This winter’s flu season has taken a dramatic turn with the arrival and rapid spread of the Covid-19 corona virus. A few weeks ago I highlighted some of the key nutrients we need for all-round immune support. These nutrients are essential in the fight against flu. But is there any evidence to say nutrition can help fight coronaviruses?
The short answer to this question is yes! In a fascinating paper from the US, researchers explore the interactions between compounds in foods and the way our immune system deals with RNA viruses – including coronaviruses.
The compounds in question include:
– Ferulic acid: an antioxidant found in many different plants
– Phase 2 inducers like sulforaphane (Phase 2 is one of the detoxification pathways in the liver; it requires plenty of glutathione, one of our most important antioxidant nutrients)
– The minerals zinc and selenium
– Anthocyanin compounds in Elderberry
– Phycocyanobilin in Spirulina: a type of cyanobacteria grown on freshwater lakes and sold as powder, tablets, or capsules
These compounds have multiple benefits for our immune defences, mainly through their modulating effects on immune cells and signalling molecules, and by providing powerful anti-inflammatory and antioxidant protection in the lungs and airways.
Nutrition and the elderly
A key observation of this paper is the way in which zinc and n-acetyl cysteine have been shown to support older peoples’ immune systems against ‘flu. In a small-scale 6mth controlled trial involving 262 elderly people, those receiving 600mg of n-acetyl cysteine twice a day* experienced significantly fewer days of ‘flu and spent much less time confined to their beds, compared to those taking a placebo.
And, although the rate of infection was comparable between the two groups only 25% of the virus-infected subjects in the NAC group developed symptoms, compared to 79% of those in the placebo group.
*(This is quite a high dose, and not recommended unless advised by a nutrition practitioner).
The benefits of zinc supplementation for the elderly were spotted as a by-product of another trial – the AREDS1 trial for eye health – that used a vitamin and mineral supplement with zinc in. As the authors note: “…This effect might be pertinent to the significant 27% reduction in total mortality observed in elderly subjects who received high-dose zinc in the AREDS1 multicenter trial”. It seems a supplement trial for healthy vision had an unexpected and positive effect on flu deaths!
Many older people take PPI (proton-pump inhibitor) medications like Omperazole, Lansoprazole, and Nexium, to manage acid reflux and heartburn. These drugs suppress the production of stomach acid; this can bring short-term relief from heartburn and reflux but it has a knock-on effect on nutrient absorption. Long term use of these meds can significantly impact zinc levels – and as a result, immune function. If you or someone you know has been taking PPI meds for more than 3 months, it’s a good idea to have your zinc levels assessed either with a GP or via a nutrition practitioner.
So the big question now is where to find these amazing nutrients? Here we go…
Zinc: poultry, shellfish (especially oysters – if you can stomach them!), red meat, pumpkin seeds, nuts
Selenium: Brazil nuts, shellfish, liver
Spirulina: use capsules or tablets, or add the powder to smoothies, pesto, and dark chocolate bark (this has to be the easiest and most enticing way of taking spirulina ever known)
Sulforaphane: found in cruciferous veggies like kale, broccoli, and cauliflower
Ferulic acid: widespread in foods including oats, rice, pineapple, nuts, bananas, spinach, beetroot
Keep your diet as varied and interesting as possible and if you feel the need for more personalised advice, get in touch with your local Registered Nutritional Therapist. York-people, you can find yours here!
Reference: M.F. McCarty and J.J. DiNicolantonio, 2020. Nutraceuticals have potential for boosting the type 1 interferon response to RNA viruses including including influenza and coronavirus Progress in Cardiovascular Diseases, https://doi.org/10.1016/j.pcad.2020.02.007