I was drawn today by an article in the Times newspaper. The heading read, ‘Cancer Drug to Help Patients cure themselves’. Looking at this in more detail: new research is looking at supporting the body’s own immune system to fight cancer and drugs are being developed to support this theory. These immunotherapies have been hailed as one of the most exciting and promising treatment modalities in years.
The immune system: A finely tuned orchestra
Remember that our immune system is our first line of defence against invasive organisms and foreign materials, including destroying mutant (abnormal) cells. Poor nutrition has been shown to result in increased infection and susceptibility and complications from immune dysfunction. One article that I read described the immune system as being like a finely tuned orchestra, containing many different instruments that work harmoniously together with one goal. And like an orchestra the different parts must be present to play their part at the right time and then stop when they have completed their function. I thought that was a perfect description.
Supporting (and fighting) our immune system
It is worth remembering that we can also do a great deal ourselves to support our own immune systems through the food that we eat. We do know that there are some foods that have been shown to be particularly beneficial for this, so I thought this was a good opportunity to revisit some of these foods. Of course, we can also look at the other side of the coin and mention foods that have been shown to deplete the immune system.
What does the immune system need
I often talk to visitors about ways to support the immune system, particularly if they are going through chemotherapy and their white blood cell count falls. The immune system is very complex and needs a wide range of nutrients to support its function. No one food has the answer but a good mixed diet is essential, including;
- Protein rich foods like eggs, fish, peas, beans and lentils. Research studies show that a deficiency of protein can result in depletion of immune cells and an inability of the body to make antibodies and other immune related cells. Animal studies have shown that inadequate protein can lead to a 25% reduction in immune efficiency.
- Plenty of fresh fruits and vegetables, trying to make them 50% of the total food intake in a day. The World Cancer Research Fund recommends 8-10 portions a day. This is because both fruits and vegetables are abundantly rich in vitamins and minerals, which include antioxidants and phytonutrients (sometimes referred to as phytochemicals). The immune system is dependent on a good supply of these nutrients. Fruits and vegetables also contain compounds that support the liver and its detoxification process, which is essential to support the immune system.
- VItamin C has had a great deal of research. Vitamin C is a water soluble vitamin which means that our body does not store it, so a regular supply is needed from our diet. Foods particularly rich in vitamin C are red peppers, broccoli, all berry fruits, oranges, tomatoes and papaya. However most vegetables and fruits contain some. Vitamin C is one of the primary anti-oxidants working alongside vitamin E, selenium and beta carotene to support the immune system.
- Garlic has been hailed as being very beneficial for the immune system. It has been shown to stimulate the production of white blood cells and acts against a wide range of non-beneficial bacteria, fungi, parasites and viruses, all of which can be a challenge to the immune system and its efficiency.
- Mushrooms have also been shown to be hugely beneficial, particularly shiitake mushrooms. Mushrooms contain a compound called beta glucan that has been shown to boost immunity, slow tumour growth, and lessen the side effects of cancer treatment. They are so easy to include in the diet. You can try them in mushroom soups, on toast, in an omelette, added to casseroles, eaten raw in salads or added to a kedgeree.
- Zinc is another nutrient that has been singled out as very essential for good immune function as it is a potent immune stimulant. So try to include some zinc rich foods in the diet regularly. Zinc rich foods are all types of fish and seafood (particularly oysters), seeds and nuts, oats, green peas and whole grain cereals. So looking at these foods it should be quite easy to reach the recommended amount of 15mg a day.
- Vitamin D research has shown that this vitamin in particular is very beneficial to the immune system. The problem is that because we live in the northern hemisphere we tend to be quite deficient in vitamin D because our main source is from the sun. Looking out of the window today that is not going to happen!! The only reliable foods to give us vitamin D are oily types of fish (like trout, tuna, mackerel, salmon and sardines), eggs (from the yolk) and fortified breakfast cereals. We have to be careful with these though because many breakfast cereals also contain lots of sugar and salt. So it may be advisable to consider a vitamin D3 supplement especially through the winter months. It is recommended that we have between 3 and 4,000 international units (i.u) a day. Vitamin D has also been shown to help reduce fatigue and boost general energy levels.
- Herbs – Some herbs have been shown to be very useful, such as Astragalus and Echinacea. They improve both T cell and B cell activity. These are cells of the immune system directly responsible for recognising and destroying rogue cells. Astragalus might not be suitable to take alongside some cancer treatments so if you are thinking of taking these herbs always run it past your oncologist first.
- Sauerkraut has been used for centuries as an immune booster because it contains compounds created during the fermentation process, A study published in the Journal of Agriculture and Food Science concluded that sauerkraut is a cancer inhibitor and is also hugely beneficial for balancing the bacteria in the gut. It contains the beneficial bacteria lactobacillus plantarum which boosts the immune system by increasing the antibodies that fight infection.
A healthy gut is important for the immune system. 60% of our immune cells reside in the gut so a good healthy digestive system helps to support the immune system. This can be achieved by preventing constipation and eating plenty of fresh fruits and vegetables. If you do suffer from a sluggish bowel then ground flaxseeds daily sprinkled over muesli or porridge or in soup or stirred into yogurt really help. Most people find that 2 tbsps a day is sufficient. It is important that if you do use ground flax seeds that you drink plenty of fluid.
Exercise My final point is that moderate exercise also helps to boost immunity. Exercising the body releases serotonin, which is the feel good factor neurotransmitter. This in turn boosts immune function. So a good walk is a good idea when you can manage it.
The other side of the coin – some things that challenge the immune system:
Sugar and sugary foods can deplete the body of essential nutrients and interfere with the fine balance of bacteria in the gut.
Alcohol is high in sugar and known to irritate the lining of the digestive tract.
Environmental and food chemicals challenge the immune system as they are foreign to the cells of the immune system, so try to keep these to a minimum if you can.
Stress can depress the immune system so it is a good idea to try and manage stress. Stress causes the adrenal glands to secrete the hormone cortisol which depresses immune function. Stress management techniques like yoga, mindful meditation etc. are very useful therapies that will help. Or you could try a calm walk where you take time to ‘smell the roses’.
Find out more
If you are interested in reading more about nutrition and the immune system you may be interested in very good book called, Eat to boost your immunity, by Kirsten Hartvig. The first part of the book gives a good comprehensive account of the immune system and how it works, then there is a section on foods that have been shown to boost immunity. The next chapters cover specific problems that can affect the immune system, like fatigue and depression. It ends with lots of lovely recipes rich in foods that support immunity, like butternut squash with red pepper and tomato, and sweet potato curry.
Eat to Boost your Immunity Paperback – 5 Jan 2012
by Kirsten Hartvig (Author)
Blog originally written by Caroline June 2014 - checked April 2020