Monday, May 19, 2014

Immunity smoothie (with science!)

I am usually a bit skeptical of foods and drinks that claim medicinal powers. In large part, this is because most claims don't come with supporting scientific data. I'm also aware that there are many myths about what does or doesn't help with various illnesses and ailments. I think we all have our personal "I think this works" approach! I'm not denying that there will be beneficial products or foods that aren't yet well studied - I am sure there are. However, I don't think firm claims should be made unless the data are already in.

Immunity smoothie - murky, but tasty

To give you an example, Vitamin C was lauded as a cure for the common cold for years. Many of us still think it helps to prevent illness, and vitamin companies trade off that belief to promote their products. However, there is no evidence to suggest that Vitamin C can prevent colds in the general population, and plenty to suggest that it only slightly reduces illness severity. Last year, a large Cochrane review (you can read it in full here) concluded that supplementation of Vitamin C (i.e., taking more than a regular dietary amount) may reduce the duration of a cold by 8% in adults or 14% in children. If you have a standard 5 day cold, this means that an adult taking extra Vitamin C from day 1 could feel better after 4.6 days instead of 5. I'd be happy with that, but it's not exactly a magic fix!

In contrast, zinc supplementation is associated with up to a 50% reduction in the likelihood of developing a cold, and the duration of a cold once developed (the Cochrane review on zinc is available here).

Zinc and Vitamin C


One of the nice outcomes from extensive Vitamin C research is that we know supplementation does help for those exposed to extreme physical stress - such as long-distance runners, or people in very cold weather. For that sub-group, taking extra Vitamin C can halve your risk of a cold, which is clearly a huge benefit.

You may be wondering where I'm going with this. As the weather cools down in Australia and more people start to cough and sneeze and sniffle, I wanted to make a smoothie that would taste good and provide health benefits too. The recipe below is based on what I found could help, in terms of real foods that have supporting scientific data.

The key points?
  • The mix of orange, raspberries and kale will provide 240% of your recommended daily Vitamin C (the recommended daily amount is 75mg; you get 70mg from 1 orange, 30mg from 1 cup of raspberries and 80mg from 1 cup of kale). This is likely to be enough to provide that 8% reduction in cold duration, or halve your risk if you're a long-distance athlete or spend lots of time in the snow. It's also still well within safe daily Vitamin C levels. 
  • The hemp or pumpkin seeds will provide roughly 40% of your recommended daily zinc intake (the recommended daily amount is 8-10mg; you get 3.5mg from 30g seeds). 
  • Fresh ginger (it does need to be fresh, not dried) has been shown to have anti-viral benefits for respiratory illnesses (e.g., see this source). Including it here will round out the other health benefits and boost flavour too.

Because this smoothie calls for a decent serve of seeds, it is thick and creamy even without milk. It truly is a wholefoods flavour hit, with the winter health benefits an added bonus. The main flavour is orange, and whilst it isn't super-sweet (feel free to add sweetener if you like), it is sweet enough to enjoy.

If you're in the northern hemisphere, I'm sure it will ward of summer germs well too!


Immunity smoothie
More enjoyable than commercial vitamin tablets - and probably more effective
Makes 1 very large (meal sized) smoothie, or 2 medium serves
Vegan, raw and gluten free

High-speed blender or food processor recommended

Author: Bite-sized thoughts

Print recipe

Ingredients
1 cup kale leaves, roughly chopped
1 whole orange (skin and all), cut into quarters
1 cup raspberries, fresh or frozen (frozen will lend creaminess to the drink)
Thumb-sized piece of fresh ginger, peeled and grated
30g (3 tbsp) hemp seeds or pumpkin seeds (pepitas)
1-1/2 to 2 cups cold water

Method
If using a high-speed blender, add all ingredients and process until well combined.

If using a food processor, process the kale, orange, berries, ginger and seeds until smooth, and then gradually add the water with the food processor running.

If you don't have a high-speed blender or food processor, you could make this in a regular blender if you grate the zest of the orange, then peel and add chopped orange pieces.



What foods or routines do you turn to for protection against illness?

22 comments:

  1. I had some zinc tablets the last time I was sick and it was crazy how much they made me feel better! As for vitamin C, I am totally happy with the placebo effect. Bring on the smoothie!

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    1. Given your running distances, you're probably in the category of people who get proper Vitamin C benefits :-) It's great to hear first hand reports of zinc helping too! I'm definitely going that route next time I'm sick.

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  2. Who knew it was all about the zinc? And sadly, off the top of my head, I have no clue what is a good source of zinc. When are you moving? Because you may be lucky to have a year of summer!! :)

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    1. Unfortunately for us, the best source is seafood :P Seeds are quiet good though, as are legumes. Cocoa is reasonable but you have to eat a lot of it - not such a bad thing ;)

      We're still waiting on my husband's visa to arrive before booking flights (grr)! But, probably in about a month. We will be having a double summer!

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  3. LOVED this post Kari! I totally nerd out on nutrition! I learned in school that while zinc supplementation to a point can help with illness, too much can have the opposite effect! Happy mediums :)

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    1. Ah, it's so important to hit a balance! Thanks for sharing that Gabby, I hadn't seen that in the articles I read but did wonder.

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  4. Amen, sister! It's so so frustrating to read the countless health-claims without any scientific evidence. In that regard, I appreciate all the links you provided here. I would gulp down this immunity smoothie any day! Say no to supplements! Eat real food ;)

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    1. Yes! Thank you Min - I think we're on the same page :-)

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  5. I LOVE LOVE LOVE that you linked to scientific studies (even if I can't actually view said studies!).

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    1. Oh, you can't view them?! Bother. I know the ginger link was to an abstract only, but the two Cochrane reviews should be free / open access to everyone. I thought they linked directly to PDFs?

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  6. The orange and raspberries sell it to me - worth a shot.

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    1. I think anything with orange and raspberries will always appeal to me :-)

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  7. Very helpful nutritional information. And I think preventing illness is better provided the natural way as they don't have any chemical side effects. Eating right with proper exercise is still the best!

    Julie
    Gourmet Getaways

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  8. Thanks for your positive comments re my jogging. I'll keep you informed with how I'm doing. I take lots of supplements and haven't had a cold or the flu for years - I'd rather take doses of things to prevent me getting something than start taking something once I'm already sick in the hope that it will work magic. Do you really add the orange skin? Wouldn't that make it bitter? I'm glad you're not being wasteful! xx

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    1. I'll look forward to your jogging updates :-)

      You are definitely doing something right if you haven't been sick for years - prevention certainly is better than cure! I didn't find the orange skin bitter, largely (I suspect) because it was processed up with the juice and raspberries. I usually find peel bitter but there were no 'bits' remaining in the smoothie and the other ingredients provided the necessary sweetness.

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  9. I took Zicam (zinc) when I woke up with a cold the week of my 50K race and I think it may have helped. I like pepitas and I didn't know that they are a source for zinc. Thanks for sharing!

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    1. Gosh, a 50km race is not when you want a cold! I'm glad the zinc helped a bit then.

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  10. Wow!! This is crazy!! Science to back it up!! Sweet!! :) Sounds good to me!

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  11. Totally in love with this post.. delicious + science = beyond cool!

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    1. I'm so glad - thank you Pamela :)

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