Book SummaryKeep Sharp, by Sanjay Gupta

1-Page Summary1-Page Book Summary of Keep Sharp

In Keep Sharp, Sanjay Gupta provides advice for improving your brain health. It’s not just about improving intelligence or memory: It’s about developing a brain that is resilient and creating a brain that can build new cells and use the cells you have more efficiently. If you have a healthy, resilient brain, you’ll be happier, more productive, and better equipped to fight off cognitive decline as you age.

As a neurosurgeon and medical reporter, Sanjay Gupta has extensive knowledge of the human brain and how it functions. For Keep Sharp, he interviewed some of the leading experts on neuroscience and reviewed the latest research. Gupta explores five key components of brain health: exercise, sleep, nutrition, discovery, and connection. While these may seem like obvious components of a healthy lifestyle, we’ll show...

Keep Sharp Summary How the Brain Works

Gupta argues that to better understand how to improve your brain, you must first understand how it works. With regard to improving brain health, there are two key attributes of the brain you should understand: interconnectedness and neuroplasticity.

Interconnectedness

Gupta claims that our growing understanding of the brain has taught us that different parts of the brain function in a highly coordinated manner. Because of this, we should focus on improving the functions of every part of the brain, not just the areas we may deem most important. Not too long ago, it was thought that the brain was split up into separate parts that acted on their own: One part of the brain was used for abstract thinking, another for interpreting language. This led to the debunked theory that people are either left- or right-brain dominant. We now know, however, that much of the brain’s power and complexity comes not from the individual sections, but from the communication between each section.

Communication within the brain happens between neurons through synaptic connections, writes Gupta. There are billions of neurons, or brain cells, in the human brain, and trillions of synapses...

Keep Sharp Summary Potential Factors Leading to Cognitive Decline

Gupta claims that maintaining the quality and quantity of our neural connections can help prevent cognitive decline, but the exact causes of dementia are still unknown. Medical scientists and researchers have discovered a lot about cognitive decline, dementia, and Alzheimer’s in the last few decades, and their research suggests it’s probably due to many factors that differ for every person. If we want to take care of our brains and take measures to prevent them from declining, it will be helpful to know the suspected factors that lead to cognitive decline.

Amyloid Plaque Buildup

According to Gupta, an abundance of amyloid plaque in a person’s brain is a hallmark of Alzheimer’s disease. Amyloid is a protein that helps supply food to brain cells. For unknown reasons, these proteins sometimes become damaged and fold up into a sticky plaque that accumulates outside neurons. When plaques form, they prevent synapses from effectively communicating. If enough synapses are inhibited by amyloid plaques, the brain may lose many of its functions.

Though amyloid plaque has long been connected to cognitive decline, it is still unknown if it is a cause, an effect, or both. Some...

Keep Sharp Summary Healthy Brain Ingredient 1: Exercise

Gupta claims that regular exercise is the single most important thing to do for your brain’s health. While there are many other benefits to brain and body, exercise helps the brain in two main ways:

1. Exercise controls blood sugar: When you exercise, the sugar in your blood is used to fuel the muscles in your body instead of staying in your bloodstream. This prevents consistently high blood sugar and keeps your [restricted term] levels stable.

(Shortform note: Although exercise generally lowers blood sugar levels, it can also have the opposite effect. Some workouts, like heavy weightlifting, sprinting, and competitive sports, can increase hormones such as adrenaline, which raises glucose levels. Also, consuming too many carbs before a workout can lead to high blood sugar. To avoid this, experts recommend you choose moderately intense aerobic exercises or light weight training and that you avoid too many carbs before exercising.)

2. Exercise reduces stress: When you’re stressed, your body releases a hormone called cortisol, which has been linked to changes in the brain....

Keep Sharp Summary Healthy Brain Ingredient 2: Sleep

Gupta claims that chronic inadequate sleep leads to higher risk of many health issues including dementia and cognitive decline. Extensive research on the effects of sleep shows that sleep is more than just the body’s chance to relax: It’s a vital phase of neural activity and regeneration. In this section, we’ll first look at what happens in our brains when we sleep. Once we understand this, we’ll go over some of Gupta’s tips for consistently getting a better night’s rest.

