Just Read: Validation of Low(er) Carb High(er) Fat Diets: The PURE Study and CVD/Overall Death

I know this is not the title of the article, which is below. I am being bold on purpose, because the opposite has typically been the case around evidence for the low-fat diet (which really doesn’t have convincing evidence).

Dehghan M, Mente A, Zhang X, Swaminathan S, Li W, Mohan V, et al. Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet [Internet]. 2017 Aug [cited 2017 Aug 30]

This analysis from PURE is a cohort study of 135,335 individuals in 18 countries, analyzing their diet, biomarkers (separate paper), and causes of death overall and from cardiovascular disease.

Higher Fat in the Diet, Less Death

And, those with a higher fat intake died less. Those with a higher carbohydrate intake died more. Almost in inverse proportions.

Our findings do not support the current recommendation to limit total fat intake to less than 30% of energy and saturated fat intake to less than 10% of energy. Individuals with high carbohydrate intake might bene t from a reduction in carbohydrate intake and increase in the consumption of fats.

I have read critiques of the study around the use of food frequency questionnaires (notoriously inaccurate), confounding with people who “live healthy” etc, and find these not to hold up.

Regarding the questionnaires, the biomarkers also reflected what people reported, and those can’t be made up (see: Just Read: More Validation of Low(er) Carb High(er) Fat Diets: The PURE Study and Lipids).

In terms of people who “live healthy” those people likely followed the current dietary recommendations to eat unhealthy (high carbohydrate, low fat) – the majority of people in the study got over 60% of their calories form carbohydrates so therefore their health consciousness would have cancelled out the findings of the study, which they didn’t.

Low Carbohydrate Eating, the curious statement

This statement in the paper caught my eye –

However, the absence of association between low carbohydrate intake (eg, <50% of energy) and health outcomes does not provide support for very low carbohydrate diets. Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity and so moderate intakes (eg, 50–55% of energy) are likely to be more appropriate than either very high or very low carbohydrate intakes.

This statement seems out of place and actually makes no sense, since they didn’t test very low carbohydrate eating, and it’s not referenced. It comes across as a conventional wisdom statement, without data.

Not Fearing Fat

As I experienced following my experience at Low Carb San Diego, many (most?) of the national and international recommendations around diet are influenced by one thing – fear of eating fat. As I learned there, many of the expert statements and consensus recommendations are consistent in the way they bury data that lends to the idea that fat might be healthy.

Also as I discussed in that experience, the phobia of fat in the diet extends into the phobia of people who are obese. Both things are extremely unhealthy.

Adventures at Low Carb San Diego

One of the best statements I heard there was “You aren’t what you eat. You are what you do with what you eat.”

Happy to discuss the findings of this study in the comments – it’s been well reported and discussed, so there will be no shortage of opinions out there.

4 Replies to “Just Read: Validation of Low(er) Carb High(er) Fat Diets: The PURE Study and CVD/Overall Death”

  1. The comment about needing at least 50% carbs without any support (and in contradiction to the evidence they had just generated) is such a powerful example of the intellectual prison we are in. This is the face of confirmation bias. Another great example of the author not being able to accept the findings they had just come up with was this study : http://adc.bmj.com/content/early/2013/02/13/archdischild-2012-302941.short?g=w_adc_ahead_tab
    Here the authors found that kids who drink low fat milk gained more weight than kids who drank higher fat milk. Again, the first thought was ‘how did we mess up the study?’ Rather than, ‘our basic assumptions are wrong’.

    What will it take for national organizations to start making some real changes to the current recommendations, which drive obesity, DM and the multitude of diet related diseases which increasingly afflict the world?

    1. Ari,

      Well said, the article you referenced is fascinating about the mental models we are capable of creating. I think it will take having frank conversations like this…thanks for your thought partnership,

      Ted

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