Then I Added These 15 Foods to My Diet and Everything Changed
I would always catch a cold the three winters in a row. Not the dramatic kind of illness – no hospital trips, no emergency – just the dull, drab one which takes two weeks out of your life at a time. A severe cold wave during the month of October. Flu in January. Chest infection in March. I began to wonder it was all my immune system, it was my way of being built, it was bad luck.
It wasn’t. It was my diet.
One GP, casually, said the immune system is one of the most nutritionally-requiring systems in the body. Does not operate with the will or by inheritance of good genes. It’s fuelled by certain micronutrients – vitamins, minerals, antioxidants and helpful bacteria – which most people are not getting enough. With chronic deficiency, immunity doesn’t crash and burn; it simply under performs. You get sick more often. It takes longer to recover. There’s never a time you feel strong.
I did eventually listen to myself, and began making the correct choices in my food habits, but it took a long time after I started to see the difference. Two winters with no severe illness. Better energy. Quick healing of minor issues. This article contains all that I learned: 15 specific foods, which specific immune nutrients they provide, and the science behind how each food is important.
⚡ The statistic worth knowing
According to the WHO, nutritional deficiencies are the most widespread cause of immunodeficiency worldwide — more common than any infectious disease. You don’t need to be severely malnourished for nutrition to impair your immune function. Even subclinical deficiencies in vitamin C, vitamin D, zinc, and selenium measurably reduce immune response.
Table of Contents
How Food Actually Strengthens Your Immune System
So before we get to the list, it’s important to know what they are and how they work. They are foods that provide a specific benefit to the body; that is why they are beneficial and why there is no pill or supplement that can meet the body’s needs for them. They work by affecting the body in a certain way.
Your immune system consists out of two arms. The innate immune system is your quick response system — responds to any perceived threat immediately with physical barriers (skin, mucous membranes), white blood cells, and inflammation. Your trained army is the adaptive immune system, which creates specific responses to threats that it previously has encountered, producing specific antibodies and memory cells.
Both arms are completely nutrient reliant. White blood cells need vitamin C to be produced and activated. The immune system’s super-soldiers, T-cells, fail to mature in the absence of zinc. Vitamin A keeps the barriers in the body intact that prevent pathogens from entering the body; folate and vitamin B6 are involved in the production of antibodies. Vitamin D deficiency and sleep deprivation have a significant impact on natural killer cells, your immune system’s first line of defence.
Most critically, the gut is the site and surrounds of about 70-80% of the immune system. The gut microbiome, which is the ensemble of bacteria residing in your gut, directly controls immune function, educates immune cells and serves as the body’s first line of defense against pathogens. This is why, to an extraordinary extent, what you eat for gut health is what you eat for immunity. The article on foods your gut is begging you to eat is just as detailed, but on the connection between gut and immunity, in a way that most nutrition content doesn’t go into.
“Your immune system is not fixed at birth. It is built, daily, by what you eat. Feed it well and it will defend you. Neglect it and it quietly stops doing its job.”
The 15 Foods — What They Contain, How They Work, and How to Eat Them
01 Garlic — Allicin — antiviral and antibacterial
My grandmother used to pound raw garlic into just about anything she cooked, and never faced a serious illness until she turned ninety. I thought it might have been a coincidence, until I read through the research. In clinical studies, garlic has been found to have direct antiviral and antibacterial properties due to its sulphur compound, allicin, which is released when garlic is crushed or chopped. In a 2016 randomized controlled trial, aged garlic extract group members reported a significantly lower number of and shorter colds than the placebo group.
Allicin also helps to activate macrophages, which are the immune cells that engulf and destroy pathogens. Add it to soups, stir-fries, or salad dressings, crush it and allow to sit for 10 minutes to enable the allicin to form. Potency is lost with heat, so raw is ideal, if possible.
02 Ginger — Gingerol — anti-inflammatory and antiviral
One of those that’s been trickled down from generation to generation is ginger tea with honey and it has a solid scientific basis to back it up. Ginger is known for its immune-boosting properties thanks to its active compound, gingerol. Gingerols have been found to block the growth of respiratory viruses, decrease pro-inflammatory cytokines and significantly decrease the pain associated with sore throat tissue.
