Salt: A nutritional essential misunderstood

Many clients come to clinic proud that they’ve reduced their salt intake, believing they’ve made a positive step for their health. Most have heard the familiar message: salt raises blood pressure and increases cardiovascular risk. But surprisingly, often, after cutting back, they report feeling worse – tired, light-headed, mentally foggy.

What’s going on?

Salt is essential to human physiology. Not the hyper-processed, additive-laden kind found in packaged foods, but mineral-rich, unrefined salt that supports hydration, nerve transmission, adrenal function, and blood pressure regulation. When intake drops too low, especially in those eating real food or following a low-carbohydrate diet, symptoms often emerge: fatigue, brain fog, dizziness, poor circulation.

A personal lesson

I learned this myself in my twenties while performing at the Edinburgh Fringe. With late nights, hot venues, and poor hydration, I developed palpitations, panic attacks, and overwhelming fatigue. A GP prescribed beta blockers. They didn’t help. It wasn’t until my mum suggested a simple rehydration sachet that things shifted – almost instantly. It was a sodium deficiency.

That experience reshaped how I think about salt. It’s not just about avoiding “too much” – we also need to ask: am I getting enough, and is it the right kind for my body and lifestyle?

Are guidelines still relevant?

UK public health guidelines still recommend a blanket cap of 6 grams of salt per day – around one teaspoon. This number appears on food labels, in GP clinics, and throughout national campaigns. But is it appropriate for everyone? Especially for those who have moved away from processed foods and are preparing meals from scratch?

In this article, we’ll take a closer look at salt’s role in health and why a nuanced, context-driven approach matters more than one-size-fits-all limits.

Not all salt is created equal

Public health salt guidelines were developed in the context of diets dominated by processed foods – crisps, white bread, deli meats, and ready meals. At the time, over 75% of sodium intake came from manufactured products, not from salt added during cooking or at the table (SACN, 2003; NDNS, 2019).

The salt used in these foods is refined table salt – industrial, bleached, stripped of trace minerals, and often mixed with anti-caking agents or stabilisers. It’s a far cry from the unrefined salts used in traditional diets.

Mineral-rich varieties like Celtic sea salt and Himalayan pink salt retain naturally occurring elements such as magnesium, potassium, and calcium – cofactors vital for hydration, nerve function, and muscle contraction. These are not incidental additions; they are biologically significant.

Yet most messaging still treats salt as a single category – lumping all sources together, regardless of form or function. As more people move towards home cooking and whole foods (NDNS, 2019; FSA, 2022; Mintel, 2023), this outdated framing creates confusion. It’s no longer just about how much salt we eat, but what kind, in what context, and alongside which foods.

Understanding this distinction isn’t a fringe concern; it’s foundational for modern nutrition.

Salt is essential

Salt isn’t just about flavour – it’s fundamental to human physiology. Sodium, the primary mineral in salt, regulates fluid balance, nerve transmission, and muscle contraction, including the rhythm of the heart. It supports blood pressure, brain function, and hydration. Our innate drive to seek out salt, especially after physical exertion or sweating, is a deeply embedded survival mechanism.

When sodium levels fall too low, the consequences can be significant. Hyponatraemia – sodium deficiency, can cause nausea, headaches, confusion, cramps, and in severe cases, seizures. It’s more common than many realise, particularly among older adults, athletes, and those on long-term low-sodium diets or certain medications.

Critically, very low salt intake can trigger a rise in stress hormones such as renin and aldosterone, part of the body’s attempt to conserve sodium. This compensatory response can paradoxically raise blood pressure and worsen metabolic markers. Low sodium has been linked to increased LDL cholesterol, triglycerides, and insulin resistance – all key contributors to cardiometabolic dysfunction (Graudal et al., 2011).

For those with conditions like low blood pressure, adrenal insufficiency, or POTS (postural orthostatic tachycardia syndrome), increasing salt intake can be transformative, improving energy, stabilising blood pressure, and reducing symptoms like dizziness and fatigue (Raj, 2013; Arnold et al., 2018).

The research: Salt isn’t always the villain

Some of the most striking evidence comes from clinical settings. In heart failure patients, overly strict sodium restriction has, in several studies, been associated with higher rates of hospitalisation and mortality (Onuigbo, 2009; DiNicolantonio et al., 2013). Among older adults on diuretics, sodium depletion is a known contributor to falls, frailty, and confusion (Gankam Kengne et al., 2008).

