Quick nasty nutrition lesson today. So we like to save our food as long as we can, right? Right. Obviously.
Well, when it comes to fats (avocados, nuts, oils, even healthy fats!), do not keep them out or open for long!
Basically, fats oxidize when out too long. Whether it’s old oil that’s been sitting in your pantry for years, peanuts that have been in that jar for a few weeks, or even half an avocado you were saving from breakfast till dinner, throw. it. away. Oxidation is some serious biz, and is responsible for almost all chronic diseases (cancer, heart disease, etc etc etc).
Consuming oxidized fats introduces free radicals (reactive oxygen species) directly into your body. These things are killers! They build up to form tumors, and cause serious problems all over the body. I don’t want to dive too deep into the science of it, but free radicals are THE WORST THING EVER. The gist is: oxidized fat → depleted antioxidants, impaired glucose tolerance, alteration of thyroid hormone functions, increased lipid per oxidation, and the list goes on…
Fat that’s been oxidized is pretty much liquid free rads. Guhhhh-ross. You can oxidize fat by heating it too high, like smoking fish or frying foods (Yes! That’s partially why fried food is so awful!), but you can also oxidize fats by just letting them sit out too long. So, beware, even avoiding fried foods isn’t totally avoiding free radicals!
Side note: most of the time, fast food restaurants don’t change the oil they fry their food in. So, they’ll use the old oil to fry a new batch of fries. Once oil has already been used to fry stuff, it has created all those free radicals and has gone totally rancid! They literally fry their food in oil that already has free radicals from the first batch, and add even more frying the second, third, fourth, and even more batches!! Fries typically contain more than 10% by weight oxidized fat. SO. GROSS.
How free radicals build up in even healthy food without you knowing about it:
- Avocados saved. Sometimes we can’t eat a whole ‘cado and save the rest for later in the fridge —> NO! Just throw it away if you aren’t going to finish it!
- Old olive oil. Buy new olive oil every couple months, even if you don’t use it all! You can usually smell rancid olive oil, so if you notice the smell or taste has changed, get rid of it.
- Nuts in the pantry. Once a jar of nuts has been opened and exposed to enough air, free radicals can build up. Buy small bags of nuts that you can finish in one sitting instead!
- Over-heating or smoking coconut or olive oil. Even healthier oils can accumulate free radicals if heated too high. When sautéing veggies or making anything with oil in a pan, be sure to set the heat to medium, not high.
- Stay away from aged cheese. Yes, it’s freakin’ delicious, but aged cheeses have a ton of oxidized fat and protein, so should be consumed in moderation.