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What causes keto headaches? (And what to do about them)

From the desk of Robb Wolf

<p>A lot of people ask me about headaches on keto. They want to know if they’re normal, why they happen, and how to make them go away.</p><p><span style="font-weight: 400">Keto headaches are normal as you transition to low-carb dieting. They can also occur in veteran keto dieters that are dehydrated. And I don’t just mean water. It’s both ends of the hydration coin—water and electrolytes.</span></p><p><span style="font-weight: 400">Both situations are fixable. Later, I’ll share tips for preventing and reversing keto headaches.</span></p><p><span style="font-weight: 400">If you’re doing everything right and your keto headaches persist, keto may have nothing to do with them. A long list of medical and lifestyle factors is linked to chronic headaches. We’ll explore these too.</span></p><p><span style="font-weight: 400">We’ll also explore how the ketogenic diet is a promising therapy for migraines. Done right, keto is a force against headaches. Keto can be a headache cure as well as a headache cause.</span></p><h2><strong>What Causes Headaches?</strong></h2><p><span style="font-weight: 400">A headache is defined as a continuous pain in the head. If the headache is sufficiently intense, it may be described as a migraine.</span></p><p><span style="font-weight: 400">Migraines typically affect one side of the head and are often accompanied by nausea and light sensitivity. They’re </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6854770/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">considered</span></a><span style="font-weight: 400"> the number one contributor to disability in those under 50 years old.</span></p><p><span style="font-weight: 400">The origins of a headache can be mysterious. There are many potential causes: brain inflammation, dehydration, electrolyte issues, low blood sugar, stress, sleep, the list goes on.</span></p><p><span style="font-weight: 400">In a </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513814/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">2017 review</span></a><span style="font-weight: 400"> published in the journal </span><i><span style="font-weight: 400">Neurology</span></i><span style="font-weight: 400">, researchers examined 27 studies on people with chronic headaches. The studies were either randomized controlled trials (the gold standard of science) or high-quality observational studies. The objective was to find factors that predicted headache occurrence—in other words, what might</span> <span style="font-weight: 400">cause headaches. Here are the predictive factors supported by “moderate quality evidence”:</span></p><ul><li style="font-weight: 400"><span style="font-weight: 400">Depression and anxiety</span></li><li style="font-weight: 400"><span style="font-weight: 400">Medication overuse</span></li><li style="font-weight: 400"><span style="font-weight: 400">Poor sleep</span></li><li style="font-weight: 400"><span style="font-weight: 400">High stress</span></li></ul><p><span style="font-weight: 400">Other factors with lower quality evidence included age, BMI, and employment status. One interesting tidbit was that those with higher expectations for a headache therapy (like acupuncture) tended to benefit more from the therapy.</span></p><p><span style="font-weight: 400">The takeaway is to start with things like sleep, stress, mood, and medication when unraveling a headache problem. If the headache appears specific to keto, there are a few more factors to add to that list.</span></p><p><span style="font-weight: 400">We’ll cover those factors in a bit. First let’s talk about the use of the keto diet as a headache cure.</span></p><h2><strong>Keto for Headaches</strong></h2><p><span style="font-weight: 400">Since 1928, researchers have </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6854770/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">known</span></a><span style="font-weight: 400"> that the keto diet can help with headaches. That was when the first case series suggested keto provides migraine relief. More recently, another </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4887398/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">study</span></a><span style="font-weight: 400"> found that one month of keto dieting reduced the frequency and duration of headaches in a group of 18 migraine sufferers.</span></p><p><span style="font-weight: 400">Larger studies show promise too. For instance, one </span><a href="https://thejournalofheadacheandpain.biomedcentral.com/articles/10.1186/1129-2377-14-S1-P219" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">study</span></a><span style="font-weight: 400"> from </span><i><span style="font-weight: 400">The Journal of Headache and Pain</span></i><span style="font-weight: 400"> found that 108 migraine patients showed a 90% response rate to the keto diet, as opposed to no effect from a low-calorie diet.</span></p><p><span style="font-weight: 400">Why might keto help with headaches? In a word: ketosis. Consider the following:</span></p><ul><li style="font-weight: 400"><span style="font-weight: 400">A state of elevated ketones (ketosis) appears to be </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3219306/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">protective</span></a><span style="font-weight: 400"> against traumatic brain injury and therapeutic for neurodegenerative disease.