Our Brains During Sleep

Gupta claims that our brains perform billions of molecular tasks while we sleep. Because of this, sleep keeps us sharp, creative, and able to process information. Sleep keeps our brains healthy in three key ways, says Gupta:

1. Sleep controls our hormonal cycles: Our circadian rhythms revolve around our sleeping habits, and these rhythms dictate our hormonal patterns. These hormonal patterns help regulate our appetites, stress levels, and cellular recovery. People who don’t get enough sleep on a regular basis are likely to have issues with their metabolism and stress levels—and thus, their brain’s function.

(Shortform note: Sleep also appears to reduce stress by...

Keep Sharp Summary Healthy Brain Ingredient 3: Nutrition

Gupta claims a healthy diet is a vital part of brain health. As we’ve discussed, metabolic disorders are thought to be a leading factor in cognitive decline. While there is no general consensus on the perfect diet for brain health, there is plenty of evidence to suggest that you should eat certain foods regularly and avoid other foods as much as possible. In this section, we’ll look at why certain foods are good for your brain and why others can be potentially harmful.

Foods to Eat

Most of the foods that are good for your brain should not come as a surprise. Gupta claims that, although it’s difficult to know exactly how foods interact in our bodies, recent studies point to certain diets as being particularly healthy. For example, a Mediterranean diet is extremely beneficial to brain health. This diet consists largely of olive oil, nuts, fish, and a wide variety of fruits and vegetables.

Of these foods, Gupta mentions that berries and leafy green vegetables are especially good for the brain. One reason for this is that they are high in fiber. Fiber is beneficial because it changes the way your body metabolizes food. If you don’t have enough fiber in your diet, the...

Keep Sharp Summary Healthy Brain Ingredient 4: Learning and Discovery

Gupta argues that keeping your brain active is a vital part of maintaining its health. Learning or discovering new things stimulates the brain, and this stimulation builds a brain more resistant to disease by creating new neural connections (and strengthening existing ones). With stronger neural connections, you are less susceptible to cognitive disruption. With a greater quantity of neural connections, you can offset the disruption through the use of the other networks. This may be how some people whose brains show all the physical signs of Alzheimer’s don’t manifest any symptoms of the disease.

Can the Brain’s Adaptability Be Harmful?

Gupta argues that increasing neural networks through learning can help the brain offset disrupted communications. This neuroplasticity is a vital function, but some suggest that it can also have harmful long-term implications, especially when related to a brain injury.

After a head injury, the brain can rewire itself...

Keep Sharp Summary Healthy Brain Ingredient 5: Social Connection

Gupta claims that social interaction is crucial to our psychological well-being and thus our brain health. There is lots of evidence to support this, as strong social connections are a better predictor of long, happy lives than social class, intelligence, or genetics. Lack of social connection has been linked to disrupted sleep patterns, higher levels of inflammation, and higher levels of stress, all of which contribute to cognitive decline.

From an evolutionary perspective, the importance of social connection makes sense. Humans are a very social species. Throughout history, we’ve survived through communal living and reliance on others for food, water, shelter, and protection. In the modern world, as Gupta points out, social isolation is on the rise. Despite being connected to many people through digital media, many people lack real, close connections. If we wish to counteract this and preserve brain health, we must focus on building community with others and establishing meaningful relationships.

Social Connections and Depression

Another reason to strengthen your social connections is to prevent depression. In *[Lost...

Shortform Exercise: Review Your Weekly Habits

You can strengthen your brain by making simple lifestyle changes. Use this exercise to review how well you’re taking care of your brain on a weekly basis. You can come back to this exercise regularly to check your progress.

Did you get the recommended 150 minutes of exercise this week? If not, what stopped you? How could you increase the amount of exercise you get next week?