Fighting off the flu with nutrition

What’s the role of nutrition in reducing the severity of a cold or flu in winter?

As soon as the colder months start to settle in, the puffer jackets come out and so too do the weird and wacky wife’s tales to help stop a cold. This includes certain foods and supplements that are seen to boost immunity.

To help set the scene before we all start reaching into the supplement cupboard, it’s worth noting that our immune system is a very complex system which takes many processes and mechanisms to function optimally. We are constantly exposed to potential harms and our immune system protects us from certain diseases, however minimal or severe they may be. A long-term approach with a balanced diet, adequate sleep and physical activity will always set you up best to fight off any colds or flus each season. Maintaining a healthy defence system lowers the incidence, duration and severity of symptoms for colds and the flu.

Factors which can affect our immune function:

• Age- as we age, our immune function and organs becomes less efficient

• Excess weight- being in a larger body is an independent risk factor for the flu virus

• Poor diet- malnutrition of vitamin deficiencies can impair our immunity

• Chronic disease- autoimmune disease can potentially disable immune cells

• Mental health- ongoing mental stress can suppress the activity of good immune cells

• Lack of recovery and sleep- when we have poor sleep, cytokines cannot released effectively to fight off infection

• Environmental toxins- smoking and air pollution can suppress normal activity of our immune system

But what about foods or supplements to help with a cold/the flu?

Now that we have covered the background of supporting a healthy immune system through intake, it’s time to unpack the research around dietary supplements at the time of having a cold or flu. If you’ve covered most bases and still somehow pick up a viral infection, the evidence suggests that the supplements which MAY have a positive impact on the treatment of your cold or flu are the following:

• Vitamin C

• Vitamin D

• Zinc

• Echinacea

One study suggested the regular supplementation of vitamin C (1 to 2 g/day) has shown to slightly reduces the duration (in adults by 8%, in children by 14%) and the severity of the common cold. Similarly, supplementing with zinc may shorten the duration of colds by approximately 33%. The early they are taken from onset of symptoms usually the better. It’s also worth noting, some of these studies suggest the severity of the cold or flu was lower only when the supplement levels were high prior to onset of the virus.

Some other nutrients which have research but don’t seem to have as strong a link include selenium, iron, copper, b-carotene, folic acid, vitamins A, and E.

As always, there are more common treatments once you have flu like symptoms such as bed rest, fluid intake and pain relief when necessary. More severe cases may need antiviral medication.

What else should we know about the annual flu season?

Whilst we have learnt some lessons from COVID and are all kind of over discussion it, we still need to treat the flu (and COVID) with some seriousness. Annual death rates of the flu in Australia are 1,000 people and hospitalisations are 5,100 (not to mention the indirect effect on people’s lives and the economy overall). Influenza vaccination provides coverage to reduce the risks of flu by 40-60% amongst the overall population and has a moderate protective effect of hopsitalisations. If you’re looking for bang for buck percentages, a flu vaccine is going to go much further from a preventive point of view than a few vitamin C tables once you get a virus.

Bottomline

As mentioned previous, having a wide variety of nutrient dense foods, prior to, and throughout the flu season is going to give you the best advantage to fight off any viruses from a nutrition perspective. If you do happen to get sick, there is evidence to suggest Vit C, Vit D, zinc and echinacea may slightly reduce the severity and duration of that cold or flu. Food and supplements aren’t the only form of prevention or treatment and shouldn’t be relied upon exclusively, so book in with your doctor if symptoms get worse.