Are you getting enough (or too much) salt?
And do you know what is optimal anyway?
This article looks at the latest research and some novel insights about optimal sodium.
While we’re at it, we’ll look at some other essential minerals that you are likely missing out on.
Why is sodium important?
It’s not an understatement to say that sodium is essential for life, and sodium is arguably the most critical essential mineral.
The sodium-potassium pump is at central to how we produce and move energy around our body! The various electrolytes in your body maintain conductivity which works like a big battery. Without the right balance of electrolytes, your body can’t effectively use the energy from the food you eat.
Your adrenal gland up-regulates aldosterone to tell your kidneys to hold onto sodium when your intake is low. While avoidance of salt is often encouraged, avoidance of salt can drive insulin resistance.
How much salt do you need?
Sodium has been vilified over the last fifty years or so. This is likely because it is used in ‘junk food’ to increase our intake and used to preserve meat which also fell out of favour since the 1977 Dietary Guidelines for Americans encouraged the reduction of saturated fat and cholesterol.
Recently though, the guidance around optimal sodium intake has been changing:
- While the previous guidance was to avoid sodium and limit it 1g per day.
- The new target intake of sodium for Australians is two grams per day,
- The 2015 – 2020 Dietary Guidelines for Americans recommends less than 2.3 grams per day.
- The typical intake of sodium per day is 3.4g for Americans.
- Active people encouraged to consume more to replace the salt lost in sweat during exercise.
Salt and satiety
Our recent analysis of half a million days of MyFitnessPal data gives us an intriguing insight into our appetite for sodium (check out the Systematising Satiety article for more detail).
The chart below shows sodium intake versus % goal calories achieved by nearly ten thousand MyFitnessPal users over two months of logging.
- There seems to be a “sweet spot” between about 1.5 and 4 grams per day of sodium that drives increased hunger and increased energy intake.
- At very-low sodium levels (less than 1.5g per 2000 calories) it appears we find foods less palatable, and we eat less of them (or perhaps a very low fat low salt plant-based diet).
- Foods with a higher salt content above about four or 5 g per 2000 calories provide us with enough sodium to satisfy our appetite.
So, it appears prudent to get at least 3 g for women and 4 g of salt per day for men to manage their cravings and reduce their risk of overeating.
If you are craving salt, there is no harm in adding ‘salt to taste’. Your appetite for salt is usually a pretty good guide.
If you are active or working outside in the heat, you might need to pay attention to ensure you get enough.
However, if you consume too much, you will find your thirst increases, and you’ll end up peering it out.
A very high salt intake can cause diarrhea as your body makes sure it gets rid of the salt, so there’s no point in overdoing it.
We’re getting less sodium in our food these days
The chart below (data from the USDA Economic Research Service) shows how the sodium levels in our food have declined during the same time that our obesity rates have escalated.
Sodium in our food system has been declining since the 1960s when modern agricultural practices started to ramp up.
Rather than leaving fields to rest, farmers were encouraged to maximise the yield of their crops, growing crops in the same plot of land year after year with no additional sources of nutrients other than fertilisers (check out The Biggest Trends in Nutrition for more detail).
In time, the nutrients in our soil that nurtures the plants we eat (as well as the food that we feed to the animals that we eat) become depleted.
Eventually, rather than all the nutrients that would have been abundantly available in a thriving ecosystem, we end up eating energy from fossil fuel-based fertiliser via the products of agriculture.
However, we still have a strong drive to get the sodium we need. When salt is not plentiful animals like the elephants of Kitum Cave in Kenya go to great lengths to get sodium.
We are attracted to salty foods. Some consider fat+sugar+salt to be the signature for hyperpalatable junk food. However, it seems that salt not necessarily bad. We just have a strong appetite for this essential nutrient.
Click here for a list of foods that naturally contain more sodium.
How much salt is too much?
The recent PURE study suggests results suggest that around 4 g of sodium per day aligns with the lowest risk of death from any cause. This aligns nicely with the satiety analysis above.
But sodium isn’t the only mineral that we need to be concerned about.
Magnesium is involved in 300 essential metabolic reactions, is necessary for muscle activity and nerve impulses, regulates temperature and blood pressure, necessary to support detoxification and aids in creating strong bones and teeth.
You probably won’t be surprised to hear that we have also seen a reduction in the magnesium in our food supply.
Today, you will need to consume 4,400 calories of the typical American food supply food to get your recommended intake of magnesium.
Click here for a list of food that naturally contains more magnesium.
Again, the calcium content in our food system has also decreased significantly in recent times. Today you will need to consume more than 5,500 calories to get the recommended daily intake of calcium.
Click here for a list of food that contains more calcium.
Phosphorous (which is found in protein-rich foods such as meats, poultry, fish, nuts, beans and dairy products) has also been on the decline since the mid-40s.
Similar to sodium, we also increase our insulin to enable the kidneys to hold onto potassium and phosphate. When we have adequate alkalising minerals in our system, we won’t need as much insulin to hold onto the alkalising minerals. If you are at all concerned about insulin resistance and diabetes proactively managing your mineral intake may be the smartest thing you can do.
