Rethinking Salt: The Science of Hydration

Rethinking Salt: The Science of Hydration - Avive Hydration

For decades, sodium has been widely misunderstood.

Salt has traditionally been framed as something to reduce in our daily diet, with concerns centred on hypertension, cardiovascular disease or stroke. However, recent research provides a more balanced understanding: sodium alone is unlikely to be the primary cause of hypertension in otherwise healthy individuals, and both very high and very low sodium intakes appear to carry potential risks (Gao, 2024; Zhu et al., 2018; Graudal & Jürgens, 2018; O’Donnell et al., 2011; O’Donnell et al., 2020).

As always, the body functions best with balance, not avoidance. Let's dive into the science of sodium. 

Salt in the Modern Diet: What the Evidence Shows

While salt has often been viewed as harmful (DiNicolantonio et al., 2017), research shows that the majority of sodium in modern diets does not come from deliberate salting of food.

According to the INTERMAP study, 71% of sodium in the U.S. diet and ~90% in the U.K. comes from processed and packaged foods (Anderson et al., 2010). These foods are often nutrient-poor and contain preservatives, additives and refined ingredients. This means the concern is less about sodium itself, and more about the patterns of eating that accompany it.

When individuals shift to whole-food-based ways of eating, sodium intake naturally decreases. For many people — especially those who are active, sweat regularly or consume fewer processed foods — this reduction can lead to unintentionally low sodium levels.

Several lifestyle choices reduce sodium intake or increase sodium loss:

  • Whole-food or minimally processed diets
  • Lower-carbohydrate eating patterns
  • Intermittent fasting
  • Warm climate lifestyles
  • Regular movement (walking, Pilates, gym, hot yoga, sauna)


Lower insulin states (common in fasting or lower-carb diets) can increase urinary sodium excretion (Harvey et al., 2018). This is why individuals can feel tired, light-headed or poorly hydrated despite drinking adequate water.

Everyday Sodium Loss

Sodium is lost primarily through the urine and sweat — not only during structured exercise, but also through normal daily activity and environmental heat.

Research indicates that sodium losses can be substantial depending on temperature and sweat rate (Shirreffs & Sawka, 2011). If water is replaced without minerals, this can dilute sodium levels and compromise hydration.

This imbalance may contribute to:

  • Persistent thirst
  • Fatigue
  • Headaches
  • A feeling of being 'dehydrated but waterlogged'
  • Reduced concentration


Studies consistently show that beverages containing sodium are more effective than water alone at restoring hydration, improving fluid retention and plasma volume (Shirreffs & Maughan, 1998; Evans et al., 2017; Millard-Stafford et al., 2021).

How Sodium Supports Hydration

Despite common narratives, sodium is not the enemy. In fact, it's essential for hydration.

Two-thirds of the body’s water is stored inside cells, and one-third circulates outside them in plasma and interstitial fluid. Sodium helps regulate fluid outside cells, while potassium primarily regulates fluid inside them. This balance governs how water moves throughout the body and supports:

  • Effective hydration
  • Normal blood volume (Titze, 2008)
  • Nerve conduction
  • Muscle function


When sodium levels fall too low relative to fluid intake, water moves inefficiently. Instead of being retained, it can pass quickly through the body, leading to feelings of fatigue, bloating or poor hydration despite adequate water intake. Hydration depends on both fluids and electrolytes working together.

Why Type and Balance Matter

Most people do not consume excessive sodium from adding salt to home-cooked meals. The issue often lies in the hidden sodium within processed foods (Magriplis et al., 2011; Ahmed et al., 2023). When individuals transition to whole-food diets, their intake often falls significantly.

From a hydration standpoint, the goal is not to maximise sodium, but to maintain a moderate, sufficient intake within a balanced electrolyte profile.

Refined table salt is almost entirely sodium chloride. Unrefined salts (e.g., sea salt) also primarily consist of sodium chloride but may include trace minerals such as magnesium, potassium and calcium. While these trace minerals are not present in significant amounts nutritionally, they reflect how electrolytes often occur together in nature.

Sodium, potassium and magnesium work collectively to support:

  • Fluid balance
  • Normal muscle function
  • Circulation
  • Cellular communication


Balanced electrolyte intake supports hydration more effectively than water alone.

What Research Suggests About Daily Sodium Intake

Although guidelines from major organisations recommend relatively low sodium intakes for the general population, large observational studies show that the lowest cardiovascular risk appears within a moderate range.

Research indicates:

  • Sodium excretion equivalent to ~4,000–6,000 mg/day is associated with the lowest risk of cardiovascular events
  • Very low sodium intake (<3,000 mg/day) may be associated with higher risk (O’Donnell et al., 2011)
  • Extremely high intakes also increase risk, forming a J-shaped curve (Graudal & Jürgens, 2018; Zhu et al., 2018)


These findings do not replace individual medical guidance, but they highlight that extremely low sodium intake is not necessarily safer, particularly for active individuals or those consuming whole-food, minimally processed diets.

