Today we are sharing a summary of our research on salt. Table salt is often added to commercial dog foods when it probably isn’t needed. We share why as well as a few findings that surprised us.
For those of you short on time here is the TLDR: Dogs don’t need more salt in their food. We think the addition to many formulations comes from a quirk in AAFCO guidelines coupled with a mistake in most dog food formulators. Salt is often blamed for high blood pressure in people and thought to be bad for dogs, but it’s more complicated than that. Not only is table salt widely available, but other essential electrolytes are increasingly difficult to obtain from diet alone because food is getting less nutritious. Furthermore, there is individual variance in salt needs, but even more importantly, getting adequate magnesium, potassium and calcium for you and your dog matters greatly for reducing the risk of chronic diseases.
There’s so much wrong with the food industry today. We’ve covered in previous posts how dead and diseased animals are allowed in pet foods.
AAFCO requires dog food to be fully balanced, but how good are these numbers? The idea of guidelines is definitely helpful, but as we dug into the research a lot of recommendations just don’t make sense. Here are a few:
Precision amino acid requirements…even people don’t do this
Protein requirements of only 18% dry matter for adult dogs (SO little protein!)
Fat requirements of only 5.5% dry matter (not enough fat!)
These are just the most glaring. If you do the math, 18% protein and 5.5% fat means dog foods can legally be about 70% carbohydrates and still meet AAFCO guidelines. (The remaining dry matter, ash, another strange category, is made up of things like minerals and salts.)
If you’ve been following us for a while you probably know that we think dogs need a balance of macronutrients closer to 50% fat, 30% protein and less than 20% carbs by calories consumed. (Converting into dry matter that’s about 30% fat, 42% protein and less than 28% carbs.) AAFCO requirements can be distorted to make food grossly out of macronutrient balance.
We’ve also discussed how extrusion, the process that makes kibble, needs about 40% calories from carbs to make it work. The reality is that dog food and AAFCO guidelines are optimized for manufacturing ease and not what’s best for our pups. In fact, we would go as far as to say high-carbohydrate kibble is bad for dogs. Yet most vets still recommend it over home cooked food.
Why? The largest employer of veterinarians in the U.S. is also the largest pet food manufacturer. To put this in perspective this would be like Pepsi Co., one of the biggest packaged food companies, being the largest employer of doctors. We’ve written (as well as the NY Times) about how big food influenced the most prestigious medical journals in America by paying researchers.
How much more influence over an industry would a company have if they were also the largest employer?
How we formulate our recipes
We found so many mistakes in commercially available dog food formulation software that we had to build our own. Most of these issues are harmless, but some aren’t. We take our responsibility to you very seriously, so every value and every formula is checked and rechecked by us. Every balanced recipe and all of our balanced products are formulated exclusively with our own calculator. Though we can’t guarantee 0 mistakes, we are sure that our numbers stand alone in terms of quality and accuracy compared to anything else available.
Why is table salt added to commercial dog foods?
One of the mistakes we found while checking out commercial dog food formulators is due to AAFCO chloride requirements. For people, chloride is usually ignored because it’s so abundant on earth. In fact, in the USDA database, most foods do not list chloride content at all. It’s assumed if you live on earth and have salt that you’re getting enough chloride. Dogs also rarely have chloride deficiency.
Yet because the USDA database is the most extensive database in the world, the majority of pet food formulators use it as their primary source. Instead of separately adding chloride content, most just directly import the data. So the chloride content of many foods is listed as 0, not because these foods don’t have it, but because there is no value in the database.
When calculating deficiencies, the calculator will then show formulations being short on chloride. What’s the easiest way to add chloride? Well…sodium chloride of course, which is table salt.
What is salt exactly?
This may sound like a silly question but it’s actually quite complex. When we think of salt we usually think of the stuff we see everyday in our pantry and on our dinner tables. However, there are lots of different kinds of salts. Technically, salts are any ionic compound formed by a reaction between an acid and a base.
In simple terms this means that salts separate into ions when dissolved in a solvent. For example, sodium chloride separates into sodium ions and chloride ions when dissolved in water. See image below.
Animals use these ions to run all of the functions in their cells and bodies. For example, muscle contractions and nerve impulses are generated through a sodium-potassium pump. Three sodium ions are pumped out, while two potassium ions are pumped in creating an electrical gradient similar to how a battery produces a current. This is why muscle cramps are associated with low electrolytes, the pump starts to fail.
