Do we really need to avoid salt?
At one point, we were told fat was bad for us and should be avoided, and that most of our daily calories should come from carbohydrates. Not only did all the excess sugar lead to rampant obesity, metabolic syndrome, and diabetes, but it also turned out that dietary fat wasn’t as unhealthy as we thought.
The other villain for the past 40 years has been salt. We were (and still are) told that too much salt raises blood pressure and ultimately causes hypertension, which contributes to cardiovascular disease, but does the research support this? Surprisingly, it really doesn’t. Don’t get me wrong, hypertension is bad, but there are other ways to prevent or reduce it than just salt reduction, and salt reduction alone doesn’t make a significant impact for everyone.
A logical hypothesis, but no solid proof
Our bodies can’t pump water in and out of cells to maintain stable cellular pressure, but they can move salt in and out of cells for the same purpose. Water naturally flows through cell membranes to areas of high salt concentration, so when we have lots of salt in our bloodstreams, extra water flows into our veins and capillaries and internal pressure increases. Many wondered if too much salt on a daily basis could eventually lead to hypertension and heart disease. In 1972, the National Institute of Health examined this hypothesis and based on very little evidence concluded that excessive salt consumption over the long-term does cause chronic hypertension. The evidence they used then to support their belief was that groups who ate little salt had virtually no hypertension (although these groups also tended to eat very little sugar which can also cause hypertension), and a rat study that found that when salt-sensitive rats were fed 60 times the amount of salt the average American consumes, they developed hypertension. This spurious association led to the salt recommendations we have been using ever since.
The other big piece of research I see referenced as proof that salt should be avoided is the 2001 DASH Diet study (which stands for Dietary Approaches to Stop Hypertension). While they concluded that reduced sodium intake and increased potassium intake (more on that later) did decrease blood pressure, they never really concluded that it did or could reduce hypertension. All kinds of factors can increase or decrease your blood pressure in the short run, but this study is referenced as proof that reducing salt intake reduces hypertension despite the fact the study never came to that conclusion.
Salt-sensitivity is real
Now before I get too deep into the argument I want to explicitly state that some people are more sensitive to salt than others. This means their kidneys do not remove excess salt as efficiently which can increase vascular pressure. If you have hypertension or have been tested for salt-sensitivity and your doctor is recommending salt restrictions, then by all means listen to the person that knows your personal situation best. I am not trying to tell people to ignore their doctors. What I’m trying to do is reduce the number of things you have to freak out about on a daily basis. It seems like we’re told every day about some new thing that’s going to kill us or make us unhealthy. Since it’s impossible to be perfect about every little thing, we either ignore some advice and feel guilty for ignoring it, or limit our healthy choices because we find the recommendations too unpleasant. I find attempting to avoid salt leads to people avoiding healthy choices in favor of highly processed foods (which actually contain far more salt, but don’t taste salty so people assume it’s fine). For instance, I always tell people to eat almonds and a lot of people will respond they don’t like raw, unsalted almonds. I don’t either, which is why I don’t eat them, but I do frequently enjoy roasted almonds because the impact to my body from a little extra salt is negligible compared to the impact from grabbing a less healthy snack.
I’ve seen estimates for salt-sensitivity in the population to be as high as 25 percent and as low as 10 percent. It’s not the easiest thing to test for, but if you have hypertension in your family then your likelihood of being salt-sensitive is increased. The difficulty in testing is one of the reasons for the blanket recommendations of reduced salt for everyone, even though it doesn’t matter much for the majority of the population. Once again, while it has been shown that salt reductions can reduce blood pressure in the short-term, there isn’t much evidence to show that it actually reduces the risk of dying from cardiovascular disease in the long term.
The right amount of salt may not be a low as we’ve been told
The sodium in salt is essential for our nervous system and muscles to function properly. As I mentioned above, it is also used by your body to maintain proper cellular pressure. These are pretty important functions, so wouldn’t too little salt also cause problems? In fact it does.
One review of multiple studies showed that salt restrictions led to increased LDL cholesterol (the bad kind) and increased triglycerides in the blood. A recent mouse study showed how consuming high levels of salt on a high fat diet actually prevented fat gain in one group, while the group of mice eating high fat, low salt diets gained much more body fat. They theorized that salt reduced the digestive efficiency of fat which led to less storage. Another study showed that low salt diets quickly led to insulin resistance in healthy subjects. This could be caused by elevated cortisol levels since salt helps clear this stress hormone from our systems.
There is more to salt than just blood pressure regulation and trying to remove it from everyone’s diets seems not only unnecessary, but counter-productive. One study in the Journal of the American Medical Association showed that excessive amounts of salt (about three times the daily USDA recommendation) was associated with increased cardiovascular risk, but they also found that low levels of salt (that were still above that same USDA recommendation) was associated with an increased risk of cardiovascular death and hospitalization for congestive heart failure. The USDA recommends between 1500 mg and 2300 mg of sodium a day. The JAMA study found that below 3000 mg and above 7000 mg was associated with increased risk. The average American consumes about 3400 mg per day. This is still a high amount, but it may not actually be a dangerously high amount.
