Why The Paleo Diet Supports a Low Sodium Diet
Salt, and its addition to many of the foods we eat, has steadily become one of the more controversial topics in the nutrition world. How much is too much? How much, if any, do we need? Is salt Paleo?
In an effort to reduce the average American’s high salt intake, the FDA recently asked food companies to voluntarily reduce the sodium content of their products.
Since a large portion of added sodium in the average American diet comes from processed food, the idea is that this shift will help bring the average American diet down to the recommended daily allowance (RDA) of 2,300mg of salt per day. [1] The typical American consumes much more than this at about 3,400mg of sodium per day.
We applaud the FDA for trying to help Americans cut back on sodium, as a low-salt diet is a key part of The Paleo Diet®.
We also recognize that this is a tough challenge. Humans crave salt and will favor foods that are high in sodium. Let’s dive into why that is.
Why Do We Crave Salt and Sugar?
There are two foods that humans crave above all else—sugar and salt. The food science industry understands this well and works hard to develop foods that tickle every nerve when it comes to these cravings. This is why you’ll see sugar and salt as primary ingredients on most processed food products.
While there has been some debate about sodium, everyone agrees about the dangers of sugar—particularly processed sugar. It is one of the main drivers of our current epidemic of obesity, metabolic disease, and diabetes [2–4].
It is a less accepted notion that salt carries such dramatic health risks—particularly within the broader Paleo space. However, research finds that salt contributes to chronic diseases, including cardiovascular disease, autoimmune disease, and certain cancers. [5–16]
So, why do we crave salt and sugar? There’s an evolutionary explanation for it. The truth is that we do need at least small amounts of salt and some simple sugars to survive. Our bodies need sodium for almost all physiological functions, and despite some ketogenic diet misconceptions, our brains need glucose to function.
In Paleolithic times, both salt and simple sugars were rare. So, our bodies developed to make sure that when we encountered them, we ate them. That was the magic formula—necessary but rare—for the evolution of strong cravings. Overconsumption was never an issue, so even though our ancestors craved it, they necessarily kept their intake low. That is, until modern times.
Why Do Some Say a High-Sodium Diet Is Healthy?
Most influencers in Paleolithic eating were quick to recognize the dangers of consuming too much sugar. In fact, some have shifted to a ketogenic lifestyle, which virtually eliminates simple sugar from the diet. Yet, when it comes to salt, many of these same influencers have taken a very different direction.
In fact, there has been a trend towards promoting a diet even higher in salt! [17] This trend grew out of some highly publicized research, specifically two studies published in 2014. These studies showed that while people on a very high-sodium diet had much higher rates of heart disease, likewise, so did people on a very low sodium diet. [18–20]
It created a U- or J-shaped relationship, with the healthiest people at the bottom of the “J” curve eating around 3,000 to 6,000mg of sodium per day—which, even on the low end, is well above the recommendation of 2,300mg of sodium per day. This has led some to believe that eating even twice the RDA of sodium would improve their health.
The problem is that these studies had two fundamental flaws that caused them to mis-represent the data.
Some High-Salt Diet Research Is Flawed
Before you walk away thinking that 3,000-6,000mg of salt per day is the way to go, let’s take a closer look at the flaws in these studies.
First, these studies did not use the “gold standard” 24-hour urinary sodium measurement, the importance of which Dr. Cordain explains in detail in this article.
Second, and more critical to understand, is that the researchers did not control for people who already had heart disease at the start of the study. That’s important because when someone is diagnosed with heart disease, one of the first things doctors generally recommend is a reduction in sodium intake. So, it wasn’t that a very low sodium diet was causing high rates of heart disease. It was heart disease that was causing a very low sodium diet!
A research team identified this second flaw, and in 2016 they analyzed data from a larger study tracking 3,126 subjects over 20 years. This time, the researchers controlled for subjects who had been diagnosed with heart disease prior to the study. When they did that, the J-shaped relationship disappeared and it became a straight line—the lower the sodium in the subjects’ diets, the lower the risk of heart disease. In fact, the risk of all causes of death were lower.
