Episode Overview

Podcast: The Dr. Josh Axe Show
Episode Title: How to Hydrate Your Brain, Boost Energy & End Brain Fog
Release Date: August 18, 2025
Host: Dr. Josh Axe

In this information-packed episode, Dr. Josh Axe dives deep into the often misunderstood topic of hydration and why it’s about so much more than just drinking water. Dr. Axe explains the crucial role that electrolytes play in true hydration, how dehydration impacts the brain and body, and offers practical, actionable advice on optimizing your hydration to boost energy, improve cognition, and eliminate brain fog. He shares personal anecdotes, biblical and historical perspectives, the science behind hydration, and his top foods and tips for staying optimally hydrated.

Key Discussion Points

1. Hydration: Beyond Water ([00:14])

• Hydration means more than water intake; it’s about water plus ELECTROLYTES.
• When dehydrated, the blood becomes more concentrated, cells shrink, and the body struggles to regulate temperature and detoxify.
• Stat: 75% of people today are dehydrated, impacting memory, focus, and overall health.
• The brain is approximately 75% water; mild dehydration can even shrink brain volume, impairing focus and memory ([01:36]).

2. Warning Signs & Symptoms of Dehydration ([02:36])

• Common signs: Headaches, muscle cramps (often potassium or magnesium deficiency), constipation, brain fog, low energy, weakness, irritability, low blood pressure, dizziness.
• Overhydration Risk: Excessive salt and water can also cause high blood pressure—balance is key.

3. Personal Story: The Daniel Fast ([[04:26] – [06:40]])

• Dr. Axe shares his experience of a 21-day Daniel fast (only fruits, vegetables, and nuts, with zero salt).
  • Resulted in significant weight loss, no enjoyment in food, weakness, lightheadedness, and moodiness.
  • “One of the things I noticed was nothing tasted good. ... When I was doing this fast, I will tell you, I felt weak, I felt lightheaded, I felt a little bit moody.” ([05:04])
• On reintroducing salt (specifically Celtic sea salt): “My energy and hydration improved drastically. I really noticed a difference and it made me realize one, it wasn't just food, ... the salt was one of the things that I was craving the most.” ([06:41])

4. The Sodium-Potassium Pump ([07:30])

• Sodium brings water and nutrients into cells; potassium helps flush them out.
• Imbalanced intake (e.g., too much sodium/not enough potassium) leads to water retention, inflammation, and poor hydration.

5. Top 10 Causes of Chronic Dehydration ([10:13] – [18:35])

Dr. Axe lists and explains the most common reasons people are chronically dehydrated:

1. Drinking water without adequate electrolytes.
2. High caffeine and alcohol use—both are dehydrating ([11:10]).
3. Low salt intake, especially when cutting out processed foods but not adding quality salt back in.
4. Sweat loss from activity or heat.
   • “You can lose up to 1.5 liters of fluid per hour of exercise in the heat.” ([12:25])
   • Potentially deadly: Hyponatremia from only drinking water during endurance activities ([13:34]).
5. Modern indoor lifestyles—dry air from heating or AC increases water loss through skin/breath.
6. Not eating enough hydrating foods—processed diets lack water and electrolytes.
7. High stress levels—raises cortisol and fluid loss, alters kidney function.
8. Illness—fever/vomiting/diarrhea cause rapid fluid/electrolyte loss.
   • “Dehydration from diarrhea is actually a leading cause of death of children worldwide.” ([16:32])
9. Not drinking enough water.
10. Older age—thirst mechanism declines, dehydration is the leading cause of hospitalization for those over 65.

6. Electrolytes Explained ([19:55])

• Electrolytes = minerals with electrical charge: sodium, potassium, magnesium, calcium, chloride, phosphate.
• “Water needs these minerals to get inside your cells. Without these electrolytes, water cannot get inside your cells.” ([20:14])
• Potassium: Second most abundant electrolyte, yet 98% of Americans are deficient due to low fruit/vegetable intake and high sodium consumption.

7. Dr. Axe’s Top Electrolyte Sources ([21:40])

Sodium

• Sea salt (Celtic, red, pink), olives, miso, fermented foods (pickles, sauerkraut, kimchi), celery, and bone broth.

Potassium

• Watermelon (“my favorite hydrating food”), coconut water, potatoes (particularly sweet), bananas, avocados.

Magnesium

• Leafy greens (especially spinach), pumpkin seeds, dark chocolate.

Calcium

• Sardines, sesame/tahini, yogurt, kale, spinach.

8. The Hydration Power of Foods ([23:00])

• Up to 20% of daily water intake is from foods (fruits/vegetables).

• Top Hydrating Foods:

  • Watermelon (92% water, plus potassium, lycopene, Vitamin C)
  • Cucumbers, lettuce, celery (95%-96% water)
  • Strawberries, oranges (91%)
  • Zucchini, tomatoes (94%)
  • Coconut water (very high potassium, magnesium)
  • Sweet potatoes, avocados, bone broth

• DIY Electrolyte Drink Recipe ([36:40]):

  • 8 oz water, juice of 1 lemon, 2 tsp local honey, 1/4 tsp gray Celtic sea salt.

