Skip to content
  • About
  • Contact
  • Contribute
  • Book
  • Careers
  • Podcast
  • Recommended
  • Speaking
  • All
  • Physician
  • Practice
  • Policy
  • Finance
  • Conditions
  • .edu
  • Patient
  • Meds
  • Tech
  • Social
  • Video
    • All
    • Physician
    • Practice
    • Policy
    • Finance
    • Conditions
    • .edu
    • Patient
    • Meds
    • Tech
    • Social
    • Video
    • About
    • Contact
    • Contribute
    • Book
    • Careers
    • Podcast
    • Recommended
    • Speaking

Is what we know about dietary fats wrong?

Albert Fuchs, MD
Conditions
April 3, 2014
Share
Tweet
Share

Most humans have spent most of human history nearly starving to death. So it’s no surprise that we spend a lot of time thinking about food. And it’s no surprise that food has acquired cultural, social, and religious significance in almost every society. Because food is so important, and because it’s nearly impossible for us not to ascribe powerful effects to anything important to us, every society imbues special health properties to various foods.

From believing that some foods are aphrodisiacs to believing that some foods improve sleep or fertility or athleticism, superstitions about the effects of food on health are ubiquitous. But we are modern, rational creatures that would never subscribe to such claptrap. Right? Wrong. We also cling to our own mythology about the health effects of food but we dress up our ignorance in scientific words. We (correctly) sneer at anyone who asserts that ingesting powdered rhinoceros horn improves erectile function. After all, there’s no scientific reason to even believe such a thing, and the connection between a rhinoceros horn and erectile dysfunction is purely visual. That’s like eating a giraffe because you want to be taller.

But take the assertion that eating saturated fat increases the risk of heart disease. We all believe that. After all, saturated fat is a molecule. Molecules are very scientific, which means there are men in white lab coats somewhere with blinky machines proving that saturated fats are very very bad to eat. In fact, current cardiovascular guidelines from respected groups like the American Heart Association suggest low consumption of saturated fats and high consumption of polyunsaturated fats. And the American Heart Association would never recommend rhinoceros horn.

A recent study is an important reminder that we know much less than we believe, but before we dive into it, allow me a paragraph to make sure we know what we’re talking about.

There are three families of energy containing molecules in food: fats, carbohydrates, and proteins. Fats are further subdivided into saturated fats and unsaturated fats. Saturated fats are typically found in dairy products and fatty meats and are typically solid at room temperature (like butter, lard, and beef fat). Unsaturated fats are found in vegetable oils and fish oils and are typically liquid at room temperature (like olive oil).

For decades we have been hearing and repeating to our patients that saturated fats are unhealthy for hearts and unsaturated fats are healthy. A meta-analysis (study of studies) published in the Annals of Internal Medicine attempted to review all the studies that have ever examined the link between saturated and unsaturated fats and cardiovascular health. What they found was underwhelming. There were 45 observational studies, the kind that I routinely criticize in my posts and urge readers to ignore. There were 27 randomized studies that looked at the effects of fatty acid supplementation on heart disease. All of them tested whether supplements of unsaturated fatty acids (like fish oil) helped prevent stroke and heart attacks. None of them tested whether supplements of saturated fatty acids (lard capsules!) increased cardiovascular risks.

The results were meh. The data as a whole showed no significant increase in risk from saturated fats, nor decrease in risk from unsaturated fats. The authors conclude: “This analysis did not yield clearly supportive evidence for current cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of saturated fats.”

Not surprisingly none of the experts quoted in the media coverage said the simple truth, which is that we have no idea if dietary fats affect health apart from the calories they contain. It would be nice to hear an expert declare, “We have no clue about whether some fats are healthy or unhealthy,” since that statement would be solidly supported by the evidence.

How did saturated fat’s bad reputation ever get started? I’m not sure. It’s conceivable some observational study that should have been ignored suggested that saturated fat was unhealthy. It’s also possible that saturated fat’s ignominy began because lard and butter look so much like the fat in a cholesterol plaque that blocks an artery. Olive oil is liquid. How could that block an artery? Maybe the whole idea was as simple-minded and as visual as the rhinoceros horn remedy.

Albert Fuchs is an internal medicine physician who blogs at his self-titled site, Albert Fuchs, MD.

Prev

4 reasons why patients may become angry

April 3, 2014 Kevin 22
…
Next

Sharing secrets with my grandmother

April 4, 2014 Kevin 8
…

Tagged as: Obesity

Post navigation

< Previous Post
4 reasons why patients may become angry
Next Post >
Sharing secrets with my grandmother

ADVERTISEMENT

More by Albert Fuchs, MD

  • Processed meats and cancer: How much is too much?

    Albert Fuchs, MD
  • This is the best way to treat chronic insomnia

    Albert Fuchs, MD
  • Paying people to quit smoking. Does it work?

