Did you know nutrition can help you protect yourself from flu this winter
December '17
As winter draws in, for many of us coughs, colds and flu go hand in hand. Winter lurgies start to lurk around every corner from public transport, the office, kids bringing them home from school or nursery. 15 years ago, prior to becoming a nutritionist, I would be ‘ill’ all winter. A permanent cold which would intermittently get worse and develop into tonsillitis or flu. Now I rarely get ill, even when those around me are holed up in a mass of tissues and a duvet. Obviously, my immune system is much more robust, but as flu is not really a thing you would ever go to see a nutritionist for, I have never looked into what I am doing specifically to protect myself. So I thought it is was about time I changed that and then shared the knowledge so you too can go through winter still feeling full of energy and fighting fit.
These are my top nutritional and lifestyle tips that have been scientifically studied to show protection against winter infections;
Green tea has been identified by a growing number of studies over the last 25 years that its polyphenols called catechins have antiviral properties[1]. The mechanism isn’t fully understood and it may work differently for different viruses. It maybe for influenza’s case that it structurally prevents the replication of infected cells. More recently scientists have looked at specific applications of this for particular viruses especially for widespread viruses that effect vulnerable populations. Two studies of interest use green tea as a preventative measure for elderly in care homes[2] and children in primary school[3]. Both studies showed very promising results in reducing the levels of infection. As a nutritionist I would only recommend giving organic decaffeinated beverages to these groups.
More studies are needed to confirm whether the practical application of green tea in the prevention of winter flu is robust. However, from personal experience of drinking green tea every day, I have only succumbed to flu once in the last 5 years even when those around me seem to catch it much more often.
Echinacea used to be very popular as an immune supporting herb, however poor quality products have meant that a lot of people haven’t found it as effective as its potential. There are 3 different species of Echinacea commonly grown. The active ingredient in the Echinacea which boosts the immune system are called alkylamides, these are only found in two species (angustifolia and purpurea)[4] and then in certain parts of the plant i.e. root. Many cheap products on the market contain the other species, pallida, which is weak and will have little or no immune boosting effect. It is important to look at the label to check it has the right species. If it just says Echinacea, I would choose a different product that does specify.
Reishi and Cordyceps are medicinal mushrooms which like all of their class are immune system supporters and have protective qualities against disease. Research into Reishi indicates protection against flu[5] as does cordyceps[6]. You can now buy them in teas or in powder form to add to smoothies etc.
Vitamin D is probably one of the most well researched and compelling areas to keep you well. It is a vitamin we produce in our skin in reaction to exposure to sunlight. However, living in the UK, and many of us having a predominately indoor lifestyle, means that many or even most of us are deficient. In 2006 Public Health England, the governments health advisor body recommended that we all started taking 10mcg or 400 i.u. as minimum supplementation[7], yet most of us don’t. Having found out a number of years ago that I had low levels even after I had been on sunny holiday, I take 1000 i.u. every day. A large study [8]combining many different previous studies (meta-analysis of 25 published papers) in the British Medical Journal, BMJ, this year, found that supplementation protected against respiratory tract infection.
Black Elderberry. A number of preliminary studies over the years have shown how extract taken from this berry may help treat the flu virus, shortening its length and severity[9][10]. Flu is actually hard to treat as it is not a bacterial infection so cannot be treated with anti-biotics. Those who have taken black elderberry have been found to have high level of antibodies, the body’s immune cell that fight against the virus[11]. You can take it once you have symptoms or equally through the winter months as it provides helpful nutrition in terms of high levels of antioxidants.
