Using Salt to Optimize Mental & Physical Performance

Salt and Its Effects on Health and Performance

• Salt regulates blood pressure
• Brain regulates appetite for salt or aversion to salt
• Sensing salty tastes mediates sugar cravings and consumption
• Salt system regulates aspects of health, athletic performance, cognitive performance, aging, and dementia

Neuropod Cells and Sugar Cravings

• Neuropod cells are neurons in the gut that detect fatty acids, amino acids, and sugar
• When sugar is ingested, neuropod cells send electrical signals to the brain, evoking dopamine release
• Dopamine promotes craving, motivation, and action
• Gut sensing of sugar is subconscious and works in parallel with conscious taste sensing

Artificial Sweeteners and Gut Sensing

• New study from Diego Bohórquez’s lab at Duke University
• Neuropod cells can distinguish between sweet, caloric substances (sugar) and sweet, non-​​caloric substances (artificial sweeteners)
• Artificial sweeteners can evoke an insulin response under certain conditions
• Artificial sweeteners may disrupt gut microbiome in animal models, but unclear if this applies to humans
• Some people find artificial sweeteners helpful for avoiding excessive caloric intake, while others dislike the taste or are wary of potential health effects

Future Exploration

• Understanding how artificial sweeteners are consumed and registered in the gut and how this changes brain function
• Examining the potential strategy behind food manufacturers adding artificial sweeteners to foods
• Investigating how salt and salt sensing can adjust cravings for other substances, such as sugar and water
  Nutritional Neurobiology and Salt
• Salt (sodium) has many important functions in the brain and body 
  • Regulates fluid balance, salt appetite, and appetite for other nutrients
  • Technically a mineral; 1 gram of table salt contains about 388 milligrams of sodium
• Brain has a blood-​​brain barrier (BBB) to protect it from harmful substances 
  • Ovaries and testes also have barriers for similar reasons
  • Some brain regions have weaker barriers to allow certain substances in

Salt and the Brain

• Neurons in the brain sense levels of salt in the body 
  • Brain regions with weaker barriers allow for this sensing
• Understanding salt intake and regulation can help determine when more or less salt is needed 
  • Factors to consider include blood pressure, activity levels, sweat, and cognitive/​​physical demands
• Proper salt intake supports neuronal function and other biological functions 
  • Electrolyte drinks like Element can help maintain proper salt levels

Circumventricular Organs and Thirst

The Kidney’s Role in Fluid Balance

• Kidneys filter blood through a series of tubes and loops 
  • Responds to hormonal signals like vasopressin (antidiuretic hormone) to retain or release fluid
• Urine is filtered blood 
  • Kidneys decide what substances to retain or release based on their concentration in the blood

Osmolarity and Vasopressin

• Osmolarity is detected by the OVLT (Organum Vasculosum of the Lamina Terminalis) in the brain 
  • Signals to the super optic nucleus and releases vasopressin into the bloodstream
  • Vasopressin acts on the kidney to either hold onto or let go of fluid
• Vasopressin also involved in desire, love, and attachment 
  • Acts through different mechanisms for its antidiuretic effects

How Antidiuretic Hormone Works

• Vasopressin increases the permeability of tubes in the kidney 
  • Prevents fluid from reaching the bladder and filling it
  • No urge to urinate as the bladder does not fill
• Kidneys use sodium to conserve water 
  • Water tends to follow sodium
  • Sodium concentration affects water retention or release

Complexity of Sodium and Fluid Balance

• No simple formula for sodium levels and water balance 
  • Depends on blood pressure, hormone levels, exercise, etc.
• Example: During certain phases of the menstrual cycle, hormonal fluctuations can cause water retention (edema)
  Estrogen and Water Retention
• High estrogen levels can cause water retention in both males and females 
• Athletes and bodybuilders taking anabolic steroids like testosterone, which can convert to estrogen, may experience water retention
• Estrogen acts as a diuretic, complicating the relationship between estrogen levels and water retention

Salt Intake and Health

• Knowing your blood pressure is crucial for determining appropriate salt intake
• High salt diets can be detrimental to brain health and function
• Low salt diets can also negatively impact brain health and function
• Most studies focus on the negative effects of high salt diets, but few control for other dietary factors