The easiest immune supporting drink you can make is fresh grated ginger, in hot water, with lemon and honey. It is also a great addition to stir-fries, soups and smoothies. Root is to be kept fresh, between 1 and 2 centimetres per day during the winter period.
03 Citrus Fruits — Vitamin C — white blood cell production.
Vitamin C is the most popular immune nutrient for good reason — it does work! Most people are not aware of this: Vitamin C is needed for the creation and activity of white blood cells, especially neutrophils and lymphocytes. It is also a strong antioxidant that helps safeguard immune cells from the oxidative damage they receive while performing their role of combating disease-causing organisms.
The classic sources are oranges, grapefruits, lemons and limes, but actually it’s the kiwis (food number 12) that have more vitamin C per gram. Adults should consume 65–90mg per day (about 1 medium orange) Vitamin C is not stored in the body and therefore regular doses are more important than supplements in high doses for a short period of time.
04 Spinach — Vitamin C and folate — antibody synthesis
Now, spinach is a food that is on just about every health list, and that’s twice for the immune system. It supplies vitamin C, used by white blood cells, and folate (vitamin B9), required for the rapid cell division that occurs during a “flare-up” of infection when new immune cells and antibody molecules are made.
Some of the nutrients in spinach are actually more bioavailable when they are cooked light, as the cooking helps to break down the oxalates that hinder absorption. One of the easiest immune-strengthening foods to incorporate into your diet daily without a second thought is spinach, which can be sautéed, added to soups, or blended into smoothies, where it’s taste is not noticeable.
05 Broccoli — Vitamins A, C, E and sulforaphane — multi-layer defence
The first food on this list may be the most nutritionally complete immunizer food, broccoli. It contains vitamins A, C and E, which act at three different levels of the immune system, plus a compound called sulforaphane, which turns on the body’s own antioxidant defence system. The study by Johns Hopkins also revealed the discovery of a gene program that is activated by sulforaphane to trigger a process of creating a cascade of antioxidant enzymes for an extended duration that surpasses the duration of sulforaphane.
The trick is to not over cook it. A major loss of vitamin C and a decrease in sulforaphane occurs if broccoli is boiled until it becomes a dull army green. Both methods retain the nutritional content but enhance the flavour to a great degree: steam for four or five minutes, or roast at high heat.
06 Turmeric — Curcumin — immune modulation and anti-inflammation
The active compound, curcumin, is found in turmeric and has been studied in many areas of immunology research.The compound in turmeric, curcumin, has been used in Ayurvedic medicine for years and studied thoroughly in modern research in immunology. The major immune action of curcumin is modulatory, not stimulatory, to calm the immune system rather than activate it. This is important because just as much of a problem with an overactive immune system as with an under-active system.
It’s the important fact that most people don’t know: Curcumin is highly poorly absorbed on its own. Curcumin is better absorbed by up to 2,000% when consumed with black pepper, which contains piperine. One of the best and most delicious ways to get a daily dose is to have golden milk (turmeric, black pepper, milk, honey).
07 Yogurt — Probiotics — gut-immune axis support
This is the food that has the strongest link to immunity and gut health. The live-culture yogurt includes beneficial bacteria, namely Lactobacillus and Bifidobacterium strains, which help to colonise and support the gut microbiome. The microbiome is essential to a healthy immune system, with 70–80% of the immune system located around the gut.
Look for plain Greek yogurt that has “live and active cultures” in the ingredients. Flavoured yogurts can be ultra high in sugar, which actively inhibits immune function and negates the probiotic effect. One serving of plain greek yoghurt each day, topped with fresh fruit, honey and seeds is one of the best single food hacks for your immune system.
08 Almonds — Vitamin E — immune cell protection and antioxidant defence
Vitamin E is a fat-soluble antioxidant that helps guard against oxidative damage to the immune cells, which would otherwise be injured and would be fighting an infection. It also plays a role in T-cell proliferation and the production of immunoglobulins. A portion of 28g of almonds contains an estimated 7.3mg of vitamin E, which is about half the recommended daily intake for one portion.
