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March 21, 2022 • read

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How to boost your immune system with food

What you eat can have a major impact on your quality of life. From your earliest days to the last years of your life, nutrition has a profound impact on your health. One of the major ways it does this is through your immune system. Here’s how nutrition affects your immune system and what to eat to help you boost your immune system naturally.

Why is it important to have a healthy immune system?

Without a healthy immune system, your body can’t fight off infections, viruses, or pathogens effectively. Normal bacterial flora — microorganisms that survive on another living organism — for example, can help prevent pathogens from settling in by competing for attachment sites or essential nutrients.

Viruses, bacteria, and fungi are all around in the environment, and if they have the opportunity, they can make you ill. Your immune system is your body’s natural defence against foreign substances, and it’s always on alert for signs of an invasion. Without it, these microscopic pests would have free reign, replicating in your body, and making you sick.

The immune systems of immunocompromised individuals — those who have HIV/AIDS or are undergoing chemotherapy or radiation for cancer, for example — can’t mount a proper defence against an invading virus. This makes them overly susceptible to normally inconsequential infections like the common cold. A virus that would only be a nuisance to someone with a fully functioning immune system can be serious in an immunocompromised person. It might even be life-threatening.

How is nutrition related to our immune system?

It’s clear that nutrition and the immune system are related and recent research is showing just how much. Your immune system has many different components, which rely on a number of different micronutrients. A nutrient-deficient diet deprives your immune system of the building blocks it needs to function properly.

Additionally, a diet high in calories but low in nutritional elements is more likely to make you overweight or obese. Being overweight or obese contributes to high blood pressure, a higher risk of heart disease and stroke, and makes you more likely to experience sleep issues. In turn, these conditions negatively affect your immune system.

What you eat can also have a positive effect on your immune system. Certain foods may actually amplify your immune functioning by providing the vitamins and minerals your body needs to power your immune system and all its different components.

Are there any foods that are bad for my immune system?

Because it requires a number of nutrients to function properly, malnutrition is the most significant dietary issue affecting your immune system. The best way to keep your immune system healthy is to eat a varied and balanced diet. That being said, there are some substances that aren’t beneficial to your immune system.

It has long been known that a diet high in saturated fats and processed foods can lead to obesity and heart disease. Research shows, however, that these unhealthy elements also promote inflammation. If you have chronic inflammation, it can actually impair your immune response, both to transmissible illnesses like the flu, and to non-transmissible ones, such as cancer, cardiovascular disease, and depression.

Saturated fats and highly processed foods aren’t necessarily the worst foods for your immune system, however. One of the most problematic substances for it is sugar.

How sugar affects your immune system

In addition to contributing to obesity and diabetes, eating a high-sugar diet alters the balance of gut bacteria. This can lead to leaky gut syndrome, triggering inflammation. Acute inflammation is part of your immune response, and when your body is exposed to a pathogen, it’s what you want to happen. Chronic inflammation, however, is a problem and actually leads to a weakening of the immune system.

So while natural sugars like the ones found in fruits and vegetables are okay, it’s best to steer clear of or limit foods with added sugar. Yes, this means the high fructose corn syrup found in things like icing, but also “natural” sugars like maple syrup.

A high-sugar diet doesn’t just spur inflammation, it may also inhibit phagocytosis. Phagocytosis is the way your cells neutralize pathogenic and foreign particles, and it’s a crucial part of your immune functioning. Not only that, but sugar affects the way your white blood cells operate.

If you have too much sugar in your blood, your white blood cells just can’t perform as well. It’s one of the reasons that diabetics get more infections. Limiting processed sugars in your diet isn’t just good to keep your blood sugar stable or your overall health, it also benefits your immune system.

Why is family nutrition important?

Research shows that children eat a more nutritious diet when they’re a part of regular family meals. Eating together sets your child up for healthy eating habits for the rest of their life. It also gives you more control over what they eat.