</span></li><li style="font-weight: 400"><span style="font-weight: 400">Compared to glucose, ketones are a </span><a href="https://eurekamag.com/research/004/357/004357390.php" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">cleaner burning</span></a><span style="font-weight: 400"> and more efficient source of energy for the brain.</span></li><li style="font-weight: 400"><span style="font-weight: 400">The aging brain </span><a href="https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/nyas.12999" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">loses its ability</span></a><span style="font-weight: 400"> to use glucose but not its ability to use ketones.</span></li><li style="font-weight: 400"><span style="font-weight: 400">Beta-hydroxybutyrate (the main energy ketone) </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4352123/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">suppresses</span></a><span style="font-weight: 400"> the NLRP3 inflammasome, a driver of inflammation.</span></li></ul><p><span style="font-weight: 400">Inflammation reduction may be the key to why keto helps with headaches. The keto diet reduces brain inflammation, and brain inflammation has been </span><a href="https://pubmed.ncbi.nlm.nih.gov/29568973/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">linked</span></a><span style="font-weight: 400"> to migraines.</span></p><p><span style="font-weight: 400">But if your headache is </span><i><span style="font-weight: 400">caused</span></i><span style="font-weight: 400"> by keto (directly or indirectly), inflammation probably isn’t to blame.</span></p><h2><strong>Causes of Keto Headaches</strong></h2><p><span style="font-weight: 400">Many things can cause a headache. But a headache specific to keto? That shortens the list. Here are the main causes of keto headaches:</span></p><h3><strong>#1: Transitioning to ketones</strong></h3><p><span style="font-weight: 400">Your brain normally </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3900881/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">runs on glucose</span></a><span style="font-weight: 400"> for energy. When you eat carbohydrates, those carbs break down to glucose and cross the blood-brain barrier to power your neurons.</span></p><p><span style="font-weight: 400">When you go keto, you stop eating carbs for the most part. This decreases the brain’s glucose supply, which can result in headaches, brain fog, and hunger.</span></p><p><span style="font-weight: 400">Glucose isn’t the only brain fuel though. Lactate, pyruvate, medium chain triglycerides (MCTs), and ketones can also cross the blood-brain barrier to sate your brain’s ravenous appetite.</span></p><p><span style="font-weight: 400">Ketones are the big one here. On a keto diet, ketones become the main source of fuel for your brain. That’s why your liver creates ketones out of fatty acids. You need the backup brain fuel.</span></p><p><span style="font-weight: 400">But the </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5858534/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">brain takes time</span></a><span style="font-weight: 400"> to keto-adapt. It might take a few hours, a few days, or in rare cases a week or more. Once the brain is running on ketones, the lower supply of glucose doesn’t matter. Ketones are the fuel now.</span></p><h3><strong>#2: Too many carbs on keto</strong></h3><p><span style="font-weight: 400">Carb restriction is the fundamental rule of </span><a href="https://drinklmnt.com/blogs/health/ketogenic-diet-what-you-need-to-know" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">the keto diet</span></a><span style="font-weight: 400">. Restricting carbs keeps the hormone insulin low, and low insulin tells your liver to start burning fat and making ketones.</span></p><p><span style="font-weight: 400">A good rule of thumb is to keep carbs below 10% of daily calories. (Around 30 grams of net carbs per day). This level of carb restriction is generally sufficient for ketone production (ketogenesis) to commence. These ketones can then fuel your brain.</span></p><p><span style="font-weight: 400">A higher carb diet (over 100-150 grams of carbs per day) also provides lots of brain fuel as glucose. It’s in the middle—low-carb but not keto—that things get tricky.</span></p><p><span style="font-weight: 400">For example, if you eat 50 grams of carbs per day, that might be too high to make ketones but too low to provide adequate glucose for the brain. Understand that the brain </span><a href="https://www.ncbi.nlm.nih.gov/books/NBK22436/#:~:text=The%20brain%20lacks%20fuel%20stores,body%20in%20the%20resting%20state." target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">consumes</span></a><span style="font-weight: 400"> about 120 grams of glucose per day when ketones aren’t around.</span></p><p><span style="font-weight: 400">True, you have glucose backup systems. You can make your own glucose (gluconeogenesis) and access stored glucose (from glycogen), but these sources are likely inadequate to feed a glucose-hungry brain.</span></p><h3><strong>#3: Dehydration</strong></h3><p><span style="font-weight: 400">A lot of keto flu symptoms (including headaches) are blamed on dehydration. Thanks to all this press, most people on keto </span><a href="https://drinklmnt.com/blogs/health/how-much-water-should-you-drink-on-keto" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">tend to drink enough fluids</span></a><span style="font-weight: 400">.