the scope of dichotomy. It can’t escape being thrown into one camp or the other. And like fat, salt is one of those things that hit close to home for me, since I also have a family history of high blood pressure, stroke, and heart disease.
My heritage is South Korean. Though I was not born in South Korea, Korean parents gave birth to me, and from a young age I ate somewhat traditional Korean foods. I say somewhat because it was typically poor-class Korean fare reserved mainly for people who have no money but just need to put something in their mouth. As long as I can remember, I usually ate a porridge made of white rice, raw eggs, and soy sauce three times a day.
Now that I am older, I can cook and buy my own food. Korean cuisine is still an intricate part of my life, but I have some variety now, although I am still poor. So how does Korean food relate to what I want to talk about today? My topic today is salt, and if there is one thing food-related that Koreans love, it’s salt. Kimchi, soup, noodle dishes, side dishes, meat dishes… you name it and most likely the dish will have a truckload of salt. It’s not uncommon to see a serving of a certain dish to have over 1g of salt. Even I think it’s crazy how much Koreans love salt.
But it’s also not a surprise that Koreans suffer very high rates of high blood pressure (HBP). According to the Korea Centers for Disease Control and Prevention, one in four South Koreans over the age of 30 have high blood pressure. At the moment, it is THE CHAMP for causes of death in South Korea—diabetes trailing behind it. To this day, there are a handful of culprits responsible for giving Koreans HBP, but one thing that authorities, especially health figures, agree on is that high salt consumption is killing Koreans.
Or is it?
Being a maverick, I want to explore the theory that high salt consumption is like digging ourselves an early grave. Salt is like many of the other contentious issues in health and nutrition—there are two sides to the coin. I like to look at both sides to the argument. In this case, I want to get you to know the pros and cons salt consumption, and in specific, what kind of risks high salt consumption carries, as well as the risks of low salt consumption. In this post, I want to go over the perceived benefits of sodium restriction.
Being a South Korean and having a family history of HBP, I have always wanted to talk about salt. It’s another one of those hotly debated topics that no one seems to agree on, yet everyone feels that they have the answers. I, of course, do not have the answers, but I hope to shed some light with this post. And of course, salt is one of those things that are, surprise surprise, context-dependent.
Again, this pesky word, context-dependent. Why can’t we just figure out what nutrients cause what? Because you’re not a cell in a petri dish, I am assuming you are a human being that eats more than just salt. As such, salt will never act in isolation and will influence your health depending on your current health, lifestyle, physical activity levels, genetics, and to a certain degree, gender.
The cure for the world is in this dish. Source
“In the past year, how many times per week did you eat hot dogs, or sausage, or deli meats?”
If you don’t remember, welcome to the club. This type of question is typical when researchers are trying to figure out dietary habits of people in their studies. Do you think it’s accurate to just ask you what you ate for the past year, extrapolate your current nutritional status based on what you thought you ate 3 weeks ago, see that your blood pressure is a bit elevated, and blame it on salt? Well, that’s exactly how many of the current guidelines on salt came to be. On the other hand, better research is coming out using trials and more accurate statistical models. Before we get into the studies and what they show on salt intake, let’s take a cursory tour of salt, your new best friend.
Food Frequency Questionnaire. One tool, but not the end-all-be-all. Source
What is salt?
Chemically, it’s a combo of two elements, Na (sodium) and Cl (chloride), but it’s usually just referred to by authorities as salt, dietary salt, sodium or dietary sodium. And when researchers conduct studies on salt’s health effects, they measure how much sodium you piss out, or urinary sodium excretion. Chlorine also does some stuff in the body; for the most part, however, it’s just attached to the hip of sodium and goes along for the ride.
When you hear the term ‘electrolyte’, you are hearing what we call a group of minerals that carry an electrical charge and are responsible for fluid balance, muscle function, blood pH, and other metabolic processes. Sodium and chloride, along with calcium, potassium, magnesium, and phosphorus, are the more common electrolytes.
