Everyday Health, Immunity, Nutrition

Superfoods & Super-nutrients to protect you from infection

The right to be adequately kitted out before you go into battle is topical in the current political climate. This concept also applies to the defensive forces that protect our bodies from infections and chronic disease. Your immune system will not work if it is not fully charged with adequate supplies of the right nutrients – a nutritional deficiency equates to a lack of military equipment. It is serious!

There are a collection of vital nutrients in foods which offer building blocks for the body’s defence systems.  Here we outline the details of those that are most important. With a little help from our super nutrients for immunity – you can get your forces fighting fit.

We have covered how your immune system works in a previous article: How to boost your immune system. Here we explore the role of the ‘bug fighting micro nutrients’ that help our bodies when we are under attack.


Hard as it is to believe, although oxygen is fundamental for life – the very same gas can be responsible for mass destruction in the body. Oxygen can attach to specific chemicals and produce volatile compounds that travel around the body looking for something to react with and change, these are called free radicals. Continuing the warfare theme: naturally occurring chemicals called antioxidants are nature’s version of the free radical disposal unit! They are perfectly formed to extinguish the damage.

When free radicals are not extinguished, protective outer membranes of cells, genetic materials and any of the protein, carbohydrate or fat based structures in the body are attacked and damaged. Concentrations of free radicals are found when there is an infection in the body, if they have been introduced by pollution (e.g. car fumes, chemicals in food (e.g. acrylamide in burnt meat or fried foods) or cigarette smoke) or when there are insufficient levels of antioxidants in the diet to extinguish their presence. Eventually free radicals build up; literally chemically degrading your healthy tissues – resulting in degenerating health and disease.

Many of the most well known vitamins and minerals are powerful antioxidants. These include: Vitamins A, C, E, and Selenium. However, as always, nature is more complex and sophisticated and together with these antioxidants, there are literally hundreds of chemicals found in fruit, vegetables, spices and herbs known as phytochemicals that all work as antioxidants. Each of these contribute to the detailed and interrelated web of soldiers in the army that make up our immune defences.

Vitamin A – Retinol

Animal-sourced vitamin A (retinol) has been widely studied in relation to its immune system boosting properties. Hundreds of studies have been summarised in a review on the role of retinol in immunity, scientists do not understand exactly how it works but vitamin A is known to increase the action of our fighter cells1 (white blood cells) and play a pivotal role in maintaining the structure and functionality of our physical barriers to infection. These are:

  • cell membranes which literally block out unwanted viruses, bacteria and pollution from each cell in the body
  • mucous membranes which include our skin, respiratory tract, lining of our gut and our genito-urinary tract.

Vitamin A supplementation has been shown to reduce severity of symptoms and chances of death from a range of serious infections including: measles, diarrhoea, measles related pneumonia, HIV and malaria1. If you are taking a range of supplements or eat high quantities of vitamin A rich foods (especially liver) be aware that it is possible to have too much Vitamin A, for the national safety guidelines see http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Vitamin-A.aspx .

Carotenoids / Betacarotene

It is also possible to make enough vitamin from carotenoids. Carotenoids are either listed as ‘mixed carotenoids’ or beta-carotene; the most commonly isolated form of these chemicals. Carotenoids are ‘phytochemicals’, with hundreds of variations making your best source fresh fruit, vegetables and herbs and spices. Look out for deeply coloured fruit and vegetables, generally those which are red, orange, yellow in colour are great sources of carotenoids. For example: carrots, sweet potatoes, red and yellow peppers, tomatoes etc. A recent study showed how effective coloured potatoes (e.g. yellow or purple potatoes) are at reducing the levels of free radical damage in a group of men3.

For food sources of Vitamin A.

Vitamin C

Vitamin C is famous for its immune boosting and antioxidant properties. In a rigorous review of its ability to prevent and reduce symptoms in the common cold, it was shown that taking Vitamin C does reduce cold like symptoms. The dosages are still debated4.  Vitamin C has been proven to be a powerful antioxidant to decrease the impact of free radicals in the body. It also has the ability to recycle other vital antioxidants including: Vitamins A and E. Vitamin C increases immune response by increasing the rate of production of immune fighting cells (T cells) when the body becomes infected. 5 Vitamin C has also been shown to directly tackle the bugs responsible for infection i.e. viruses6. Without Vitamin C it is impossible to absorb iron, another immune boosting super nutrient7.

For food sources of Vitamin C:

Vitamin E

Vitamin E is an antioxidant that is fat soluble and has been shown to boost immunity by:

  • increase the number, strength and production of infection fighting cells by the body7, and when supplemented decreases chemicals in the body that can lower your immunity8. Vitamin E works with Vitamin C and an antioxidant enzyme made in the body using Selenium (glutathione) to protect the membranes of cells from damage by oxidation during infection. Vitamin E is recycled by Selenium8.  In a study of healthy Asian adults, supplementing with Vitamin E was shown to lower the measures of damage by free radicals in the body and improve immune strength9.

