After fifty odd years of scientific misassumption and an active media industry, it is no surprise that fat has become the villain. Consequently the food industry has been reducing our fat intake ever since, and where fat once enhanced a healthy diet, it is now laden with suspicion. A fatal error in modern science.
Why Do We Fear Fat?
In the mid-1900s, cases of coronary heart disease increased dramatically. Heart disease occurs when the arteries surrounding the heart become built-up with cholesterol and saturated fat, reducing the flow of blood to the heart. Known effects of heart disease include stroke, heart attack, and often death. In response to this rising concern around the heart, Ancel Keys, a Professor from the University of Minnesota, released a study saying that heart attacks and strokes were consequences of a high-fat diet[i]. His conclusion was drawn from observing patients with heart concerns who consumed fatty meats and diary foods, and he made an assumption that dietary saturated fat increased saturated fat in the arteries. His study permeated the field of nutrition, and it soon became public knowledge that saturated fat should be restricted as it leads to heart disease[ii].
Keys’ assumption that dietary saturated fat led to increased levels of saturated fat in the blood was his greatest mistake.
Current evidence shows that there is little, if any, association between eating saturated fat and the saturated that fat clogs the arteries[iii]. The take home message is that eating saturated fat does not lead to an increased risk of heart disease. Furthermore, today’s nutritional scientists indicate that the reduction of dietary fat has led to an increased intake of carbohydrate, which has had a detrimental effect on our hearts.
In response to Keys study, a group of researchers set out to investigate the association between heart disease and the saturated fat found in dairy. They performed an observational study over twelve years on 1,752 rural Swedish men[iv]. The results found that eating fruit and vegetables combined with a moderate to high intake of saturated fat from dairy reduced their risk of heart disease. We already know that fruits and vegetables are wonderful for our health, but interestingly, when the subject’s intake of dairy was reduced, the positive reduction of heart disease was no longer present. This compels us to consider whether a diet consisting of saturated fat is actually a healthy diet after all; one that aids the heart instead of harms it.
In response to the national health recommendations that saturated fat intake should be reduced in order to prevent heart disease, our carbohydrate intake increased, which ironically coincided with the growth of diabetes, heart disease, metabolic syndrome, and hormone imbalances. A study in 2009 examined the effect of swapping the average daily fat requirement with carbohydrate instead, to understand the impact of increased carbohydrate on the heart[v]. Paradoxically, the results from 344,696 participants showed that by replacing saturated fat with carbohydrate increased the risk of heart disease.
Subsequently, Volek and Phinney performed a study of twenty subjects, ten of which followed a low-fat / high-carbohydrate diet, and another ten who followed a low carbohydrate diet consuming three times the amount of saturated fat than the first group[vi]. After twelve weeks, the low-carbohydrate / high-fat group showed 30% less fat in the blood than the low-fat / high-carbohydrate group. This is profound! It suggests that dietary saturated fat has little to do with levels of saturated fat in the blood. In actual fact, it shows that carbohydrate has a pronounced effect on saturated fat in the blood and arteries.
The Fear Of Fat Obliterated
What this means is that when we consume healthy dietary fats, the body does not store it as saturated fat in the arteries. The body uses healthy fats for fuel, to build hormones, to transport vitamins around the body, for reserve energy, and to insulate our precious organs. It is important to note here, that I am not suggesting we eat a bounty of fat - a balanced and healthy eating regime includes a combination of nutrients, and it is variety that makes food enjoyable!
In contrast, it is highly likely that a diet high in carbohydrate is the culprit for clogged arteries and heart disease[vii]. It would be good to see more research done in this area to get to the bottom of this saga.
In the mean time, enjoy drizzling coconut oil over your salad, dressing your green beans with a dollop of butter, and nibbling away on roasted chicken, skin and all! There are so many wonderful foods to eat that support your optimum health; copious amounts of vegetables, fruit, meat and whole grains (if you’re that way inclined), and fat; saturated, polyunsaturated, omega-3, and some monounsaturated fat. Good quality fats to consume are avocados, eggs, meat, some diary and nuts, coconut oil, olive oil, fish, and organic butter. Fat provides our food with flavour, so enjoy!
