Vitamin A
Why is it important?
This vitamin is important for keeping the mucus membranes in the nasal cavity healthy; to provide good defensive barriers against inhaled germs. Vitamin A also boosts the production of white blood cells, which are the cells that help us fight infection.
Vitamin A also stops virus replication, so in a way stops them in their tracks. Low vitamin A is linked with poor wound healing, repeat infections and night blindness.
Which seasonal foods are rich in vitamin A?
Vitamin A is found in many yellow, orange and red foods, in the form of beta-carotene. Beta-carotene is converted to vitamin A in the digestive system. At the moment there are an abundance of root vegetables this colour such as carrots, pumpkin and golden kumara. So your mum was not lying when she said carrots could help you see in the dark.
Also persimmons are orange in colour and a good source. We are not just looking at orange foods though. There are a number of green vegetables high in Vitamin A.
You may be interested to know that these vegetables would be orange if they did not contain chlorophyll. Good sources around at the moment are spinach, cabbage, kale and other green leafy vegetables and brussel sprouts, broccoli, capsicum and celery.
High sources available all year round are eggs and oily fish.
Vitamin C
Why is it important?
Most people are aware that vitamin C can help prevent colds. The reason being is that it is used in every cell in the body and in this way is important for the immune system. If we become ill it is quickly depleted as it is a major component of white blood cells and it also stimulates white blood cell production.
As mentioned before white blood cells are the army that protects your body from invasion, so you can see how important vitamin C is. It is worth noting that Vitamin C is depleted by alcohol, certain medications (for example the oral contraceptive pill) and most significantly by smoking.
So people taking medicines or smoking and drinking regularly will need more vitamin C than others.
Which seasonal foods are rich in vitamin C?
Vitamin C can be found in most green vegetables, so we have double the reason to be enjoying the green leafy vegetables and others mentioned previously. Kiwifruit are an excellent source as are feijoas and persimmons.
The other major fruit category is citrus fruits, so start enjoying those tangerines, oranges and lemons!
It is also worth noting that vitamin C is easily killed by heat. Therefore eat some fruit and vegetables raw and try to steam rather than boil when cooking.
Zinc
Why is it important?
Zinc has antiviral properties and is released into the saliva to help kill any ingested bacteria and viruses. Like vitamin A it strengthens the barriers in the mucous membranes and it is used extensively by the immune system. Studies show a 50% reduction in cold duration when taking zinc.
Which seasonal foods are rich in Zinc?
When you are enjoying those pumpkins for their vitamin A, don’t throw away the seeds as they are a rich source of zinc. In fact most nuts and seeds are a good source of zinc. Beans, lentils and grains are good sources, so start making those hearty winter soups.
Herbal immune boosters
Garlic
This is a fantastic food that has so many excellent properties. With regards to immunity it is anti-microbial, antiviral and anti-fungal. This means it helps kill bacteria and viruses and boosts the immune system by increasing Natural Killer Cells.
Many of these actions are due to the compound called allicin that has been proven to induce an antibiotic action over the Staphylococcus aureus strain of bacteria and many other strains.
Staphylococcus aureus is one of the bacteria causing respiratory infection and as garlic is excreted through the lungs it is in the right place to kill it. Also garlic can help loosen a cough and with expectoration.
So make sure you start adding it to your soups and stews for prevention or if you feel a cold coming on. Onions like garlic are sulphur-containing vegetables and have the same antimicrobial actions, so pop them in too.
Echinacea
This immune booster is quite well known these days. It can be taken to enhance the immune system or if you fall sick it can help to get rid of bacterial and viral infections quickly.
One way it does this is by inhibiting an enzyme that invaders in the body use to enter the tissues. Therefore it helps prevent a hostile take over. It also boosts the production of the white blood cells that patrol the body and fight infection.
There are 2 species of Echinacea, angustafolia and purpurea and for immune boosting purposes a blend of both seems to work best. I also like this herb for when you have sore throats as it has local anaesthetic properties that help to relieve the pain.
Astragalus
This is an herb used extensively in Traditional Chinese Medicine and is effective for exhaustion. It is a great immune system booster and is also great for helping to support the stress response.
So for those people who get completely over stressed and seem to fall sick all the time this is a great herb. It can also help to support high blood pressure.
The Digestive System
Since 70% of the immune system is in the digestive tract it is very important. So start the winter with a healthy digestive system and make sure you have plenty of those good bacteria.
Good bacteria look after the mucous membranes, help to increase T Cells for immunity and help us absorb our nutrients. This is why taking a probiotic at the start of the cold and flu season can be helpful.
Also I have come across many people, especially children who keep getting sick and being put on courses of antibiotics. These antibiotics kill the bacteria (they do nothing for viruses) well enough, but they also kill the good bacteria.
If probiotics are not taken alongside or afterwards the immune system is already at a disadvantage and before you know it they are back on the antibiotics again.
