Eating for Immunity

Have you heard the phrase, “An apple a day keeps the doctor away”? Do you think it’s true?

The most important message to take from this phrase is that we need proper nutrition to be healthy and fight off illness. It is true that diet plays a huge role in how the immune system functions. Other factors are important too, such as adequate sleep, managed stress, and consistent physical activity.

What exactly is the immune system?

The immune system is a complex network of cells that work together to fight off harmful pathogens. There are three levels of immune system defense:

1. Skin and mucous membranes help “catch” pathogens before they enter our bodies.
2. Innate immunity occurs in which immune cells destroy foreign pathogens.
3. Adaptive immunity occurs in which immune cells recognize pathogens from previous exposures and are therefore equipped with better defense mechanisms.

What should we eat to promote a healthy immune system?

Whenever I feel a cold coming on, my mom tells me to take vitamin C. And I have also been led to believe that over-the-counter zinc can shorten colds. And now with COVID-19, everyone is interested in vitamin D supplements – So what do we need to avoid getting sick?

We all want the quick fix, but in reality, we need a balanced diet for our immune system to be at its best. A balanced diet is full of fruits, vegetables, legumes, whole grains, lean protein, low-fat dairy, and unsaturated oils. These types of foods provide a variety of essential nutrients, all of which help keep us healthy.

Why are nutrients so important for immune function?

• All cells require adequate nutrients to properly carry out their functions, and immune cells are no different.
• Immune cells are unique as they replicate, or proliferate, at a high pace and are constantly ridding of foreign invaders.
• Because of their fast-paced functions, adequate nutrition including vitamins, minerals, adequate protein and calories are necessary fuel to keep immune cells thriving.

 Impacts of specific nutrients can have on the immune system:

Vitamin A

• Vitamin A keeps our skin and mucous membranes healthy to protect against invading pathogens.
  • Eat bright orange or dark green veggies to get your fill of this nutrient.

Vitamin C

• Essential for maintaining healthy skin.
  • Eat oranges, colored bell peppers, broccoli, strawberries and potatoes.

Vitamin D

• It helps control the inflammatory response and can reduce the severity of infection.
  • Eat fortified dairy and breakfast cereals, or fatty fish (tuna or salmon), and take a walk in the sunshine to get your days’ worth of this nutrient.
  • Many Americans do not get enough vitamin D, speak with a medical professional to determine if you would benefit from supplements.

Vitamin E

• Vitamin E is an antioxidant that protects immune cells from oxidative damage and helps control inflammation.
  • Eat a variety of nuts, seeds, unsaturated oils, and even spinach to get enough of this nutrient.

Zinc

• Zinc is necessary in allowing immune cells to replicate at appropriate rates.
  • Eat a variety of oysters, roast beef, oatmeal, pumpkin seeds, and fortified cereals.

Probiotics

• Prevents overgrowth of pathogens in the gut
• The “good” bacteria that promote a healthy gut and beyond.
  • Good sources include yogurt, fermented vegetables such as sauerkraut or kimchi, fermented teas called kombucha, and pickles fermented in a salt brine (not quick vinegar pickles).

So can an apple a day keep the doctor away?

Sure, as long as it’s part of a balanced diet! Remember that all nutrients are important and there is no one quick fix for supporting the immune system. Strive to consume a healthful diet full of variety and talk to a medical professional before resorting to supplements.