by Dr Vanessa Ingraham 

We all know that a diet rich in vegetables and fruit boosts our immune system and keeps us feeling our best, but will an apple a day really keep the doctor away this flu season? 

These days, apples are one of the least nutritious fruits we can consume. Not only are they prone to insect predation and doused with pesticides (1), modern apples have been selected for sweetness and most varieties do not contain much more than some dietary fibre and a little bit of vitamin C.  That's not to say apples are bad, but we can find other delicious fruit and vegetables that pack a far more powerful flu-preventative punch. Nutrients such as the polyphenols and carotenoids in brightly coloured fruit and vegetables support our immune system’s ability to fight infection while dampening low-grade systemic inflammation. Polyphenol-rich foods can also help prevent and treat common colds and flus (2). 

In New Zealand, one of our favourite polyphenol-rich foods is the tiny but mighty blackcurrant. Researchers at Japan’s Asahikawa Medical College examined the effects of blackcurrants against influenza virus A and B (IVA and IVB).  The results showed both viruses were inactivated up to 99.9 per cent when incubated with blackcurrant extracts at a low pH. When IVA-infected cells were treated with blackcurrant extracts, the virus was completely suppressed in six hours. This study showed that not only can blackcurrant extracts inhibit IVA and IVB on contact, they also may prevent further infection by blocking the viruses’ ability to leave infected cells (3). 

Blackcurrants are also one of the densest known sources of the polyphenol antioxidant class called anthocyanins, which have been shown to help our immune system defend us against other viral infections, such as those that cause enteritis and common colds (4). 

Studies have shown that anthocyanins can prevent influenza viruses from penetrating human cells and may inhibit viral release once the cell is infected (5). 

Technically the only way to resist a flu virus is to have antibody protection against it, either from past infection or arguably from vaccination. But increasing evidence suggests anthocyanins may help by making the immune system more efficient at addressing and clearing a virus if it does encounter one (6,7).  The way the polyphenol anthocyanins in blackcurrants work with the immune system means that if we do get sick, the severity and subsequent tissue damage from the infection may be decreased (8), thus allowing us to recover faster. 

While we need more clinical trials to prove blackcurrants’ efficacy in preventing and treating colds and flus, extensive research has revealed antiviral effects. Also, because of how they work, the ability of anthocyanins to destroy certain viruses is not affected by viral mutations (9), unlike some pharmaceuticals, which are rendered useless once a virus becomes resistant. 

No antiviral medication is 100 per cent effective, and blackcurrants will not be a magic bullet for flu prevention if a highly processed diet and excessive emotional stress are also present. However, given the safety and long history of consuming polyphenol-rich fruit and vegetables, I feel confident recommending blackcurrants as part of a holistic cold and flu treatment or prevention plan. 

Blackcurrants have been shown to benefit those with seasonal flu, and are a wonderful complement to an already healthy wholefood diet.  

Here are some ideas for immune-boosting, influenza-soothing, anthocyanin-rich recipes. 


Warming Red Shot For Cool Winter Nights 

  • 2 tsp manuka honey
  • 1 Red Shot
  • whole organic lemon, cut into quarters
  • ½ tsp ginger
  • ½ tsp cinnamon
  • 3-4 cloves or ½ tsp clove powder


Add all ingredients except Red Shot and active manuka honey to boiling water in a mug and stir. Allow to cool to taste then add Red Shot and honey. 

If you are already sick or have been around those with colds/flu, use active manuka 10+ UMF or 200+ MGO. This functional ingredient is not vegan. If using another sweetener, use only enough to taste, or omit completely. 


Blackcurrant yoghurt 

Probiotics, as found in active yoghurt cultures, are also powerful immune modulators. Probiotics have been shown in multiple studies to ease the severity of colds and flus and speed recovery.

  • 3 tbsp coconut yoghurt — Doctor’s Best, Cathedral Cove and CoYo are all good brands
  • 1-2 Red Shots
  • 2 tsp pumpkin seeds — a good source of zinc, which benefits immunity
  • 5-7 brazil nuts, crushed — an excellent source of selenium, needed for immune response

Optional: 1-2 tsp manuka honey — if you are sick or have been around those with colds/flu, use active manuka 10+ UMF or 200+ MGO

Optional: 1 tsp licorice powder — licorice is also a potent and naturally sweet antiviral agent. It is available at healthfood stores. Use with caution if you have high blood pressure 

Add all ingredients to a bowl and mix.


1) http://www.ewg.org/release/apples-top-dirty-dozen-list-fifth-year-row

2) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3878739/

3) https://www.ncbi.nlm.nih.gov/pubmed/12601672

4) https://www.ncbi.nlm.nih.gov/pubmed/24660461

5) https://www.ncbi.nlm.nih.gov/pubmed/17572513

6) http://www.nzblackcurrants.com/assets/images/Health-Benefits-review-updated-9-November-2012.pdf

7) https://www.ncbi.nlm.nih.gov/pubmed/17634269

8) https://www.ncbi.nlm.nih.gov/pubmed/20229526

9) https://www.ncbi.nlm.nih.gov/pubmed/18241960


Red shot powder in a bowl

Get Started

Nutrient Rescue is 8 powerful New Zealand grown nutrient-dense superfoods, taken in a single shot every day. So you can improve your nutrition fast, simply and affordably. We’ve done 99.999% of the prep for you, now it’s up to you to do the rest.

What’s included?

✓ 30 days supply of Double Shot.

✓ Free Starter Kit – including shaker, shaker ball, scoop, purple tin and fridge magnet to remind you to shot daily*. That’s $19.50 worth of value for free.

What is the cost?

All you pay for is one pouch of Double Shot - $69.41

We give you the rest for free to help you succeed.

If you tick Auto-renew when you buy then you’ll get everything for only $69.41, and we’ll make sure you get your supply of Double Shot delivered to your door every month. You can pause, skip and cancel your subscription at any time.

*A free Starter Kit is supplied if this is your first time purchasing from Nutrient Rescue.

“I have been taking my shots for about 2 months now. After being sick 8 times this year with colds (yes 8 times!) I was almost at my wits end. Catching public transport to and from work and working in an office open floor plan have not helped when other people cough over you all the time. However, since I started taking my shots every day I haven’t had ONE cold!!!! It has been such a relief and everyone has noticed how much more energy I have (looking a lot brighter in the skin). My partner noticed so much and now he’s hooked too!!! I also got three other colleagues into them.”

Shelby Wilson

“In the mornings I used to drag myself out of bed and felt like I had been run over by a bus. It usually took me a strong coffee and half an hour of just sitting to wake up properly. After about two weeks of taking the shots I noticed I was getting up feeling energised and ready for the day. It has really helped to maintain energy levels throughout the day and I am more inclined to be active as I have more energy! Amazing! I feel content that I am supporting and nourishing my body for myself, my family and my future health.”

Tania Englebretsen

“This product is so amazing. I’ve had a coffee everyday in hand daily (twice sometimes) just to survive since having my first baby 17months ago. I’ve only been taking this for a week, sometimes twice a day depending on how busy the day is, and even after having less than 5hours sleep most times, I no longer NEED coffee and have energy to work nightshift without coffee, no after noon slump, the list of benefits goes on. Thank you so much 🙂 So Grateful.”