PDF Summary:Brain Wash, by David Perlmutter and Austin Perlmutter

Could your daily habits be sabotaging your health and happiness? In Brain Wash, neurologist David Perlmutter and physician Austin Perlmutter argue that our modern lifestyles—filled with technological distractions, processed foods, and chronic stress—are impairing our brain function and decision-making abilities. This leads to a cycle of choices that damage our health, relationships, and mental well-being, increasing our risk of chronic disease, anxiety, and depression. The Perlmutters suggest simple lifestyle adjustments to reclaim your health and happiness in the modern world.

This guide explores the science behind how modern habits affect our brain’s reward systems and stress response. We’ll discuss strategies for improving your brain health—from managing technology use to improving diet and sleep, and practicing mindfulness. We’ll also examine insights from other health experts and provide additional lifestyle tips.

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The Perlmutters explain that many of us eat a lot of processed foods because they’re designed to be addictive. Specifically, these foods are addictive because:

1. Marketing tactics create emotional connections. Food companies create positive associations with their processed products through advertising, cartoon characters, and celebrity endorsements that target children from a young age. When children grow up seeing these ads and eating these foods, they can develop strong preferences for them that extend into adulthood.

(Shortform note: In Fast Food Nation, Eric Schlosser says that McDonald’s pioneered many of the marketing tactics food companies use today to create emotional bonds with children. The company introduced beloved mascots like Ronald McDonald and Grimace, built playgrounds at restaurants, and partnered with toy companies and movie studios to make eating at McDonald’s an exciting experience for kids. These strategies were so successful that by the early 2000s, entire food industry marketing departments focused solely on building brand loyalty in children as young as two years old—studying their psychology, analyzing their artwork, and even categorizing different ways that kids beg their parents for what they want.)

2. Processed foods activate your brain’s reward pathways. The more your reward circuits are activated, the stronger the connections become, making it increasingly difficult to resist unhealthy foods.

(Shortform note: Processed foods are hard to resist because they may actually be addictive substances, not unlike drugs. Addiction researchers point out that about 14% of people show signs of genuine food addiction, meaning they experience strong cravings and difficulty cutting back despite wanting to stop.)

3. Processed foods impair decision-making. When you eat foods high in sugar and refined carbs, your body stores more belly fat. Excess fat creates inflammation in your body that weakens your prefrontal cortex, causing you to eat more impulsively. This leads to a destructive pattern where bodily inflammation from poor food choices impairs your decision-making, which then leads to even more poor food choices.

(Shortform note: In How Not to Diet, Michael Greger explains that processed foods themselves cause inflammation, not just the excess fat your body develops from eating them. While normal inflammation helps your body heal from injuries like a stubbed toe, the fats in processed foods, especially saturated and trans fats, create a constant state of inflammation throughout your body that disrupts your hormones, leading to higher blood sugar, increased appetite, and a slower metabolism.)

Foods to Eat and Avoid

To break the habit of unhealthy eating, the Perlmutters recommend transitioning to a diet that reduces inflammation and supports better brain function. This means eating whole, nutrient-dense foods while avoiding processed foods and refined carbohydrates. Eat more locally sourced foods and prepare more meals at home rather than relying on processed options.

(Shortform note: The Perlmutters don’t elaborate on the benefits of buying locally sourced foods, but other health experts explain that local produce typically travels shorter distances from farm to table, which means it retains more nutrients like vitamin C and antioxidants that otherwise degrade during long-distance transportation and storage. You can find local foods by visiting farmers’ markets, joining a community-supported agriculture (CSA) program, or checking labels at your grocery store’s produce section.)

For protein sources, the Perlmutters suggest choosing wild-caught fish, grass-fed meat, and pastured eggs from free-range chickens. You can also include modest amounts of gluten-free, unrefined grains or seeds like wild rice, quinoa, buckwheat, and millet. Healthy fats should come from sources like extra virgin olive oil, avocado oil, and nuts.

(Shortform note: Though many health experts recommend consuming grains as part of a healthy diet, some advise against them due to their lectin content. In The Plant Paradox, Steven Gundry explains that lectins are toxic proteins produced by plants as a defense mechanism and that they’re harmful to your health. For this reason, Gundry puts whole grains, quinoa, and seeds, as well as oils made from lectin-containing plants like vegetable, corn, and peanut, on his list of foods to avoid. However, he does agree with the Perlmutters that you should eat wild and grass-fed protein sources since they’re more lectin-free than grain- and soy-fed produce.)

