Image Credit: @kevinv033 / Flickr. This image has been modified.

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.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

7 responses to “The True Shelf Life of Cooking Oils

Comment Etiquette

On, you'll find a vibrant community of nutrition enthusiasts, health professionals, and many knowledgeable users seeking to discover the healthiest diet to eat for themselves and their families. As always, our goal is to foster conversations that are insightful, engaging, and most of all, helpful – from the nutrition beginners to the experts in our community.

To do this we need your help, so here are some basic guidelines to get you started.

The Short List

To help maintain and foster a welcoming atmosphere in our comments, please refrain from rude comments, name-calling, and responding to posts that break the rules (see our full Community Guidelines for more details). We will remove any posts in violation of our rules when we see it, which will, unfortunately, include any nicer comments that may have been made in response.

Be respectful and help out our staff and volunteer health supporters by actively not replying to comments that are breaking the rules. Instead, please flag or report them by submitting a ticket to our help desk. is made up of an incredible staff and many dedicated volunteers that work hard to ensure that the comments section runs smoothly and we spend a great deal of time reading comments from our community members.

Have a correction or suggestion for video or blog? Please contact us to let us know. Submitting a correction this way will result in a quicker fix than commenting on a thread with a suggestion or correction.

View the Full Community Guidelines

  1. 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.



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

  3. What about algal oil? I’ve recently tried the Thrive brand of algae oil and really love it. Supposedly it’s really healthy and more stable for cooking at higher heat. Does anyone know about this oil?

  4. Blake you asked about Algal oil. I did a PubMed search and found three studies on algal oil, two focusing on use as a supplement but one which you may wish to look at. (You did not indicate you were using algal oil for supplementation of DHA.)
    If you compare to other oils algai might see be be promising. However, the key is it’s still OIL, highly processed and harmful to our arteries. There are many ways we can cook without oil. Have you tried simply cutting down on the oil. Onions saute fine without oil, and water, vegetable broth or reduced salt soy sauce work fine as substitutes for oil.

Leave a Reply

Your email address will not be published. Required fields are marked *

Pin It on Pinterest

Share This