Dr. Bill's Healthy Immune Tips for Back to School

Dr. Bill's Healthy Immune Tips for Back to School


Hello parents and teachers.  It’s back to school time!  Now in my 50th year in medical practice, one of the top questions I still get is: “Dr. Bill, what can I do to keep my kids from getting sick this school year?”
My answer:  Help your children grow a healthy immune system.

Here’s our five-step plan on how to do it:


What we parents and doctors have learned over the recent years is how fear sabotages a healthy immune system.  Here’s a quick course in immune-system health and how to imprint it into your children. 

Imagine your children worried about all the “stuff” they hear about and you need to assume the role of your child’s most trusted health coach. Besides following the guidelines from your local healthcare provider, your lessons could go something like this: “Don’t worry, honey, you have within you a giant army called your ‘immune system army,’ or ISA.  Trillions of tiny troops flow through your body all day and night on search-and-destroy missions to get rid of germs before they can make you sick.  Let’s meet my favorite troop called your “NK cells” (natural killer cells or, for a younger child, you may want to call them “natural knockout cells”).  They are called “natural” because unlike other fighters in your immune system they don’t need to be preprogrammed with previous exposure to the germ to fight.  They’re already armed and ready.  

Let’s follow the diagram below to see how your ISA will take care of you.  Suppose a germ comes into your body.  Your NK cells are drawn like a magnet toward the germ, glom onto the germ, then fire a biochemical dart (appropriately called a perforin) to perforate the germ and release a bunch of enzymes into the germ and blow it up.  Then comes your clean-up crew, called macrophages (“big eater” cells), that eat up the leftovers from the germs and keep your body healthy and clean. 

Meanwhile, your child is thinking, “Wow, that’s really going on inside of me?  I feel better already.” 

Next lesson: the better you train your soldiers, the better they will fight for you.


Your NK cells like to be “preloaded” (a term I use frequently in my medical teachings to help parents remember that parenting, in a nutshell, is giving your children the tools to succeed in life.  “Preloading” means equipping them with the tools. 

First, you need to believe that your NK cells are going to take care of you.  Dwell more on your ISA inside of you, which you can control, rather than worrying about all the “stuff” outside of you which you can’t control.  The better you feed your ISA, the better they will fight for you.  And, you have to train them by moving them.  Remember, “sit and stew is bad for you.”  That’s why soldiers go out and train in the fields. 

Finally, you need to get a good night’s sleep so your immune system army can rest and refresh and get preloaded for your next day at school. 

This is the dialogue I have with my family and patients.  You can personalize this to the age and learning level of your children. 



A smart food and grow food breakfast preloads your child to have a smarter and healthier day.  Above all other organs the brain is affected, for better or worse, by what you eat.  If you put junk food into a child’s brain, you get back junk behavior, junk learning, and a weakened immune system.  Scientific studies show that children who begin the day with a brainy breakfast:

  • Miss fewer school days because of illness.
  • Were more attentive and learned better in class.
  • Had fewer “D’s,” such as ADD and ADHD.

Smart components of a brainy breakfast are:

  • Omega-3 fats: helps build smart brain cells
  • Protein: perks up the brain.
  • Fiber-filled carbs: provide a steady supply of fuel.
  • Antioxidants: lessen wear and tear and facilitate repair.

Here’s a diagram of the Sears family back-to-school smoothie we call “school-ade.”


  1. Smoothies
  2. Salads with spices
  3. Salmon
  4. Smart snacking
  5. Science-based supplements.  One of my favorite science-based supplements to add to my daily smoothie is Hawaiian Spirulina, which research has shown may support a healthy immune system.  It is around sixty percent protein and rich in powerful antioxidants that your family needs, such as beta carotene, iron, B-vitamins, vitamins K1 and K2, and more.  My second favorite science-based supplement is Hawaiian Astaxanthin, which provides support in balancing the immune system and reinforces overall immune function. Astaxanthin is potent antioxidant and is the red pigment found in wild salmon, #3 on my 5-S diet.   


Movement mobilizes your immune system.  Again, imprint into your children:

“Sit and stew is bad for you.”


Here’s how this happens, and get ready to “WOW!”  Exercise increases the number and “killing ability” (called cytolytic strength) of your NK cells.  Movers have a higher number of NK cells and a smarter immune system army than do sitters.  If your NK cells could talk, they would say: “Move us more and we’ll fight better for you.” 

Imagine if you were in charge of strategizing for your immune system army.  Where would you station your NK cells so they could be quickly mobilized?

Answer:  The lining of your blood vessels, called the endothelium.  This allows your NK cells to quickly enter the bloodstream and travel anywhere in your body to attack the germs.  Your white blood cells, of which NK cells are just one type, set up camp in the lining of your blood vessels where they are armed, ready, and waiting to be called upon if needed.  In immune-speak your ISA cells are “marginated.”  When you move, your blood flows faster over the lining of your blood vessels and prompts the NK cells to “demarginate” and go on search-and-destroy missions throughout your body to gobble up the germs and then return back to their endothelial camp. 

Want to have some fun with your friends?  Imagine taking a brisk walk and boasting, “I’m mobilizing my immune system army inside.”  As an added perk, in general, the better you exercise, the more NK cells are released into your bloodstream.  So, the fitter you become, the fitter your immune system becomes. 

A study that validated my medical practice experience that children who move more stay healthier and learn better is the Naperville Study (google it).  Researchers had students with learning problems come to school early and run around the schoolyard for intense exercise.  Those early movers showed remarkable improvement in their grades, their ability to focus in class, and showed less “attention problems.” 

That makes sense!  Increased movement increases blood flow to the brain, which is why I call movement “grow food” for the child’s brain.



“Don’t worry, be happy.”  Feeling depressed can depress your immune system.   


Here is my science-made-simple journey of your ISA during a good night’s sleep.  When you drift into a peaceful night’s sleep, your brain’s natural immune system army – called the glymphatic system – reports for action.  First, your brain’s natural ISA, called glia cells, increase in number and travel around the brain and, like microscopic garbage trucks, clean up the waste, or “stuff,” that accumulated in your brain during your busy and worrisome day. 

Next, the rivers of fluid flowing throughout your brain, called the lymphatic system (another part of your ISA), widen during quality sleep.  After a good night’s sleep you wake up “refreshed” and “preloaded” to begin the day.  Children need a good night’s sleep to enjoy a smarter school day.  

Dr. Bill’s good-night sleep tip.  Before your children go to bed, have them list five things they like about themselves and post it on the bathroom mirror to be read and meditated on while they brush their teeth, such as:

  1. I am smart.
  2. I am pretty.
  3. I am a good soccer player.
  4. I am…
  5. I am…

For younger children, lie down with them and have them recite “five things I like about me…” as they drift off to sleep. 

Upon awakening, have your children say five things they are thankful for – the “attitude of gratitude”: “I am thankful for my friends at school…”  Then, they can go off to school with a happy brain that is ready to learn better. 

Consult your healthcare provider before starting a new diet, exercise, or health program.

*These Statements have not been evaluated by the Food and Drug Administration.  This product is not intended to diagnose, treat, cure, or prevent any disease.

Scientific references and further reading:


Dr. Sears serves on Nutrex Hawaii's Medical Advisory Board.