Additionally, the Perlmutters encourage you to support your gut bacteria by eating probiotic foods (like kimchi and yogurt) and prebiotic foods (like dandelion greens, onions, garlic, and leeks).

(Shortform note: Dieticians explain the difference between probiotics and prebiotics: Probiotics are the good bacteria in fermented foods that help break down what you eat and support your immune system. Prebiotics, on the other hand, are carbohydrates your body can’t digest but which serve as food for good bacteria, allowing them to multiply and function better. Experts say most people get enough probiotics and prebiotics through their diet, but you can also take supplements if needed.)

Tip #3: Get Regular Exercise

Another habit the Perlmutters suggest for improving brain health is to exercise regularly, aiming for at least 20 minutes of aerobic activity five days per week. They explain that exercise changes how your brain works, making it function better.

(Shortform note: While the Perlmutters’ suggestion of 20 minutes of aerobic exercise is a good starting point, you may want to incorporate a mix of different activities to maximize the health benefits of exercise. Unlike aerobic exercise, which uses energy from oxygen, anaerobic activities like weightlifting and interval training tap into your muscles’ energy stores. These short bursts of intense exercise strengthen your bones, build muscle mass, and help prevent the natural 1% muscle loss that typically occurs each year after age 27.)

According to the Perlmutters, exercise improves your brain health in two ways:

First, when you exercise regularly, your brain gets better at making decisions and controlling emotions. This happens because exercise increases blood flow to the prefrontal cortex, which supports the growth of neural connections and improves cognitive function.

(Shortform note: For this reason, Barbara Oakley and Terrence Sejnowski recommend interspersing study sessions with exercise to make learning more effective. In Learning How to Learn, they explain that when you exercise, your body produces a hormone called BDNF that helps your brain cells grow more dendritic spines—tiny receivers that help brain cells communicate with each other. Oakley and Sejnowski write that stronger connections between neurons make it easier to remember what you’ve learned.)

Second, exercise reduces inflammation, improves insulin resistance, and helps regulate cortisol levels when done in moderation. The Perlmutters explain that these combined effects allow the prefrontal cortex to better moderate emotional responses while boosting your mood at the same time. As a result, you can find it easier to make smarter choices about everything from what to eat to how to spend your time.

(Shortform note: As a word of caution, high-intensity workouts without proper recovery can actually trigger more inflammation and weaken your immune system. When you push too hard without breaks, your body stays stressed, unable to reap the anti-inflammatory benefits that moderate exercise provides. So, aim for consistent, moderate activity and get adequate rest for more intense workouts. You don’t have to do much to reap the benefits; even a 20-minute brisk walk or light jog can trigger anti-inflammatory responses in your body.)

Tips for Exercising

According to the Perlmutters, any movement is better than none when it comes to protecting your brain health and ability to make good decisions. The key is making physical activity a consistent priority, even if you begin with just a few minutes per day. Here are some tips for doing so:

1. Make exercise social and scheduled. Partner with a friend for workouts, join group classes, or schedule regular walking dates. Working out with others increases accountability and makes exercise more enjoyable. The added social connection provides extra motivation while giving you the dual benefits of movement and meaningful interaction.

(Shortform note: If you prefer exercising alone, you can still get accountability and feel connected through fitness apps with social features. Research shows that fitness apps with social elements like sharing achievements, comparing progress with others, and joining virtual challenges make users more likely to stick with their exercise routines.)

2. Set yourself up for success. Block specific workout times in your calendar and treat them as important appointments. Making exercise a non-negotiable part of your schedule helps build the habit. The Perlmutters also recommend you prepare workout clothes the night before, especially for morning exercise, so it takes less effort for you to get going.

(Shortform note: Blocking workout times and preparing clothes reduces what Shawn Achor (The Happiness Advantage) calls activation energy—the effort needed to start an activity. By setting clear rules and removing obstacles, you’re much more likely to follow through. Achor notes that even a 20-second delay (like having to search for workout clothes in the morning) can be enough to discourage you from doing something when your motivation is low. When you establish these supporting systems and make exercise as frictionless as possible, you set up an environment that naturally guides you toward keeping your workout commitment instead of having to rely on willpower alone.)

3. Create a balanced routine. Include a mix of cardio (like walking, swimming, or cycling), strength training, and stretching. Start with small, manageable amounts of activities that you enjoy and gradually increase duration and intensity. Remember that even small amounts of movement, like standing up for two minutes every hour, provide benefits.

