Your body’s immune system protects you from disease. This complex network of organs, tissues, cells, antibodies, and other substances works together to help fight off infections and repair damaged tissue. When it does this, it produces chemicals called cytokines that alert other parts of the immune system to respond.
The immune system consists of three main components:
1. The innate immune system, which includes our natural defense mechanisms such as white blood cells, macrophages, and complement proteins.
2. The adaptive immune system, which is responsible for learning about foreign invaders and developing immunity.
3. The nervous system, controls every aspect of the immune response and communicates with the brain and other parts of the body.
There are many things we do every day that impact our ability to maintain good health. These include eating nutritious food, getting enough sleep each night, exercising regularly, avoiding stress, managing chronic conditions, and maintaining strong social support systems.
What factors can depress our immune system?
As we age, our internal organs begin to deteriorate. We lose muscle mass, our bones become brittle, and our heart, lungs, liver, kidneys, pancreas, stomach, intestines, and brain starts to slow down. This is called aging.
Our immune system begins to decline around 30 years old. By 50 years old, most people are already experiencing some level of immunosuppression.
Environmental toxins (like smoke and pollution), excess weight, and a diet high in processed foods all contribute to weakening the immune system.
Chronic diseases like diabetes, cancer, cardiovascular disease, arthritis, asthma, depression, anxiety, and Alzheimer’s disease can all cause the immune system to weaken. Mental stress and lack of sleep can also suppress the immune system.
Lack of sleep and rest help the body fight off infections. When you don’t get enough sleep, your white blood cells don’t work as well. They aren’t able to kill bacteria and viruses as quickly. You end up getting sicker faster.
A lack of sleep can lead us to catch colds or flu more often.
Foods That Strengthen Immune System
Blueberries are packed with antioxidants and flavonoids that can help you fight off viruses. A study published in the Journal of Agricultural Food Chemistry found that people who ate blueberry products such as yogurt, juice, and bread had fewer colds than those who didn’t eat the foods.
Cherries contain anthocyanin compounds that act as powerful anti-inflammatory agents. Anthocyanin helps reduce swelling and inflammation, and it can even prevent cancer cells from growing.
Apples are loaded with quercetin, a compound that fights against bacteria and viruses. Quercetin also reduces inflammation and protects against heart disease.
Grapefruit contains high levels of vitamin C, which makes it one of the best fruits for fighting off colds. Vitamin C also boosts immunity, and it can protect against certain types of cancers.
5. Dark chocolate
Dark chocolate contains antioxidants and other vitamins and minerals that help protect cells from free radicals — molecules that cause cell damage. Antioxidants are found naturally in fruits, vegetables, nuts, and seeds. They prevent cellular oxidation, which occurs when oxygen interacts with certain chemicals within the body. Oxidation damages DNA and proteins, resulting in aging and disease.
Chocolate is rich in flavonoids, such as catechins and procyanidins, which have been shown to improve blood flow and lower blood pressure. Chocolate also contains magnesium, potassium, copper, zinc, iron, manganese, phosphorus, calcium, and selenium. These elements work together to keep you healthy.
The American Heart Association recommends eating 2 ounces of dark chocolate daily. This amount provides about 75% of the recommended daily intake of antioxidant flavonols. Flavonols are compounds that make up most of the cocoa bean and include quercetin and kaempferol. Both of these flavonols have been shown to reduce inflammation, which plays a role in heart disease.
Cocoa powder is another source of flavonols. One cup of unsweetened cocoa powder supplies approximately 25 mg of flavonols. However, one ounce of dark chocolate contains around 150 mg of flavonols, according to the USDA National Nutrient Database.
Dark chocolate is high in calories. A single square of dark chocolate contains 120 calories, while a serving of milk chocolate contains 70 calories. If you eat too much chocolate, it could lead to weight gain.
But moderate consumption of dark chocolate does not increase your risk of obesity. In fact, studies show that people who consume small amounts of dark chocolate tend to weigh less than those who don’t.