Sodium and Potassium Excretion Study

• Published in the Journal of the American Medical Association in 2011
• Examined urinary sodium and potassium excretion and risk of cardiovascular events
• Found that the hazard ratio for health risks was lowest at 4–5 grams of sodium excretion per day
• Hazard ratio increased dramatically at 7–12 grams of sodium excretion per day

Dietary Recommendations for Americans

• 2020–2025 recommendations suggest consuming no more than 2.3 grams (2300 milligrams) of sodium per day
• Most people likely consume more than this due to processed foods
• The study mentioned above suggests that 4–5 grams of sodium per day may be associated with even lower health risks than the recommended 2.3 grams
• Context is important, as the incidence of hypertension has increased and the relationship between salt intake and other dietary factors is unclear
  Sodium Intake and Health
• Sodium intake can affect blood pressure 
  • High blood pressure: caution with increasing sodium intake
  • Low blood pressure: may benefit from increased sodium intake
• Orthostatic disorders: low blood pressure, dizziness, fatigue 
  • May benefit from increased sodium intake
  • American Society of Hypertension recommends 6–10 grams of salt per day (2400–4000 mg of sodium)
  • Canadian Cardiovascular Society recommends 10 grams of salt per day (4000 mg of sodium)
• Context is vital: know your blood pressure and adjust sodium intake accordingly
• Moderate increase in salt intake generally not detrimental if consuming enough water
• Salt intake is homeostatically regulated: if craving salt, likely need it 
  • Follow salt cravings in the context of healthy, non-​​processed foods

Sodium Intake and Exercise

• Galpin Equation: body weight (in pounds) divided by 30 = ounces of fluid to drink every 15 minutes 
  • Designed for exercise, but also applicable for mental capacity
  • Start exercise hydrated with electrolytes (sodium, potassium, magnesium)
• Fluid and salt intake important in hot, cold, and dry environments
• Neurons signal through action potentials, requiring sodium, potassium, and magnesium
  Hydration and Electrolytes
• Most people are probably under hydrating and not getting enough electrolytes (sodium, potassium, magnesium) 
• It’s important to balance salt intake and hydration
• Galpin equation: body weight in pounds divided by 30 = ounces of fluid to drink every 15 minutes (average)
  • Not strict recommendations, but a guideline for maintaining hydration during activities

Adapting to Salt Intake

• Body adapts to a certain level of salt intake over time
• Hormones like aldosterone regulate sodium excretion from the kidney
• Glucocorticoids help regulate metabolism and are released from adrenal glands
• Salt appetite may not be the best indication of how much salt to ingest or avoid

Salt and Human History

• Salt was a valuable and sought-​​after substance throughout human history
• People were paid for labor in the form of salt
• Salt was scarce and expensive in certain regions of the world

Sea Salt vs. Table Salt

• Sea salt contains other minerals that can be beneficial to health
• Table salt is sufficient for most purposes, but sea salt may provide additional benefits

Too Little Salt and the Nervous System

• Kidneys regulate salt and fluid balance
• Adrenal glands produce glucocorticoids like aldosterone, which impact fluid balance and salt cravings
• Relationship between stress system (glucocorticoid system) and salt craving system
• Ingesting salt can help increase blood volume and blood pressure in cases of blood loss (hypovolemic thirst)
  Sodium, Stress, and Anxiety
• Low dietary sodium can exacerbate anxiety in animal models 
• Evidence for this in humans as well
• Stress response: elevated heart rate, blood pressure, ability to maintain movement and resistance to challenges
• Short-​​term stress activates the immune system
• Long-​​term stress has negative effects on health
• Increasing sodium intake can stabilize blood pressure and help resist stressors
• Craving for salty foods during stress is a hardwired biological phenomenon

Electrolytes: Magnesium and Potassium

• Magnesium:
• Many people get enough from their diet
• Some supplement with different forms of magnesium
• Magnesium malate: reduces muscle soreness from exercise
• Magnesium threonate: promotes transition into sleep, depth of sleep, and possibly cognitive function
• Magnesium bisglycinate: alternative to threonate for sleep promotion
• Magnesium citrate: effective laxative
• Potassium:
• Works closely with sodium in regulating balance in the body and brain
• Recommendations for sodium-​​potassium ratio vary
• Low-​​carb diets may require more sodium and potassium intake
• High-​​carb diets may require less sodium and potassium intake
• Intermittent fasting and caffeine consumption can affect sodium and water balance