Athletes are now routinely cautioned about the dangers of overhydration without electrolyte replacement – one of the main causes of exercise-associated hyponatraemia (Hew-Butler et al., 2015).

These outcomes cast doubt on blanket sodium restriction. The PURE study, which followed over 100,000 people across 18 countries, found the lowest cardiovascular risk in those consuming between 3 and 6 grams of sodium per day (roughly 7.5 to 15 grams of salt) – well above the UK’s recommended maximum of 6 grams (Mente et al., 2016).

Further research, including the DASH-Sodium trials and analyses in Frontiers in Nutrition, suggests that sodium is not inherently harmful when consumed as part of a nutrient-dense, unprocessed diet. In fact, moderate salt intake appears to carry the lowest risk, particularly in the context of good metabolic health.

Salt and symptom relief

For anyone shifting to a whole-food or lower-carbohydrate lifestyle, a drop in sodium intake is almost inevitable. Without processed foods (where most dietary sodium typically comes from), salt consumption can fall dramatically. And unless it’s consciously replaced, symptoms like fatigue, dizziness, brain fog, or even palpitations often follow.

These symptoms are frequently misattributed to poor diet adaptation or “low energy availability.” But more often, they’re the result of a hidden electrolyte deficit. One key reason lies in insulin’s role in sodium retention. As carbohydrate intake decreases, insulin levels fall, leading the kidneys to excrete more sodium. This phenomenon, known as the natriuresis of fasting, is well documented and biologically predictable (Frontiers in Nutrition, 2025).

This physiological shift helps explain why so many people experience light-headedness, low energy, or headaches in the early phases of dietary change. The body isn’t failing to adapt; it’s simply lacking the sodium it needs to operate optimally under new conditions.

Restoring unrefined salt, alongside adequate hydration and other key electrolytes, can often resolve these symptoms quickly and effectively. It’s a small adjustment, but one that makes a substantial difference in how people feel day to day.

Salt sensitivity: What it’s really telling you

As with all aspects of nutrition, salt needs are highly individual. While restriction is often overstated, some people do notice symptoms after salty meals, such as bloating, headaches, or an increase in blood pressure. This pattern is commonly described as salt sensitivity, estimated to affect around 26-28% of adults in the UK and the US. It tends to be more prevalent among older adults and in those with hypertension, insulin resistance, or impaired kidney function.

But salt itself isn’t always the root cause. Often, it’s simply exposing an underlying imbalance already at play.

Salt sensitivity frequently reflects deeper metabolic issues such as insulin resistance, magnesium deficiency, chronic inflammation, or dysregulation of the kidneys or adrenal glands. In these cases, removing salt doesn’t resolve the problem. In fact, it can worsen fatigue, lower blood pressure further, and disrupt hydration.

The solution lies not in restriction, but in restoration: improving insulin sensitivity, replenishing key minerals, reducing inflammation, and supporting overall metabolic resilience. When these foundations are addressed, salt tolerance typically improves, without the need for chronic limitation.

When to test, not guess

If you’re unsure where you stand, functional testing can offer clarity. A standard blood panel can check key electrolytes like sodium, potassium, and magnesium, alongside kidney function – each of which plays a role in salt regulation. For a more complete picture, cortisol and aldosterone testing can highlight adrenal patterns that affect fluid balance and sodium retention.

If symptoms like fatigue, dizziness, salt cravings, or fluid retention persist, it may be worth exploring beyond electrolytes. Tests for insulin resistance, thyroid markers, and low-grade inflammation can uncover metabolic imbalances that influence how your body processes salt.

Rather than guessing or blindly restricting, testing allows you to personalise your approach and understand what your symptoms are really pointing to.

Salt has spent decades in the dietary spotlight for the wrong reasons. But emerging research makes one thing clear: blanket restrictions don’t work for everyone, especially those with stable metabolic health and a whole-food diet.

For individuals who eat unprocessed food, exercise regularly, manage stress, or work physically demanding jobs, the greater risk is often not too much salt, but too little. Sweat loss, low-carb eating, and conditions like low blood pressure or adrenal dysfunction all raise sodium requirements, not lower them.

After years of fear-based messaging, salt has been sidelined in conversations about recovery and resilience. Yet when used intentionally in its natural, unrefined form, it can be a powerful tool for restoring hydration, energy, and balance.

Rather than fear salt, it’s time we understood it. For many, bringing it back isn’t a risk; it’s simply a return to what the body actually needs to function well.