6. Oily fish
Omega 3 fatty acids are essential fats found in foods like salmon, sardines, mackerel, herring, tuna, trout, and anchovies. They’re important because they help keep our bodies healthy and strong. In fact, some studies suggest that omega-3s help reduce the risk of rheumatoid arthritis (RA).
The American College of Rheumatology recommends eating about one serving per week of fish rich in omega-3s such as salmon, sardines, and herring.
7. Sweet potatoes
Sweet potatoes are nutritious and delicious. They contain vitamin A, potassium, fiber, iron, folate, and magnesium. They are rich in antioxidants like beta carotene, lutein, zeaxanthin, and lycopene. Sweet potato contains vitamin B1, vitamin B2, vitamin B3, niacin, pantothenic acid, folic acid, vitamin E, zinc, copper, and manganese.
Sweet potatoes are a good source of dietary fiber, protein, carbohydrates, calcium, phosphorus, sodium, iron, thiamine, riboflavin, niacin, vitamin B12, vitamin K, folate, potassium, magnesium, phosphorous, selenium, iodine, vitamin B6, vitamin C, vitamin D, vitamin B5, vitamin B9, vitamin B10, vitamin B11, vitamin B13, vitamin B15, vitamin B17, vitamin B18, vitamin B19, and vitamin B20.
Broccoli is one of the most versatile vegetables you can eat. It tastes great raw, cooked, steamed, stir-fried, sautéed, roasted, and even baked. You can use it in salads, soups, casseroles, pasta dishes, sandwiches, pizza toppings, and much more. It is high in fiber, protein, vitamins A, B6, K, C, E, and folate.
Eating broccoli regularly can help prevent certain types of cancers such as breast, prostate, colon, lung, skin, stomach, mouth, esophagus, pancreas, liver, bladder, kidney, brain, thyroid, cervical, uterine, ovarian, testicular, leukemia, lymphoma, multiple myeloma, and others.
Garlic is commonly used as a home remedy for preventing cold sores. However, there is no scientific evidence that it works. In fact, some studies show that garlic actually increases the risk of infection. While garlic might help prevent colds, it doesn’t seem to do much about those pesky cold sores.
Broccoli is rich in nutrients, especially vitamin K, which helps build strong bones and teeth. Vitamin K also boosts immunity, helping prevent colds and flu.
Spinach is high in iron, calcium, potassium, and folate. These minerals are essential for good health. They contribute to healthy eyesight, blood cells, muscles, nerves, and heart function.
Broccoli helps maintain regular bowel movements. This vegetable contains fiber, which keeps food moving through your digestive system. Fiber aids digestion and prevents constipation.
Ginger contains many nutrients including vitamins, minerals, antioxidants, and anti-inflammatory compounds. These properties make it useful for treating digestive disorders such as nausea, indigestion, diarrhea, and stomach cramps. Ginger also improves circulation and lowers blood pressure.
Studies show that ginger reduces inflammation, improves digestion, and lowers cholesterol levels. However, there is still insufficient evidence to prove that ginger prevents cancer or cardiovascular diseases. More research needs to take place before we can say anything conclusive about its effectiveness against these health issues.
12. Green tea
Green tea contains many health benefits. You probably know about its antioxidant properties, but did you know it could reduce your risk of certain types of cancer? Or that it might help lower cholesterol levels? Or that it may even help protect against Alzheimer’s disease? These are just some of the findings from recent scientific research.
In fact, there is little evidence that drinking too much green tea will cause side effects like those associated with caffeine intake. However, since most people drink coffee anyway, it’s best to stick to one cup per day. If you do decide to add a second cup, make sure it doesn’t contain added sugar.
Sunflower seeds are a good snack choice because they’re high in vitamin E, which helps boost immunity and fight infections. They also provide protein, fiber, magnesium, and phosphorus.
Almonds are rich in potassium, calcium, manganese, and phosphorus. All of these minerals work together to keep bones strong and healthy.
