Science Catch-up. Coconut oil as unhealthy as beef fat and butter?


by Alejandra "Alex" Ruani — Get free science updates here.

Welcome to our Thursday’s Science Catch-up: curated links by The Health Sciences Academy. Get our email updates every other Thursday here (it’s free).

Let’s catch you up with studies and news that recently made the headlines!

Click on your favourite topics to read our summary:

1. Coconut oil as unhealthy as beef fat and butter?

2. White vs brown bread, but no winner?

 

Coconut oil as unhealthy as beef fat and butter?

Review link

“Coconut oil as unhealthy as beef fat and butter,” the BBC reported a few days ago…

If you find this confusing, you’re not alone. I got so many questions about it, so let’s clear things up!

First of all, where does this story come from?

Replacement of saturated fat with other types of fat or carbohydrates (AHA, 2017)

A new paper released by the American Heart Association (AHA) recommends to “replace” saturated fats by unsaturated fats to decrease your heart disease risk:

  • Saturated fats are abundant in animal foods (butter, cheese, cream, beef fat) but also in plant foods (coconut oil being one of the main ones).
  • Unsaturated fats include Omega 3s (such as ALA from flaxseeds, or DHA from oily fish), Omega 6s (such as GLA from vegetable oils) and Omega 9s (such as oleic acid from olives and avocados).

What’s the recommendation based on?

The AHA recommendation is based on looking at controlled feeding trials where the incidence of heart disease was reduced when saturated fat intake was replaced with unsaturated fat intake.

In contrast, when the trials used carbohydrates to replace sat fats, heart disease risk didn’t go down.

What’s the main glitch?

While the AHA authors use the word “replace” across their paper, I personally think that a complete “replacement” is impossible to achieve. Why?

Saturated fat is present in so many plant foods too, from nuts and seeds, to avocados, to olive oil… And the participants’ diets were quite rich in those foods, too! So I’m not sure about the accuracy of their language choice…

As you can see on this table, even sunflower oil and corn oil contain saturated fat (around 5% to 11%):

Saturated fat content in common foods (AHA, 2017)

What should we make of this?

What you need to remember is that in nutrition science there are no “absolutes”… For that reason, it’s best to avoid making blank statements based on news articles, particularly when you advise your clients.

You should also keep in mind that most scientific studies report averages, so individual variability is often left “out of the picture”.

But individual variability matters…

This means that we cannot say that saturated fat is unhealthy for most people. Or that saturated fat is healthy for most people.

Each of us is intrinsically different, metabolises nutrients differently, and responds differently to identical diets.

For example, there are several genes associated with inefficient fat metabolism. So if you cannot metabolise saturated fat or ketone bodies properly, a high fat diet (or even a ketogenic diet) can do more harm than good!

Caution: There are definitely some individuals who may want to minimise saturated fat in their diet. This includes those with a genetic disorder called Familial Hypercholesterolemia and those who have the Epsilon4 mutation at the ApoE gene. Today, we know that about 26-30% of the population carries that mutation. A lot of us!

What to do next?

In times of conflicting dietary advice, sharpening your “junk science radar” is important. Let me help you with that, right now…

Here’s a list of must-read resources we’ve prepared for you. Make sure you go through them ASAP, so next time a client or colleague asks you about the saturated fat saga, you’ll know what to say (and what not to say!):

 

White vs brown bread, but no winner?

Study link

Here’s another example of nutrition news that make great headlines, but when you look at the study you find something entirely different…

A few days ago, the Daily Mail reported: “Is wholemeal bread really any better for you? People who eat white are no less healthy, study finds.”

The Daily Mail reporter suggested that there is no difference between the two types of bread in terms of health effects.

But when you look at the study, you see a different story:

The glycaemic response to white or whole wheat sourdough bread varied from person to person (Korem et al., 2017)

  • The responses varied from person to person, depending on the type of bread eaten for a week and gut bacteria composition.
  • There were only 20 participants. That’s a very small group, so we can’t extrapolate this to “everyone” else.
  • Their blood glucose and other biomarkers were measured for a week. This is too short to gather meaningful data.

What did the experiment involve?