Almonds are also a great source of healthy fats that help the body absorb the fat-soluble vitamins like vitamin E, vitamin A and vitamin D — making this little nut a big nutritional punch.
09 Sunflower Seeds — Selenium and vitamin E — T-cell activity
There is no one food rich in selenium, but sunflower seeds are one of the most selenium-dense foods available, and selenium is a mineral that most people’s diet is lacking. The activation and proliferation of T-cells, the most targeted weapons of the adaptive immune system, are dependent on selenium. Studies have indicated that selenium deficiency predisposes individuals to viral infection and mutation and compromises immune function.
Sunflower seeds are a good source of selenium, adding a tablespoon to a salad or onto yogurt makes a significant contribution. When eaten together with their vitamin E, sunflower seeds provide a real double protection against the immune system in one affordable, small nutritious food.
10 Green Tea — EGCG catechins — antiviral and anti-inflammatory
Green tea has a group of polyphenols called catechins, and the most widely studied is EGCG (epigallocatechin gallate). EGCG has been shown to have direct antiviral activity against influenza and other respiratory viruses, and anti-inflammatory properties that modulate but don’t overpower the immune response. It also has L-theanine, an amino acid which helps stimulate the creation of compounds that fight germs in T-cells.
Green tea offers a relatively high dose of EGCG with 1-3 cups per day, but not as much caffeine as coffee. Making the simple switch from coffee to green tea for your daily fix is one of the easiest and best dietary changes for immune health.
11 Salmon — Omega-3 fatty acids and vitamin D — regulate immune response
It is a combination of two of the most essential nutrients for the immune system provided by Salmon. EPA and DHA are the two main types of omega-3 fatty acids that are the most important regulators of immune-related inflammation. They do not down-regulate the immune response, but rather they do not let it get out of control. Salmon contains a considerable amount of vitamin D, which has been demonstrated in clinical studies to have some protective effect against respiratory tract infections. The article on why scientists are calling vitamin D the closest thing to an anti-ageing pill explains everything about how extraordinary this one nutrient is — and salmon is one of the few foods it can’t be gotten from.
The NHS suggests 2 portions of oily fish a week. One of those meals that’s as good for your immune system, cardiovascular health, and taste buds as it is to eat is baked, grilled, or poached salmon with a side of roasted vegetables and brown rice.
12 Kiwi — Highest vitamin C per gram — rapid immune cell activation
One nutritionist friend of mine said that if she had to pick one fruit to boost immunity, it would be kiwi, and she isn’t wrong. A kiwi has approximately the same amount of vitamin C as a medium size orange per gram. It also contains vitamin K, potassium, folate and various other antioxidants that act together with the vitamin C and not independently.
A single kiwi a day is actually enough for an average adult to get their daily dose of vitamin C. The skin is edible and the skin has more fibre — if possible, wash thoroughly and consume the skin. If the tartness is too much, those who prefer can mix it in a smoothie with banana and spinach, and the resulting concoction will still pack a serious nutritional wallop but won’t be quite as tart.
13 Sweet Potato — Beta-carotene (vitamin A) — mucosal barrier defence
The beta-carotene in sweet potatoes has an orange hue and transforms into vitamin A when consumed, which plays a key role in maintaining the integrity of the mucosal barriers within the nose, throat and lungs. These are the first line of defence: physical barriers which prevent pathogens entering the body in the first place: the immune system’s physical barriers. It has been directly proven that Vitamin A deficiency is linked to higher susceptibility to respiratory infections.
One medium sweet potato contains more than the daily value (DV) of beta-carotene. One of the most versatile and inexpensive immune foods in any supermarket all year round, sweet potatoes are roasted, mashed, added to soups or used as an alternative to baked potato.
14 Blueberries — Flavonoids — respiratory immunity and antioxidant defence
Researchers from the University of Auckland discovered that those who consumed foods high in flavonoids were 33% less likely to catch a cold than those who didn’t. Blueberries are especially high in a flavonoid called pterostilbene, which seems to boost the immune system’s natural immunity against respiratory pathogens.
