Seasonal Flu Strikes! Understanding Flu Symptoms and Immunity-Boosting Diet

Analysis 1⟫ What is Influenza? What Are Its Symptoms?

Question 1⟫ What is Influenza? How Does It Spread?

Influenza (flu) is an acute respiratory illness caused by the influenza virus, classified into four types: A, B, C, and D. In Taiwan, the predominant strains are type A (H1N1, H3N2) and type B. Flu outbreaks are most common in autumn and winter (November to March) but can occur year-round. It is important to note that influenza is caused by a different virus than the common cold, so it is not just "the latest cold going around"!

Influenza is highly contagious and spreads easily in crowded places. The primary transmission routes are droplet infection and direct contact. Being in an enclosed, poorly ventilated space significantly increases the risk of virus transmission.

Question 2⟫ How Long Is Influenza Contagious? What Is the Incubation Period?

The incubation period for influenza typically ranges from 1 to 4 days. An infected person can transmit the virus starting from 2 days before symptoms appear until about 5 days after onset. The highest transmission risk occurs within the first 3-4 days of illness. Most people recover within a week, but immunocompromised individuals and young children may remain contagious for weeks or even months.

Question 3⟫ What Are the Symptoms of Influenza?

Influenza symptoms appear suddenly, last longer, and are more severe than those of the common cold, affecting the entire body. Symptoms include high fever lasting 3-4 days, cough, headache, runny nose, sore throat, muscle aches, general fatigue, and weakness. Some individuals may also experience nausea, vomiting, or diarrhea.

Question 4⟫ Who Are at High Risk for Severe Influenza Complications?

Most flu cases are mild and resolve within 1-2 weeks. However, high-risk groups—including the elderly, pregnant women, infants, people with chronic diseases, and individuals with obesity (BMI ≥30)—are more susceptible to severe complications such as pneumonia, encephalitis, myocarditis, and neurological symptoms, which can be life-threatening. If symptoms appear, seeking medical attention early is crucial.

Question 5⟫ How Can You Tell If You Have Influenza?

Both the flu and common cold cause respiratory symptoms, but influenza has a more sudden onset, with high fever lasting several days, severe muscle aches, and fatigue, whereas the common cold mainly presents with mild respiratory symptoms. The Taiwan CDC advises that if you experience "One Fever (persistent high fever for more than 2 days), Two Aches (headache, noticeable muscle aches), and Three Fatigue (extreme tiredness)," you should suspect influenza.

Analysis 2⟫ Strengthening Immunity with 6 Key Nutrients from Natural Foods

The most effective way to prevent influenza is through vaccination. However, maintaining a strong immune system through diet can help optimize immune function and enhance the body’s defense against viruses and bacteria.

Nutrient 1⟫ Vitamin A

• Function: The mucosal barrier covering the respiratory and digestive tracts serves as the immune system’s first line of defense against pathogens. Vitamin A plays a crucial role in maintaining the integrity of epithelial cells, supporting cell regeneration and repair in these tissues, thus strengthening immunity.
• Food Sources: Dark green leafy vegetables, carrots, bell peppers, animal liver, pumpkin.

Nutrient 2⟫ Vitamin C

• Function: Vitamin C has antioxidant properties, aids in repairing damaged cells, and enhances immune cell activity.
• Food Sources: Citrus fruits, strawberries, guavas, kiwis.

Nutrient 3⟫ Vitamin D

• Function: Vitamin D regulates innate and adaptive immune responses, stimulates the production of proteins that help identify intracellular pathogens, and enhances antimicrobial protein production in epithelial and immune cells. Studies suggest that low vitamin D levels are associated with increased infection risk.