Gut Bites MD

Christopher Damman, Associate Professor of Gastroenterology, School of Medicine, University of Washington. Editor-in-Chief of Gut Bites MD.

We tend to vilify some ingredients like salt – relegating them to the public health enemy list – while elevating others to the level of wishful magic bullets. Salt, Sugar, and Fat are all great examples of the usual criminal suspects, and indeed they have been linked to a multitude of adverse health outcomes.  

The nuanced truth is that in the right amount they are absolutely critical for a healthy diet. The problem is that they are often present in added concentrations that are much too high and not complemented by other important nutrients that help balance them.  

Pumped About Ratios

Physiology teaches us that the nutrients in food can complement each other. Fiber helps meter the absorption and direct the metabolism of sugar, and a healthy blend of unsaturated and saturated fats is critical to keep the membranes surrounding our cells healthy.  

Sodium and potassium are a similar dynamic duo. The minerals play different but complementary roles in the body. In the simplest terms, sodium supports the water in our blood vessels – it is the major contributor to blood pressure – and potassium supports the water in our cells – imagine our body as a collection of the tiniest bags of potassium rich fluid. 

For every two sodium molecules in the body, it’s optimal to have three corresponding potassium molecules. This is owing in part to tiny molecular pumps that exist within each and every one of our cells that serve to deliver the minerals to their respective compartments. For every two sodium it funnels out of the cell, it transports three potassiums in. 

This effectively keeps our cells plumped and our blood pumped. These same pumps exist alongside other transport channels within our gut cells helping regulate how much sodium and potassium are absorbed from food and within our kidney cells helping regulate how much sodium and potassium are excreted into our urine.  

Amazingly, our gut microbes also have the same ancient pumps in their cell membranes and follow the same basic rules for maintaining sodium and potassium balance. The sodium and potassium we ingest influences their vitality too and their metabolites critical for our health. 

The universality of the pump hints at the importance of an ideal average intake of around 2000 mg of sodium and 3000 mg of potassium in our diet for a ratio of 2:3.  But our current diets, steeped in ultra-processed foods, are flipped to a ratio of 3:2, or over 3000 mg of sodium and under 2000 mg of potassium. 

Due Process

Processed foods in particular are deplete in potassium and brimming with sodium. This is owing to the milling, sorting, and extracting that is involved with ultra-processing. The tiny bags of potassium fluid cells are broken and the potassium rich fluid is spilled and left to waste while sodium is added.

There are good reasons for adding sodium. It helps preserve food and has been used since the beginning of civilization to do so in fermented foods. It also might help sell food because it can lead to hyper-palatability and cravings, especially when combined with other nutrients like sugar and saturated fat.

Next time you’re in a grocery store, take a look at the ingredient label on a few of the boxes – twinkies, cheetos, or coke.  You’ll find a zero next to potassium and big numbers next to sodium. 

Or take a look in your cupboard at seemingly innocuous crackers, rice krispies, or salad dressing and you’ll find a story not too different. Then look at fresh, fruits, and vegetables, meat, nuts, seeds, and beans on the USDA website and you’ll see they are all loaded with potassium and low in sodium.

Americans in particular are eating a diminishing amount of whole foods and an increasing amount of ultra-processed foods. As a result, 90% percent of people get too much sodium, and over 90% of people don’t get enough potassium. Along with fiber, calcium, and vitamin D the USDA’s 2020-2025 Dietary Guidelines for Americans highlighted potassium as one of the deficient nutrients of ‘greatest concern’ in our food system.

But just as there’s alarm in reviewing labels, there’s also hope. The USDA recently revamped the Nutrition Facts food label to mandate that potassium amounts are listed. Increasing awareness is half the battle, and public demand can help incentivize companies to shift the sodium and potassium profiles of processed foods.

Health in Focus

Why should you care, you might ask? High potassium foods have been shown to predict weight loss in the treatment of metabolic syndrome, and sodium to potassium ratios vs. sodium alone might be a better predictor of blood pressure, cardiovascular disease and metabolic disorders like diabetes, overweight, and obesity.

In fact, a recent New England Journal of Medicine trial showed that not only decreasing sodium, but increasing potassium lead to fewer cardiovascular events and lower death rates. Some of the latest data is also suggesting that these outcomes may intriguingly be related to our gut microbiome’s cells as much as it is related to our body’s cells.

Focusing on ratios of sodium and potassium vs. absolute numbers may also be more generalizable to the range of nutritional health needs. While the vast majority of people would do best to decrease sodium and increase potassium, there are some individuals where decreasing both or increasing both is important so balance becomes a more universal goal.  

Folks that are endurance athletes or have adrenal insufficiency for example may need more potassium and sodium. And folks with kidney disease or that are taking certain blood pressure medications need to be careful about not getting too much sodium and potassium.

Let’s Get Practical

So what to do?  The wise adage of Michal Pollan from Omnivore’s Dilemma provides some good general guidance. “Eat food, mostly plants, not too much.” In addition, I would add that it’s important to think about balancing your nutrients with particular attention to sodium and potassium. Here are some specific pointers on how. 

1. Increase whole foods.  Plant-based (e.g. beans, nuts, seeds, fruits, vegetables, and whole grains) and animal-based (e.g. lean meats and seafood).  Whole foods contain intact cells chock full of potassium, as well as other vital nutrients like minerals, fiber and polyphenols.  

2. Limit processed foods.  Salty Meats (e.g. hotdogs, sausage, bacon, jerky), Salty Treats (pretzels, chips, crackers), and Salty Sneaks (soda, salad dressings, cookies, and cakes).  These have high sodium, low potassium, and are missing many other vital nutrients.

3. Emphasize complementary pairings.  Without it being a habit, it is OK to have processed foods from time to time. If you do, consider eating them in combinations (e.g. chips and guacamole, cereal and fruit, saltines and sardines, sausage and black beans). There are reasons these foods are paired.  

4. Use a nutrition ratio calculator. Lastly, consider your own creative combinations and recipes –  bananas and bacon anyone?  This food ratio calculator can be used as a guide for helping choose those combinations that might be healthiest.

Christopher Damman, Associate Professor of Gastroenterology, School of Medicine, University of Washington. Editor-in-Chief of Gut Bites MD.

MD-authored food & microbiome digests and first-in-class food quality calculator to power your microbiome.