(Shortform note: In Atomic Habits, James Clear explains that starting small can lead to bigger behavior changes because it alters your identity. When you start exercising regularly, even in small ways, you begin to see yourself as someone who prioritizes fitness. This creates a powerful feedback loop: The more you exercise, the more you see yourself as someone who exercises, which motivates you to continue to do so. When these small movements become part of who you are rather than just something you do, you’re more likely to stick with them and gradually build up to longer, more comprehensive fitness routines.)

Tip #4: Reconnect With Nature

The fourth healthy habit the Perlmutters recommend is to spend more time in nature. They explain that modern life keeps most people indoors and disconnected from the natural world.

(Shortform note: In Braiding Sweetgrass, Robin Wall Kimmerer writes that when you spend time in the natural world, you witness examples of cooperation and mutual support that can shift your perspective on life. For instance, fungi and algae work together to help each other survive, and pecan trees coordinate their nut production across entire forests to ensure their collective survival. These natural patterns remind us that we’re part of a larger living system and aren’t meant to exist in isolation, helping us restore a sense of connection with the world.)

Research shows that getting out in nature benefits both your physical and mental health:

1. Physical health: When you spend time in natural settings, your stress hormones decrease, and your immune function improves. Being out in nature also lowers inflammation in your body and helps activate your parasympathetic nervous system, which promotes relaxation and healing. These biological changes also strengthen your prefrontal cortex while calming your amygdala, helping you think clearly and better control your impulses.

(Shortform note: Virtual reality (VR) nature experiences may be able to provide many of the same healing benefits as real outdoor environments. Research involving hospital patients showed that virtual natural environments reduced pain levels, anxiety, and fear, while also improving cognitive function in elderly patients. VR scenes featuring both blue elements (like water) and green elements (like forests) are especially effective at promoting healing and relaxation. This technology could be particularly valuable for people who can’t easily access nature, like hospital patients or people in urban environments.)

2. Mental health: Nature can help restore your depleted attention and let your brain recover from the constant stimulation of modern life. Spending time in nature reduces symptoms of depression and anxiety while increasing your happiness, life satisfaction, and feelings of connection to others. The Perlmutters point out that even brief exposure to natural environments can boost your mood, cognitive function, and creativity.

(Shortform note: To make the most of nature’s restorative effects on your mind, consider going somewhere where there’s water. In Blue Mind, Wallace J. Nichols writes that when you spend time near water—whether it’s an ocean, a lake, or even a fountain—your brain shifts into a more peaceful state. Simply looking at water or listening to water sounds can trigger calming effects, as these experiences remind us of being in the womb and tap into deep evolutionary connections with blue environments.)

The Perlmutters explain that nature’s benefits come through multiple pathways. Plants and trees contain compounds called phytoncides that boost immune function and promote relaxation. Being exposed to sunlight also helps your body produce vitamin D, which is necessary for brain health and serotonin production. Also, the visual experience of natural beauty and awe makes people more generous, trusting, and empathetic toward others. Even the beneficial bacteria we encounter in natural settings may help support our gut microbiome.

(Shortform note: In Awe, Dacher Keltner describes awe as a feeling of connection with something bigger than yourself. Awe makes you feel closer and more empathetic to others because it reduces activity in the region of your brain that engages in self-centered thinking. At the same time, it stimulates areas of your brain that process sounds, shapes, and colors, immersing you in inspirational experiences and letting you assign meaning to them. In addition to nature, Keltner writes that music, art, spirituality, and the awareness of birth and death can also inspire awe.)

The Toll of Urban Living

In The Nature Fix, Florence Williams writes that our brains are hardwired to need nature through what scientists call biophilia—an innate attraction to the natural world that developed over the course of human evolution.

However, since 2008, over half the world’s population lives in cities where exposure to nature is limited. Williams explains that city dwellers face constant noise, endless distractions, and artificial environments that keep us in a state of chronic stress. Also, the indoor lifestyle of city living deprives us of sunlight exposure, leading to vitamin D deficiency so severe that some UK children have developed rickets (a bone disease). The lack of vitamin D also contributes to nearsightedness because sunlight shapes how our eyes develop.