Other Tips To Strengthen Immune System
1. Eat more whole plant foods
Eating plenty of whole plant foods like broccoli, kale, spinach, beans, nuts, seeds, and berries will increase your antioxidant intake, according to nutritionist Rachel Krantz. “Antioxidants are compounds that neutralize free radicals,” she explains. “Free radicals are molecules that cause damage to cells, including cancer.”
Fiber helps feed your gut microbiome, which plays a huge role in keeping harmful pathogens out of your body. “The fiber in food binds to bacteria in your digestive tract, making it harder for those pathogens to stick around,” says Krantz. She recommends eating 25 grams of fiber per day.
Antioxidants found in fruits, vegetables, and spices help protect you against viruses and other diseases. “They help prevent inflammation, which is linked to heart disease, diabetes, obesity, and even Alzheimer’s,” says Krantz, adding that they’re also great for skin health.
2. Get enough sleep
Sleep is one of those things we don’t really think about much, but it’s very important for our physical and mental health. Getting enough sleep helps us perform better at work, recover faster from illness, and even live longer.
A recent study found that people who slept fewer hours had shorter telomeres—the protective caps at the ends of chromosomes that keep them intact. Telomere length predicts longevity. So getting enough shut-eye could mean living longer.
But how do we know what “enough” sleep actually looks like? And are there specific times of day when we’re most vulnerable to falling asleep during the day? We turned to Dr. Michael Breus, author of The Sleep Solution, to find out. He says 8 hours is ideal, but he recommends 7 to 9 hours per night for adults.
Breus says we spend 20% of our lives sleeping, and that includes naps. But he warns against taking daytime naps because they disrupt the body’s natural circadian rhythm. Instead, try setting aside 15 minutes each morning to wind down before bedtime. This might include reading, meditating, listening to music, or doing some light exercise.
And while you’re trying to fall asleep, avoid screen use. Screen time is associated with lower quality sleep. If you must check your email or browse social media, turn off your phone an hour before bedtime. Also, limit caffeine intake to no more than three cups of coffee or tea throughout the day.
3. Eat more healthy fats
Healthy fats, like those found in olive oil and salmon, may help you live longer, according to recent research. A study published in PLOS One suggests that people who eat more omega-3 fatty acids, like those found in salmon and chia seed oils, have lower rates of cardiovascular disease, diabetes, cancer, Alzheimer’s, and Parkinson’s disease. Researchers believe that eating healthy fats boosts our immune system, helping us fend off illnesses.
The researchers analyzed data from over 2 million adults, ages 45 to 84, living in Spain. They compared participants who had high levels of omega-3 fatty acids in their blood to those who did not. The team followed the subjects for about 15 years and looked at how many died during that period.
People who ate healthier diets, including more fish, nuts, and olive oil, survived longer. In fact, the risk of death declined by 8% for every one unit increase in the amount of omega 3 fatty acids consumed.
4. Limit added sugars
Added sugars are one of the most common sources of calories in Americans’ diets. They’re found in many processed foods, including bread, cereals, condiments, dairy products, desserts, snack foods, sauces, soups, sweetened beverages, and yogurt.
The American Heart Association recommends limiting added sugars to no more than 10% of daily calorie intake. A serving size is about half a cup of regular ice cream, a single cookie, or a tablespoon of syrup. For kids ages 9 to 13, it’s about 3 teaspoons of added sugar.
While some people enjoy sweets, too much added sugar isn’t good for you. It contributes to weight gain and increases the risk of heart disease, diabetes, tooth decay, and cavities.
5. Eat more fermented foods or take a probiotic supplement
Eating fermented foods such as yogurt, kefir, sauerkraut, kimchi, pickles, olives, cheese, wine, beer, and miso may help you avoid getting sick. Probiotics are live microorganisms — usually bacteria — that feed on food and produce beneficial substances called “probiotics.”
These include vitamins B12 and K2, plus enzymes, amino acids, antioxidants, and short-chain fatty acids. Some studies suggest that consuming probiotics may reduce the risk of certain types of cancer and heart disease, and may even lower cholesterol levels.
6. Stay hydrated
Drinking plenty of water helps keep your body functioning properly. Water also flushes out toxins, which can boost your immunity.
