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With Sakara Science Council Member Dr. William Li

As the weather starts to chill and cold-and-flu season commences, fortifying our body’s natural defenses (in particular, our immune system) is top of mind—be that through high-quality sleep, supplements, mindfulness, movement, and nutrition. 

For tips that go beyond doubling down on our orange juice intake that really delve into the science behind our immunity, we tapped Dr. William Li, Sakara Science Council member, physician, vascular biologist, and best-selling author of Eat to Beat Disease: The New Science of How Your Body Can Heal Itself

Read on for his immunity-boosting intel. 


All Hail Our Health Defense Systems

How you’re feeling at this very moment is the direct result of how well your five health defense systems are working—consisting of angiogenesis (blood cell production), cell regeneration, bacteria in the gut microbiome, DNA protection, and immune response activation. 

“The reason we're healthy is the result of these health defense systems that are hardwired in our bodies, that are working really hard on our behalf,” says Dr. Li. “In fact, they're firing on all cylinders from the day we're born until our very last breath.”

And yet, when they’re working at their very best, keeping us in tiptop shape and able to chip away at everything on our to-do lists, we likely don’t even realize it. 

“[Our health defense systems] are invisible,” says Dr. Li. “We don't feel them. We don't feel our circulation. We don't feel our stem cells regenerating us from the inside out… We don't feel our immune system revving up to actually protect us from invaders outside of the body, or even invaders inside the body like cancer cells. That's how we're wired. We just feel great.” 

We can bolster our health defense system through a myriad of methods, from incorporating regular movement to managing stress to getting a solid night’s rest (which is when our body flushes out the toxins that hamper our health defense systems).


Foods for a Thriving Immune System

To keep our bodies thriving and our health defense systems operating without a hitch, Dr. Li notes the incredible importance of nutrition, too. “Healthcare's what we do all the time, for ourselves, at home,” says Dr. Li. “And the place that it most often happens during the day is in your kitchen.”

For bolstering the immune system in particular—which Dr. Li recommends we think of not as an on-off switch, but rather as a shield that we make iron-clad through diet and lifestyle choices—there are certain foods we can reach for.

In general, this immunity-boosting shopping list is divvied into two parts: foods that help calm system-wide inflammation and foods that help ramp up the T cell “super soldiers” (that then prevent and fight any bacteria or viruses attempting to invade). 

For ramping up our immune defense:

  • Foods with anthocyanins, a natural dye that helps jack up our T cells and natural killer cells: purple potatoes, blueberries, blackberries
  • Akkermansia-rich foods: pomegranates
  • Foods with sulforaphane, a bioactive and natural chemical that helps bolster immunity: Broccoli sprouts, broccoli

 For calming inflammation: 

  • Vitamin C-rich foods: red bell peppers, tomatoes, strawberries, guava, kiwi, broccoli
  • Gut-friendly prebiotic foods (that help produce inflammation-lowering short-chain fatty acids): fiber-rich leafy greens (like kale), pears, chicory root, bananas, oats, apples

“In general, the principles of healthy eating for your health defense system is to stay attuned to your body,” says Dr. Li. “Focus on the things that scientists have shown us are good for our health, like a plant-rich diet. Try to cut down, cut out, or rarely eat the things that are not so good for us, like ultra-processed foods.”


When Sickness Strikes

Still, every so often, we still wind up calling off work, bound to our bed and craving nothing but soup and saltines. What’s happening in our bodies then? 

“When we're feeling sick our immune defense system springs into action,” says Dr. Li. “When your inflammatory cells are going to work, and your super soldiers are going to work, they release these substances to get rid of the bacteria virus called cytokines.” 

“[Cytokines] are like the cleaning agents of the immune system that scrub out all the things you don't want to have in your body,” continues Dr. Li. “But you know how cleaning agents can be kind of noxious and smell funky… same deal with the cytokines. If you have a lot of them, they can actually make you feel crummy, and that's why we feel so bad when we get the flu.”

It's not the bacteria that's making our bodies chilled and achy, but our immune system fighting on our behalf. To support it, Dr. Li recommends tending to our microbiome, eating foods with dietary and soluble fibers that’ll help the body lower inflammation, like apples or mushrooms, and sipping on tea, which has an anti-inflammatory effect.

Soup does wonders, too. Broth, especially when it’s rich in herbs, spices, and veggies, lowers the cytokines and calms a bit of inflammation to help us feel better. Honey, a natural antibiotic, is another great addition to your sickcare line-up, coating your throat in a protective layer and preventing it from getting dried out (which is when bacteria sneak in). 

“We practice medicine on ourselves and the prescriptions that we give ourselves don't require a doctor,” says Dr. Li. “We encounter food three times a day, sometimes more, and we have to make a decision… Those simple decisions actually have huge consequences.”

We’ve said it before and we’ll say it again, Sakaralite: Food is medicine. 

Hungry for more? Tune in to Dr. Li’s free virtual masterclass on Wednesday, September 28 at noon EST.

Filed Under: Dr. william li, Food is medicine, Immune system, Immunity

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