What Doesn’t Kill You Makes You Stronger

sarah cuff Food for Runners, Run Recovery, Superfoods for Runners, Supplements Leave a Comment

What doesn’t kill you makes you stronger. It’s a line from a Kelly Clarkson song. Which is a twist on philosopher Friedrech Nietzsche’s words, “That which does not kill me makes me stronger.”

I always take questions at the end of each talk I give and a few weeks ago, received a really great one I want to share with you today. The question was… What is the difference between antioxidant-rich and anti-inflammatory foods?

Runners World published the book The Runners’ Body (Tucker & Dugas, 2010) and in chapter 14 it discusses how exposure to certain things in a large dose can be toxic, but in a small dose can prove beneficial. Too much can ‘kill you’ but small amounts can ‘make you stronger’. This is the framework in which antioxidants and anti-inflammatories are best discussed.


Antioxidants are natural compounds found in food that prevent oxidative damage. Oxidants (otherwise known as free radicals) enter our bodies by way of pollution, cigarette smoke, rancid or oxidized foods including processed cooking oils, alcohol, medications, UV rays, pesticides, and toxins. This makes oxidants sound like a bad thing – and in large amounts they most certainly are. In large amounts free radicals damage healthy cells and tissues, which stimulates the formation of more free radicals and further damage – a domino reaction.

However, free radicals are normally found in our bodies in small numbers – they are required for destroying viruses and bacteria and producing vital hormones and activating enzymes. Additionally, the act of running creates free radicals that cause muscle damage. Sounds bad, but in fact some muscle damage is required in order to lead to overall strengthening and help the muscle to tire less quickly in the future.

How do we keep excessive free radicals in check? Two ways:

  1. Limit exposure to large amounts of known damaging free radicals such as cigarette smoke, too much alcohol, too many pesticides, too many medications, etc.
  2. Eat a wide variety of antioxidant-rich food. This includes foods rich in the carotenoids, vitamins C and E, zinc, selenium, anthocyanins, flavonoids, polyphenols such as epigallocatechin gallate (EGCG), methionine (an amino acid) and enzymes such as coenzyme Q10 (to name only a few).

What about supplementing with antioxidants (vitamins/mineral/antioxidant supplements)? Research continues to suggest that supplementation (extracting compounds normally found in nature and consuming them in much higher doses than you’d ever be able to consume through food) interferes with gains you’d normally expect from endurance training. In fact – in doses high enough – they actually act as free radicals. A little makes you stronger, too much can kill healthy cells.


Our antioxidant defence system and our anti-inflammatory defence system are interrelated. When our cells become overloaded with free radicals, this initiates our bodies natural inflammatory response. Inflammation is necessary for healing – a little is a must. However too much delays healing. Again, a little makes you stronger, too much can cause excessive damage. Just as running creates free radicals, it also creates some inflammation – which is fine. However if you run too much (relative to running experience), too frequently and tissues are unable to heal between workouts (especially paired with a poor diet), chronic systemic inflammation will result.

Inflammation itself is blood rushing to an area to help it heal. White blood cells move in and clean up the area, then other cells come along and stimulate tissue regeneration. Too many free radicals tend to create excess inflammation, which appears to slow this process of healing down.

Anti-inflammatory foods limit the production of pro-inflammatory cytokines and other compounds (pro-inflammatory foods, on the other hand, tend to increase production of these compounds). Anti-inflammatory foods include omega-3 fatty acid rich salmon, hemp hearts and chia seeds; antioxidant & fibre rich fruits, vegetables, nuts, seeds and whole grains as well as olive oil and red wine. Pro-inflammatory foods include trans fats and excessive amounts of starches, sugars, processed meats and sugar-sweetened beverages.

It’s interesting to note that fat cells produce inflammatory cytokines that cause systemic inflammation. High amounts of abdominal fat specifically lead to high levels of chronic inflammation throughout the body. Therefore maintaining a lean body composition will not only make you feel lighter on your feet, it will reduce your overall inflammation levels, thereby helping you to recover faster and avoid injury.

Antioxidants VS Anti-Inflammatories

As mentioned, there is a lot of overlap between antioxidant rich foods and anti-inflammatory foods. Many act both as antioxidants and as anti-inflammatories. The primary difference between the two is the role they play – and many nutrients are able to play both roles.

Here are my top 5 antioxidant rich foods and top 5 anti-inflammatory foods:

Top 5 Anti-Inflammatory Foods

  1. Omega-3 Fatty Acids (wild salmon, halibut, mackerel, trout, chia seeds, hemp hearts, pumpkin seeds, walnuts)
  2. Ginger
  3. Turmeric (curcumin)
  4. Matcha tea and green tea
  5. Pineapple and papaya

Top 5 Antioxidant Rich Foods

  1. Kale (and all dark leafy greens)
  2. Tart cherries (and pure tart cherry juice)
  3. Blueberries
  4. Strawberries and raspberries
  5. Raw cacao

Eating a wide variety of colourful foods is a great way to ensure you are getting all the nutrients you need to keep oxidants in check and manage inflammation. In reaching for supplements, you run the risk of taking in too much at once and preventing cellular adaptation to exercise (such as this study which demonstrated taking only 1g Vitamin C daily decreases training efficiency). Vitamin E, fish oil supplements – there are studies continuing to come out that suggest long-term high dosage is damaging to our health. But in moderation (through filling our diet full of antioxidant rich and anti-inflammatory foods), these nutrients will help give us optimal health and help us run stronger. What doesn’t kill you makes you stronger.

Happy running!

Sarah J Cuff, RHN

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