Insulin, a hormone secreted when carbohydrate is consumed, does another thing to our bodies that promote saturated fat storage. When insulin levels are high (due to carbohydrates) our muscles find it difficult to use the carbohydrate in our blood for fuel. What this means is that the unused carbohydrate is taken to the liver to be converted into fat, and is then stored in the body. Furthermore, a diet high in carbohydrates also encourages our livers to produce yet more saturated fat.
Please see ‘References’ below for further information on the studies presented in this article.
[i] Blackburn, H. (n.d.). On the trail of heart attacks in seven countries. University of Minnesota . Retrieved from http://sph.umn.edu/site/docs/epi/SPH%20Seven%20Countries%20Study.pdf
[ii] Volek, J., & Phinney, S. (2013, May 14). The Sad Saga of Saturated Fat. Retrieved from http://www.artandscienceoflowcarb.com/the-sad-saga-of-saturated-fat/
[iii] Howard, B. V. (2006). Low-Fat Dietary Pattern and Risk of Cardiovascular Disease: The Women's Health Initiative Randomized Controlled Dietary Modification Trial. Jama-journal of The American Medical Association. doi:10.1001/jama.295.6.655
[iv] Holmberg, S., Thelin, A., & Stiernström, E. (2009). Food Choices and Coronary Heart Disease: A Population Based Cohort Study of Rural Swedish Men with 12 Years of Follow-up. International Journal of Environmental Research and Public Health. doi:10.3390/ijerph6102626
[v] Jakobsen, M. U., O'Reilly, E. J., Heitmann, B. L., Pereira, M. A., Balter, K., Fraser, G. E., Ascherio, A. (2009). Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies. American Journal of Clinical Nutrition. doi:10.3945/ajcn.2008.27124
[vi] Volek, J., Phinney, S. D., Kossoff, E., Eberstein, J. A., & Moore, J. (2011). The art and science of low carbohydrate living: An expert guide to making the life-saving benefits of carbohydrate restriction sustainable and enjoyable. Lexington, KY: Beyond Obesity.
[vii] Krauss, R. M., Blanche, P. J., Rawlings, R. S., Fernstrom, H. S., & Williams, P. T. (0). Separate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia1-3. Nutrition.
American Heart Association, Inc. (2015, January 12). Saturated Fats. Retrieved from http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Saturated-Fats_UCM_301110_Article.jsp
Department of Medicine, Department of Veterans Affairs Medical Center, San Francisco, CA 94121, USA. Epidemiol. (1995). Serum fatty acids and the risk of coronary heart disease.
DiNicolantonio, J. J. (2014). The cardiometabolic consequences of replacing saturated fats with carbohydrates or Ω-6 polyunsaturated fats: Do the dietary guidelines have it wrong? Open Heart, 1(1).
Hite, A. H., Feinman, R. D., Guzman, G. E., Satin, M., Schoenfeld, P. A., & Wood, R. J. (2010). In the face of contradictory evidence: Report of the Dietary Guidelines for Americans Committee. Nutrition. doi:10.1016/j.nut.2010.08.012
Keys, A. (1980). Seven countries: A multivariate analysis of death and coronary heart disease (ed.). Cambridge, Mass.: Harvard University Press.
Noakes, T. D. (2013). The Women’s Health Initiative Randomized Controlled Dietary Modification Trial: An inconvenient finding and the diet-heart hypothesis. South African Medical Journal, 103(11), 824-825.
Siri-Tarino, P. W., Sun, Q., Hu, F. B., & Krauss, R. M. (2010, March). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824152/
Volek, J. S., Phinney, S. D., Forsythe, C. E., Quann, E. E., Wood, R. J., Puglisi, M. J., Feinman, R. D. (2009). Carbohydrate Restriction has a More Favorable Impact on the Metabolic Syndrome than a Low Fat Diet. Lipids. doi:10.1007/s11745-008-3274-2