Whether fresh or frozen, blueberries have a similar immune-boosting effect, and can be enjoyed on top of Greek yogurt, stirred into oats or eaten on their own as a snack. This is one of the most readily available foods, usually it is more affordable than fresh blueberries and can be found throughout the year.
15 Mushrooms — Beta-glucan polysaccharides — macrophage activation
Mushrooms are the least known food in this list that boosts immunity. They have polysaccharides or beta-glucans, which are complex sugars that directly stimulate macrophages, the big immune cells that phagocytose pathogens and cell debris. Although common button mushrooms offer some beta-glucan, the most extensive research is in the case of shiitake and maitake varieties.
Mushroom is one of the few food sources of vitamin D, especially when sun exposure or UV exposure. Mushrooms are now available at some supermarkets that have been “sun-exposed” to boost their vitamin D levels. Mushrooms are highly affordable immune foods, and they can be eaten cooked in soups, stir-fried, or served as an ingredient on whole-grain toast with garlic.
All 15 at a Glance — Quick Reference Table
| Food | Key nutrient | Immune benefit | Best way to eat |
| Garlic | Allicin | Antiviral, antibacterial | Raw in dressings, cooked in meals |
| Ginger | Gingerol | Anti-inflammatory, antiviral | Ginger tea, stir-fries, smoothies |
| Citrus fruits | Vitamin C | White blood cell production | Morning glass of juice or whole fruit |
| Spinach | Vitamin C + folate | Antibody synthesis, cell repair | Lightly cooked, salads, smoothies |
| Broccoli | Vitamins A, C, E + sulforaphane | Multi-layer immune defence | Steamed or lightly roasted |
| Turmeric | Curcumin | Immune modulation, anti-inflam | Golden milk, curries, with black pepper |
| Yogurt | Probiotics (live cultures) | Gut-immune axis support | Plain Greek yogurt, daily |
| Almonds | Vitamin E | Antioxidant, immune cell protection | Handful as a snack, almond butter |
| Sunflower seeds | Selenium + vitamin E | T-cell activity, oxidative defence | On salads, in trail mix |
| Green tea | EGCG catechins | Antiviral, anti-inflammatory | 1-3 cups daily, replace coffee |
| Salmon | Omega-3 + vitamin D | Regulate immune response, reduce inflam | 2x per week, baked or grilled |
| Kiwi | Highest vitamin C per gram | Rapid immune cell activation | One kiwi daily, skin-on optional |
| Sweet potato | Beta-carotene (vitamin A) | Mucosal barrier defence | Roasted, mashed, in soups |
| Blueberries | Flavonoids (pterostilbene) | Respiratory immunity, antioxidant | Fresh or frozen on oats, yogurt |
| Mushrooms | Beta-glucan polysaccharides | Macrophage activation, innate immunity | Cooked in soups, stir-fries |
The Nutrients Your Immune System Cannot Work Without
The 15 foods above all have these specific immune-boosting nutrients. It is easier to create a balanced diet with the knowledge of what nutrients do.
- Vitamin C: Supports the production of the white blood cells, and also acts as an antioxidant to protect the immune cells that are actively combating infection. It is not stored in the body, and must be consumed on a daily basis.
- Vitamin D: Regulates immune cell function, decreases risk of respiratory infections. Deficiency is widespread in the UK and directly linked to increased susceptibility to illness. It’s important enough that vitamin D is now considered by scientists to be the closest thing to an anti-ageing pill — and it should be a staple in any immune system diet.
- Zinc: Necessary for the development of T cells and antibody production. Immune response can be measurably affected even by the mildest of deficiencies. High in sunflower seeds, almonds and garlic.
- Omega-3 fatty acids: Counteract inflammation arising from the immune system and stops the immune system from getting out of hand. The richest food sources are salmon and other oily fish.
- Probiotics: Influence gut immunity via the gut-immunity axis, and thereby the gut microbiome. Plain Greek yogurt is the most easily available source each day.
What Quietly Weakens Your Immune System — The Habits Working Against You
It makes a huge difference to add these 15 foods. However, they need to be used in conjunction with other measures that are actively weakening immunity.
