Foods that boost your immune system: to keep in mind during the cold and rainy season

In the past, I already knew that I got the flu twice a year, in the first quarter of the year and the last. Children get it between six and eight times a year. Now, with the proper precautions, it can be avoided, its frequency reduced or at least, it can be relieved more quickly.

You probably know the basic precautions against the flu, such as washing your hands before leaving the bathroom and when you get home, as well as keeping your distance to try to avoid contagion. Have you ever wondered why some people, even when in close contact with people with a cold, do not get infected?

The difference lies in the immune system. If a person has a strong immune system, it does not allow viruses or bacteria to enter the body. When the doctor tells us that our defenses are low, it is because our immune system is not working at 100 percent.

How to strengthen the immune system

One of the most powerful tools to strengthen your immune system is found in your kitchen: your food.

But let's see how foods can help you strengthen your immune system.

Let us remember that the proper functioning of the immune system is subject to three variables: diet, climate-environment and lifestyle.

The human body has mucous membranes in the nose, eyes and mouth, which use white blood cells to combat any attack on the body.

Similarly, the body has T lymphocytes (which develop in the thymus and represent the cellular immune response) and B lymphocytes (which develop in the bone marrow, then migrate to the different lymphatic tissues that are responsible for the humoral immune response). These lymphocytes are very important because they are responsible for the production of antibodies and the destruction of abnormal cells.

How foods affect the immune system

A diverse group of phytochemicals (bioactive chemical compounds present in plants) is needed to create a strong barrier against pathogens (harmful or foreign elements) that would otherwise make us sick.

Because the immune system weakens with age, it is important to consume more foods that strengthen this system as the years go by.

Studies show that certain nutritional deficiencies weaken proper immune function in older people. Even in people as young as 35, poor nutrition wreaks havoc on the immune system. ( 1 )

The good news is that by improving their nutritional habits, adults who consume at least 5 servings of vegetables and some fruits develop an enhanced natural defense against stress. ( 2 )

We have mentioned the many benefits of eating vegetables several times, as they contain fiber and nutrients that help keep the body detoxified. Today we are going to focus on those specific nutrients that your body needs to have a rock-solid immune system.

Some of the vitamins and minerals crucial for immune health include the B complex, especially vitamins B ₆ and B _12; Beta carotene, Vitamin C, Vitamin D, Vitamin E, Folate, Iron and Zinc.

Foods that contain vitamins and minerals for good immune health

Kiwi

It turns out that eating kiwi has been shown to reduce the duration of the flu. In fact, it can reduce the susceptibility to the flu in children by 50% and can shorten the convalescence time in older people with respiratory infections. ( 3 )

Kiwi fruit is high in vitamin C, folate, potassium and antioxidants such as alpha-tocopherol and lutein. It has been shown to have positive effects on immune response and prevent many ailments.

Many people remove the peel, but if you include it, you triple the amount of fiber you get from this food. Additionally, the peel has a unique prebiotic property that greatly benefits the colon and the entire microbiome.

Garlic

Garlic has been used in medicine for years and one of the reasons is because it contains a compound called alliin which releases and catalyzes the enzyme alliinase when garlic is chopped and that is when it increases immune function. Chopped garlic also provides an additional amount of sulfoxide compounds with healing properties.

Cooking fresh garlic may decrease its ability to fight flu symptoms, but some studies have shown that chopping garlic and letting it sit for 10 minutes before heating it can protect its immune capabilities from being destroyed by cooking.

Aged garlic extract may reduce the severity and duration of both colds and flu.

Onion

Photo by Ylanite Koppens

Onions contain two important components for strengthening the immune system: the antioxidant flavonoids anthocyanin and quercetin; and alliin.

Red and yellow onion varieties have a high quercetin content, which is known to have anti-cancer, anti-inflammatory and antiviral properties. The highest concentration is found in the outer rings of the onion.

Ginger

Ginger has many medicinal uses and is well known for its anti-inflammatory and antioxidant properties. It also has antimicrobial effects that can help protect you from infectious diseases.

Gingerol is the main bioactive compound in ginger, responsible for many of its medicinal properties, including its anti-cancer properties. Gingerol is related to the substances capsaicin and piperine, which are active compounds found in peppers (there are several types such as black, white, red, green, cayenne) and which give them their spicy taste and unique medicinal properties, in the same way that curcuminoids are found in turmeric.

You can get ginger rhizome at the market and store it in the freezer. When you want to use it, grate a piece over your food or in smoothies. You can also boil it with water and drink it hot.

Green tea

Green tea contains about 40% polyphenols by weight and this must make it the most powerful of teas.

Green tea contains compounds called catechins, as well as the antioxidant quercetin and the amino acid L-theanine , which greatly strengthen the immune system.

Green tea is an immune protector. A study showed that women under 50 who drank green tea at least three times a day reduced their risk of breast cancer by 37%.

An interesting fact is that gargling green tea has been shown to reduce the incidence of flu among the elderly.

Cruciferous vegetables

A study published in the journal Cell showed that cruciferous vegetables such as kale, Swiss chard, Chinese cabbage, broccoli and Brussels sprouts are a source of a chemical signal that is sent to the immune system to function optimally.

Cruciferous vegetables contain beta carotene, lutein, zeaxanthin, folate, and vitamins C, E, and K. They also contain high levels of sulfur-containing compounds called glucosinolates that form sulforaphane, a phytochemical known for its immune-boosting and anti-cancer properties. Once cut and chewed, these vegetables release anti-cancer compounds called isothiocyanates .