</span></p><p><span style="font-weight: 400">To be clear, the keto diet </span><i><span style="font-weight: 400">does </span></i><span style="font-weight: 400">have a </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5858534/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">diuretic effect</span></a><span style="font-weight: 400">. This is driven by low levels of insulin, which signal the kidneys to excrete more water.</span></p><p><span style="font-weight: 400">What about all the water lost from glycogen breakdown? Doesn’t that cause dehydration symptoms?</span></p><p><span style="font-weight: 400">This is a common point of confusion. While it’s true that glycogen is mostly water, accessing that water by breaking down glycogen doesn’t decrease blood volume. (Blood volume is a primary marker of </span><a href="https://drinklmnt.com/blogs/health/how-to-stay-hydrated" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">hydration status</span></a><span style="font-weight: 400">).</span></p><p><span style="font-weight: 400">In fact, breaking down glycogen </span><i><span style="font-weight: 400">increases</span></i><span style="font-weight: 400"> blood volume. When you split apart glycogen, you </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334560/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">release water into circulation</span></a><span style="font-weight: 400">. Eventually, you pee it out, but that water needn’t be replaced. On keto, you operate in a glycogen-depleted state. </span></p><h3><strong>#4: Electrolyte disturbances</strong></h3><p><span style="font-weight: 400">If you’re several days into keto and the headaches still haven’t resolved, you’re probably low on electrolytes.</span></p><p><span style="font-weight: 400">There are two main reasons keto dieters tend to be short on these crucial minerals:</span></p><ol><li style="font-weight: 400"><span style="font-weight: 400">Low insulin levels on keto </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5858534/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">increase electrolyte loss</span></a><span style="font-weight: 400"> through urine.</span></li><li style="font-weight: 400"><span style="font-weight: 400">It’s hard to consume enough sodium and potassium on a healthy low-carb diet.</span></li></ol><p><span style="font-weight: 400">Let’s talk about reason two. It’s hard to get enough </span><a href="https://drinklmnt.com/blogs/health/what-causes-keto-flu-and-6-keto-flu-remedies" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">sodium on keto</span></a><span style="font-weight: 400"> because most dietary sodium comes from refined foods. When you eliminate these pseudo-foods, the salt shaker needs to work overtime.</span></p><p><span style="font-weight: 400">And it’s hard to get enough potassium because many potassium-rich foods are too high-carb to be keto. This list includes potatoes, carrots, and most fruits.</span></p><p><span style="font-weight: 400">Deficiencies in both these electrolytes can cause headaches. What dosage do you need for optimal health? Based on published evidence, shoot for </span><a href="https://pubmed.ncbi.nlm.nih.gov/22110105/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">4–6 grams sodium</span></a><span style="font-weight: 400"> and </span><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6181280/" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">3.5–5 g potassium</span></a><span style="font-weight: 400"> per day from diet and supplements.</span></p><h2><strong>Keto Headache Remedies</strong></h2><p><span style="font-weight: 400">The cures for keto headache follow from the causes above. Here’s a quick list:</span></p><ul><li style="font-weight: 400"><b>Allow a grace period.</b><span style="font-weight: 400"> Allow at least 3 days for transitioning from glucose to ketones. But also mind the other tips during this period.</span></li><li style="font-weight: 400"><b>Take MCTs and exogenous ketones.</b><span style="font-weight: 400"> During the grace period, use MCT oil and exogenous ketones to raise ketone levels and mitigate symptoms.</span></li><li style="font-weight: 400"><b>Watch your carbs.</b><span style="font-weight: 400"> If you’re low-carb but not keto, you might find yourself short on both glucose and ketones to fuel your brain. That will make your brain sad.</span></li><li style="font-weight: 400"><b>Eat electrolyte-rich foods.</b><span style="font-weight: 400"> Meats, nuts, and leafy greens are good sources of potassium and magnesium. Check out this </span><a href="https://drinklmnt.com/blogs/health/electrolyte-rich-foods-and-when-to-supplement" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">post</span></a><span style="font-weight: 400"> to learn more.</span></li><li style="font-weight: 400"><b>Be liberal with the salt shaker.</b><span style="font-weight: 400"> 4–6 g of sodium per day (the bare minimum for keto folks) is about 2–3 teaspoons of salt. A pinch of salt won’t stop keto headaches. Salt liberally.</span></li><li style="font-weight: 400"><b>Drink electrolyte water.</b><span style="font-weight: 400"> This bullet is probably the best keto headache “hack”. To hydrate without diluting blood sodium levels, add electrolytes (especially sodium) to your water and drink to thirst. </span><a href="https://drinklmnt.com/products/LMNT-Recharge-electrolyte-drink" target="_blank" rel="noopener noreferrer"><span style="font-weight: 400">LMNT</span></a><span style="font-weight: 400"> makes this easy.</span></li></ul><p><span style="font-weight: 400">Will these tips cure every headache? Of course not.</span></p><p><span style="font-weight: 400">Most keto-related headaches, however, won’t withstand them. Give them a shot and let me know how it goes.</span></p>