The Roundup - Edition 42

The Roundup

by Chris Kresser

Last updated on

Here is The Roundup, Edition 42, bringing you the best from around the web from the past two weeks!

Blast from the Past

Bill Lagakos (of the site Calories Proper) recently wrote an article on the “essential” fatty acids found in vegetable oil, and how they’re not really essential when DHA intake is adequate. Omega-3 fats like DHA and EPA cannot be synthesized by the body and thus we must consume them to prevent a fatty acid deficiency, and while omega-6 fats like linoleic acid (LA) and alpha linolenic acid (ALA) are able to prevent symptoms of deficiency like dermatitis, that doesn’t mean they are required to prevent this condition as is often thought. This means that DHA may be the true “essential” fatty acid that we need to consume to prevent deficiency.

In fact, while a diet completely free of LA and ALA is basically impossible to design, a diet consisting of fat solely from coconut oil and fish oil is able to prevent the symptoms that come from an essential fatty acid deficiency, and supplementing with LA and ALA is completely unnecessary when eating seafood. In other words, you definitely don’t need vegetable oils to be healthy. You just need to eat fish.

Back in 2010, I wrote an article about how fish is a far more bioavailable source of the omega-3 fats DHA and EPA than LA and ALA. The conversion of ALA to EPA and DHA is extremely limited: less than 5% of ALA gets converted to EPA, and less than 0.5% of ALA is converted to DHA. This is important to understand is because most vegetarians and vegans believe that our need for EPA and DHA can be met by consuming flax oil and other plant sources of ALA. But the conversion numbers above clearly indicate that this isn’t the case.

Since DHA appears to be the essential fatty acid that we need to consume, rather than supplementing with LA and ALA, we should be consuming foods that provide DHA – namely, fatty fish. That’s why I recommend one pound of fatty fish per week for most people, even if you have been told to avoid fish for mercury concerns. Fish is not only safe to eat, but a good idea to eat for good health and longevity.

Research Report

  • New research points to a link between sleep duration and obesity—specifically, consistent short sleep durations may lead to increased risk of obesity and possible death.
  • Breaking up sitting time with bouts of standing improves fatigue and musculoskeletal discomfort in overweight office workers.
  • Just 15-45 minutes of meditation per day may reduce frequency and severity of migraines.
  • Recent evidence shows that the gut microbiota controls immune system function and onset, development, and resolution of some common inflammatory diseases.
  • “Metabolically healthy” obesity is often a short-lived condition, and may ultimately prove to be a myth in the long run.

Worth a Look

  • Stephan Guyenet explains how obesity and diabetes are closely connected, and how the obesity epidemic is likely driving the rapid increase in diabetes prevalence.
  • The Atlantic explains how liver, a Paleo superfood, became a patriotic dish to consume during World War II. Good nutrition for the entire population was considered to be part of the war effort.
  • NSFW: South Park did an episode on gluten earlier this month. Did you see it?
  • Babies may benefit from being in the womb beyond the 39th week, as a higher birth weight equals higher test scores later in life.
  • As interest in fecal microbiota transplants grows, you’ll soon be able to use a poop pill to treat C. difficile infections.
  • Is reading your kids an e-book as good as reading them a printed book? Research says perhaps not.

For the Foodies