What are immune support vitamins? What are the immune-boosting foods? And what are the worst nutritional components for the immune system? I answer all of these questions about eating to boost immunity in this guide.
Immune-boosting foods that boost your immune defense are a hot marketing tool. From food products and supplements that claim to “support immunity” to magazine articles recommending the best “immune superfoods,” the idea of eating food to boost immune function seems to be everywhere. Perhaps this is a good thing, because infectious diseases are the leading cause of disease in the world. And given the pandemic outbreak, along with cold and flu season, it’s tempting to buy hope that you’ll eat your way to a stronger immune system. While good nutrition can indeed help support the immune system, it is important to separate the hype from the truth. So, let’s delve into the science about vitamins for the adult immune system, immune-supporting vitamins, and immune-boosting foods.
This is your immune system
You can take credit for your immune system for allowing you to thrive in a busy, interactive world. The immune system is the body’s protection network that prevents the invasion of harmful substances, such as bacteria, viruses, and chemicals, as well as protecting against the development of cancer. When your immune system is healthy, you have many barriers to protect against invaders, including the skin, inflammatory responses, and specific immune responses, such as certain types of white blood cells that destroy pathogens.
Your gut plays a very important role in your immune system; It is the body’s largest immune system, accounting for 25 percent of immune cells. There are more than 400 types of bacteria in your gut, and they have important symbiotic (beneficial) relationships with your body. Simin Meydani, DVM, Ph.D. Director Jan Mayer US Department of Agriculture human nutrition research center on agingHNRCAand the Nutritional Immunology Laboratory at Tufts, the gut flora (the group of microorganisms, mostly bacteria) is called the “forgotten organ of the body.” Learn more about the gut microbiota over here.
As you age, your immune system diminishes. Meydani reported that there is an increased incidence of infectious diseases (and morbidity and mortality from infectious diseases) in the elderly because they are more susceptible to infection, pathogens are more virulent, and there is a negative change in gut bacteria. Moreover, marginal nutritional deficiency is also common in the elderly.
Once you become infected, a vicious cycle begins – the infection hampers your ability to boost nutrition due to loss of appetite, fever, and diarrhea, thus weakening your immune system. To make matters worse, scientists now know that nutritional deficiencies can cause the virus to become more virulent.
Nutrition and the immune system
One of the most important ways to maintain a healthy immune system is to promote good nutrition. “When a pathogen enters the body, the immune system recognizes it and the body produces an army of specialized immune cells to get rid of the pathogen,” Maidani explains. And what do immune cells need to grow in numbers? “Essential nutrients such as vitamins, minerals, amino acids and essential fatty acids,” she adds. This is the root of the relationship between diet and immunity. “Nutrients are essential for the optimal function of the immune response and for stimulating defense against pathogens. Nutrient deficiencies, in addition to aging, can impair host defense and increase the incidence of pathogens,” says Medani.
Build your immune defense with diet
The following nutrients appear promising for their effect on the immune system.

1. Vitamin C
Many people strongly believe that high levels of vitamin C boost their immune function and help fight off colds. Unfortunately, the science has not been concrete, with some studies showing that it boosts immune function, while others have shown no effect. According to the National Institutes of Health, more than 30 clinical trials have examined the effects of vitamin C on cold prevention, but they generally do not support a significant reduction in risk. However, it is important to get enough of this antioxidant vitamin in your diet through foods, so be sure to include it. Daily sources of foods rich in vitamin C, such as papaya, red pepper, broccoli, strawberries, citrus fruits and tomatoes as part of your healthy diet.
2. Vitamin E
Its documented role in the immune system led immunology researchers to study vitamin E in a field-led study published in Journal of the American Medical AssociationVitamin E supplementation has been found to reduce the risk of upper respiratory tract infections, particularly the common cold. Foods full of vitamin E include nuts, olives, and leafy green vegetables.

3. Zinc
Studies show that people with low blood zinc levels have twice the frequency of pneumonia (as well as longer duration and use of more antibiotics) compared to those with adequate zinc levels, according to my field. in a study in American Journal of Clinical NutritionTaking zinc supplements reduced the incidence of infections by 65 percent. But when it comes to colds, Medani says, “the jury is still out. Some studies show zinc helps and shortens the duration of colds, while other studies don’t show that effect.” It’s still a good idea to make sure you get enough zinc in your diet to support a healthy immune system, including Plant sources such as beans, nuts and whole grains.
4. Vitamin D
While more evidence is needed, scientists recognize that the sunshine vitamin may have important functions within the immune system. Research shows that TB patients respond better when treated with vitamin D or sunlight. In addition to sunlight, you can find vitamin D in fortified foods and drinks, as well as light-exposed mushrooms. Pescatrine can be found in salmon and sardines.
5. Calories
The potential immune benefits of calorie restriction have attracted researchers’ interest. In the CALERIE study (Comprehensive Evaluation of the Long-Term Effects of Reducing Energy Intake), overweight participants, divided into two groups, reduced their calorie intake by 10 percent and 30 percent, for six months, resulting in significant improvements in response. Immunosuppressants were found in both groups, with the best effects seen in the 30 percent group. “I don’t recommend that people who are not overweight benefit from calorie restriction. Field urges to eat enough, but not too much. If you reduce calories too much and that results in nutritional deficiencies, it’s not good for the immune system.”
6. Probiotics
These microorganisms can exert health benefits by improving the number of beneficial bacteria in the gut. “Several studies show that the right types of probiotics increase the immune response,” says Medani. study in Nutrition Journal It was found that a fermented milk drink containing Lactobacillus strain Shirota bacteria significantly increases the activity of the natural killer cell (an important immune cell). However, only certain strains of probiotics have been tested for their immune benefits. Thus, it is important to seek clinical evidence.

7. Mushroom
Mushrooms have captured the interest of scientists in immunology research. When mice were fed a powder made from white mushrooms, natural killer cell activity increased significantly, according to a study published in Nutrition Journal. It is a good idea to include mushrooms in your diet more often.
bottom line
So should you take mega doses of essential nutrients to boost your immune system? We cannot say for sure. Sometimes, if you take supplements in more than the required level, immune function can decrease. “It’s not always the case that better is better,” says Medani. Additionally, nutrients seem to affect people’s immune systems differently. Meydani explains that people can be “responsive” or “non-responsive” to certain nutrients, based on genetic differences.
Many food companies and the media have made far too many claims about the ability of certain foods to strengthen your immune system. It’s important to keep in mind that foods synergistically contain nutrients that work in unison to provide health benefits versus supplements that only provide one or two nutrients. The best approach to promoting a healthy immune system is to follow a nutrient-rich diet that meets all of your body’s needs. Here are more reasons to make every bite count, with delicious, whole foods packed with nutrients.
Check out the following blogs on how to build your immune defense:
Top 5 ways to use mushrooms
Learn all about probiotics
Feed your small intestine for health
Written by Sharon Palmer, MSFS, RDN
picture: Watermelon Bok Quinoa Tofu BowlSharon Palmer, MSFS, RDN
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