The participants ate the same amount of digestible carbohydrates from either white bread or whole wheat sourdough bread for a week. This means that the whole wheat sourdough group ate MORE bread because whole wheat has less digestible carbohydrates (and a lot of fibre).

Participants ate either white or whole wheat sourdough bread for a week. Postprandial blood sugar response varied across subjects (Korem et al., 2017)

The researchers tried to explain the individual differences based on an “algorithm” they came up with regarding gut bacteria composition. This algorithm is what they intend to use to commercialise a stool test with diet recommendations.

But we don’t know who funded this study, which remains a complete mystery… Typically, you’d see this information disclosed in the paper.

Also, when I looked at the statistical analyses, there’s a lot of supporting data that is missing, so the origin of some of the conclusions is still unclear…

The key takeaways?

While I love the notion of personalised nutrition around your own “bacterial fingerprint”, we’re at very early stages of microbiomics research and it’d take many, many years before we get there!

In the meantime, if you’re a bread lover without a sensitivity, whole grain is preferred because of the benefits of getting more fibre into your diet.

Fibre has been linked to lower bowel cancer risk and a more favourable microbiota composition in your gut. For example, “good” bacterial strains feed from fibre and even covert it into butyrate, which has been shown to have protective epigenetic effects.

Also, higher fibre meals help balance your blood sugar, preventing a sudden spike after a meal. Good blood sugar management is important for improved brain performance and lower diabetes risk.

To conclude, when you see news headlines suggesting that everything you knew about healthy eating is wrong, take it with a pinch of salt!

 

 

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The-Health-Sciences-Academy-Alejandra-Ruani-small1-right
Alex Ruani leads the research division at The Health Sciences Academy, where she and her team make sense of complex scientific literature and translate it into easy-to-understand practical concepts for students. She is a Harvard-trained scientific researcher who specialises in cravings and appetite neurobiology, nutrition biochemistry, and nutrigenomics. Besides investigating and teaching the latest advances in health and nutrition science, Alex makes it easier to be smarter with her free Science Catch-ups every other Thursday.
Connect with Alex via email.


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6 Comments

  • Betiana

    Reply Reply June 22, 2017

    Very useful Alex! I enjoy your explanations thank you!

  • Joanne

    Reply Reply June 22, 2017

    Finally! Someone has put it out there! We are all different in so many ways, how can we say, for definite, ‘this is the diet we all should live by if you have this’ or ‘go on this diet if you have that’, etc.

    Although not a professional anything, I was in nursing for 13 years, prior to that the fitness industry for 10 years and the mechanics of the body are fascinating BUT the one thing I learned, DEFINITIVELY, is that no 2 people are identical in every way and so it makes sense that using guidelines for health and longevity is wise but we each need to experiment and work out for ourselves (or with professional assistance) what our individual needs are.

    ps. This site is truly fantastic. Thank you for all your work and efforts.

    Joanne

  • Richard

    Reply Reply June 24, 2017

    I didn’t bother looking at the results when I saw 20 participants.
    That isn’t a study, it’s an experiment.
    As Joanne pointed out and this site has always promoted, there is no one size fits all, we are all different in so many ways.
    That’s why I like your emails, no rubbish, just what, and how it’s been found and in a lot of cases the study is just too small to be conclusive.
    100 years from now, the “perfect diet” will still be discussed because it doesn’t exist because of our individuality.

  • Sabrina

    Reply Reply June 24, 2017

    excellent analyses Alex! I always feel elevated by your explanations, you are leg!

  • Anastasia Ellis

    Reply Reply June 26, 2017

    I think that people will read what they want from any experiment.
    They will use any evidence to back up their own ideas rather than being open to the results from a scientific study. People like facts that reinforce there own bias or will bend the truth to add weight to their own preconceptions. Hence, why people like “reports” like this – most people eat white bread (even though the general consensus is that it is not as healthy as wholemeal) so they will justify it with reports like this.

  • Keith

    Reply Reply July 4, 2017

    Thank you Alex – so good to see you raising awareness of ‘bad science’ or mis-interpretation of research for news purposes.

    I realise journalists are not necessarily deliberately distorting the data, but at least a simple understanding of the limitations of ’20 participants’ and what that means for generalisation, is a good place to start.

    Great work!

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