At the very least, with the amount of salt in processed food, no one is at risk for consuming too little sodium, but I don’t see anything to suggest that salt restriction is a magic cure. Avoiding processed foods in general will help immensely, but mainly because it will cut down on the amount of simple sugars we consume each day. My biggest problem with these hard-number USDA recommendations is that they require people to read all the labels on every ingredient they eat and mathematically tally up their totals of micro and macro nutrients. This is not only time consuming (which ultimately leads to people abandoning this practice and going back to their old habits), but it misses the point that healthy eating is pretty easy when you follow these simple rules:
- Eat lots of whole fruits and vegetables
- Eat reasonable portions of lean meat
- Focus on healthy fats (liquid at room temperature verses solid)
- Focus on whole grain carbohydrates
- And ultimately, try to eat a minimal amount of processed food (anything with a label on it)
When you focus on restriction, you focus on denying yourself the pleasures of food. Like I said above, I enjoy roasted almonds and there is plenty of evidence to suggest they’re good for me. However, if I became too focused on avoiding salt, I would likely avoid them altogether. I’ve seen this with my clients concerning vegetables as well. Since they find vegetables to be kind of bland, they just avoid them entirely instead of throwing a little salt and spice on them to improve the flavor. Avoiding vegetables entirely is far more harmful than any salt you sprinkle on top. Trying to avoid salt can also inadvertently cause you to avoid the other important half of the equation: potassium.
Don’t just get less sodium, get more potassium
Potassium basically works as the antithesis of sodium, and it actually helps down regulate blood pressure. It’s much like omega-3 and omega-6 essential fatty acids. You probably hear a ton about the importance of omega-3 fatty acids in your diet, but you rarely hear about omega-6 even though it’s just as vital. Much like sodium, we already get a ton of omega-6 in everything we eat so we need to add omega-3 to restore the proper balance our bodies need. That is something the DASH diet gets right. It not only focuses on reducing sodium, but increasing potassium. Unfortunately, some favored foods that contain potassium (like dairy) also contain sodium. You can get lots of potassium and minimal sodium in fruits and vegetables like bananas, avocados, spinach, but other high-potassium foods like potatoes get avoided because they’re not quite as good without a little salt on top. Another study published in JAMA Pediatrics monitored the eating habits and blood pressure of 2185 girls for ten years (starting at the age of 9 or 10) and determined that high potassium had more beneficial effects on blood pressure than sodium restriction. Most people already don’t get enough potassium each day, so focusing on salt restriction might accidentally reduce your potassium intake as well. You’re better off trying to add healthy foods that provide potassium than you are by avoiding adding some salt to your favorite dishes.
So why is high blood pressure bad?
Chronic high blood pressure forces your heart to consistently work harder. This increased workload can lead to a dangerous condition known as cardiomegaly, or enlarged heart. There are different kinds of enlarged hearts, but high blood pressure typically causes the left ventricle to thicken which can increase the risks of a stroke or heart failure. The enlarged heart is actually the danger rather than the high blood pressure itself, but doctors try to focus on getting blood pressure down to prevent the chain reaction that ultimately leads to heart failure. Interestingly, a new study has found that even in the presence of chronic high blood pressure, it’s the presence of fructose that allows the heart to grow uncontrollably into a diseased state. Previous studies have demonstrated that high-fructose diets increase mortality risks with hypertension, but this latest study has determined the mechanism.
Chronic high blood pressure does encourage the heart muscles to grow, but without proper fuel, growth is stifled. To get the fuel your stressed heart muscles need, the body turns on enzymes to quickly process sugar through glycolysis. These molecules favor fructose and can process it easily, allowing for rapid growth. The researchers not only found this enzyme in samples taken from human heart patients, but they also found that if they suppressed this molecule in hypertensive rats, it prevented cardiomegaly. As I mentioned above, the excessive amounts of high-fructose corn syrup in our diets not only contributes to high blood pressure, but it also makes it more likely to cause cardiovascular disease. This gets back to my simple advice of avoid anything with a label on it as much as possible.
Minor note: sea salt or iodized salt
I have heard from some people that they are worried that standard iodized table salt contains all kinds of strange chemicals and additives and that natural sea salt is healthier. If you’re eating enough salt for these compounds to ever become a problem then you’re likely far too high on the salt consumption scale anyway. I haven’t seen any evidence that sea salt is better for you than table salt, but I have found plenty of evidence that the iodine added to table salt is very good for you. If you’re interested, it’s worth a read to see how adding iodine to salt raised the IQ in our nation by 3.5 points. Ultimately, go with what you prefer. Like I said, the point of this article is to give you one less thing to worry about and from what I’ve seen, the difference between the two types of salt is negligible.
So should you avoid salt or not?
As I stated earlier, if you are being treated by a physician that recommends salt restriction, then you should definitely stick with the game plan. If you have a history of hypertension in your family, then you should probably be on the lower end of the scale when it comes to salt consumption, but you should also (along with everyone else) focus on higher consumption of potassium rich foods (here are some examples), reduce the amount of processed foods you eat, and consider a lower carbohydrate diet.
High fructose corn syrup not only contributes to hypertension, but it can also increase the likelihood of it leading to cardiovascular disease. The less of it you have in your diet, the less the salt you eat will impact your body. Insulin decreases the amount of sodium excreted by the kidneys, so a low carb diet will improve your kidneys’ ability to flush excess salt from your system. A low carb diet will be especially helpful for salt-sensitive people.
And of course, exercise has been shown to significantly reduce hypertension (not just short-term blood pressure), so always be sure to include fitness in your weekly routine.
Don’t feel bad if you put a little salt on top of your favorite foods. It’s mainly the salt in processed foods that puts people over the top. Once again, if you follow these simple rules of eating healthy, you don’t need to worry about counting up all the calories and nutrients on every label, you can just relax and enjoy your meals. Remember:
- Eat lots of whole fruits and vegetables
- Eat reasonable portions of lean meat
- Focus on healthy fats (liquid at room temperature verses solid)
- Focus on whole grain carbohydrates
- And ultimately, try to eat a minimal amount of processed food (anything with a label on it)
