The True Shelf Life of Cooking Oils


Cooking oil manufacturer “best-by” dates were recently put to the test by comparing the development of rancidity between almond oil, avocado oil, hazelnut oil, macadamia oil, grape seed oil, rice bran oil, toasted sesame oil, and walnut oil. Find out which oil starts going rancid within just a few weeks in my video The True Shelf-Life of Cooking Oils.

The best way to keep and consume walnut oil is, of course, within the walnut itself. In my video What Women Should Eat to Live Longer I noted that the Harvard Nurses Health Study found that eating just two handfuls of nuts per week may extend a woman’s lifespan as much as four hours of weekly jogging. No reason you can’t do both though! :)

Which kinds of walnuts are best? Black walnuts or English—also known as common—walnuts? I would have guessed black just based on their rich flavor and color, but I would have been wrong. In a study I profile in my 2-min. video Black Versus English Walnuts, when subjects were given a salami and cheese sandwich on white bread smeared with 2 spoonfuls of butter and then a big handful of either black or English walnuts, something very different happened.

When we whack our arteries with that kind of load of saturated animal fat, within hours our blood vessels become inflamed and stiff. Eating English—but not black—walnuts with the salami sandwich appeared to diminish the damage, which perhaps relates to the finding that English walnuts have nearly 10 times the antioxidant capacity of black walnuts.

The anti-inflammatory power of certain nuts is really quite astonishing. See my video Fighting Inflammation in a Nutshell as well as Dietary Treatment of Crohn’s Disease for other anti-inflammatory strategies.

I explore why animal foods may be so inflammatory in my three part video series:

  1. The Leaky Gut Theory of Why Animal Products Cause Inflammation
  2. The Exogenous Endotoxin Theory
  3. Dead Meat Bacteria Endotoxemia.

I also give an abbreviated summary of it in my full-length “live” presentation Uprooting the Leading Causes of Death.

If you haven’t yet, you can subscribe to my videos for free by clicking here.

Michael Greger, M.D.

Image credit: @kevinv033 / Flickr

  • iftah weiss roi

    Aren’t all cooking oils go pretty much rancid when COOKED?
    I heard it from some source and I jusr can’t find more info about this stuff.
    Once and for all, is it healthy or not to cook with oil? even if it is olive oil.



  • vegank

    Is using Sesame oil in cooking considered unhealthy? That is , a drop or two just to add the fragrance.

  • walley

    Why wasn’t olive oil included as it is the oil that most people use rather than only include oils that nobody uses.

  • Fidel Castrati

    Can you access this study and share the levels of arsenic detected in the rice bran oils tested? Thanks.