Of all the cruciferous vegetables, kale contains the highest amount of polyphenols that enhance the body's defenses against pathogens, especially if it has been cooked (for no more than 3 minutes).

Try chopping cruciferous vegetables and mixing them into salads (chopping, splitting, or otherwise handling them causes the vegetable to release the sulforaphane substance that is where the immune benefits come from). You can also add them to soups, pizzas, or blend them into smoothies.

Probiotics, prebiotics and fermented foods

Photo by Ivanyawa for Pixabay

Digestive health has a huge impact on the proper functioning of every part of the body, including the immune system.

Some of the most important players in intestinal health are probiotics (good bacteria that live in the colon) and prebiotics (what good bacteria feed on).

Probiotics can be found in supplement form, but are also abundant in fermented foods such as sauerkraut, miso paste, kefir, and oriental foods such as tempeh and kimchi. These foods appear to help reduce the risk of respiratory infections.

A study published in 2003 observed the ability of the probiotic strains Streptococcus thermophilus and Lactobacillus acidophilus to protect cells from the most harmful forms of E. Coli bacteria.

Prebiotics are abundant in plants such as jicama, chicory root, garlic, onion, watercress, Jerusalem artichoke, dark green leafy vegetables and kiwi peel.

A 2011 study published in the Journal of Gastroenterology found that prebiotics have powerful anti-inflammatory and anticancer properties, as well as providing good support for mineral absorption and immune protection against disease.

Learn more about prebiotics and probiotics here

Red fruits

Red berries get their dark purple, pink, red and blue hues from substances called anthocyanins that help treat many conditions such as hypertension, colds and urinary tract infections.

Berries also have a high concentration of antioxidants such as vitamin C that helps prevent cell damage and inflammation. One of the antioxidants found abundantly in berries is ellagic acid, known to prevent tumor growth and strengthen the immune system of the oral mucosa.

In 2013, 445 compounds were tested for their ability to naturally boost human immunity. The results were published in the journal Molecular Nutrition and Food Research and show that resveratrol found in red grapes and a substance called pterostilbene found in blueberries have the greatest positive impact on immunity. ( study )

In 2018, a review of the effects of berries and their phytochemicals on the digestive and immune systems found that whole berries had properties that boost immune system function.

You can add berries to your salads, smoothies and desserts to get all the immune-boosting properties they provide.

Recipe for elderberry syrup:

Ingredients:

4 cups of water

2 cups dried elderberries

1 cinnamon stick

1 piece of peeled ginger (approximately 2 cm wide)

2/3 cup raw honey, if possible, or yacon syrup if you have sugar problems.

Preparation:

Heat the water, elderberry, cinnamon and ginger in a pot on the stove over low heat for 30 minutes.

Strain the mixture and then add the honey or yacon syrup to the liquid until well mixed.

Store in a glass jar.

Citrus fruits

You've probably seen and heard people drinking orange juice for its vitamin C content and to prevent colds. Did you know that consuming the whole fruit instead of juice is more effective?

Citrus fruits contain high levels of protective antioxidants like vitamin C that strengthen your immune system and make you less vulnerable to disease.

Sometimes when people are stressed, their immune function decreases. This is one of the reasons why people under a lot of stress get sick easily (even if they eat healthy). One study found that simply smelling citrus fragrances can reduce stress-induced immunosuppression.

Mushrooms

There are many species of mushrooms and virtually each one has its own unique health-protective benefits.

The medicinal use of mushrooms is ancient. Today, science is just beginning to understand the important properties of these fungi.

Only the white button mushrooms found on the market have been shown to improve immune function in the mouth and respiratory tract. Other, lesser-known varieties appear to attack strong viruses and cancer cells.

A study published in 2015 followed 52 adults between the ages of 21 and 41 who ate a daily serving of about 100 grams of Shiitake mushrooms for a month. The results showed improved functioning of T cells (lymphocytes produced in the bone marrow) and a reduction in inflammation that had not been seen with drug intervention.

Include mushrooms in your diet unless you have problems with allergies and intolerances to certain foods.

Apples

Some studies have shown that apples have strong antioxidant activity. This is important because antioxidants help protect cells from oxidative damage and help lower the risk of infections and certain diseases.

In a 2010 study where some mice were fed soluble fiber and others insoluble fiber, it was found that those fed soluble fiber showed profound, positive changes in their immune systems, increasing production of the anti-inflammatory protein Interleukin-4 and recovering much faster from a bacterially induced illness.

Add green apples to your vegetable juice and water apples or creole apples to your smoothies and salads.

Sunflower seeds

Sunflower seeds contain a large amount of vitamin E (82% of the daily requirement in ¼ cup).

Vitamin E is a powerful antioxidant known to reduce the risk of inflammation-related diseases, protect the body from cellular damage, and combat disease-promoting oxidative stress. Sunflower seeds also create antibodies that help fight infections.

Red peppers

Red peppers contain twice as much vitamin C as red berries, plus vitamin E and beta carotene, which give them an immune boost.

A 2010 study found that capsaicin present in red peppers provides an anti-inflammatory effect and this is due to inhibiting the production of pro-inflammatory cytokines.

Red peppers can be prepared in several ways, remember to include them in your meals, especially if you feel that your immune system is weakened.