In addition to sodium, potassium and chloride, animals also need calcium, magnesium, phosphate, bicarbonate and many others in small amounts. These essential electrolytes allow animals to conduct electricity in their bodies. The ratio of sodium to potassium in cells is so important that low sodium from drinking too much pure water can cause death.
Dogs can actually tolerate A LOT of salt. But is it bad for them?
According to many early studies from the 1950-1970s dogs have a very high adaptability for salt. One small study fed 2.5g of salt per kg of body weight for over 250 days. To put this in perspective this is like a 170 pound person taking about 40 teaspoons of salt daily! Despite initial variations in blood pressure, as the study continued, the dogs easily adapted to the high salt diet. When salt was suddenly removed, the dogs’ blood pressure dropped, but normalized within three weeks.
Some “prescription formulations” for kidney and bladder stones are formulated with additional salt in order to dilute urine and help to remove the stones. The problem with dogs today having too much salt is poor metabolic health from high carbohydrate diets coupled with limited water to reduce the need for walks. In other words, modern pets are less healthy than they were in previous eras.
Is table salt bad for people?
Scientific consensus is constantly changing. For example, in the last two decades eggs have gone from heart attack food to healthy food. The consensus on salt consumption for people is also starting to change. Despite the belief that sodium sensitivity is the main driver of hypertension (high blood pressure) and thus contributing to cardiovascular disease (CVD) in people, several recent studies have questioned that conclusion.
Starting in the 1970s, studies showed that increased sodium intake was associated with a higher incidence of high blood pressure. In the 1990s the NIH funded the DASH studies (Dietary Approaches to Stop Hypertension) that further showed the connection between high sodium diets and increased blood pressure.
Although short in duration, DASH studies were rigorous studies that controlled sodium intake and measured heart disease markers in addition to blood pressure. Other variations of the the study kept sodium constant and limited sugar and meat while increasing vegetable and fruit intake. The conclusion of researchers was that reduction in sodium decreased blood pressure. However, increasing vegetable and fruit intake while holding sodium constant also reduced blood pressure!
A 2021 reanalysis of the Framingham Offspring Study showed that increases in potassium and magnesium were associated with lower CVD risk, while lowering sodium was not. Other studies have associated subclinical magnesium deficiency with age-associated diseases such as Alzheimer’s Disease and CVD. One Korean study calculated the greatest risk to hypertension to be a high ratio of sodium to potassium, while increased magnesium and calcium intake reduced the odds.
Furthermore, there appears to be a lot of variance in individual needs and electrolyte loss. For example, some people have very salty sweat. (One sign is salt stains on shirts after workouts.) If you are one of those people you may need more electrolytes than the average person.
Foods are getting less nutritious
Modern agriculture with selective breeding and innovative practices have increased crop yields massively. Plant hardiness and resistance to pathogens along with intensive irrigation, fertilizers and pesticides now produce enough food to easily feed all of earth’s inhabitants. Hunger today is mostly about inefficient distribution, waste and poverty rather than food scarcity.
The biggest drawback from this explosion in productivity is that the nutrient levels in foods appear to be declining. According to multiple studies, there is a loss of diversity, quantity and bioavailability of micronutrients. Furthermore, as processed foods replace many of the natural foods in industrialized countries, the problem is two-fold, over consumption of calories with a shortage of essential nutrients.
Commercial dog foods are fortified with synthetic vitamins and minerals, yet there is evidence deficiencies can still occur. This is more common in lower cost feed that uses poorly utilized nutrients and is exacerbated by the high carbohydrate content.
For people, the challenge is greater due to our affinity for salt. Because sodium chloride is widely available we can easily exceed our requirement of sodium while being deficient in other essential electrolytes. This can cause strain to the delicate balance in cells described above.
For our personal diets we do not limit sodium consumption but instead include lots of electrolytes from various sources including coconut water and hydration salts. Also, we supplement with magnesium and calcium.
Conclusion: Table salt is not as bad as once thought
However, excess sodium intake needs to be balanced with plenty of water and minerals from fresh food or supplements.
For pups, the research suggests that they can tolerate very high sodium levels, especially if they are healthy and eating real food diets. However, excess table salt can lead to more water consumption and more potty breaks. If they consume too much salt without adequate water this can put excessive strain on their kidneys.
That’s all for this week. Happy New Year!
All the best,
Joelle and the Precious Creatures Team