Milk is a great source of calcium, vitamin D, other vitamins, micronutrients and milk protein – whey and casein. It has always been considered essential for growth and maintaining of lean mass – including bones and muscles. Most people would gulp cartons of milk for the above reasons. However, most people are ignorant of the fact that milk fat has beneficial effects on your health as well.
Milk fat has never enjoyed the same amount of popularity compared to its calcium, vitamin D or protein content. Companies have been marketing milk and milk products with low fat content. This ‘low-fat milk’ is apparently better for you than whole milk. Or is it?!
Milk Fat May Not Be Unhealthy After All!
Emerging evidence – as opposed to previous school of thought – suggests that fat present in whole milk may serve a number of beneficial roles in improvement of human health and prevention of disease.
Obesity and Cardiovascular-Metabolic Diseases
Incidence of obesity (as stated in another article) is now so high that it can be safely referred to as a ‘pandemic’. Even more worrying is the fact obesity increases the risk of developing Type-2 diabetes and/or cardiovascular diseases (CVD).
This ever increasing incidence of obesity coupled with the potential to cause cardiovascular-metabolic disease has had severe repercussions – diabetes and CVD are now leading causes of death in America (Grundy et al., 2005; Hite et al., 2010). Furthermore, the management and treatment of these metabolic conditions causes a high economic burden – in Northern America alone, a whopping $600 billion are spent annually to fight these conditions (Ariza, Vimalananda, & Rosenzweig, 2010; Dall et al., 2009).
Not surprisingly, the management and prevention of obesity and its resultant ill-effects has become a public health and economic priority.
A plethora of effective interventions are suggested by clinicians, obesity experts, fitness professionals and dieticians to counter this pandemic. Exercise combined with healthy food intake seems to be the best way to go about it.
In recent years, a lot of attention has been attached to dairy products and the benefits afforded by it. However, a lot of people tend to use the ‘apparently healthier option’ of low-fat milk.
Well, research now suggests that whole milk may be a better option. Growing evidence points towards ingestion of milk fat reducing the risk of cardiovascular-metabolic diseases. And, fat from milk does not, for reasons discussed below, behave like saturated fat from other sources. Let us have a closer look at what milk fat comprises of and why it is healthier than most people think.
Milk Fat and Its Beneficial Effects
Milk contains both saturated and unsaturated fats (fatty acids). That unsaturated fatty acids are ‘healthy’ is common knowledge. However, recent research now suggests that saturated fat from fortified cow’s milk may also be healthy.
Saturated fatty acids contained in milk are palmitic acid, stearic acid and myristic acid (USDA National Nutrient Database for Standard Reference, Release 23 – 2013). It has always been thought that reducing fats from milk helps reduce the risk of CVD – hence the low-fat varieties at the supermarket (!). However, researchers are now beginning to question this theory (Mente, de, Shannon, & Anand, 2009; Siri-Tarino, Sun, Hu, & Krauss, 2010) especially since it has now been conclusively shown that saturated fats from milk provide protection from CVD by increasing high density cholesterol (HDL) and HDL: Total cholesterol ratio (a better predictor of future development of CVD than HDL or total cholesterol alone) (Mensink, Zock, Kester, & Katan, 2003; Rice, Cifelli, Pikosky, & Miller, 2011) – HDL is the good cholesterol which protects from heart disease.
Saturated fats from milk also differ from saturated fats from other sources in a very important way: whereas eating other saturated fats causes hypercholesterolemia (increased cholesterol in blood) and elevated serum triglycerides (increased triglycerides in blood), milk fats prevent these events from occurring.
Not surprising then that milk fat has never been associated with increasing the incidence of cardiovascular-metabolic diseases (German et al., 2009; Pfeuffer & Schrezenmeir, 2007; Elwood, Pickering, Givens, & Gallacher, 2010).
Monounsaturated Fatty Acids in Milk
An important ingredient of milk fat which protects from cardiovascular-metabolic diseases is a monounsaturated fatty acid (MUFA), oleic acid. Apparently, 25% of milk fat is made up of oleic acid – only palmitic acid is present in higher quantities in milk (USDA National Nutrient Database for Standard Reference, Release 23 – 2013).
