Saturated Fats, not too Bad!

Saturated fats are unfairly labeled as the worst nutrient. Saturated fats occur naturally in animal products, dairy products, and eggs, are chemically stable due to there being no double bonds in their hydrocarbon chain, and are typically solid at room temperature. Research from the 1960s and 1970s, based on ecological studies, animal studies and short term metabolic trials looking at total cholesterol and low density lipoproteins (LDLs), found that increased saturated fat intake increased the risk of heart disease (Micha & Mozaffarian, 2010). Due to these early findings, the current saturated fat recommendation is 7-10% of total energy (Volk et al., 2014). These current recommendations are fundamentally flawed, as intake of saturated fats have no effect on heart disease risk, and substituting saturated fats for carbohydrates causes excess weight gain and metabolic diseases.

Recent evidence suggests that saturated fats have no to scant effect on risk for heart disease. In a metanalysis by Chowdhury et al. (2014) examining total saturated fatty acid intake and biomarkers found null association between increased saturated fats and heart disease risk. Saturated fats generally raise total cholesterol and LDLS, but also lowers triglycerides and raises high-density lipoprotein (HDL) and specific saturated fats have different effects on serum lipid profile and should not be generalized (Micha & Mozaffarian, 2010). Dietary fat consumption was also not correlated with higher blood pressure, weight gain, diabetes, and systemic inflammation (Micha & Mozaffarian, 2010).

By restricting saturated fat, people fill the void with sugar. The excess carbohydrates are converted into body fat and this causes an increase serum tryglycerides, increased insulin resistance, increased hypertension, and higher risk of heart disease (Lawrence, 2013). A diet of gradually replacing saturated fats with carbohydrates among obese subjects was found to increase the proportion of plasma palmitoleic acid, which may be impair metabolism of carbohydrate, leading to an accumulation of body fat (Volk et al., 2014). Replacing saturated fats for carbohydrates can impair normal carbohydrate metabolism. Also when people try to avoid foods with saturated fats, they tend to eat high sugar and highly processed substitutes, and they feel less full due to the satiety of fats. Restricting saturated fats can lead to increased carbohydrate consumption, leading to weight gain and impaired metabolism.

Replacing saturated fats with carbohydrates and avoiding saturated fats has not been a successful recommendation. Since the initial recommendations of 7-10% of caloric consumption from saturated fats, obesity rates and metabolic diseases rates have skyrocketed. Instead of shunning a nutrient with low cardiovascular disease risk, saturated fats should be incorporated into a healthy diet. Cutting back on excess sugary carbohydrates will do more to reduce weight gain and disease risk then eliminating saturated fats. Instead bad sources of saturated fat like candy, pizza, burritos, chips, and tacos, which are all highly processed or sugary, should be replaced with healthier sources of saturated fats like lean meat, nuts and seeds.

References

Chowdhury, R., Warnakula, S., Kunutsor, S., Crowe, F., Ward, H. A., Johnson, L., . .Angelantonio, E. D. (2014). Association of dietary, circulating, and supplement fatty acids with coronary risk: A systematic review and meta-analysis. Annals of Internal Medicine, 160(6), 398-408.

Lawrence, G. D. (2013). Dietary fats and health: Dietary recommendations in the context of scientific evidence. Advances in Nutrition, 4(3), 294-302.

Micha, R., & Mozaffarian, D. (2010). Saturated fat and cardiometabolic risk factors, coronary heart disease, stroke, and diabetes: A fresh look at the evidence. Lipids, 45(10), 893-905.

Volk, B. M., Kunces, L. J., Freidenreich, D. J., Kupchak, B. R., Saenz, C., Artistizabal, J. C., . . . Volek, J. S. (2014). Effects of step-wise increases in dietary carbohydrate on circulating saturated fatty acids and palmitoleic acid in adults with metabolic syndrome. PLoS ONE, 9(11), 1-16.