    Albert Fuchs, MD

More in Conditions

  • Psychiatrist tests ketogenic diet for mental health benefits

    Zane Kaleem, MD
  • The myth of biohacking your way past death

    Larry Kaskel, MD
  • Why Hollywood’s allergy jokes are dangerous

    Lianne Mandelbaum, PT
  • Coconut oil’s role in Alzheimer’s and depression

    Marc Arginteanu, MD
  • Ancient health secrets for modern life

    Larry Kaskel, MD
  • How the internet broke the doctor-parent trust

    Wendy L. Hunter, MD
  • Most Popular

  • Past Week

    • The human case for preserving the nipple after mastectomy

      Thomas Amburn, MD | Conditions
    • Nuclear verdicts and rising costs: How inflation is reshaping medical malpractice claims

      Robert E. White, Jr. & The Doctors Company | Policy
    • IMGs are the future of U.S. primary care

      Adam Brandon Bondoc, MD | Physician
    • Why I left the clinic to lead health care from the inside

      Vandana Maurya, MHA | Conditions
    • Why doctors must fight for a just health care system

      Alankrita Olson, MD, MPH & Ashley Duhon, MD & Toby Terwilliger, MD | Policy
    • How doctors can think like CEOs [PODCAST]

      The Podcast by KevinMD | Podcast
  • Past 6 Months

    • Health equity in Inland Southern California requires urgent action

      Vishruth Nagam | Policy
    • How restrictive opioid policies worsen the crisis

      Kayvan Haddadan, MD | Physician
    • Why primary care needs better dermatology training

      Alex Siauw | Conditions
    • Why pain doctors face unfair scrutiny and harsh penalties in California

      Kayvan Haddadan, MD | Physician
    • How a doctor defied a hurricane to save a life

      Dharam Persaud-Sharma, MD, PhD | Physician
    • What street medicine taught me about healing

      Alina Kang | Education
  • Recent Posts

    • Why doctors must fight for a just health care system

      Alankrita Olson, MD, MPH & Ashley Duhon, MD & Toby Terwilliger, MD | Policy
    • Affordable postpartum hemorrhage solutions every OB/GYN can use worldwide [PODCAST]

      The Podcast by KevinMD | Podcast
    • When cancer costs too much: Why financial toxicity deserves a place in clinical conversations

      Yousuf Zafar, MD | Physician
    • Psychiatrist tests ketogenic diet for mental health benefits

      Zane Kaleem, MD | Conditions
    • The hidden rewards of a primary care career

      Jerina Gani, MD, MPH | Physician
    • Why physicians should not be their own financial planner

      Michelle Neiswender, CFP | Finance

Subscribe to KevinMD and never miss a story!

Get free updates delivered free to your inbox.


Find jobs at
Careers by KevinMD.com

Search thousands of physician, PA, NP, and CRNA jobs now.

Learn more

View 7 Comments >

Founded in 2004 by Kevin Pho, MD, KevinMD.com is the web’s leading platform where physicians, advanced practitioners, nurses, medical students, and patients share their insight and tell their stories.

Social

  • Like on Facebook
  • Follow on Twitter
  • Connect on Linkedin
  • Subscribe on Youtube
  • Instagram

ADVERTISEMENT

ADVERTISEMENT

  • Most Popular

  • Past Week

    • The human case for preserving the nipple after mastectomy

      Thomas Amburn, MD | Conditions
    • Nuclear verdicts and rising costs: How inflation is reshaping medical malpractice claims

      Robert E. White, Jr. & The Doctors Company | Policy
    • IMGs are the future of U.S. primary care

      Adam Brandon Bondoc, MD | Physician
    • Why I left the clinic to lead health care from the inside

      Vandana Maurya, MHA | Conditions
    • Why doctors must fight for a just health care system

      Alankrita Olson, MD, MPH & Ashley Duhon, MD & Toby Terwilliger, MD | Policy
    • How doctors can think like CEOs [PODCAST]

      The Podcast by KevinMD | Podcast
  • Past 6 Months

    • Health equity in Inland Southern California requires urgent action

      Vishruth Nagam | Policy
    • How restrictive opioid policies worsen the crisis

      Kayvan Haddadan, MD | Physician
    • Why primary care needs better dermatology training

      Alex Siauw | Conditions
    • Why pain doctors face unfair scrutiny and harsh penalties in California

      Kayvan Haddadan, MD | Physician
    • How a doctor defied a hurricane to save a life

      Dharam Persaud-Sharma, MD, PhD | Physician
    • What street medicine taught me about healing

      Alina Kang | Education
  • Recent Posts

    • Why doctors must fight for a just health care system

      Alankrita Olson, MD, MPH & Ashley Duhon, MD & Toby Terwilliger, MD | Policy
    • Affordable postpartum hemorrhage solutions every OB/GYN can use worldwide [PODCAST]

      The Podcast by KevinMD | Podcast
    • When cancer costs too much: Why financial toxicity deserves a place in clinical conversations

      Yousuf Zafar, MD | Physician
    • Psychiatrist tests ketogenic diet for mental health benefits

      Zane Kaleem, MD | Conditions
    • The hidden rewards of a primary care career

      Jerina Gani, MD, MPH | Physician
    • Why physicians should not be their own financial planner

      Michelle Neiswender, CFP | Finance

MedPage Today Professional

An Everyday Health Property Medpage Today
  • Terms of Use | Disclaimer
  • Privacy Policy
  • DMCA Policy
All Content © KevinMD, LLC
Site by Outthink Group

Is what we know about dietary fats wrong?
7 comments

Comments are moderated before they are published. Please read the comment policy.

Loading Comments...