THE THING ABOUT SALT…
To salt or not to salt? You’ve heard it all: salt is simply bad for you, or this salt is good and this other one is bad, or salt is the best thing for you, pour it on! As with most things health related, the answer is not black or white, optimal salt intake depends on multiple factors.
Salt is mainly composed of sodium chloride. Sodium is an essential component of our well being, it’s in all our bodily fluids, and is necessary for things like water balance regulation, muscle contraction and expansion, nerve stimulation, and proper adrenal function. We need the “right” amount for proper function. Our kidneys regulate sodium levels and are in charge of excreting it when levels rise. It does this through thirst & urination signals and our appetite for salt.
Salt is directly correlated to blood pressure. In excess, salt can lead to hypertension (aka high blood pressure), and even weight gain. Sensitivity to salt, and how well our kidneys are able to excrete it, is individual. As we age, we tend to become more sensitive to the effects of salt on blood pressure. Research done by Dr. Rick Johnson, a nephrologist, revealed that this is not just a result of aging, but rather of kidney inflammation. Low grade inflammation reduces blood flow to the kidneys and hinders their ability to get rid of salt. The question then becomes, what is driving kidney inflammation? According to his research, it seems that it’s high levels of uric acid. What’s behind high uric acid levels? It could be a number of reasons, but a common one is fructose. More on this in the next section.
Sodium and potassium, which are both electrolytes, work symbiotically to maintain body fluids and blood volume. Potassium is found in vegetables and fruits, some of the richest sources include: beet greens, swiss chard, potatoes, acorn squash, spinach, bok choy, lima beans, mushrooms, tomatoes, sweet potatoes, bananas, cantaloupe, dates, and nectarines.
Low potassium, relative to sodium levels, can lead to increased blood pressure. Inversely, increasing potassium relative to sodium levels may help to lower blood pressure. Studies have shown that for people with hypertension, the salt to potassium ratio in their diets appears to be more strongly associated with blood pressure outcomes than either sodium or potassium alone.
SALT & FAT STORAGE
Did I catch your attention? I’m not referring to salt making you retain fluids, which may make you look like you’ve gained weight. I’m talking about increased fat composition. I’ll explain…
If your diet is high in salt and you’re not properly hydrated, this can trigger your body to store more fat!
It’s essentially an evolutionary survival mechanism of fat storage for survival during periods of food and water scarcity, so that our bodies can obtain hydration and energy from stores of fat if needed. For the majority of modern humans, this survival mechanism is no longer useful because we don’t normally have to withstand long periods of time without food or water.
THE (simplified) SCIENCE
High concentrations of salt in our body activates an enzyme that converts glucose to fructose. This fructose is practically made in our bodies. Fructose is the sugar that is involved in energy storage rather than energy production (glucose is the sugar for energy production). Fructose is only metabolized in the liver, and its byproduct is uric acid. Aha! High levels of uric acid signal to the body to make and store fat. As part of this mechanism, excess salt, like excess dietary fructose from sources like fruit (elevated fructose from fruit happens mostly from juicing, not from eating whole fruit), table sugar (half glucose and half fructose), honey, maple syrup, and high fructose corn syrup, leads to switching on the fat storage signal, and consequently to gaining weight (Dr. Rick Johnson and Dr. David Perlmutter are leading experts on this).
What’s important to highlight here is that the conversion from salt to fructose happens when sodium serum osmolality is high. This is basically the concentration of sodium in your blood. To prevent this, make sure you drink enough water to stay hydrated throughout the day, watch your sodium intake (beware of the hidden/high salts in processed foods), and increase the amount of potassium-rich foods you eat. A simple way to gauge how well hydrated you are is by how often you urinate and how dark your pee is. When you are not well hydrated, your urine is darker in color and you don’t pee much. A pale yellow colored urine is a good marker of sufficient hydration.
FUN FACT: As a child, I thought that camels carried water in their humps, and it’s what allowed them to survive in the heat of the desert. In reality, their humps are fat storage vessels to keep them hydrated when water is not available.
HYDRATION TIPS
Signs of dehydration include headaches, brain fog, muscle cramps, weakness, and for pregnant women it can cause premature contractions.