This may be even more important if you are following a low carb or ketogenic diet as ketones require more alkaline buffers. The body up-regulates insulin to recycle alkalising minerals to suppress ketones. You may end up with higher ketones if you have low electrolytes.
We used to believe that sodium drove hypertension (i.e. high blood pressure). However, we now understand that elevated blood pressure has more to do with too little potassium than too much sodium (ref, ref, ref, ref).
Just like the other minerals, we are also seeing a decline in the amount of potassium.
Potassium is the principal cation of intracellular fluid and a critical component of lean body tissues. The movement of potassium out of cells and sodium into cells changes the electrical potential during depolarisation and repolarisation of nerve and muscle cells.
Today, potassium is harder to obtain from our food or even from supplements (note: potassium tablets are limited to 99 mg per tablet, so would need nearly fifty tablets to get your DRI for potassium). You will need to consume 5,200 calories of typical western diet foods to get your recommended intake of potassium.
While many people focus on sodium, Paul Jaminet and others point out that palaeolithic diets were naturally high in potassium and low in sodium.
“Salt was rare and highly valued, so we evolved mechanisms for protecting against the threat of low sodium levels. However, because potassium was plentiful in times gone by, we have not developed similar mechanisms to protect us against low potassium levels, even though they are every bit as devastating to our health.”
Data from the PURE study shown below indicates that we need at least 2 g of potassium per day to mitigate the risk of cardiovascular events. Our risk of death from any cause continues to reduce with more potassium. While 2 g per day seems to be an inflection point, there doesn’t seem to be a downside of getting more potassium like there is with sodium.
The ratio of sodium to potassium in the diet may be more important than the amount of either one alone. Our Paleolithic hunter-gatherer ancestors took in about 11,000 milligrams (mg) of potassium a day from fruits, vegetables, leaves, flowers, roots, and other plant sources, and well under 700 mg of sodium. That’s a sodium-to-potassium ratio of 1 to 16. Today, we get more sodium (3,400 mg) than potassium (2,500 mg), for a ratio of 1.36 to 1.
The ideal potassium:sodium ratio is not clear. It seems it is important to have at least more potassium than sodium, with 2:1 being better than 1:1. Some people suggest 4:1 is better, and some even suggest 10:1. While possibly ideal, super high ratios are impractical with our modern food environment.
If your potassium and salt intake are low, then you will probably feel better if you add more salt. But if you are getting plenty of potassium, you probably won’t need as much sodium. While there’s probably no harm in adding ‘salt to taste’ it’s more important to prioritise potassium.
In the Nutrient Optimiser algorithm, we have set a minimum 1:1 potassium:sodium ratio which means that it recommends that most people chase some more potassium before they worry about supplementing sodium.
Click here for a list of foods that contain more potassium.
What does this all mean?
While our optimal mineral requirements are hard to determine precisely, it seems that the quantity of minerals in our diet has been decreasing over time. It is now harder to get the essential minerals we need from food.
While there is no need to be scared of sodium, you may not need to worry as much about sodium if you are getting plenty of magnesium, potassium, calcium and phosphorus from our diet.
The safest approach is to track to ensure that you are meeting the recommended daily intake levels for these essential minerals and prioritise foods that contain more of the nutrient you need more of.
Check out Nutribooster to identify foods that contain foods that contain the nutrients you need more of.
Can I just add some salt?
Some people like to use salt to boost their mineral intake. But the reality is that most salts do not contain significant quantities of anything other than sodium.
The table below shows how many grams of table salt, Redmond Real Salt and Lite Salt you would need to get the Estimated Average Requirement for a few of the key minerals. For completeness, we’ve also shown the amount of potassium citrate and magnesium citrate you’d need if you got all of your recommended daily intake from supplements.
While you only need to consume 6 g of salt to get the estimated average daily requirement of sodium, you need to consume 3.6 kg of mineral or 47.5 kg of table salt to get your required intake of potassium (not recommended)!
So, while unrefined salt might be marginally better than table salt, it only has trace amounts of other elements, and you will need to make an effort to get the minerals you need to thrive.
Which minerals do YOU need to supplement with?
It’s worth checking out which nutrients you are currently not getting enough to see if you need some more. We’ve designed the Nutrient Optimiser to review your diet to identify the nutrients you need more of and highlight the supplements and foods that will help you get more.
So if you have a few days of your regular diet logged in Cronometer (free app), we’d love you to head over to the Nutrient Optimiser to check out the free report to see which foods will provide you with the nutrients you’re not currently getting enough of. The free report will also highlight which micronutrients you should consider supplementing.
While it’s probably a good idea to use a natural salt like Redmond Real Salt or Celtic Sea Salt which has a broad range of minerals in them, you may need to consider supplementing with some other mineral sources.
A lite salt is an excellent option to provide a blend of potassium and sodium for general use. However, potassium citrate, or magnesium citrate or calcium citrate powder may be necessary if your diet is poor.
How Can I Calculate My Nutrient Intake?
If you’re interested in checking if you’re getting just enough dietary phosphorus, you can check your nutrient profile using our Free 7-Day Nutrient Clarity Challenge.
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