Keep Sharp by Dr. Sanjay Gupta

Keep Sharp

Dr. Sanjay Gupta

Reviewed by Hank Bitten, NJCSS Executive Director

I selected this book with the intention of discovering a resource for Psychology teachers who need relevant information to support their teaching about the brain. As a history educator, I recognize my pedestrian level of understanding how my brain works. As I write this book review, I am using millions of brain cells or neurons but also rewiring my brain to adapt to a new subject area and audience.

The first new thing I learned from reading this book was a respect for my own brain.

My brain “weighs less than most laptop computers, yet it can perform in a way that no computer can or ever will.” (p. 30)  It is the power of my brain that enables me to think in ways beyond my basic survival instincts. My awareness of diet and nutrition is limited to my narrow perspective of fitness and weight control. In Keep Sharp, I became aware of the importance of nutritional foods in controlling the amount of inflammation in my arteries and blood vessels in my brain. The brain also thrives on oxygen and activity. There is a relationship between time spent on individual and team sports with memory and a positive learning impact. (p. 102) I also am more aware of getting outdoors for exercise and fresh air, even during cold and wet weather.

I have become more aware of how my brain regulates every part of my body regarding hormonal secretions, cognitive memory, and a daily cleansing ritual similar to how my anti-virus software deletes hidden files on my computer. The benefits of exercise and movement are critical in reducing the harmful effects of sugar remaining idle in our blood which causes dramatic fluctuations in glucose and insulin impacting brain structure and development.

“Without a healthy brain, you cannot even make healthy decisions. And with a healthy brain comes not only a healthy body, weight, heart, and so on, but also a stronger sense of confidence a more solid financial future thanks to smart decisions, better relationships, more love in life, and heightened overall happiness.” (p. 76)  

The second new thing I found of interest was the statistical or factual information presented in the book

For example, here are five observations:

  1. The brain uses 20 percent of my energy and oxygen intake. Since 75% of our brains are composed of water (similar for the heart) that dehydration affects our cognitive skills and attention immediately. (p.36)
  2. The brain is the last organ in our body to mature, which is why teenagers are vulnerable to risky behaviors and in need of emotional learning and support. For some of us, the brain does not reach maturity until about age 25.  There is also a difference between our chronological age and vascular age, which explains why people in their eighties are able to compete in marathons or swim across the English Channel as Otto Thaning, from South Africa, did in 2014 at age 73!
  3. “In 2018, researchers from Columbia University showed for the first time that healthy older folks can generate as many new brain cells as younger people.” (p. 67)
  4. By the age of eighty-five and older, about a third of the people have dementia. (p.95) “Two-thirds of Americans with Alzheimer’s disease are women, and we don’t have an understanding yet why this is the case or what causes women to be at a higher risk.” (p. 82)
  5. “Nearly 35 percent of all U.S. adults have what’s called metabolic syndrome, a combination of health conditions you don’t want to have, such as obesity, high blood pressure, insulin resistance, type 2 diabetes, or a poor lipid profile.  Since 2005, researchers have been finding correlations between diabetes and a risk for Alzheimer’s disease, especially when the diabetes is not controlled and a person suffers from high blood sugar.” (p. 58)

The third insight I enjoyed were the metaphors presented to illustrate in practical ways how the brain functions.

For example, the metaphors of understanding the brain as a town or a puzzle are useful illustrations for students:

“I think the brain is like a town.  The important structures such as the houses and shops are in nearly constant use, and they probably represent 10 to 20 percent of our brains. The rest, however, are the roads than connect all these shops and homes.  Without the roads, information could not get to where it needs to go.  So, while the roads are not in constant use, they are necessary.” (p. 82)

“When you recall a memory, it is like assembling a giant jigsaw puzzle from a few small pieces to get it started.  As the pieces come together, link, and define an image, they begin to tell a story, convey a picture, or share knowledge.” (p. 41)

Perhaps the most significant information I learned in Keep Sharp was in Chapter 6, “The Need for Sleep and Relaxation.” 

Sleep controls our hormonal cycles and our circadian rhythm.

“Sleep is essential for consolidating our memories and filing them away for later recall.  Research is showing that brief bursts of brain activity during deep sleep, called sleep spindles, effectively move recent memories, including what we learned that day, from the short-term space of the hippocampus to the “hard drive” of our neocortex.” (p. 137)

Dr. Sanjay Gupta references numerous research studies throughout the book. The University of Rochester study on the glymphatic system provided me with insight into how my brain functions by decluttering information I process during the day and removing dangerous metabolic chemicals preventing inflammation and reducing feelings of depression.  However, regular sleep is the process for the optimal performance of our brains on start-up upon waking up.

Many psychology teachers emphasize the relationship of nutrition to behavior.  This book provides useful information regarding the evidence of research studies in this area. For example, in 2014, the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability reported that diet and exercise contributed to preserving cognition.  A similar conclusion was reached in the United States by the Alzheimer’s Association on reducing the amount of sugar in the blood. (p. 164). “Increasing fruit intake by just one serving a day has the estimated potential to reduce your risk of dying from a cardiovascular event by 8 percent, the equivalent of 60,000 fewer deaths annually in the United States and 1.6 million deaths globally. (p. 167) This is significant because hypertension and diabetes contribute to inflammation and plaque in the brain.  People with high levels of blood sugar, even if they are not diabetic and of normal weight, releases hormones and cytokines that cause cognitive deterioration.

Other areas in Keep Sharp that are related to the high school Psychology and Sociology curriculums are the role that loneliness from the divorce and the death of a spouse have on human behavior and the human body. Researchers at the University of Michigan found that married people are less likely to experience dementia as they age, and divorcees and those who are widowed or never-married are twice as likely to develop dementia! (p. 190) The demographics of this population is roughly 60 million Americans, or 20% of our population. (p. 192). It is the quality of relationships that appears to have an effect on our brains.


It is important to teach brain functions and brain health in high school because it supports behaviors for a longevity and cognition. According to the FDA, 99.6 percent of over 400 drug trials relating to Alzheimer’s Disease and dementia have resulted in failures.  The cost of care, supplements, and medications for dementia and Alzheimer’s are in the billions of dollars each year. By 2030, the millennials will begin turning 45, the Generation-Xers 45, and the baby boomers 85. This is a scenario for a major health crisis.

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