You're fried

If I could invent a food that illustrates nearly all of the shortcomings of the American diet, it would be French fries, the familiar fixture of fast food.

What we have come to view as French fries contain just about every one of the unhealthy ingredients that lead us down the path of obesity, diabetes, heart disease, high blood pressure, etc.

Let's take them one by one:

Potato starch--Potato starch exerts an effect on blood sugar similar to that of table sugar, only worse. (Glycemic index french fries 75; glycemic index sucrose 65.)

Advanced Glycation End-products (AGEs)--AGEs form when proteins and fats are subjected to high temperature cooking; the longer the high temperature, the more the food reaction creating AGEs proceeds. AGEs are the likely culprit in roasted and fried foods that made it appear that saturated fats were bad, when it was really AGEs all along. AGEs have been shown to block insulin's effects, increase blood sugar, cause endothelial dysfunction and high blood pressure.

Acrylamides--Acrylamides, like AGEs, are created through high-temperature heating. French fries are unusually rich in AGEs. Brewed coffee also contains a small quantity, while French fries contain 82-fold greater quantities, among the highest of all known sources of acrylamides.

Oxidized oils--The amount of oxidized oils will depend on what sort of oil was used for frying. As more restaurants are trying to get away from hydrogenated oils, many are turning back to polyunsaturates. Others are turning to commercial-grade oils that contain both hydrogenated and polyunsaturates. If oils are permitted to oxidize, then they will trigger oxidative phenomena in your body upon consumptions, e.g., LDL oxidation (Staprans 1994).

In other words, the innocent appearing French fry unavoidably triggers oxidation, all the phenomena triggered by high blood glucose (high insulin, glycation, visceral fat accumulation), along with the cascade of effects arising from AGEs and acrylamides.

Top your French fries with some ketchup made with high-fructose corn syrup that exagerrates AGE formation, visceral fat, and distorts postprandial (after-eating) effects.

Is it any wonder that we've lost control over diet?

Comments (26) -

  • Keenan

    10/12/2010 10:34:29 PM |

    Adding fat to potato starch will significantly decrease its GI, will it not?

    I think a much healthier alternative would be yams/sweet potatoes fried in coconut oil/butter/ghee (less prone to oxidation) and consumed with protein and fat (say, a steak).  That should give you far more nutrients, much lower blood sugar spike, and avoid the oxidation problems of frying in PUFA.

  • Carlos

    10/13/2010 12:01:19 AM |

    Are the dietary AGEs from frying really the concern, or is it all the carbs from the potato starch causing in vivo glycation that we should really be worrying about and avoided? You would have to have a seriously leaky gut for an undigested AGE from frying to get absorbed in the small intestine.

  • Steven Horvitz, D.O.

    10/13/2010 12:29:09 AM |

    I keep as low processed carb as possible, but my one vice is french fries.
    Why did you have to guilt me into removing my favorite food?

  • Anonymous

    10/13/2010 1:13:51 AM |

    I can't imagine eating boiled T-bones. What's left after frying and roasting?

  • Anne

    10/13/2010 1:27:34 AM |

    The AHA has a page  with heavy duty oils used in restaurants. Many of them have TBHQ and/or dimethylpolysiloxane. TBHQ is used to keep the oil from becoming rancid and the dimethylpolysiloxane is an antifoaming agent. I can't imagine that either is good for us.

  • Martin Levac

    10/13/2010 1:57:06 AM |

    Dr Davis, without sugars, there is no glycation, thus there is no advanced glycation end products either.

    Fried bacon for example would not contain AGEs because it would not contain sugars to begin with. This seems to indicate that the real culprit is the sugars, not the frying. But then, if we fry bacon in vegetables oils, then forget about the sugars or the frying, it's the oil. Also consider that ketosis stimulates chaperon mediated autophagy:

    Basically, if your diet induces ketosis, you got nothing to worry about. First because such a diet contains little to no sugars. And second, whatever AGEs are there are taken care of promptly enough. HbA1c comes to mind.

  • Darwin's Doctor

    10/13/2010 3:44:06 AM |

    1. Peel the skin off the potato.
    2. Throw away the inside of the potato.
    3. Bake the skin.
    4. Eat and enjoy the skin. It's loaded with fiber.

  • Hans Keer

    10/13/2010 5:55:26 AM |

    And ... dear doctor, don't forget to mention that potatoes are nightshades. They contain lectins and glycoalkaloids. These cause a leaky gut and autoimmune diseases

  • Anonymous

    10/13/2010 8:06:44 AM |

    French fries used to be fried in beef tallow before the CSPI stepped in. Proper french fries are made from fresh potatoes and fried twice. The "french fries" served in most restaurants are just frankenfood - precooked, preGodknowsWhat. The French still know how to prepare them properly...And by the way, isn't there the thing called "the French paradox"? Seems that they manage to stay leaner and healthier in spite of the consumption of "pommes frites". They DO, however, still eat real food - and this maybe one of the major aspects of good health.

  • Hoop

    10/13/2010 8:55:03 AM |

    French fries are partly pre-cooked in factories that use fats heated for days on end. The cheaper brands go thru the darker more heat damaged oils later in the cycle, The oils I've seen used are AV oil (animal fat with hydrogenated fats) and palm oil.
    These days it is likely soy oil.