A More Thoughtful Understanding of Hydration

Avive beautylytes™ are formulated with this evidence in mind. Rather than adopting the same approach as many popular high-sodium performance-drinks, Avive focuses on:

  • A moderate, supportive level of sodium for daily intake (just 200 mg per serve)
  • Electrolytes such as potassium and magnesium to support inner balance
  • Clean, purposeful ingredients to support inside-out wellness 


For individuals who walk regularly, sweat daily, live in warm climates, practise fasting or simply want more effective everyday hydration, balanced electrolytes can support how water is absorbed and utilised.

When viewed through a scientific lens, sodium is not something to fear. It is:

  • Essential for fluid balance
  • Necessary for normal nerve and muscle function
  • A key part of maintaining hydration in everyday life


Effective hydration is about more than drinking water — it’s about supporting how the body absorbs, retains and uses that water. The science is clear: sodium and other balanced electrolytes make that process more efficient.

References:

Ahmed M, Ng AP, Christoforou A, Mulligan C, L'Abbé MR. Top Sodium Food Sources in the American Diet. Nutrients. 2023;15(4):831. https://doi.org/10.3390/nu15040831

Anderson CA, Appel LJ, Okuda N, et al. Dietary sources of sodium across multiple countries: the INTERMAP study. J Am Diet Assoc. 2010;110(5):736–745. https://doi.org/10.1016/j.jada.2010.02.007

DiNicolantonio JJ, Mehta V, O'Keefe JH. Is Salt a Culprit or an Innocent Bystander in Hypertension? Am J Med. 2017;130(8):893–899. https://doi.org/10.1016/j.amjmed.2017.03.011

Evans GH, Miller J, Whiteley S, James LJ. A Sodium Drink Enhances Fluid Retention During Post-Exercise Recovery. Int J Sport Nutr Exerc Metab. 2017;27(4):344–350. https://doi.org/10.1123/ijsnem.2016-0196

Gao J. Sodium intake and public health. Res Methods Med Health Sci. 2024. https://doi.org/10.1177/26320843241235586

Graudal N, Jürgens G. Conflicting Evidence on Salt Reduction Guidelines. Prog Cardiovasc Dis. 2018;61(1):20–26. https://doi.org/10.1016/j.pcad.2018.04.008

Harvey CJDC, Schofield GM, Williden M. Low-carb diets, ketosis and sodium excretion. PeerJ. 2018;6:e4488. https://doi.org/10.7717/peerj.4488

Magriplis E, Farajian P, Pounis GD, et al. Hidden sodium in children’s diets. J Hypertens. 2011;29(6):1069–1076. https://doi.org/10.1097/HJH.0b013e328345ef35

Millard-Stafford M, Snow TK, Jones ML, Suh H. The Beverage Hydration Index. Nutrients. 2021;13(9):2933. https://doi.org/10.3390/nu13092933

Munson EH, Orange ST, Bray JW, et al. Sodium Ingestion and Hydration Effects. Front Nutr. 2020;7:549413. https://doi.org/10.3389/fnut.2020.549413

O'Donnell MJ, Yusuf S, Mente A, et al. Urinary Sodium and Cardiovascular Risk. JAMA. 2011;306(20):2229–2238. https://doi.org/10.1001/jama.2011.1729

O’Donnell M, Mente A, Alderman MH, et al. Salt and Cardiovascular Disease. Eur Heart J. 2020;41(35):3363–3373. https://doi.org/10.1093/eurheartj/ehaa586

Shirreffs SM, Maughan RJ. Water vs sodium-containing drinks after dehydration. Am J Physiol Renal Physiol. 1998;274(5):F868–F875. https://doi.org/10.1152/ajprenal.1998.274.5.f868

Shirreffs SM, Sawka MN. Fluid and Electrolyte Needs. J Sports Sci. 2011;29(S1):S39–S46. https://doi.org/10.1080/02640414.2011.614269

Titze J. Water-free Sodium Storage and Hydration Physiology. Blood Purif. 2008;26(1):95–99. https://doi.org/10.1159/000110573

Veniamakis E, Kaplanis G, Voulgaris P, Nikolaidis PT. Sodium Intake and Hydration Physiology. Int J Environ Res Public Health. 2022;19(6):3651. https://doi.org/10.3390/ijerph19063651

Zhu Y, Zhang J, Li Z, et al. Sodium Intake and Cardiovascular Outcomes. BMC Cardiovasc Disord. 2018;18:192. https://doi.org/10.1186/s12872-018-0927-9


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