What are antioxidants, and are they good for dogs too?

Updated September 2019

There is a lot of hype surrounding antioxidants – they are often mentioned in TV advertising for various products or in glossy magazines. But what exactly are they, what do they do, are they important and should you give your dog antioxidant supplements to ensure he gets enough in his diet?

Antioxidants help fight oxidation which is the normal chemical process that we associate with things breaking down. For example, the rust on your bicycle is caused by oxidation. When you cut and apple and it starts to go brown – that’s also caused by oxidation.

But oxidation is also an essential part of everyday living inside the body (ours and our dog’s). When your dog breaks down food, exercises or make new cells – all of these activities involve oxidation. And oxidation produces ‘free radicals’ – uncharged molecules which react with and injure other molecules.

It’s tempting, therefore to consider free radical as the ‘evil baddies’ and antioxidants as the super-heroes that help us and our dog battle their destructive tendencies but it’s a bit more complicated than that.

Your dog’s immune system uses free radicals to attack and kill invading viruses and other pathogens so they actually help to keep your dog healthy. A certain amount of free radicals are therefore necessary for the body to function properly. Too many and they are like loose cannons.

Accumulated free radical damage that has built up over time is associated with aging diseases such as arthritis, cognitive dysfunction and heart disease. Many cancers are also thought to have their origins in inflammation and oxidative damage to DNA.

Although your pooch may not be as sensitive to ‘growing old’ as we are and certainly don’t need to lather themselves in anti-aging face cream it’s obviously important to do all we can to stave off these serious conditions and protect the health of our four legged friend.

So is a diet high in antioxidants good for your dog?

Yes, antioxidants from your dog’s diet appear to be of great importance in controlling the damage caused by free radicals. Your dog is more likely to be exposed to more environmental pollutants and harmful chemicals such as pesticides, insecticides, and cigarette smoke which cause more free radicals to potentially wreak havoc inside your dog’s body.

Unfortunately many dogs don’t eat enough (or any) fresh fruit and vegetables which are often rich in dietary antioxidants and help to limit the free radical’s internal destruction. As a result it may be necessary to add antioxidant supplement to your dog’s diet.

Since antioxidants counteract the harmful effects of free radicals, you might think that we should all consume as many antioxidants as possible, and encourage our dog to do the same. But this is not the case – consuming mega doses of antioxidants can be harmful. If you are interested in giving your dog antioxidant supplements, talk to your vet about what dose is right for your dog.

Alternatively, simply look at boosting your dog’s dietary intake of antioxidants.

How to select antioxidant rich foods

Antioxidants are present in foods as vitamins, minerals and phytonutrients, among others. They are often identified in food by their distinctive colors:

  • Green of broccoli, kale, green beans and spinach
  • Red of cranberries, raspberries, pomegranates and ripe tomatoes
  • Orange of carrots and sweet potatoes
  • Yellow of mangos, squash and banana
  • Blue-purple of blueberries, blackberries and red cabbage.

See what you dog enjoys and add a small amount of these types of fruits and vegetables to his or her diet.

Antioxidant supplements and cancer

Antioxidant supplements are considered, by some, to be especially important if your dog is suffering from cancer. Their usefulness in cancer once already diagnosed, is however largely unknown, and some suggest they may even be harmful.

Cancer cells generate free radicals too but in far greater amounts because of their tremendous growth rate. When enough free radicals accumulate they have the ability to cause a cell to commit suicide! Ironically cancer cells pose a danger to themselves by generating so many free radicals. Some immune system cells create free radicals to target cancer cells in this way – so increasing the antioxidants that will neutralize the free radicals that are attacking the cancer may be counterproductive. These pro-oxidant therapies, including some conventional chemotherapy treatments introduce even more free radicals into and already unstable environment in an effort to force the cancer cells to self destruct.

So while antioxidant could help decrease the risk of cancer by mopping up free radicals, these free radicals also definitely help to kill cancer cells once present. Of course, this paints a very confusing picture and more research will be needed before we understand the complex relationship between cancer and antioxidants.