Ultra-processed food is the most significant deceptive food for the immune system: refined sugars and seed oils create a state of chronic low grade inflammation that consumes immune resources and keeps the immune system from responding to real threat.
Probably the most dramatic single factor is poor sleep. It’s been discovered that sleep deprivation (less than 6 hours) for one night lowers natural killer cell activity, which is your body’s speedy strike force in the immune system. Basically, chronic sleep loss weakens the immune system from within.
Chronic stress increases cortisol, which directly inhibits innate and adaptive immunity. Sitting lowers immune surveillance. Alcohol disrupts the first line of defence against pathogen, the mucosal barriers. None of these is solved by putting garlic on your dinner table and that’s why diet is essential, but not enough. It’s not the whole building, it’s the base of it.
A Simple 3-Day Immune-Boosting Meal Plan
How to make the best of these foods within a 3 day realistic, inexpensive eating plan. At least 15 foods are used in each meal and the total cost of the whole plan is less than £30 per week in the UK.
Day 1
| Meal | What to eat |
| Breakfast | Greek yogurt + blueberries + sunflower seeds + drizzle of honey |
| Lunch | Spinach and sweet potato soup with wholegrain roll + garlic butter |
| Dinner | Baked salmon with steamed broccoli + brown rice + ginger-soy dressing |
| Snack | Kiwi + small handful of almonds + green tea |
Day 2
| Meal | What to eat |
| Breakfast | Oat porridge + blueberries + sunflower seeds + golden milk (turmeric + black pepper + milk) |
| Lunch | Grilled chicken wrap with spinach, tomato + garlic yogurt sauce |
| Dinner | Mushroom and broccoli stir-fry with ginger, garlic + brown rice |
| Snack | Orange + handful of almonds + green tea |
Day 3 (Simplest Day)
| Meal | What to eat |
| Breakfast | 2 scrambled eggs + spinach + wholegrain toast |
| Lunch | Tinned salmon salad with kiwi, mixed leaves + olive oil |
| Dinner | Roasted sweet potato + steamed broccoli + Greek yogurt dip + garlic drizzle |
| Snack | Blueberries + green tea + 2 squares dark chocolate (bonus antioxidants) |
The Bottom Line — Your Immune System Is Built Every Day
No supplement, no powder, no pill can do what these 15 whole foods do — not due to any one compound, but thousands of cofactors that are distributed in natural ratios and proportions that the body was designed for.
I didn’t have to have lost the winters to illness every year. In hindsight, it was the natural result of a lack of immune support. The patch was not a complex one, but rather a consistent one. Note: Garlic is added into cooking. A kiwi most days. 2 times a week for salmon. Replace processed snack foods with Greek yogurt. Third coffee for green tea.
Your immune-boosting starter checklist:
1. Add garlic and ginger to cooking at least four times a week
2. Eat one kiwi or one orange daily for consistent vitamin C
3. Have Greek yogurt (live cultures) every day for gut-immune support
4. Eat oily fish (salmon, mackerel, sardines) twice a week for vitamin D and omega-3
5. Include broccoli or spinach at least four days a week
6. Replace one coffee daily with green tea
7. Add sunflower seeds or almonds as your go-to snack
8. Eat blueberries (fresh or frozen) three to four times a week
9. Use turmeric with black pepper in cooking at least twice a week
10. Roast or steam mushrooms into your meals two to three times a week
Begin with three foods that you don’t eat regularly on a consistent basis from this list. Make them a part of your next shopping list. Build from there. That’s what will be noticed by your immune system and you!
Of the 15 foods, how many do you already eat and which one are you going to start eating this week? Add it to the comments below!
⚕ Medical Disclaimer
The information in this article is provided for general informational and educational purposes only and does not constitute medical or nutritional advice. The content on Pure Vitality Tips is not a substitute for professional guidance from a qualified doctor, registered dietitian, or other healthcare provider. The foods discussed in this article support general health and immune function but are not intended to prevent, treat, diagnose, or cure any disease. If you have a health condition, food allergy, or are taking medication, please consult a qualified healthcare professional before making significant dietary changes. Individual results vary. Reliance on any information on this website is solely at your own risk.
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