9. Balancing Sodium: Not Too Much, Not Too Little ([27:35])

• Cites a 2023 study: sodium restrictions below 2.5 grams/day may increase risk for heart failure in older adults.
• “Balance is key. … For people with heart failure, restricting dietary sodium intake to levels below the standard recommended maximum dose of 2.3 grams per day does not bring additional benefits and may increase the risk of death.” ([28:12])
• Historical fun fact: “Salary” comes from "salarium," or salt money—salt was once so valuable Roman soldiers were paid with it. ([29:22])

10. How Much Salt Do You Need? ([31:52])

• Sedentary: 1,500–2,300 mg/day (about two-thirds to one teaspoon)
• Light activity: 1–1.5 tsp/day
• Active & sweating: 1.5–2 tsp/day
• High heat & heavy sweating: 2–4 tsp/day (4,000–6,000 mg)
• Fast food easily exceeds these—best to use a high-quality sea salt, not table salt

11. Electrolyte Pack Warning & Recommendations ([33:14])

• Most commercial electrolyte powders (especially those with a 5:1 sodium:potassium ratio) are too high in synthetic sodium, not whole-food based.
  • “Most of the electrolyte powders you're taking today have artificial sweeteners, they have dyes, they have fillers, they have this high synthetic amounts of sodium. That's not what you want.” ([34:47])
• If you’re not an endurance athlete, use a 2:1 or 1:1 sodium:potassium ratio (he prefers 1:1).
• Look for powders with natural sources: celery juice, watermelon juice, coconut water, pomegranate, natural sea salts.

12. Homemade Electrolyte Drinks ([36:40])

• Water + lemon + honey + Celtic sea salt
• Coconut water + a pinch of sea salt
• Watermelon juice + a pinch of sea salt
• Avoid refined table salt (bleached, stripped of minerals)—use sea salt or Himalayan salt instead.

Notable Quotes & Memorable Insights

• “75% of people today are dehydrated. ... Even a 1 to 2% dehydration can impair your memory and focus.” ([01:36])
• “When I was doing this fast, I will tell you, I felt weak, I felt lightheaded, I felt a little bit moody.” — Dr. Josh Axe ([05:04])
• “Sodium brings water and fluid and nutrients … into the cell and potassium flushes things out of your cell. It's kind of like this sodium-potassium pump. One pumps it in, one pumps it out.” ([07:30])
• “Drinking too much water during endurance activities ... can also dilute the sodium content in your blood. … There are cases of people … who died. This condition is called hyponatremia … it can actually kill you.” ([13:34])
• “Potassium is the one we're most deficient in. ... When you consume these electrolytes, they really should be consumed together because they work together to support the functioning of your body.” ([20:47])
• “It’s all about balance. You want sodium, you want potassium, you want water, you want them in the right doses.” ([26:52])
• “Salary literally means salt money … because it's that valuable.” ([29:23])
• On hydration basics: “Hydration isn’t just about drinking water all day long, especially if you’re not thirsty or not very active. It’s about H2O plus electrolytes. You need both.” ([38:07])

Timestamps for Important Segments

| Timestamp | Segment | |-------------|----------------------------------------------------------------| | 00:14 | Why hydration is misunderstood; importance of electrolytes | | 01:36 | Dehydration’s impact on brain health and function | | 02:36 | Warning signs and symptoms of dehydration | | 04:26–06:40 | Dr. Axe’s personal story about salt deficiency during fasting | | 07:30 | Sodium-potassium pump explanation | | 10:13–18:35 | Top 10 causes of chronic dehydration | | 19:55 | What are electrolytes and why they matter | | 21:40 | Dr. Axe’s top food sources for key electrolytes | | 23:00 | Top 10 hydrating foods | | 27:35 | The importance of sodium balance and recent sodium research | | 29:22 | The historical value of salt and origin of “salary” | | 31:52 | Recommended daily salt needs by activity level | | 33:14 | Electrolyte powder ratios & key advice | | 36:40 | Homemade electrolyte drink recipes & tips | | 38:07 | Hydration recap: importance of water plus electrolytes |

Tone & Style

Dr. Axe combines practical health science with biblical and historical references, delivering advice with a conversational, motivational, and holistic tone. He emphasizes a nuanced, natural, and individualized approach rather than one-size-fits-all recommendations.

Takeaway Summary

• Hydration is more than water—it’s H₂O plus a balance of electrolytes, especially sodium and potassium.
• Dehydration is widespread, and its impact reaches from headaches and constipation to impaired cognition and chronic diseases.
• Natural, whole-food sources of electrolytes—fruits, vegetables, bone broth, sea salt—are far superior to processed sports drinks or table salt.
• Strike a balance; both over- and underconsumption of salt can be harmful.
• Make your own electrolyte drinks, focus on variety, and adjust your intake to your level of activity and environment.
• Listen to your body, and remember: staying hydrated supports not just physical health but mental sharpness, mood, and overall vitality.

For More…

Check out Dr. Axe’s book The Biblio Diet for further insights on hydration, salt, and biblical principles of health, or visit his website for natural health resources.