Tips for Going Outside

To spend more time in nature, the Perlmutters suggest you start with simple daily actions like opening windows to let in sunlight or keeping plants in your office or workspace. You can even consider using essential oils that contain phytoncides. However, the Perlmutters recommend spending at least 30 minutes per week in actual nature settings by walking in parks or hiking in the mountains. For more nature exposure, you can go on nature-focused vacations like ecotours. The key is to treat being in nature as a regular, intentional practice rather than an occasional thing you do by accident.

(Shortform note: Research shows that spending just five to 10 minutes in a room with houseplants makes people feel happier and more satisfied compared to those in plant-free rooms, especially in enclosed spaces like offices and apartments. While artificial plants are better than no plants at all, real plants are more effective: Having five or more leafy plants within 10 feet of you produces the strongest positive effects on your mood. You can also consider color for specific mood effects. Bright green or yellow-green leaves tend to boost cheerfulness, while purple and green flowering plants relax the body and reduce anxiety and blood pressure.)

Tip #5: Improve Your Sleep

According to the Perlmutters, another way to improve your brain health is to get adequate sleep. Sleep deprivation creates serious health problems because sleep affects virtually every system in your body, especially your brain. They note that about one-third of American adults get less than the recommended seven hours of sleep per night.

(Shortform note: A “sleep machismo” culture—the belief that getting less sleep is a sign of dedication and toughness—may explain why so many Americans fall short of the recommended seven hours of nightly rest. You might recognize this attitude when people brag about their four-hour nights or shame others who prioritize rest. To prioritize sleep, we must rethink our cultural attitudes toward rest and treat it as a biological necessity rather than a luxury.)

The Perlmutters explain that poor sleep harms your brain in two ways:

1. Bad decision-making: Sleep deprivation increases activity in the emotional, reactive part of your brain while decreasing activity in your prefrontal cortex. When you don’t get enough sleep, you become more reactive to stress, more likely to feel anxious or depressed, and less able to control your impulses. Poor sleep also triggers inflammation in your body and disrupts hormones that regulate hunger and mood. This makes you more likely to make poor choices when it comes to food and other behaviors.

(Shortform note: Have you ever felt strangely energetic after a bad night’s sleep? This burst of energy doesn’t mean your body works better with less rest. Instead, it’s because your brain releases stress hormones to cope with insufficient rest. Though you may get a temporary energy boost, your memory and attention become immediately impaired after just one night of poor sleep. When that initial stress response fades, you’re left more vulnerable to the impaired judgment and reduced ability to regulate your behavior that the Perlmutters warn about.)

2. Brain waste: Sleep deprivation prevents your brain from cleaning out harmful waste products that build up during the day. Your brain has a special cleaning mechanism called the glymphatic system that removes waste products. This process only happens during sleep, and when it’s disrupted, toxins can accumulate and damage your brain cells. The buildup of waste materials can eventually lead to conditions like Alzheimer’s disease and depression. The Perlmutters add that this cleanup process becomes less efficient as you age, making good sleep habits even more important for older adults.

(Shortform note: Research suggests that sleeping on your side is the most effective position for clearing out brain waste, while sleeping on your back may increase your risk of neurodegenerative diseases like Alzheimer’s. If you want to maximize your brain’s nighttime cleaning, sleep experts recommend lying on your side with slightly bent knees (not fully curled up), using a supportive pillow for your head, and placing another small pillow between your legs to keep your spine straight. This position not only helps your brain clear toxins but can also reduce snoring, help with sleep apnea, and ease back pain.)

Tips for Getting Better Sleep

The Perlmutters recommend several strategies to improve the duration and quality of your sleep:

1. Manage your light exposure. Get bright natural sunlight in the morning to reset your body’s clock, but minimize your exposure to blue light in the evening hours before bed. Blue light is a specific wavelength of light from digital screens that tricks your brain into being alert and blocks your body’s production of melatonin—the hormone that helps you fall asleep. Wear blue-light blocking glasses if you must use devices at night, or enable night mode settings that reduce blue light emission. When you go to bed, keep your bedroom dark, as even small amounts of light can suppress melatonin production, disrupting your sleep quality.

(Shortform note: In Why We Sleep, Matthew Walker reveals just how sensitive our bodies are to artificial light. A typical bedside lamp produces 200 times more light than a full moon, and this artificial illumination can suppress your melatonin by up to 50%. Walker adds that we respond strongly to blue light because of our evolutionary past as marine creatures (since blue light penetrates water best), making modern screens particularly disruptive to our sleep.)

