by The Health Sciences Academy — 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?
“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?
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%):
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!):
- [CASE STUDY] Saturated fat confusion? How to make sense of clashing headlines
- When ketogenic dieting isn’t for everyone (or how fat becomes lethal, even without weight gain)
- Why is Harvard sticking the knife into butter again?
- Food debate: Has the time come to exonerate saturated fat?
- Balancing the evidence: Fresh study suggests negative impact of saturated fats
- Sat fat debate: ‘Butter is not back’
- Adaptation to high-fat diet had profound effect on genes
- Saturated fat promotes metabolic disorders?
- Keto for fat loss debunked?
White vs brown bread, but no winner?
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 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).
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!
Available upon individual purchase. Learn more here! Does Fat Really Make You Full? How Many Egg Yolks a Day Can I Eat? Meat-Based or Plant-Based: What Did Paleo Humans Really Eat?Science Reports:
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