With what is possibly the largest macronutrient-disease association study ever conducted, researchers discovered that the more dietary fat populations consumed, the better.  Over 135,000 participants from 18 different countries on 5 different continents were followed for 10 years.  This prospective follow-up study investigated how carbohydrate, fat, and protein levels influenced all cause mortality as well as risk for a variety of cardiovascular diseases.

In a study design that could be described as the antithesis of Ancel Keys’s 7 Country Study, ultimately more of a well-told story than a scientific analysis and which resulted in saturated fats being maligned for the next 50 years, detailed intake histories were collected in present time prior to following the subjects for the next 10 years and recording any major health event.  This type of prospective follow up study design eliminates more of the recall bias and error associated with retrospective designs.  Additionally, the diversity of the populations followed ranged from rural to urban, from high SES to low, and from those influenced by contemporary dietary advice to those not.

The American Heart Association’s recommendations of limiting fat intake to 30% of calories, with less than 10% coming from saturated fat, received its most damaging blow to date when the authors concluded that this evidence suggests a cardiovascular preventive diet that is exactly opposite as to what is currently recommended.  Although this is certainly not the first study to raise questions around the archaic, yet persistent and widely accepted low-fat dietary mantra, it produced such a massive amount of pro-fat data that it simply cannot be written off as previous investigations have been.

Our understanding of how limited the safe metabolism of carbohydrates is, especially those that digest into simple sugars rapidly, helps support these more recent findings.  The insulin required in order to drive glucose into cells calls for a variety of health degenerating processes when its levels significantly exceed those found in a fasting state.  Small dense LDLs become too common in circulation, the triglyceride to HDL ratio starts to climb, and inflammation levels rise.  Although most often portrayed as “clean burning”, refined carbohydrates are to our mitochondria much like burning high sulfur coal is to air quality.  This handful of influences alone would explain the associations drawn between an increased risk of Alzheimer’s, neurodegenerative diseases in general, cardiovascular disease, cancer, and of course the now pandemic levels of metabolic syndrome based around insulin resistance.  The increased risk of all cause mortality with each increase in the percentage of calories consumed in the way of carbohydrates, underscores the array of diseases now associated with excess carbohydrate intake.

Unfortunately many individuals associate these findings with a diet low in vegetables. This is not an accurate understanding of nutritional science.  Vegetables, even some starchy root vegetables for that matter, are not the greatest contributors of dietary carbohydrate. While carrots and beets contain significant amounts of carbohydrate and sugar, their contents will have minimal influence on total carbohydrate levels at the end of the day because their carbohydrate density (amount of carbohydrates per 100g of any given food) is actually quite low.  This means that the amount of carrots, beets, or sweet potatoes that need to be eaten to reach the level of carbohydrates found in a similar weight or portion of cereal or bread product is enormous. People just simply don’t eat the quantity of vegetables necessary to spike insulin to an unhealthy level.  Sweeteners, sweetened foods and beverages (including those sweetened with “all natural sweeteners” such as agave, fruit juice, and fruit juice concentrates), as well as grains, cereals, and anything made with the flour derived from these pulses, possess the highest carbohydrate densities and are essentially the heavy hitters that we all need to be careful around.

The fats that elicited the lowest all cause mortality were both saturated and monounsaturated fats.  These are best found in grass-fed butters, extra virgin coconut oil, extra virgin olive oil, coconut, almonds, avocado, and hazelnuts, to name a few of the better sources.  Although polyunsaturated fats did increase an individual’s risk of stroke, when compared to the consumption of other fats in this study, it is largely the high omega 6 fatty acid containing seed oils that are responsible for this. Avoid the use of canola, soybean, safflower, sunflower, and of course corn oil.  In summary, these findings and those of smaller, less diverse investigations, should make the transition from sugar to healthy fats a more comfortable one.  Even for those of us who have been more indoctrinated with the low-fat-is-best belief system.

 ~ John Bagnulo MPH, PhD.