Dehydration can lead to numerous health issues such as headaches, lack of focus, and impaired physical performance. You don’t want to drink too much or too little because it could cause serious medical conditions.
The best way to avoid dehydration is to drink enough water each day to make your urine light yellow or straw-colored. If you’re thirsty, you probably aren’t drinking enough water.
Drink plenty of fluids throughout the day, especially during exercise. Water helps replace lost electrolytes like sodium and potassium. These minerals are important for muscle contraction and nerve function.
You can find out how much fluid you need based on your age, gender, and activity level. However, most people require about 2 liters (0.5 gallons) of liquid per day. This amount varies slightly depending on your height and weight.
If you’re exercising intensely, you’ll lose even more moisture through sweating. To prevent overheating, drink frequently.
7. Engage in moderate exercise
Moderate exercise boosts immunity. A study published in the journal Preventive Medicine found that people who exercised moderately had lower levels of antibodies against the influenza virus compared to those who didn’t exercise regularly. In addition, regular moderate exercise helped keep your body fit.
A study published in PLOS One found that people who exercised regularly experienced better fitness outcomes than those who didn’t exercise. And a review article published in Current Sports Medicine Reports found that moderate exercise improves health and reduces the risk of chronic diseases like diabetes and cardiovascular disease.
8. Manage your stress levels
Stress affects everyone differently. Some people cope well while others struggle. Managing stress is important because it can cause health issues such as heart disease, depression, insomnia, high blood pressure, and even cancer.
If you don’t deal with stress properly, it can affect your immune system and make you vulnerable to colds, flu, and other illnesses.
Here are some tips to manage stress and keep yourself healthy.
1. Exercise regularly
3. Get enough rest
4. Stay connected
5. Practice mindfulness
9. Kick the Nicotine Habit
The good news about quitting smoking is that it helps you live longer. The bad news is that you have to stop smoking to reap those benefits. In fact, research suggests that people who smoke are likely to die sooner than nonsmokers.
Smoking causes many problems including lung cancer, emphysema, and heart attacks. It also increases your chances of developing diabetes, osteoporosis, and arthritis.
Quitting smoking doesn’t just help you live longer; it’s also beneficial to your overall health. Quitting smoking will reduce your risk of stroke, heart attack, and respiratory infections.
10. Wash Your Hands
Germs are everywhere, even on your hands. You probably know how important it is to keep yourself clean and healthy, but did you know there’s something else lurking around your home that could make you sick too?
Germs are everywhere, especially on your hands. Soap and hot water are great tools to help you wash off those germs, but what about everything else? We’ve got some tips to help you get rid of germs where they live – on your hands.
11. Maintain a Healthy Weight
Excess weight can cause health issues such as diabetes, heart disease, high blood pressure, arthritis, and others. Maintaining a healthy body weight includes reducing stress, maintaining a healthy diet, getting sufficient rest, engaging in regular exercise, and other methods.
12. Avoid Too Much Alcohol
Alcohol affects our immune systems, making us more vulnerable to colds and flu, according to the Centers for Disease Control and Prevention. A study published in the journal Addiction found that people who drank alcohol regularly tended to develop liver disease. And drinking too much alcohol can increase the risk of heart attack or stroke.
The CDC recommends limiting yourself to two drinks per day for men and one drink per day for women. If you do choose to drink, stick to moderate amounts—no more than five drinks per week for men and four drinks per week for women.
In conclusion, if you’re looking for ways to strengthen your immune system, here are a few ideas to consider: eat lots of fruits and vegetables (they have tons of antioxidants), drink lots of water (it flushes toxins from your body), exercise regularly (this boosts endorphins which boost immunity), and sleep well (your body needs rest to fight off infections). And remember: when it comes to your health, prevention is always better than cure.
Bharat Sharma is a Delhi-based writer who loves reading and writing research-based topics revolving around health, fitness, and nutrition. His love for writing started during his teenage and continues till date. After his graduation, he worked for GE Money, and IBM, but later found his true love i.e. blogging.