2. Maintain consistent sleep patterns. Make it a goal to get at least seven hours of sleep each night, since this amount is necessary for proper brain function and health. Set regular sleep and wake times to help regulate your circadian rhythm—your body’s natural cycle of sleep and wakefulness.

(Shortform note: While seven hours of sleep is the standard recommendation, sleep needs can vary significantly between individuals. A small group of people known as short sleepers can function well on just six hours of sleep due to genetic differences, while long sleepers require 10-12 hours. However, don’t assume you’re a short sleeper just because you regularly get less sleep—true short sleepers maintain their brief sleep pattern even on weekends and never feel tired during the day. Most people who sleep less than seven hours are actually suffering from sleep deprivation, even if they’ve grown used to it.)

3. Avoid sleep medications when possible. Sleeping pills don’t produce natural, restorative sleep and may have harmful side effects, including increased risks of cancer, depression, and dementia. Instead of relying on medications, focus on developing healthy sleep habits and addressing any underlying sleep disorders with help from medical professionals.

(Shortform note: In Why We Sleep, Walker echoes the Perlmutter’s advice, adding that sleeping pills can trap you in a vicious cycle: When you take pills to sleep, you feel groggy the next day, so you drink caffeine to stay alert, which then makes it harder to sleep at night, leading you to rely even more on sleeping pills. However, if you need a little extra help getting to sleep, Shawn Stevenson (Sleep Smarter) suggests including nutrients like tryptophan, vitamin C, and omega-3s in your diet or trying herbal supplements like kava kava, chamomile, and valerian.)

Tip #6: Practice Mindfulness

Lastly, the Perlmutters recommend that you practice mindfulness—a type of meditation where you focus on becoming fully present in the moment. They argue that being surrounded by constant stimulation means you must reclaim control over your distracted mind by actively choosing to make time for quiet reflection.

(Shortform note: Though mindfulness may seem simple, it can be difficult to practice. In A New Earth, Eckhart Tolle explains that we often live in a state of mindlessness, where our ego controls our thoughts and behaviors, driving us to compare ourselves to others and judge things as “good” or “bad.” Tolle says that mindfulness is the key to overcoming our ego. He provides strategies in addition to mindful meditation—for example, approaching every task with acceptance or enjoyment and ignoring your ego’s demands for recognition. These mindfulness techniques not only combat distraction, but they can also help you stop being judgmental, obsessing over material possessions, and resisting things you can’t change.)

Mindful meditation physically changes your brain by preserving brain thickness as you age. The Perlmutters explain that people with thicker brain tissue typically have better cognitive function and memory than people with thinner brain tissue. Meditation also strengthens your prefrontal cortex while reducing activity in your amygdala, allowing you to control your emotions better and make smarter decisions throughout the day.

(Shortform note: Meditation may become even more important as we age. Research shows that our brains naturally start to shrink in our 30s and 40s, and this happens even faster after age 60. The frontal lobe—the region that meditation helps preserve—is one of the areas most vulnerable to age-related thinning. This thinning leads to weaker connections between brain cells, which can slow down your thinking and make it harder to control emotions or make decisions.)

Tips for Mindful Meditation

To practice mindful meditation, the Perlmutters suggest you begin with basic deep breathing exercises: Find a comfortable position to sit. Close your eyes, let your body relax completely, and then take a deep breath in through your nose. After taking in as much air as possible, release the breath slowly, taking about 20 seconds to let it all out. Repeat this process five times.

(Shortform note: In Mindfulness in Plain English, Bhante Gunaratana explains that breathing is an ideal focus point because it’s always available, costs nothing, and demands the right level of attention. Unlike watching TV or listening to music, breathing requires subtle effort and focus. You have to work to stay aware of it, but not so hard that you interfere with its natural rhythm. Your breath also anchors you to the present moment since each breath exists only briefly before the next one begins.)

In addition to breathing exercises, you can also use meditation apps, attend classes, or listen to guided meditations. Regardless of how you practice mindfulness, make it a habit. The Perlmutters recommend practicing twice daily for at least 12 minutes. Consistency, the authors argue, helps rewire the brain and create lasting benefits for your mental well-being and cognitive function.

(Shortform note: In Wherever You Go, There You Are, Jon Kabat-Zinn echoes the benefits of meditation practices for cultivating mindfulness, and he also recommends creating small reminders to be mindful in your daily life. For example, when you put on your shoes, sit down before a meal, or greet a loved one, pause and pay attention to what’s happening in the present moment. This allows you to create longer moments of mindfulness in your day.)