In addition to reducing risk for most metabolic diseases, oleic acid plays some other important roles (Gillingham, Harris-Janz, & Jones, 2011). Some of the benefits afforded by oleic acid are:
• Favourably affects HDL: Total Cholesterol ratio (Rice et al., 2011)
• Favourably affects blood lipid and blood lipoprotein levels (Rice et al., 2011)
• Reduces triglycerides and elevates HDL
• Reduces blood pressure (Alonso, Ruiz-Gutierrez, & Martinez-Gonzalez, 2006)
• Causes increased fat oxidation (Kien, Bunn, & Ugrasbul, 2005)
• Helps maintain insulin sensitivity (Gillingham et al., 2011) and thus reduces incidence of Type-2 diabetes
A number of other constituents of milk – CLA (conjugated linoleic acid); for instance – have the ability to favourably affect risks associated with metabolic disorders.
The unique structure and behaviour of saturated fats in milk and the amount of MUFA like oleic acid and CLA makes milk and other dairy products an important cog in the wheel to fight cardiovascular-metabolic diseases. Although, a lot of researchers have called for more in-depth research into milk fat, we can, for now, safely assume that whole milk is in fact healthier than the low-fat variety. And, the undue importance given to use of low-fat milk is unwarranted.
Alonso, A., Ruiz-Gutierrez, V., & Martinez-Gonzalez, M. A. (2006). Monounsaturated fatty acids, olive oil and blood pressure: epidemiological, clinical and experimental evidence. Public Health Nutr., 9, 251-257.
Ariza, M. A., Vimalananda, V. G., & Rosenzweig, J. L. (2010). The economic consequences of diabetes and cardiovascular disease in the United States. Rev Endocr.Metab Disord, 11, 1-10.
Dall, T. M., Mann, S. E., Zhang, Y., Quick, W. W., Seifert, R. F., Martin, J. et al. (2009). Distinguishing the economic costs associated with type 1 and type 2 diabetes. Popul. Health Manag., 12, 103-110.
Elwood, P. C., Pickering, J. E., Givens, D. I., & Gallacher, J. E. (2010). The consumption of milk and dairy foods and the incidence of vascular disease and diabetes: an overview of the evidence. Lipids, 45, 925-939.
German, J. B., Gibson, R. A., Krauss, R. M., Nestel, P., Lamarche, B., van Staveren, W. A. et al. (2009). A reappraisal of the impact of dairy foods and milk fat on cardiovascular disease risk. Eur J Nutr., 48, 191-203.
Gillingham, L. G., Harris-Janz, S., & Jones, P. J. (2011). Dietary monounsaturated fatty acids are protective against metabolic syndrome and cardiovascular disease risk factors. Lipids, 46, 209-228.
Grundy, S. M., Cleeman, J. I., Daniels, S. R., Donato, K. A., Eckel, R. H., Franklin, B. A. et al. (2005). Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation, 112, 2735-2752.
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, 26, 915-924.
Kien, C. L., Bunn, J. Y., & Ugrasbul, F. (2005). Increasing dietary palmitic acid decreases fat oxidation and daily energy expenditure. Am J Clin Nutr., 82, 320-326.
Mensink, R. P., Zock, P. L., Kester, A. D., & Katan, M. B. (2003). Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr., 77, 1146-1155.
Mente, A., de, K. L., Shannon, H. S., & Anand, S. S. (2009). A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease. Arch.Intern.Med, 169, 659-669.
Pfeuffer, M. & Schrezenmeir, J. (2007). Milk and the metabolic syndrome. Obes Rev, 8, 109-118.
Rice, B. H., Cifelli, C. J., Pikosky, M. A., & Miller, G. D. (2011). Dairy components and risk factors for cardiometabolic syndrome: recent evidence and opportunities for future research. Adv. Nutr., 2, 396-407.
Siri-Tarino, P. W., Sun, Q., Hu, F. B., & Krauss, R. M. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr., 91, 535-546.