    And for someone else on the topic of bacon it should be noted most bacon has added sugars. So it will be an AGE source
    to some extent.

  • Martin Levac

    10/13/2010 10:49:52 AM |

    Fried bacon is a different beast. My butcher makes it from fresh meat and the sugar in it comes probably from the milk he dips the bacon in before he fries it. And the absolute quantity of this sugar would be insignificant in terms of preventing ketosis which would allow ketosis to take place along with its CMA.

    Even if there was a lot of AGEs in the food, I doubt that it would have any significant effect. Instead, I believe that it's the AGEs that are formed inside the body as a result of hyperglycemia that is most harmful. Again, HbA1c comes to mind.

  • Anand Srivastava

    10/13/2010 1:10:09 PM |

    The moral of the story, don't use refined oils. Use the most naturally saturated oils as you can find, like Coconut oil or Ghee/Tallow. Then fry away, not too frequently.

    Regarding AGEs, I don't think they matter too much from the food source, as they will first get digested.

    Also humans have been cooking meat and Tubers (some form of potatoes) for ages, possibly more than a million years ago. So heating the oils should not be considered bad.

    Why do we like the fried crispy potatoes or bacon more than the raw one? Has it got something to do with our evolution.

  • GK

    10/13/2010 3:30:41 PM |

    Fries?  Meh, small potatoes.

    I nominate the donut:  white flour and white sugar deep fried in hot vegetable oil.

    There's your poster boy of dietary badness.

  • Geoffrey Levens

    10/13/2010 4:21:35 PM |

    Dang, no GMO corn in them there fries!  Oh well.

    "I can't imagine eating boiled T-bones. What's left after frying and roasting?"

    Try putting in well covered baking dish and cook at very low temp, maybe 225 or 250, for longer time depending on thickness of the meat. Maybe toss in some mushrooms and onions and a wee bit of red wine or even water. It will come out super tender and juicy.

  • Anonymous

    10/13/2010 4:31:44 PM |

    "I can't imagine eating boiled T-bones. What's left after frying and roasting?"

    Use a slow cooker.

    I would like to announce that I am a recovering vegetarian. Started by reducing wheat. Have not had Fries for the longest time because of the unsaturated veg/canola oil.

    Need to loose some weight so will try Atkins' methods but I am gonna miss beans and beer :-(

  • Anonymous

    10/13/2010 6:21:18 PM |

    i use virgin coconut oil for some homemade french fries. is that bad too?

  • Tommy

    10/13/2010 7:21:37 PM |

    "I am gonna miss beans and beer"

    I'm sure your friends won't


    10/13/2010 11:01:36 PM |

    I love (hate) how a hamburger plate with a bun and a Mountain of fries,  gives the three to four ounces of ground beef (and maybe not the best grade of beef but still..) a bad reputation as the cause of all things evil in our diet.  Wake the F up people.

  • Tommy

    10/13/2010 11:14:04 PM |

    Not to change the subject but a couple of people mentioned coconut oil. I have read Barry Sears insisting that coconut oil promotes inflammation.
    He also says it raises LDL.  This seems contrary to anything else I've read.

  • Anonymous

    10/14/2010 6:04:07 AM |

    tommy i think barry is misled

  • Stage IV Melanoma

    10/14/2010 12:48:27 PM |

    Good article! Thank you so much for sharing this post.Your views truly open my mind.

  • Dr. William Davis

    10/14/2010 1:55:25 PM |


    You may be confusing endogenous AGEs with exogenous AGEs.

    Endogenous AGEs are formed via glucose-mediated glycation. Exogenous AGEs are formed via a long list of reactions that involve carbohydrates, fats, and proteins. Exogenous AGEs are not indicated by HbA1c.

  • Eva

    10/16/2010 4:59:09 AM |

    Darwin's docter, you might want to do a tad of research on potato skins before suggesting people eat them.  Most of the poisons in a tater are in the skin, including potent goitrogens.  Eating the peel is probably not a good idea.

  • Jack

    10/18/2010 11:55:29 AM |


    Very interesting factoids for sure!
    Let me pose this question to you.
    If you could eat a few french fries once in a while, would it be enough to satisfy that fried food craving?  Well, the real answer here might be discipline and moderation.  We, unfortunately, will someday die of something.  If you are afraid of eating french fries or any other fatty bad food every once in a while there is a problem or fear that you will be missing something on this less than perfect earth.  Eat the fries,
    enjoy the fries, and do the best you can within the moderate framework of life, and for goodness sake, don't be afraid of food.  It is not the real enemy.  The real enemy is a fallen world.
    Pass the fries!!   Jack

  • farseas

    12/6/2011 11:46:27 AM |

    The way I cook meat now (mostly) is to put a roast or chicken into a tightly covered pan, add a generous amount of olive oil, season it, and throw it into the oven at 200 degress for about 14 hours.  

    It will be absolutely delicious with no risk of AGE's at such a low temperature.

    Make sure it is a tight fitting lid or it will dry out too much.  If you want to make a great chili, add the onions, garlic, tomatoes, and seasonings after 10 hours of cooking.  Cook four more hours.
    Hide from your kids or it will all disappear in a short time.

    I use a glass pan and always avoid cooking anything in aluminum.

  • Dr. William Davis

    12/6/2011 5:27:50 PM |

    Excellent, Farseas! This can be a part of an effective youth-preserving, anti-aging strategy, by the way.