It’s confusing. So much health “news,” so many people so sure of one thing or another, so much controversy, so many contradictions–it’s no wonder people don’t know what to think. But if you want to avoid catching a virus this winter (whether the cold, the flu, or, well…you know) your best bet source of information probably isn’t the media clamor. The media is full of opinions, both expert and amateur, about masks, vaccines, immune “boosters,” and so much more. There is still a lot we don’t know for sure about what this winter is going to look like, but there is one thing I do know for sure, and I don’t think any medical professional would disagree: The healthier you are, the better you’ll be able to fight off infections.

There are always exceptions, of course. Sometimes perfectly healthy people have a bad outcome when they get sick, sometimes because of an underlying health condition they didn’t know about. However, for the most part, your best chance of getting through flu season without too much suffering is to build a strong foundation of health that will support your immune system.

Your Immune System

The whole purpose of the immune system is to keep you from getting sick, and to heal you when you get sick or injured. Your immune system is naturally very good at this—if it wasn’t, there wouldn’t be so many of us! Your immune system is a complex biochemical masterpiece of defense and repair, involving intricate interactions throughout your body that help you destroy viruses, bacteria, cancer cells, and other pathogens that threaten your health and survival, all without you knowing it’s happening.

But the truth is, you have quite a lot of control over what your immune system is doing. There is no more powerful influence on the immune system than lifestyle. Specifically, what you eat, how much you move, how well you sleep, how much water you drink, and how well you maintain social connections all influence immune health in various ways. Yet, these are exactly the things many people have compromised over the past year, while staying in, stressing out, and keeping their distance from other people. How you live is up to you, however, so let’s see if we can inspire you to make lifestyle decisions that are in the best interest of your immune system.

Diet and Immunity

I like to start with food because you get to make dietary choices—in other words, have an opportunity to build up or tear down your immune system—multiple times a day! Your diet provides the building blocks for immunity, and also determines the composition of the microbiome in your gut, which produces many components of your immune system. Let’s look at what you can do to optimize those processes.

First, no matter what you are eating, if you eat too much and too often, you may decrease the effectiveness of your immune system. Constantly eating increases pro-inflammatory cytokines, which increase your overall inflammation, making you more vulnerable to infections. Constant eating and overeating also decrease your T cell production. T cells specifically target foreign particles and you need them when you encounter infectious agents like viruses. Eating a little less, and eating less often (three meals with no snacks, or just two meals with periods of intermittent fasting), are both likely to help your body increase T cell production and reduce inflammation. (By the way, we know undereating also impairs immunity, but that’s more likely in the case of famine or malnutrition over long periods of time).

What you eat matters, too. First, let’s look at fat. Diets high in saturated fat tend to slow down the immune response and increase inflammation, while diets high in omega-3 fatty acids (like in fatty fish) tend to reduce inflammation and strengthen the immune response. If you choose salmon over bacon or a burger and just say no to cheese and fried food, you’re on the right track.

Diets high in sugar tend to restrict the action of neutrophils (a type of white blood cell that help to heal damaged tissue and resolve infections) and phagocytes (another type of white blood cell that absorbs bacteria and other foreign or dying cells). Diets high in fiber, resistant starch, and fermented foods (like yogurt and pickled vegetables) help the microbiome produce short-chain fatty acids that support a healthy immune response and decrease inflammation.

Sugar also feeds pathogenic bacteria in your microbiome, leading to overgrowth of fungi like Candida albicans, which can actually kill immune cells. Candida can work with pathogenic bacteria to form sticky biofilms along your intestinal walls that protect inflammatory bacteria so they can multiply, making your microbiome even more imbalanced, inflamed, permeable, and less able to produce a healthy immune response.

Counteract that effect by quitting the sugar and focusing on microbiome-friendly foods. Prebiotics (fiber and resistant starch, which you can get from vegetables, berries, citrus fruits, sweet potatoes, and legumes) feed beneficial bacteria, and probiotics (like in fermented foods and also in supplements) help bolster your microbiome’s beneficial microbe populations.

This is the time of year when sugary treats are everywhere, but if you remember that sugar makes you more vulnerable to viruses and fiber makes you less vulnerable, you may have an easier time passing on the gingerbread and candy canes in favor of orange slices or raspberries and yogurt.

To summarize, the best immune-supporting diet keeps both saturated fat and sugar on the low side, while emphasizing fiber, micronutrients, lean protein, fatty fish, fermented foods, and non-processed monounsaturated and polyunsaturated fats (like those from olives, nuts, seeds, avocadoes, and cold-pressed plant oils). In other words, aim for a lower-carb Mediterranean Diet (such as the Vibrant Diet), and keep your portions sizes reasonable and your snacks few and far between.

Vibrant Immune-Supportive Soup

When your immune system is activated—when you actually do catch a virus and have a fever and other immune responses—you need even more nutrients to support that elevated action, but not necessarily more calories. Soup is hydrating, can be packed with vegetables and lean protein, and isn’t high normally high in fat, so it’s a great “sick food.” Those cans of soup may look easy, but making soup at home is easy, too, and much more nutritious, with less sodium and no preservatives. It’s also relaxing—I highly recommend learning how to make your own simple soups.

I don’t use a recipe to make mine. Instead, I like to lightly sauté lots of onions, garlic, celery, carrots, red peppers, and mushrooms (or whatever vegetables I happen to have—zucchini, butternut squash, green beans, shredded cabbage or chopped kale) in olive or avocado oil. For protein, I add some shredded cooked chicken or a can of prepared lentils (or a half cup dry lentils) and cover with vegetable or chicken broth or stock.

Simmer for about an hour, or until everything is tender. During the last 10 or 15 minutes of cooking time, I stir in my favorite herbs and spices. I like oregano, basil, thyme, rosemary, a bit of smoked paprika, and a few dashes of cayenne pepper.

I hope you’ll try this soup, not just as a remedy, but as a preventive. It’s the perfect light supper to keep you nourished without overburdening your system.

When you practice good health habits, you’ll feel better, and your immune system will have the tools it needs to keep you feeling that way all winter long. Be smart, stay positive, and prioritize your health, and I predict you will have a vibrant holiday season. (Keep an eye out for my next blog, where I’ll talk about other lifestyle interventions that also influence immunity.)

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