Your kids learn their eating habits from you. If you wrinkle your nose every time you see a brussel sprout or eat Pizza Pockets over the sink, chances are your kids will too. This doesn’t mean you have to eat heaping quantities of vegetables you hate, but it’s important to model the behaviour you want to see. Even if broccoli isn’t your favourite, put a floret or two on your plate and eat it. If you don’t make a big deal out of it, your kids might not either.

Offer a variety of options, make family meals a low-pressure affair, and don’t fret if they refuse green beans 15 times in a row. Taste test number 16 might just be the charm.

How can I strengthen my family’s immune system through nutrition?

If you’ve got little ones in daycare, you’re likely dealing with illness after illness. Some sickness is unavoidable in the early years because children’s immune systems aren’t mature enough to fight off everything. Add that to a toddler’s predilection to put everything in their mouth and rarely wash their hands, and you’ve got a recipe for illness.

Even if you don’t have young children, chances are you and your family still battle a number of colds throughout the year. Luckily, eating a balanced diet that includes certain immune-strengthening foods can help you to boost your family’s immune system naturally.

Which foods and vitamins can boost my immune system?

Calcium plays a vital role in your immune system’s response. It functions as a sort of messenger, signalling the immune system when it’s time to go on alert or time to power down.

While dairy products like milk and yogurt are well-known sources of calcium, dark green vegetables like spinach and broccoli are also good alternatives. Tofu, however, blows the competition out of the water. One cup of tofu has more than double the calcium in a glass of milk.

Vitamin C
Vitamin C is an essential micronutrient for human beings. Severe vitamin C deficiency causes scurvy and can be fatal. Vitamin C is also a powerhouse when it comes to the immune system.

Without adequate stores of it, you’re at higher risk of infections — especially respiratory infections.Vitamin C is found in all fruits and vegetables, but kiwi, citrus fruits, broccoli, guava, and bell peppers contain especially high amounts of it.

Vitamin D
Vitamin D is an anti-inflammatory and immune regulating, which means that getting enough of it is crucial to maintaining a healthy immune system. While it’s found in fatty fish like salmon and sardines — along with omega-3 fatty acids — vitamin D is rare in most foods, and about one-third of Canadians don’t get enough of it. Speak to your healthcare provider about taking a vitamin D supplement if you think you may be deficient.

Vitamin E
Your body needs vitamin E — it’s an essential building block for making T-cells. T-cells are a critical part of your immune system, helping your body fight off both foreign pathogens and cancer. Studies show that taking higher than needed levels of Vitamin E supplements may be helpful in increasing your immune response, especially in older adults. Vitamin E-rich foods include sunflower seeds, almonds, peanuts, avocados, trout, and spinach.

Antioxidant-rich foods
Foods containing certain vitamins and minerals — such as vitamin C, E, copper, and zinc, for example — serve as antioxidants. Antioxidants help to boost the immune system by neutralizing free radicals, which damage membranes and even DNA within your body. Antioxidants are found in many foods including red kidney, pinto, and black beans, berries, pecans, and dark, leafy greens.

Signs you have a weak immune system

You don’t have to have a serious illness to experience a compromised immune system. You can be seemingly healthy and still have a weak immune system. According to the College of Family Physicians of Canada, adults have an average of four to six colds a year. If you find you get sick more often than that, or if it takes you longer than a week to feel better after one, you may have a weak immune system.

Wounds that seem to take forever to heal and feeling chronically tired are other possible indications that your immune system isn’t functioning optimally, as is gut dysbiosis, also known as regular tummy troubles.

Proper nutrition is a key component of a healthy immune system. Without a proper diet, your body doesn’t have the materials it needs to run your immune system at its peak. If you feel like you’re constantly sick, or think your diet might be affecting your health, it could be time to speak with a professional.

A registered dietitian can help you formulate a nutritional plan that takes your lifestyle and goals into account, and can help you tailor your diet for a stronger immune system. Book an appointment with a registered dietitian today and take the first step towards better health.

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