Three Foods, One Glass: The Green Juice Nutritionists Recommend for Stronger Immunity

Spinach, apple and celery come together in a simple green drink rich in vitamin C, flavonoids and minerals. It is not a cure or a shield against colds, but it can be an easy, tasty way to add more plants to your day and support your body's natural defences.

Most of us spend more on vitamin pills every winter than on the fruit and vegetables that contain those very same vitamins. Yet one of the easiest ways to close the gap costs less than a cup of coffee, takes three minutes to make and needs only three ingredients you can find in any supermarket or farmers' market: spinach, an apple and a stalk of celery. The surprising part? Almost nobody actually makes it.

Australian entrepreneur and filmmaker Joe Cross became one of the world's best-known faces of green juice after he documented his own turnaround in the film Fat, Sick & Nearly Dead. Overweight, dependent on steroid medication and struggling with a chronic autoimmune condition, he decided to change his diet radically. The drink he relied on day after day was his now-famous Mean Green Juice, a blend of leafy greens, celery, apple, cucumber, lemon and ginger, which he describes as his favourite way to support his immune system. His 60-day juice-only programme is extreme and not something nutritionists recommend without medical supervision, but his story shows one thing clearly: when greens come in a glass, many people suddenly start "eating" far more vegetables than they ever did on a plate.

It is true that we can never avoid flu and colds one hundred percent, but we can help our body stay well nourished so that its natural defences have everything they need. And one of the simplest ways to do that is with natural food that we can find in every shopping centre or market.

Among home-made habits for supporting immunity, a green juice made from just three ingredients has become a favourite in recent years: spinach, apple and celery. It is a simple recipe that you can prepare in a few minutes, yet it delivers a generous dose of nutrients.

Why a juice and not a salad?

Many people say: I'd rather eat an apple and a handful of spinach than make a juice. And that is perfectly fine. The problem is that most people simply do not eat enough fruit and vegetables during the day. The World Health Organization recommends that everyone over the age of 10 eats at least 400 grams of fruit and vegetables a day, which is roughly five portions. Yet a 2023 study published in the CDC journal Preventing Chronic Disease, which analysed data from more than 30,000 adults in nine European and Central Asian countries, found that in most of the populations studied, a large share of people did not reach this target. Health statistics from the Slovenian National Institute of Public Health (NIJZ) also point to a worrying downward trend in the daily consumption of fresh fruit.

Blended drinks and smoothies are therefore a handy solution. You can fit a whole handful of spinach, a whole apple and a stalk or two of celery into a single glass. The body gets a concentrated dose of vitamins and minerals, and for many people it is simply easier to drink greens than to chew through a big bowl of them.

A nutritionist's tip: use a blender rather than a juicer whenever you can. A blender keeps the fibre, which is filling and feeds your gut bacteria, while a juicer throws most of it away with the pulp. The WHO also reminds us that fruit juices contain free sugars that should be limited, so a vegetable-heavy, fibre-rich blend is the smarter choice.

Spinach, green power from the garden

Spinach is a vegetable we all know, but we don't appreciate it enough. In folk medicine it was considered a plant that "cleanses the blood" and strengthens the body after illness. From a scientific point of view, it is a real treasure trove of nutrients.

According to the USDA FoodData Central database, 100 grams of fresh spinach contains:

• about 28 mg of vitamin C, which is roughly a third of an adult's daily needs (see the NIH Office of Dietary Supplements recommendations). Vitamin C contributes to the normal function of the immune system,


• plenty of beta-carotene, which the body converts into vitamin A, a nutrient that also plays a role in normal immune function,


• iron, which contributes to the reduction of tiredness and fatigue,


• folate (vitamin B9, important for the formation of new cells).

Plant iron is absorbed less efficiently than iron from meat, but eating it together with foods rich in vitamin C helps the body absorb more of it. That is exactly why spinach and apple make such a good team in a glass.

If you would like to learn more about how simple ingredients can support you through the cold season, read our article Warm Water with Turmeric Against Winter Troubles.

Apple, a fruit we should never underestimate

The apple is one of the most accessible and popular fruits in the world. The old saying goes: an apple a day keeps the doctor away. Researchers from the University of Michigan actually put this proverb to the test. Their study published in JAMA Internal Medicine in 2015, which analysed data from nearly 8,400 American adults, found that daily apple eaters did not visit the doctor less often, but they were somewhat less likely to use prescription medication. The authors joked that an apple a day may keep the pharmacist away. It is not proof of cause and effect, but it is a nice nod to an old piece of folk wisdom.

Apples contain a lot of fibre, which supports healthy digestion. One of these fibres is pectin, which acts as a prebiotic and feeds beneficial gut bacteria such as bifidobacteria and lactobacilli. It may sound unusual, but according to a review in the journal Clinical & Experimental Immunology, around 70% of the body's immune cells are found in and around the gut. So it is no wonder that experts increasingly talk about the link between gut health and our natural defences.