For food sources of Vitamin E:


The term ‘superfood’ is really a buzz word and cannot be anything other than reflective of an opinion. It is not a scientific concept nor is claiming to be a ‘super food’ a legitimate health claim. Nonetheless, understanding that some foods are MUCH better at enabling your body to protect itself from attack. If we were looking for the most legitimate way to label your food choices as immune boosting superfoods – it would have to be using the ORAC scores of foods. The higher the ORAC score of a food, the more antioxidant power it contains. For a full list and look up facility for these scores. We have chosen a selection of foods that are mainstream choices, not too expensive and contain high concentrations of antioxidants to boost your immunity.

  • Spices and Herbs: oregano, rosemary, thyme, cinnamon, turmeric, sage
  • Berries: blueberries, raspberries, black berries, cherries, strawberries
  • Nuts: pecan, almond, peanuts, pistachio, walnuts, hazelnuts
  • Beans: kidney beans, black beans, red beans, pinto beans
  • Dried fruits: raisins, prunes, dates
  • Garlic and onions

Other nutrients:


Zinc is the most important immune boosting mineral and works with Vitamin A. Zinc is pivotal in numerous mechanisms involved in beating infection including: increasing strength and production of many different types of fighter cells7 and controlling inflammation in the body when it is under attack8. Zinc has been shown to directly slow the growth of specific viruses including the common cold7. Supplementing with Zinc has been shown to reduce the length and severity of cold symptoms10.

For food sources of Zinc:


Specific sub-groups in the UK population are susceptible to iron deficiency, these include: infants, menstruating women, pregnant women and the elderly. Pregnant women with low levels of iron in their blood are more susceptible to infections11. This lowered immunity has been explained in a study that showed a reduced number of infection- fighting white blood cells in children with low iron status or anaemia, and when the children were infected their bodies were slower to make more12.

For food sources of Iron:

When you stop and think about the millions of infections that your body fights off every day, the strength and complexity of your immune system is easy to appreciate. A diverse army of defensive fighter cells and well-constructed physical barriers successfully stop us from succumbing to the diseases caused by infections – most of the time. Like ALL functions in the body, a complex web of micronutrients (vitamins and minerals and phytochemicals) combined with adequate supply of carbohydrates, proteins and health-promoting fats. Plus a range of other dietary, genetic and lifestyle factors all contribute to optimal health. We have highlighted the MOST important micronutrients involved in immune health here. Of course there are so many more nutrients that contribute to your ability to fight infection – including essential fatty acids, Vitamin D and probiotics. When you are looking to improve your immunity, think carefully about your intake of our identified super (antioxidant) foods and ensure that your multivitamin supplement contains at least the recommended daily allowance of the nutrients that are highlighted here.


1 Semba RD, 1999, Vitamin A and immunity to viral, bacterial and protozoan infections, Proceedings of the Nutrition Society, 58:719-727

2 Bhaskaram P, 2002, Micronutrient Malnutrition, Infection and Immunity: an overview, Nutrition Reviews, 60 (s5): s40-s45

3 Kaspar KL, Park JS, Brown CR, Mathison BD, Navarre DA, Chew BP, 2011, Pigmented potato consumption alters oxidative stress and inflammatory damage in Men, American Society for Nutrition, 141:108-111

4 Douglas RM, Chalker EB, Treacy B, 2004, Vitamin C for preventing and treating the common cold, Cochrane Database Systematic Review, CD00980

5 Naidu KA, 2003, Vitamin C in human health and disease is still a mystery. An overview, Nutrition Journal, 2:7

5a Geber WF, Lefkowitz SS, Hung CY, 1975, Effect of ascorbic acid, sodium salicylate, and caffeine on the serum interferon level in response to viral infection, Pharmacology, 13:228–33

6 Padayatty SJ, Levine M, 2001, New insights into the physiology and pharmacology of vitamin C, Canadian Medical Association, 164: 353-355

7 Pizzorno J, Murray MT, Joiner-Bey H, 2002, The Clinician’s Handbook of Natural Medicine, Churchill Livingstone, USA, page 390

8 Field CJ, Johnson IR, Schley PD, 2002, Nutrients and their role in host resistance to infection, Journal of Leukocyte Biology, 71:16-32

9 Lee CY, Man-Fan, WJ, 2000, Vitamin E supplementation improves cell-mediated immunity and oxidative stress of Asian men and women, Journal of Nutrition, 130: 2932–293

10 Prasad AS, Fitzgerald JT, Bao B, Beck FW, Chandrasekar PH, 2000, Duration of symptoms and plasma cytokine levels in patients withthe common cold treated with zinc acetate. A randomized, double-blind,placebo-controlled trial, Annals of Internal Medicine, 133:245–252.

11 Prema K, Ramalakshmi BA, Madhavapeddi R, 1982, Immune status of anemic pregnant women, British Journal of Obstetritc Gynaecology, 89:222–5

12 Bhaskaram C, Reddy V, 1975,Cell-mediated immunity in iron- and vitamin-deficient children. Britsh Medical Journal 3:522

Disclaimer: Seven Seas Life is not intended to provide medical advice, diagnosis or treatment. The articles are based on peer reviewed research, and discoveries/products mentioned in the articles may not be approved by our regulatory bodies, you will find no mention of Seven Seas products within the pages of the Seven Seas Life Section..Read more

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