Which fruits are good for the immune system?
Boosting your immune system is one of the best ways to keep germs away and avoid illness and infection. As you may be aware, eating lots of fresh fruit and vegetables can help to strengthen your immune response. Fruits which can help to support your immune system include:
- Kiwifruit
- Watermelon
- Grapefruit.
Read on to find out more about these fruits and why they are beneficial for the immune system.
1. Kiwifruit
When it comes to immune-boosting fruits, kiwifruits are an excellent choice. Kiwis are extremely rich in nutrients, providing a source of vitamin K, folate, potassium and fibre. However, it is their vitamin C content which is thought to be most effective in strengthening the immune system.
In fact, one kiwifruit provides 100% of your recommended daily intake of vitamin C! This is more than is found in the same quantity of orange, which is also known for its high vitamin C content.
Vitamin C is an essential nutrient when it comes to boosting the immune system. Due to its antioxidant properties, vitamin C helps the functioning of the immune system, as well as aiding the wound-healing process.
In addition to this, kiwis are a source of vitamin E. This is a potent antioxidant which can help boost the immune system and in doing so can fight off invading bacteria and viruses. Kiwis also contain polyphenols and carotenoids, both of which have antioxidant properties which can protect you from disease and enhance your immune system.
In research, kiwifruit has been shown to reduce oxidative stress* in the body and reduce the incidence and severity of upper respiratory tract infections. Also, it could potentially be more beneficial for the immune system than supplementing with vitamin C alone.1 This may be due the 'teamwork' effect of all the nutrients fruits such as kiwifruit contain. Also, nutrients often absorb better when complexed with other nutrients, as they are in foods.
In one study, kiwis were found to reduce the likelihood of developing colds or flu-like illnesses, especially in high risk groups such as those over the age of 65 and young children.2
A recent Avogel survey found that 81.8% of people regularly take a vitamin supplement. If this is the case for you, perhaps you would like to try our Immune Support.
Immune Support not only provides a rich source of vitamin C from acerola cherries, it also contains zinc, and vitamin D from lichen, all of which contribute to the normal function of the immune system. This plant-based supplement is vegan and gluten-free.
*Oxidative stress is the overproduction of harmful molecules called free radicals which may increase the risk of developing health problems such as diabetes, cancer, and cardiovascular diseases.
A.Vogel Immune Support Tablets with Vitamin D, Vitamin C and Zinc, 30 tablets
2. Watermelon
Watermelon is packed with vitamins, minerals, and other nutrients, including vitamin C, vitamin A, potassium, magnesium, and vitamins B1, B5 and B6, all of which are important in keeping the body healthy, to prevent or fight illness.
Watermelon is also high in carotenoids, including lycopene which gives watermelon flesh its red colour! Lycopene is an antioxidant which can help to protect against cell damage. It may also help to reduce inflammation in the respiratory tract, which can prevent infection and reduce symptom severity during periods of sickness.
In addition to lycopene, watermelon also contains glutathione, another antioxidant which can help to prevent damage to important cells in the body caused by harmful molecules such as free radicals. Moreover, watermelon contains a plant compound called cucurbitacin E, which has antioxidant and anti-inflammatory effects.
The combination of vitamin C, lycopene, glutathione and cucurbitacin E in watermelon is thought to lower inflammation in the body3, which has a positive effect on immune function, as well as reducing your risk of developing chronic diseases. It's now known that subclinical inflammation (inflammatory processes that are not yet severe enough to be captured in blood tests) is associated with the progression of several degenerative diseases, when present long-term.
In one study, participants were given a tomato juice rich in lycopene and vitamin C. Results found that, after consuming the tomato juice, markers of inflammation (associated with infection and disease) amongst participants went down, and antioxidants went up.4 As watermelon is also a rich source of lycopene and vitamin C, including it in your diet is a good choice.
3. Grapefruit
Although very low in calories, grapefruits are highly nutritious! They provide a whole host of nutrients which are beneficial to immune function. In particular, they are a good source of vitamin A.
Vitamin A plays an important role in supporting the immune system, and has been shown in studies to protect against inflammation and several infectious diseases.5 In addition, it is important for keeping the eyes and skin healthy. In my blog "3 key signs you have a weakened immune system", I discuss how a weakened immune system can affect skin, specifically wound healing.
Grapefruit is also packed with vitamin C. Numerous studies have shown vitamin C to be beneficial for the immune system. In research, it has been shown on several occasions to reduce the severity and duration of the common cold.6
The vitamin C content of grapefruit is also thought to be helpful in reducing fever. The pulp or juice of a grapefruit is thought to help people recover more quickly from a fever, as well as reducing the 'hot flush' feeling that occurs when the body reaches a high temperature.7 Whilst high temperatures are useful at the initial stage of an infection, persistent high temperature is uncomfortable and dehydrating. Grapefruit juice, when combined with water, is also a great way to quench thirst swiftly, especially if you are ill, and can keep you hydrated for longer.
When choosing your grapefruit, it may be beneficial to opt for red or pink varieties, as these are rich in phytonutrients called bioflavonoids. These compounds are beneficial for reactions in the body, including boosting immune response.
In addition, naringin, another flavonoid found in grapefruit, is a powerful antioxidant with antibacterial and anti-inflammatory properties, which works as a line of defence against many illnesses and infections.8
Grapefruit also contains small amounts of B vitamins, iron, copper, and, most importantly, zinc. All of these nutrients work together to boost immune function, and maintain skin health, which acts as a protective barrier to infection.9
If you would like to incorporate more grapefruit into your diet, try our avocado and grapefruit salad. Not only is this recipe refreshing, it is also rich in healthy fats and vitamins, and is a good source of folic acid, potassium and fibre. If you enjoy having grapefruit as a snack, try sprinkling some cinnamon on top, as this is another ingredient with immune-boosting properties!
What you said!
We recently ran a poll to find out if you are more prone to colds and flu when eating unhealthily. We've crunched the numbers and here are the results.
Results: Are you more prone to colds and flu when eating unhealthily?
As 52.7% of you said you are more prone to colds and flu when eating unhealthily, it's clear that diet plays an important role in maintaining a strong immune system. A healthy, varied diet full of lots of fruits and vegetables should provide you with all the essential nutrients you need for a healthy immune system.
References
1 https://www.ncbi.nlm.nih.gov/pubmed/23394995
2 https://www.nrcresearchpress.com/doi/abs/10.1139/cjpp-2012-0303#.XlT0kqj7TIX
3 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464475/
4 https://www.ncbi.nlm.nih.gov/pubmed/17640421
5 https://www.ncbi.nlm.nih.gov/pubmed/7811869
6 https://www.ncbi.nlm.nih.gov/pubmed/23440782
7 https://www.tandfonline.com/doi/abs/10.1080/07315724.2003.10719272
8 https://link.springer.com/chapter/10.1007/978-1-4615-5335-9_13#page-1