You are what you eat and drink, experts say, and this includes foods that will help your body fight infectious diseases this winter, such as colds, flu and coronavirus.
“What we eat is very important in terms of how our immune system responds to pathogens and how well it can defend itself against these pathogens,” said Dr. Simin Meydani, chief scientist and lead for the nutritional immunology team at Tufts University.
Micronutrients such as vitamin C, vitamin D, vitamin B-complex, zinc and selenium help to “pump” two essential parts of the body’s defenses. The innate immune system begins to function as the first line of defense, followed by the adaptive immune system, which sends killer T cells, antibodies and other soldiers into the fight.
Experts say how well you can activate immunity with nutrients depends on your age, overall health and stress levels.
But if you are overweight, smoke, drink alcohol, suffer from chronic illness, are over-stressed or sleep poorly, focusing on the food you eat may have benefits this winter.
It is also important to maintain a healthy weight, reduce stress, get good sleep and get regular exercise to maintain those natural defenses in the event of an illness. Without this healthy baseline, your body will have to work harder to strike at invaders, and it may lose the match.
Is there an immune-boosting diet? The answer is yes, but there’s no need to stick to a specific superfood list for your next shopping trip.
“You will not see the benefit that you want to see through eating a large amount of a single food item or food component,” Meydani said.
Therefore, the best route to a healthy immune system is to eat a large variety of fresh, colored, yellow, orange, blue, and green fruits and vegetables every day, along with some high-quality whole grains, less lean protein, and less healthy oils.
Increase volume to the desired amount
If you want to increase the effect of food on your immune system, you will need to dramatically increase the amount of fruits and vegetables you eat each day, Meydani said.
Her team investigated the immune responses of animals fed two to three servings of fruit and vegetables a day and compared them to those who ate five to six servings a day or eight to nine servings a day.
“The animals that took eight to nine servings a day had the best effect,” Meydani said, adding, “So it is not only a matter of increasing the health rations a little, but also a lot.”
Finding ways to incorporate fruits and vegetables into every meal and snack throughout the day may do more than increase your immunity. A 2017 study found a significant reduction in the risk of heart attack, stroke, cancer and early death by eating 10 servings of fruits and vegetables every day.
Are supplements necessary?
The human body is built to absorb nutrients from fruits, vegetables, nuts, grains and proteins more efficiently than processed foods or supplements.
However, people with limited access to healthy food options, those with certain medical conditions or anyone over the age of 65 may need to focus on adding specific micronutrients to their diet.
“I am not talking about the frail elderly who live in their homes… I am talking about elderly people who are healthy, but over the age of 65. For them, I think some nutritional supplements may be very beneficial,” Meydani explained.
Most people in the United States get an adequate amount of zinc from the foods they eat. But a study by a field team found that 20% of the elderly and independents had low levels of zinc in their blood, while 30% of the elderly who lived in nursing homes did not have adequate levels of zinc.
The study of 500 elderly people found that those with low blood levels of zinc had increased risk of pneumonia and duration of antibiotic use compared to people with adequate levels.
Megan Meyer, director of scientific communications for the International Food Information Council, said that using zinc emulsions in the early stages of a cold or flu, as in the first 24 hours, may give a boost to the immune system in combating pathogens. The recommended daily dose is 8 milligrams for women and 11 milligrams for men for no more than five days.
Zinc can also interfere with the effectiveness of antibiotics or negatively interact with some blood pressure medications and rheumatoid arthritis, so consult your doctor before adding it to your diet.
Selenium plays an important role in inflammation and immunity. We need the mineral in the soil that the plants absorb to activate the immune cells. It also appears to be able to reduce the inflammatory response.
Most Americans get a lot of selenium from their diet. It can be found in seafood, meat, poultry, eggs, dairy products, breads, grains, nuts, and especially Brazil nuts, which can contain up to 91 mcg.
Hundreds of studies over the years have looked at the benefits of vitamin C for the immune system. Clinical trials are underway to investigate its effect on the severity of Covid-19. Most people believe that vitamin C strengthens the immune system and prevents colds.