Context Matters for Sodium and Potassium Intake

• Carbohydrate intake, diet, and eating patterns can influence sodium and potassium needs
• Adjusting intake based on individual context is important
• Consuming fluids during fasting periods, especially caffeinated beverages, can lead to sodium excretion and the need for increased salt intake
  Caffeine, Hydration, and Sodium
• For every ounce of caffeinated coffee or tea, consume 1.5 times as much water 
  • Example: 8 ounces of coffee, drink 12 ounces of water
  • Add a tiny pinch of sodium to the water
• Caffeine consumption leads to excretion of water, salt, and potassium 
  • Replenish fluids and electrolytes, including sodium, especially after exercise

Recommended Sodium Intake

• Dr. James D. Nicolantonio, author of The Salt Fix, recommends: 
  • 8–12 grams of salt per day (3.2–4.8 grams of sodium)
  • 1.5–2 teaspoons of salt per day
  • Sodium to potassium ratio: 4 grams of potassium
  • 400 milligrams of magnesium
• These recommendations are about 1.5–2 times the current recommendations

Salt and Sugar Relationship

• Salt receptors in the mouth and gut can influence cravings for sugar
• Parallel pathways in the nervous system for salty and sweet tastes
• Processed foods often contain hidden sugars or artificial sweeteners 
  • Bypasses homeostatic mechanisms for sweet cravings
• Cleansing the palate with water and lemon juice or vinegar can neutralize overly sweet sensations
  Sensory Systems and Food Interactions
• Sugars in foods can activate neuropod cells, signaling the brain to release dopamine and increase cravings 
• Hidden sugars can lead to overconsumption
• Salty-​​sweet combinations can lead to consuming more than if the food was just salty or sweet 
  • Both sweet and salty tastes have a homeostatic balance
  • Masking one taste with the other can disrupt this balance and lead to overconsumption
• Food manufacturers exploit the brain’s separate representation of pure tastes and their combinations

Sodium Intake and Health Benefits

• To determine appropriate sodium intake, consider: 
  • Blood pressure
  • Health benefits (reducing anxiety, improving sports performance, cognitive performance)
  • Consuming unprocessed foods to better hone in on specific salt appetite and needs
• Increasing salt intake with unprocessed foods can reduce sugar cravings

Sodium’s Role in Neuron Function

• Sodium is crucial for neuron function through action potentials (electrical activity)
• Neurons communicate by changing electrical activity, going from negative to positive charge 
  • Sodium rushes into the cell, carrying a positive charge
  • This triggers an action potential and the release of chemicals onto the next neuron
• Sodium is essential for the nervous system to function
• Disruption of sodium balance (e.g., drinking too much water) can lead to hypernatremia and negatively impact brain function
  Importance of Action Potentials and Sodium
• Action potentials control all aspects of the nervous system function 
• Sodium is crucial for neurons to function
• Insufficient sodium intake can lead to confusion, dizziness, and lack of coordination

Brain Monitoring Salt and Thirst

• Brain monitors salt levels in the body and drives fluid consumption
• Hormones from the brain operate at the kidney level to retain or excrete water

Salt Intake and Health Parameters

• Optimal salt intake depends on individual factors (e.g., hypertension, pre-​​hypertension, or normal tension)
• Fluid and electrolyte intake important for athletic performance and cognitive function
• Galpin equation can help determine appropriate fluid and electrolyte intake

Stress System and Salt Craving System

• Interaction between stress and salt craving systems
• Increasing salt intake may be beneficial for some people with anxiety or stress

Salt Intake for Low Blood Pressure

• Increasing salt intake may help offset low blood pressure and related dizziness

Perception of Salt and Taste

• Perception of salty and sweet tastes can drive increased sugar intake
• Combination of salty and sweet tastes can lead to craving processed foods

Sodium and Action Potentials

• Sodium plays a critical role in action potentials, the fundamental way the nervous system functions

Determining Optimal Salt Intake

• No universal recommendation for salt intake
• Individuals must consider fluid intake, diet, caffeine consumption, and electrolyte balance
• Future tools or apps may help determine optimal sodium intake for individuals

Resources

• The Salt Fix by Dr. James DiNicolantonio