A healthy, varied diet is important in order to maintain a healthy immune system. There is no magic pill or specific food that will protect you from a virus, but an overall healthy lifestyle will give your body the best tools to fight illness. There are several things you can do to help strengthen your immune response, however, if you already have a strong immune system, there is little scientific evidence that you can actually give it an extra “boost.”
The best way to ensure your immune system is ready to fight infections is by taking a food-first approach to vitamins and nutrients. Food-first means that you focus on getting all the nutrients you need from food before resorting to supplements.
Our bodies are complex, and the immune system contains various cells and proteins that require different vitamins and minerals to function optimally to defend and limit infection. While supplements might work, real food is the optimal way to get the best possible effects of what you put into your body. Also, since scientists are still studying nutrients and how they function in symbiosis, measuring the immune response from a specific nutrient is extremely difficult. With a balanced diet, you also avoid getting excessive amounts of vitamins and minerals, which may lead to negative side effects.
Sleep – at least seven hours
Sleeping enough every night is very important for recovery and staying healthy. Research has shown that those who slept less than five hours are 4.2 times more likely to catch a cold compared to those who slept more than seven hours (1). For better sleeping habits, avoid screens, snacking late, or exercising in the hours right before bedtime.
Tips! Find a calming routine before bedtime: drink a cup of tea, read a nice book, and dim the lights at least an hour before bedtime so you can calm down. Also, always aim for seven to eight hours of sleep per night.
Vitamin D – eat salmon
The most important nutrient to fight infection and to strengthen our white blood cells tissue macrophages is Vitamin D. What’s interesting is that Vitamin D has a great impact on respiratory infections in people with deficiencies (2) and unfortunately, a lot of people in western countries are more likely to be deficient because of lack of sunlight. Elderly, obese and people with darker skin tend to be more prone to Vitamin D deficiency, especially in Nordic countries (3). Check your Vitamin D levels with your doctor if you are worried about your immune health, and supplements should only be prescribed by a professional.
Vitamin D is found in fatty fishes, such as salmon, as well as fortified milk. Salmon also contains a lot of Omega 3’s and they also have anti-inflammatory properties. So make sure you eat high-quality salmon at least 2-3 portions per week- there are plenty of salmon recipes in the Lifesum app for inspiration!
Alcohol – avoid in excessive amounts
Excessive alcohol consumption has a negative effect on the immune system. Alcohol disrupts immune pathways that can impair the body’s ability to defend against infections (4). Alcohol consumption increases the risk of many different long-term health problems. According to U.S. Dietary Guidelines for Americans, a moderate intake of one glass per day for women and two for men is fine, but excessive intake should be avoided at all times (5).
Good Hygiene
In order to stay healthy, it is important to keep good hygiene to avoid spreading bacterias and viruses. Washing your hands with soap and water is the best way to get rid of germs. If soap and water are not available, alcohol-based hand sanitizer can be used – however, it does not work as effectively as washing with soap and water (6).
Washing your hands of extra importance in situations like:
- Before, during and after preparing food
- Before eating
- After using the bathroom
- After being in public areas
- After blowing your nose
- Before touching your face/nose/mouth/eyes
There are plenty of instructions and videos on how to wash your hands the best way. A quick guide is to:
- Wet
- Lather
- Scrub (for at least 20 seconds)
- Rinse
- Dry
This whole process takes about 30-60 seconds but is one of the most effective ways of reducing the risk of spreading bacterias (6). So make sure to keep your hands clean and you will prevent yourself and the people around you from getting ill!
Other recommendations
The recommendations mentioned above are a few things to have in mind in order to maintain a healthy immune response.
In a recent review from 2020, researchers confirmed that Vitamin D, Vitamin C, and Zinc have the strongest evidence for immune support, but more studies need to be done to understand dosage and benefits with supplementing against infection (7). Vitamin C, probiotics, zinc and flavonoids are all part of a healthy diet but exaggerated intakes with supplements might have negative effects (8). Surprisingly, fruits like kiwi or oranges contain a lot of Vitamin C, in fact one kiwi contains your full recommended daily intake. If you eat two handfuls of colorful vegetables and vary them daily, along with your main meals containing both high-quality protein, carbs, and fats, you most likely don’t need to worry about any deficiencies. What’s important to have in mind is that deficiencies are very rare in healthy people and most of the health claims are made from a deficient state.
Alternative supplements such as ginseng, curcumin, echinacea, and elderberries might help prevent respiratory tract infections but the evidence and quality of studies are very low and the price of these supplements is very high. Save your money and buy some nutritious and colorful foods instead! Your body and wallet will thank you in the long run.
It’s all about prioritizing all the information we receive regarding how to boost or strengthen your immune system. Having an overall healthy lifestyle all year is the best solution, always. We tend to look for shortcuts, but doing simple things like eating nutrient-rich meals, reducing stress, avoiding sugar, exercising, and washing our hands are some of the first steps to stay healthy.
References
(1) Aric A. Prather, PhD, Denise Janicki-Deverts, PhD, Martica H. Hall, PhD, Sheldon Cohen, PhD, Behaviorally Assessed Sleep and Susceptibility to the Common Cold, Sleep, Volume 38, Issue 9, September 2015, Pages 1353–1359, https://doi.org/10.5665/sleep.4968
(2) Martineau Adrian R, Jolliffe David A, Hooper Richard L, Greenberg Lauren, Aloia John F, Bergman Peter et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data BMJ 2017; 356 :i6583 https://www.bmj.com/content/356/bmj.i6583
(3) Weishaar T, Rajan S, Keller B. Probability of vitamin D deficiency by body weight and race/ethnicity. J Am Board Fam Med 2016;29:226–32.
(4) Sarkar D, Jung MK, Wang HJ. Alcohol and the Immune System. Alcohol Res. 2015;37(2):153–5. PMCID: PMC4590612.
(5) https://www.cdc.gov/alcohol/fact-sheets/moderate-drinking.htm
(6) Centers for Disease Control and Prevention. When and how to wash your hands. 2019. https://www.cdc.gov/handwashing/when-how-handwashing.html
(7) Gombart, A.F.; Pierre, A.; Maggini, S. A Review of Micronutrients and the Immune System–Working in Harmony to Reduce the Risk of Infection. Nutrients 2020, 12, 236.
(8) https://www.sciencedirect.com/science/article/pii/S0735109718343638
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