References

• NHS (2023) – How much salt is too much? Recommends adults limit salt intake to no more than 6g per day (around 2.4g sodium). www.nhs.uk
• Public Health England (2020) – Salt Reduction Targets 2024. Sets voluntary salt targets for food manufacturers. www.gov.uk
• National Diet and Nutrition Survey (NDNS), 2016–2019 – Reports average UK adult salt intake remains above recommended levels: ~8.4g/day for men, ~6.8g/day for women.
• NDNS (2019) – Shows a gradual shift in younger adults towards cooking from scratch and reducing processed food intake.
• FSA (2022) – Food Standards Agency report on public attitudes to food; 61% of consumers report trying to avoid ultra-processed foods.
• Mintel (2023) – Market research showing increased sales of wholefood, ‘clean label’ products and a consumer trend towards minimally processed ingredients.
• Scientific Advisory Committee on Nutrition (SACN, 2003) – Salt and Health Report. Notes sodium intake affects blood pressure, but highlights uncertainty around very low sodium intake.
• Mente et al. (2016) – The PURE Study. One of the largest international nutrition studies to date. Found lowest cardiovascular risk in those consuming 3–6g sodium/day (7.5–15g salt).
• Graudal, N., Hubeck-Graudal, T., & Jürgens, G. (2011) – Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride. American Journal of Hypertension, 25(1), 1–15.
• Graudal et al. (2017) – Meta-analysis showing that low-sodium diets may raise stress hormones, insulin resistance, and cholesterol. American Journal of Hypertension.
• He & MacGregor (2009) – UK-based salt researchers highlight benefits of reduced salt, while noting risks of over-restriction in some individuals. Journal of Human Hypertension.
• Paterna et al. (2008) – Clinical study linking strict salt restriction in heart failure to higher mortality. Clinical Science.
• Raj, S. R. (2013) – Postural tachycardia syndrome (POTS). Circulation, 127(23), 2336–2342.
• Arnold, A. C., Ng, J., Raj, S. R. (2018) – Postural tachycardia syndrome – Diagnosis, physiology, and prognosis. Autonomic Neuroscience, 215, 3–11.
• Onuigbo, M. A. C. (2009) – Sodium restriction in heart failure: time for a critical reassessment. British Journal of Cardiology, 16(2), 92–93.
• DiNicolantonio, J. J., Niazi, A. K., Lavie, C. J., O’Keefe, J. H., & Ventura, H. (2013) – Sodium restriction in heart failure: a misguided therapy? Open Heart, 2(1), e000088.
• Gankam Kengne, F., Andres, C., Sattar, L., Melot, C., & Decaux, G. (2008) – Mild hyponatremia and risk of fracture in the ambulatory elderly. QJM: An International Journal of Medicine, 101(7), 583–588.
• Hew-Butler, T., Rosner, M. H., Fowkes-Godek, S., Dugas, J. P., Hoffman, M. D., Lewis, D. P., & Montain, S. J. (2015) – Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference. Clinical Journal of Sport Medicine, 25(4), 303–320.
• Mente, O’Donnell & Yusuf (2018) – Review advocating for a more nuanced, personalised approach to sodium intake. Nutrients.
• DiNicolantonio & Lucan (2014) – Opinion piece arguing sugar, not salt, may be the greater driver of cardiovascular risk. Open Heart.
• Alderman (2010) – Commentary exploring how salt guidelines have often been shaped more by policy than science. American Journal of Hypertension.
• Institute of Medicine (2013) – Comprehensive review of sodium and health outcomes. Found insufficient evidence to support targets below 2.3g sodium/day.
• Elliott et al. (1996) – The INTERSALT Study. Cross-population data linking sodium intake and blood pressure, with variations based on diet and lifestyle. BMJ.
• Liu et al. (2017) – RCT showing low sodium intake raises renin, aldosterone, and catecholamines, increasing cardiovascular risk. Hypertension.
• Van Horn et al. (2016) – DASH-Sodium follow-up showing extreme sodium restriction may impair lipid metabolism and glucose regulation. Circulation.
• Yoon & Oh (2013) – Analysis linking low sodium diets to increased insulin resistance and higher triglycerides. Nutrition Research and Practice.
• Alderman (2000) – Clinical review warning that aggressive sodium restriction may elevate cardiovascular risk through neurohormonal activation. The Lancet.