The beginning of fall brings with it a chill in the air, which serves as a quiet reminder of the impending flu season, affecting millions of people in the United States every year.
While the flu is a virus detected year-round in the United States, influenza viruses typically circulate during the fall and winter months, according to the CDC.
Getting your annual flu vaccine is evidently the most important preventative measure, according to Dr. Navya Mysore, primary care physician and women’s health expert. Flu shots, while not perfect, give your immune system a “head start” against influenza.
Washing your hands regularly and disinfecting surfaces is also important. “Good hand hygiene is important, as the flu (and COVID) is spread through respiratory droplets,” Dr. Kevin Truong, board-certified primary care and internal medicine physician at UCI Health, told Spoon University
Hygienic measures and getting your flu shot are both necessary for everyday life to stay healthy. But, with more people getting sick during flu season, is it possible for food to play a part in boosting your immune system as well?
What does it even mean to “boost your immune system”?
“Your immune system is complex, and there isn’t a single food or supplement that can simply ‘boost’ it,” Dr. Mysore told Spoon.
Dr. Truong echoed this notion, citing a difference between how getting a vaccine and eating different foods have different effects on the immune system.
“The flu vaccine [is] a form of ‘adaptive’ immunity where we provide the body with a non-harmful mimic of the virus so that it learns how to protect itself from similar forms of the virus,” he said.
Differently from the “adaptive” immunity of the flu vaccine, the intake of food helps to support the immune system by fueling cells to build proteins that fight infection and viruses, provide protection from physical or mental stress, and support
While there isn’t one single thing to eat that can instantly boost your immunity, what you eat can have a hand in helping keep the flu at bay. Here’s what nutrients to eat and which foods to find them in to strengthen your immune system against sickness, according to medical professionals.
Vitamin C
Foods like oranges, grapefruit, bell peppers, berries, broccoli, and leafy greens are naturally rich in vitamin C and other antioxidants.
“Vitamin C helps several types of immune cells work properly and protects the body from damage,” said Dr. Truong. When you’re ill, your body uses up its vitamin C stores faster than normal, so eating foods high in vitamin C may help your immune system work closer to its healthy abilities.
Vitamin D
Foods rich in vitamin D — fatty fish like salmon and sardines, fortified dairy and other foods, and eggs — play an important role in immune function, according to Dr. Mysore.
“Being low in vitamin D can weaken your response to the flu shot and is linked to catching more respiratory infections,” said Dr. Truong.
Your skin also produces vitamin D when you’re in sunlight, so going outside to soak up some sun could help strengthen your body.
Zinc
“Zinc keeps immune cells active and can act directly against viruses,” said Dr. Truong.
Meat, shellfish, beans, nuts, seeds, and lentils are all rich in zinc, a trace mineral — meaning your body only needs small amounts of it to stay healthy — that can shorten a cold by making immune system cells that fight germs.
Protein
Found in meat, fish, dairy, eggs, beans, and nuts, eating protein supports “immune cells and antibody production,” said Dr. Mysore.
Dr. Truong called protein the “building block” that a body uses to make antibodies and new immune cells. Antibodies protect the body by eliminating pathogens — microorganisms like viruses, bacteria, and parasites, and immune cells also form the body’s natural defense system against pathogens.
What else can you do to not catch the flu?
While eating these specific nutrient-dense foods will strengthen your body against viruses, both Dr. Truong and Dr. Mysore emphasized that a balanced diet and other consistent, long-term preventative measures — such as an exercise routine, managing stress, drinking enough water, and sleeping well — are the best ways to support regular immune function.
“I don’t recommend you focus solely on one type of nutrient, and instead on a balanced, varied diet,” said Dr. Truong. “Suddenly eating a balanced diet when you start to feel ill is not good preventative care, as it does not allow enough time for your body to digest and utilize the raw materials that you eat.”
“A better goal is to support normal immune function through adequate nutrition, sleep, exercise, stress management, and vaccination,” Dr. Mysore suggested. She especially highlighted the importance of prioritizing adequate sleep, since chronic sleep deprivation can have negative effects on a body’s immune function.