In a recent trial (Gupta et al, 2023), the blood pressure–lowering effect of dietary sodium reduction was comparable with a commonly used first-line antihypertensive medication. Salt in the diet is associated with chronic kidney disease. Sodium also accumulates in the skin, inducing inflammation and eczema, so feel better and look better by cutting the sodium intake that is way too high in most people.

I discuss at length in my book, Thinking and Eating For Two: The Science of Using Systems 1 and 2 Thinking to Nourish Self and Symbionts, how diet is key to all chronic diseases. All of the dietary components work together to largely determine health status – not just one and certainly not just genetic factors. Genetics has little to do with health status for most people. Hereditary factors, such as epigenetic transgenerational inheritance and protein inheritance, may have an important influence, but not genetics. It’s the exposome that counts – i.e. all of the things that you’re exposed to in life – and, all of the things that you’re parents and their parents were exposed to. That’s the transgenerational epigenetic inheritance and protein inheritance aspect of the exposome. Now research at the University of California, San Francisco (UCSF) and UC Berkeley, suggests that high levels of dietary sodium may raise the risk of developing atopic dermatitis.

Many factors can influence health, including that of the skin. I’ll discuss salt here, but other factors such as dairy play a big role too – both for cardiovascular health, and skin health. For example, the induction of antibodies (IgE) by the consumption of dairy can lead to cardiovascular disease and death. And dairy, loaded with antigens such as lactose, whey, and casein (even found in mothers milk because of dairy consumption by mom) can be destructive to the skin, even causing cancer.

As Gupta et al (2023) discovered, dietary sodium reduction significantly lowered blood pressure (BP) in the majority of middle-aged to elderly adults they studied. The decline in BP of those who went from a high- to low-sodium diet was independent of hypertension status and antihypertensive medication use, and was consistent across subgroups. Needless to say, reducing sodium intake did not result in adverse events.

Sodium is an essential mineral and osmolyte for the human body. It is the major cation in the extracellular fluid and as such plays a crucial role in homeostatic processes such as regulation of blood volume, osmolarity, and blood pressure. Therefore, sodium plasma concentration is maintained within a relatively narrow range of around 140 mmol/l. The sodium concentration in the interstitial space (the space in between our cells) can be much higher. We consume just the right amount of sodium when we eat a plant based diet without added sodium. If we eat too much sodium, that excessive salt intake may induce several adverse effects, causing microvascular endothelial inflammation, anatomical remodeling, and functional abnormalities, even in normotensive subjects (those with normal blood pressure). More recent studies have shown that changes in sodium plasma levels not only exert their effects on small resistance arteries, but may also affect the function and structure of large elastic arteries. The issue of salt-sensitivity, which refers to individual susceptibility in terms of BP variations following changes in dietary salt intake, has also been recently debated in its pathophysiological mechanisms and clinical implications.

Excess sodium is also stored in the skin.  In the skin microenvironment, higher sodium concentrations enhance macrophage function, potentially leading to innate immune system-based inflammation. Several studies have provided significant evidence that an elevated sodium concentration has an immunomodulating effect by augmenting proinflammatory and antimicrobial macrophage function as well as T-cell activation. And now we know that sodium has accumulated to high levels in the skin of psoriasis patients (Maifeld et al, 2021). Psoriasis is an inflammatory skin condition, and restricting salt in your diet will help to reduce that inflammation. Same for eczema. Reduce the salt because, for one factor, salt promotes the growth of a bad bacteria called staph aureus which is found in patients who have bad flare ups of eczema. With high salt, the skin is unable to repair itself – it’s in a constant state of inflammation.

Cut the salt and your immune system will operate more normally. It requires time to adjust your taste to the low sodium diet – most of us are addicted to salt. But in time, you lose the addiction, and actually begin to better taste all of the other flavors in your food that were masked by the salt. Bon appetite, Pas de sel!