In addition, apples contain some vitamin C and plenty of polyphenols. The word polyphenols refers to natural substances in plants that protect them from harmful environmental influences. In our body, they act as antioxidants that help protect cells from oxidative stress. Most of them sit in and just under the skin, so don't peel your apple before blending.

Celery, the underrated green stalk

Celery is often overlooked, but in folk medicine it was considered a plant that "calms the nerves" and strengthens the body. It contains compounds that are being studied for their anti-inflammatory potential.

Among them are flavonoids such as apigenin and luteolin, as well as other polyphenols. (Flavonoids are natural plant pigments that protect plants from pests; in humans, they are being researched for their role in calming inflammation and oxidative stress.)

A 2025 systematic review and meta-analysis published in Frontiers in Nutrition looked at randomised controlled trials on celery preparations and blood pressure, blood sugar and blood fats. Some studies showed encouraging results, although most of them used concentrated celery extracts rather than a stalk in your morning drink, so the findings should be seen as promising rather than definitive.

In addition, celery contains potassium and vitamin K, which play a role in normal blood pressure and healthy bones.

The combination of three foods: a true nutrient boost

When you combine these three ingredients into a drink, you get a blend that works on several levels:

• vitamin C, mostly from spinach and partly from apple, contributes to the normal function of the immune system,


• flavonoids and polyphenols from celery and apple act as antioxidants,


• fibre (if you use a blender) supports digestion and the gut microbiome,


• minerals such as iron and potassium support energy levels and overall wellbeing.

If you drink a glass of this green blend every day as part of a varied diet, you are giving your body a steady supply of nutrients it needs to function well, especially during the colder months.

What does science really say?

It is worth being honest: no single drink can guarantee that you won't catch a cold. A 2016 meta-analysis in the journal Advances in Nutrition, covering 14 studies, suggested that flavonoids may help reduce the incidence of upper respiratory tract infections in otherwise healthy adults, although those studies mostly used supplements rather than juices. Similarly, the well-known Cochrane review on vitamin C and the common cold found that regular vitamin C intake did not prevent colds in the general population, but was linked to a modestly shorter duration of symptoms. The message is clear: good nutrition supports your immune system, but it works best together with sleep, movement and fresh air.

Sleep, by the way, is one of the most underrated pillars of strong defences. Read more in our article When you sleep too little, your belly grows.

Home wisdom: how our ancestors did it

Our ancestors didn't have juicers or blenders, but they still knew how to use the power of these foods. They dried apples and used them in winter to make a warming tea. They ate spinach in soups and stews, often together with garlic, another traditional winter favourite. And they added celery to soups, believing that it cleanses the body.

Although we use modern appliances today, the essence remains the same: ingredients as fresh as possible, without industrial additives.

If you enjoy traditional winter drinks, you may also like our recipe Heals the joints and repels colds.

How to make the juice at home

For preparation you only need:

• a handful of fresh spinach,


• one apple (unpeeled, core removed),


• one stalk of celery,


• half a glass of water.

Blend everything together in a blender until smooth. If you prefer a thinner texture, add a little more water, or use a juicer, keeping in mind that you will lose some of the fibre. A squeeze of lemon is an optional extra that brightens the flavour and adds a little more vitamin C. It is best to drink the juice right away, as vitamin C gradually breaks down on contact with air and light.

Readers who make this drink regularly often say the first glass tastes "very green", but that after a few days they start looking forward to it. A green apple such as Granny Smith gives a fresher, less sweet taste, while a sweeter apple softens the flavour of the celery for beginners.

How much juice should you drink?

One large glass a day is enough. There is no need to overdo it, as the body works best on a balanced diet. The juice should be a complement to your meals, not a replacement for them.

A few words of caution from a nutritionist:

• Spinach is rich in oxalates. If you are prone to kidney stones, talk to your doctor about how much spinach is right for you.


• Spinach and celery contain vitamin K. If you take blood-thinning medication such as warfarin, keep your intake of leafy greens consistent and consult your doctor before making big changes.


• Celery is a known food allergen in Europe. If you have ever reacted to it, leave it out.


• Wash all produce thoroughly before blending.

A small habit, a big difference

Green juice from spinach, apple and celery is a cheap, simple and tasty way to add more plants to your day and support your immune system as part of a healthy lifestyle. If you include it in your daily routine, you will give your body a steady supply of vitamins, minerals and plant compounds, and many people say they simply feel lighter and more energetic.

In a world where people spend thousands on dietary supplements, part of the answer is right at your fingertips in the form of three foods you can buy at any market. It is one of those habits that shows nature often offers the simplest solutions, if we know how to use them.