On Sodium, The Paleo Diet Agrees with the Food & Drug Administration
We recently received an email from a reader criticizing our position because we were in alignment with the RDAs of several micronutrients. There was an implication that if we agreed with the FDA or USDA on anything, we’d lose credibility.
Our position is always the same—we follow the science. When our assessment of the science matches the messaging of the FDA, we’re all the happier. We see no reason to disagree with the FDA or the USDA for its own sake. In this case, we fully support the FDA’s push to encourage processed food companies to reduce their high sodium levels.
We have always promoted a low-sodium diet here at The Paleo Diet and in this case, we believe the current RDA of 2,300mg per day is at the high end of what we should consume.
Five Reasons The Paleo Diet Is a Low Sodium Diet
We have written extensively about sodium and its health implications over the past few years. Since there is so much information to comb through, here are five of our key takeaways to help you understand why we stand behind a low-sodium diet.
1. It’s nearly impossible to eat too much sodium on The Paleo Diet.
The good news is that if you’re eating a true Paleo Diet and staying away from added salt, you simply won’t hit the upper levels of sodium. Dr. Cordain wrote extensively about this in a response to a reader who defended the idea that 3,000 to 7,000mg of sodium per day is healthy. Even if you’re eating 2,500 calories per day of only Paleo foods, it is virtually impossible to eat more than the RDA of sodium.
If we look to the typical hunter-gatherer society, we can see that they ate very little sodium—less than 1,200mg per day. [13] A typical modern Paleo Diet with no added salt usually falls in the 1,600-2,200mg range and even lower if you eat more fruits than vegetables.
2. Too much sodium increases inflammation, which can lead to many chronic diseases.
The science behind how excess salt contributes to inflammation is very complex, and covered in more detail in two articles by Marc Bubbs and Dr. Loren Cordain. As a quick explanation, salt collects in our cells, which causes an increase in two highly inflammatory immune cells called CD14+ macrophages and Th17 cells. [10,15] Imbalances in these two cell types have been connected with almost all autoimmune diseases, heart disease, and some cancers. [15,21–27]
3. Excess sodium contributes to cardiovascular disease.
As I mentioned earlier, there is a straight-line relationship between sodium consumption and heart disease. In other words, the more you consume, the higher your risk. [20] This is due in part to the inflammation mentioned above. Plus, as Dr. Cordain detailed in a recent article, too much sodium can contribute to key steps in the formation of the atherosclerotic plaque in our arteries that in turn lead to heart attack and stroke. [28–34]
4. Too much sodium can contribute to cancer.
An increased risk of cancer is another consequence of the accumulation of excess sodium within our cells. It does so by damaging our DNA, increasing oxidative stress, and fundamentally impairing metabolism within the cells—an effect called the Warburg metabolism. [35-42] Increasing the ratio of potassium to sodium in our diets can prevent many of the negative effects. That brings us to our fifth and most important point.
5. Increasing potassium while reducing sodium can reverse many of these negative health effects.
Sodium and potassium have a synergistic relationship. The ideal ratio in our bodies is between 5 to 1 and 10 to 1 potassium to sodium. But the typical Western diet flips the ratio and can have twice the sodium as potassium or worse. [43] As Dr. Mark J. Smith explained in this article, all of our cells use potassium to pump sodium out of cells, which helps reverse many of the inflammatory effects detailed above. When the sodium-to-potassium ratio in our diet resets to its natural level, research shows that it has a protective effect against cancer, reduces blood pressure, and even prevent bone loss [19,44–51]. Our best sources of potassium are vegetables and fruit, and it is nearly impossible to eat enough of these healthy foods on a high sodium diet to reach a healthy ratio of 5-to-1 or better.
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Trevor Connor, M.S.
Dr. Loren Cordain’s final graduate student, Trevor Connor, M.S., brings more than a decade of nutrition and physiology expertise to spearhead the new Paleo Diet team.
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