Electrolyte drinks/sports drinks include both sodium and potassium to help with quick rehydration when you’ve lost fluids from sweating, vomiting, blood loss, or having diarrhea when sick (severe cases require IV fluids). People who go on low carbohydrate diets can also experience electrolyte imbalance and dehydration by lowering their insulin levels, which causes the kidneys to release excess water.
Quality counts: avoid most common “sports drinks” especially if you’re not actually being active. The problem with sports drinks is that most are high in glucose and fructose too. If you're an athlete, the glucose can be helpful in a pinch for a quick energy boost, you’re utilizing it as opposed to storing it. Fructose is only added to make them taste better. However, drinking the typical sports drink regularly while staying sedentary can become a problem—the excess glucose and fructose leads to high blood sugar, insulin resistance, and weight gain.
An alternative to sugary, high fructose sports drinks is to make your own low sugar electrolyte drink. It’s easy and inexpensive. Just add a pinch of salt (about 1/4- 1/2 teaspoon) to one quart of water, plus the juice of one lemon or one small orange for a little potassium.
Click here for a recipe that I adapted from Botanical Medicine for Women by midwife and physician Dr. Aviva Romm. It’s one that she used regularly as a midwife to prevent dehydration in pregnant women with severe nausea and vomiting, but it can be used by anyone looking to replace lost electrolytes.
THE TAKEAWAY
Salt/Sodium is important for various physiological processes.
Salt and blood pressure are directly correlated. Know what your blood pressure is!
Adjust your consumption of salt accordingly, and make sure to stay well hydrated to avoid high blood sodium concentration.
Consume foods high in potassium to help regulate sodium levels.
Excess salt without proper hydration can trigger the body to produce fructose. This fructose, as well as dietary fructose is metabolized in the liver. Its byproduct is uric acid, which can ‘turn-on’ the fat storage mode.
High levels of uric acid can also lead to kidney inflammation, lowered ability to excrete salt, and consequently high blood pressure.
Watch for signs of dehydration (dark scant urine, headaches, muscle cramps, brain fog, weakness, premature contractions in pregnant women).
Many commercial ‘sports drinks’ are loaded with glucose and fructose, which is a problem especially if you’re inactive. Making your own is easy and inexpensive.
Here are a few excellent podcasts that explore the topic of salt extensively:
Huberman Lab’s Using Salt to Optimize Mental and Physical Performance!, where scientist Andrew Huberman takes a deep dive into the biology and neuroscience of salt
The Drive’s AMA #33: Hydration—electrolytes, supplements, sports drinks, performance effects, and more, where Dr. Peter Attia details everything related to hydration
Better!’s Nature Wants You To Be Fat with Dr. Rick Johnson, where Dr. Stephanie Estima speaks with Dr. Rick Johnson about everything fructose, including how diets higher in salt can activate endogenous fructose production.
REFERENCES
Lustig, Robert, 2021. Metabolical. Harper Wave. 1st ed.
Johnson, Rick. The Metabolical Effects of Fructose. The Drive Podcast, episode #87
Daniel I. Feig, Beth Soletsky, Richard J. Johnson, 2008. Effect of Alloopurinol on Blood Pressure of Adolescents With Newly Diagnosed Essential Hypertension: A Randomized Trial. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684336/
Kogure, Nakaya et al. Sodium/potassium ratio change was associated with blood pressure change: possibility of population approach for sodium/potassium ratio reduction in health checkup.
PMID: 32801312, PMCID: PMC7815510 DOI: 10.1038/s41440-020-00536-
https://pubmed.ncbi.nlm.nih.gov/32801312/
Perez, Vanessa, and T.Chang, Ellen. Sodium-to-Potassium Ratio and Blood Pressure, Hypertension, and Related Factors. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4224208
2020-2025 Dietary Guidelines for Americans
https://www.dietaryguidelines.gov/food-sources-potassium
Romm, Aviva. Herbal Medicine for Women Manual, Herbs for Childbearing Women, Unit 3
Frothingham, Scott, 2018. What’s the Relationship Between Gout and Sugar? https://www.healthline.com/health/gout-and-sugar#gout-and-soft-drinks
Fallon, Sally, 1995. Nourishing Traditions: The Cookbook That Challenges Politically Correct Nutrition. ProMotion Publishing