Sodium is a necessary component of our physiology and thus, our diet. We need to eat sodium for survival. That’s why we have created intricate sodium regulation processes, such as the Renin-Angiotension Aldosterone System (RAAS), which inhibits urine production during times of salt scarcity. It’s also responsible for maintaining arterial pressure, tissue perfusion, fluid balance inside and outside of cells, and is involved with proper nerve and muscle function (Atlas). In fact, proper functioning of the RAAS is important for heart muscles and just generally keeping you alive.
Additionally, the taste for salt does not get distorted as much as sugar. What I mean by this is that the mechanism for detecting salt in our foods is very precise and accurate. If a food is too salty, most people will notice and may even be turned off by it. This could possibly be an evolutionary mechanism that pressured humans to seek out salt, which is necessary for survival. In contrast, foods that are high in sugar were meant as a reward or treat, thus suggesting they were not necessary to hunt down deer.
Health effects of too much salt
Many, MANY, studies have looked into the health effects of salt. In particular, these studies wanted to study the effects of salt consumption on blood pressure and health since an elevated blood pressure places greater stress on the walls of the blood vessel, damaging them over time. In turn, this places people at a greater risk of heart disease, stroke, and organ failure. Some of the most influential studies were done using observational and epidemiological studies, following hundreds of thousands of people over years and measuring their dietary salt intake through questionnaires, self-reported intake, and observation, although there were quite a few randomized controlled trials, as well.
The latest to have come out was a study that measured the average global consumption of salt and how that translates into cardiovascular deaths. In it, researchers concluded,
“[The] 1.65 million deaths from cardiovascular causes that occurred in 2010 were attributed to sodium consumption above a reference level of 2.0 g per day… These deaths accounted for nearly 1 of every 10 deaths from cardiovascular causes (9.5%)”. (Mozaffarian)
Quite staggering numbers. For reference, 2.0g is actually lower than the 2.3g that we are often told are our daily sodium targets. For people who are over 51 or have hypertension or are diagnosed with kidney, liver, and heart failure, that number drops down to 1.5g.
More than ten years ago, U.S. health authorities devised a plan called DASH (Dietary Approaches to Stop Hypertension) to tackle the ongoing problems of heart disease. Its main premise is to control blood pressure through mainly sodium manipulation. Studies have been done on this diet and they showed promising results. There’s even a DASH-diet book. A meta-analysis done in 2013 pooled together high-quality study designs implementing the DASH program and found this:
“Results showed that a DASH-like diet can significantly protect against CVDs, CHD, stroke, and HF risk by 20%, 21%, 19% and 29%, respectively. Furthermore, there is a significant reverse linear association between DASH diet consumption and CVDs, CHD, stroke, and HF risk”. (Salehi-Abarqouei)
How much difference does all of this make?
Based on these studies, health authorities began to go knife-happy (some encouraging nudges from some pharmaceutical companies may have played a role here) and recommended people slash their sodium consumption. Food corporations began to stick labels on their foods stating “low-sodium”, “no sodium”, “no salt added”, etc. The nutritional bandwagon just got much heavier.
But when looking at these studies, we can’t just take “decreased blood pressure” for an answer… unless of course that’s all you’re looking for. The problem with just walking away with an answer like that is that you’re left asking a looming question:
“Will it be worth it?”
This is absolutely a no-brainer if you’re in critical condition or suffering from an end-stage condition where death is staring you right in the face, such as cirrhosis, end-stage kidney failure, stage five cancers, etc. But at this point, not much will help you in the way of nutrition therapy; dietitians and the rest of the medical team are simply trying to make the passage to the other side of the river as painless as possible.
What if you’re healthy or have room to improve? Do you really need to cut sodium to 2.3g per day? As a frame of reference, ¼ teaspoon of salt is usually about 400mg of sodium, so 1 teaspoon would be about 1600mg of sodium. Per day, you’re looking at 2 tsp of salt.
By following the DASH diet and reducing your sodium intake to 2.3g, you will reduce your systolic blood pressure by 1.3 mmHg if you don’t have clinically diagnosed hypertension. By further reducing sodium to 1.5g per day, you will reduce your systolic blood pressure by an average of 7.1 mmHg (Sacks). Other studies using a low-sodium diet showed average systolic reductions of 1 to 4 mmHg (Taylor).
If you think 1.5g of sodium is an awfully low number, that’s because it is. For some people, the super reduction of sodium only leading to a 7.1 mmHg drop in their blood pressure may not be worth it. Indeed, it may not be if you’re healthy. However, for some people, that level of reduction may be necessary and can actually knock them out of stage 1 or 2 hypertension. Of course, it’s not as if you don’t have to cut salt, but for the sake of discussion, what if you want to?
Just cut sodium?
The ironic thing is that researchers don’t attribute the decrease in blood pressure to sodium alone. In the original DASH studies, the subjects were put into either a control diet (restricted sodium but eating standard American fare) or the DASH diet. Of course, the DASH diet lowered BP a bit more than the control diet, but the DASH-diet also had higher levels of fruits, vegetables, and dairy; not to mention the DASH groups had nutrition education, which is crucial in patient self-efficacy. Also, the DASH-diet recommends limiting alcohol.
By increasing F, V, and dairy, you’re increasing levels of vitamins and minerals. The main minerals that researchers are bringing into the equation of BP reduction are calcium, magnesium, phosphorus, and most importantly, potassium. Potassium acts in opposition of sodium because they carry opposite charges and are found on opposite sides of the cell membrane. Whereas moderate sodium consumption inactivates the RAAS, potassium activates it. However, potassium-induced activation leads to a relaxation of the blood vessels which lead to more elastic blood vessel walls, reducing the force of blood flow (Haddy; Aaron). By having a good balance between the two, you maintain a desirable electrolyte balance. In the DASH-diet guidelines, we’re told to consume 4.7g of potassium per day.
There is one thing that the DASH diet did uncover: sodium can and does fiddle around with blood pressure. As noted above, the control diet ate a reduced-sodium Standard American Diet (SAD), yet still saw BP reductions. So just by reducing how much salt you ate, you can see almost immediate drops in blood pressure. But how beneficial the magnitude of those drops will be really depends on where you currently are with your health.
Before we wrap up this post, let me say a few things that are often overlooked when considering how influential certain nutrients are on your health.
You could do everything right and still be unlucky. In the hospital, awfully bad things can happen to you at the drop of a dime. After a perfect surgery, you may be recovering with the proper nutrition support, but still pass because of an infection that wasn’t seen in the cards. In the same vein, these studies looking at how sodium restriction lowers blood pressure can really only look at one thing. RISK. Lowering blood pressure does not guarantee your safety, but it lowers your risk. Don’t make the mistake that lowering risk means you won’t still escape what Mother Nature has in store for you. If that was a bit morose, I apologize.
Finally, it’s highly unlikely that you are leading a lifestyle exactly similar to the subjects in the studies. If they smoked, drank, or engaged in activities that affected blood pressure (think stress), then they kept smoking, drinking, or engaging in activities that affected blood pressure. Their habits were “adjusted” for by researchers using an algorithm to standardize so their habits do not skew the results of the studies. Let’s remember that research studies shed light on an issue, not stand for a direct translation.
I will close with this quote from an editorial from the Journal of the American Medical Association, which will segue nicely into the next post about the drawbacks of sodium restriction:
“Reducing sodium can lower blood pressure in both normotensive and hypertensive patients. There is no direct evidence that it reduces cardiovascular mortality” (JAMA).
Your feedback is always appreciated.
Live life strong,
Atlas SA. The renin-angiotensin aldosterone system: pathophysiological role and pharmacologic inhibition. J Manag Care Pharm. 2007 Oct;13(8 Suppl B):9-20.
Sacks FM, et al. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. DASH-Sodium Collaborative Research Group. N Engl J Med. 2001 Jan 4;344(1):3-10.
The Letter. JAMA. 2014 Jun 4; 311(21):2229.