Tuesday, November 8, 2011

Truth on Tuesday

 Debunking Milk Myths

“Should I be drinking Soy Milk, Almond Milk or Cow’s Milk?”

“Wait, isn’t milk bad for you?”

“What is the craze with Coconut Milk?”

I get asked these question a lot. With so many milk and dairy-free milk alternatives how do you know which one should you be pouring over your cereal in the morning? Should you even be drinking milk? The quick answer to that last question is, unless you are allergic to dairy then yes, you should be drinking milk.

·        As you are well aware, milk is essential for proper bone growth and development, especially in children and adolescents. Other benefits related to daily consumption of milk include blood pressure maintenance, reduced risk of cardiovascular disease, improved sleep quality, and decreased symptoms of PMS in women. Additionally, drinking milk can be helpful in weight maintenance. While whole milk contains about 120 calories and 5 grams of fat per cup, you can opt for a lower fat version such as 2% or skim. Fat Free or Skim milk contains the same amount of protein as Whole Milk but with less fat and calories.
·         Recently, you may have read about debate against the promotion of milk in our diets.  Some common issues with milk consumption among Americans include everything from contamination, to promotion of certain diseases like autism, cancer, and heart disease.
o    Contaminants of interest include pesticides and polychlorinated biphenyls (PCBs).  Since these contaminants do not readily leave the body they can build up, possibly having detrimental effects on the immune, reproductive, and central nervous system.   Research also shows links between polychlorinated biphenyls and cancer (1). 
o   A compound called insulin-like growth factor (IGF-I) found in cow’s milk has been associated with both prostate and breast cancer when found in high concentrations (2). 
o   The European Journal of Clinical Nutrition stated in 1994, "Milk consumption correlates positively with cholesterol levels in blood as well as coronary mortality. In comparisons between 17 countries, there is a good correlation between national cholesterol levels and mortality from ischemic heart disease." 
·         It is worth noting that the associations with milk and heart disease are most likely due to the high saturated fat content of whole milk and full-fat dairy products.  However, it is important to consider whether it is actually the contents found in milk and dairy products, or merely the saturated high fat content that lead to the occurrence of heart disease. 

What about soy milk?

While soy milk is not technically milk, it's a popular milk substitute for vegans since it’s derived from a plant source.  It is made from soybeans, which are soaked, finely ground, and then strained. Soy milk does not contain any lactose, so it is also a suitable alternative lactose intolerant individuals. One cup of soymilk contains about 7 grams of protein, 4 grams of carbohydrate, 4 grams of fat, very little saturated fat, and no cholesterol.  Fortified soy milk contains about 300 mg of calcium and approximately 120 mg of Vitamin D. 


Various animal studies have shown the bone sparing effects of the isoflavins found in soy protein, and many recent studies show promising effects in humans as well (1).  These effects can be attributed to the isoflavones, suggesting 83 mg of isoflavones daily may improve spinal bone mineral density in post-menopausal women (2).  One cup of soy milk contains 20-40 mg of isoflavones, so one could achieve this amount in 2-3 cups of soymilk.  The only downfall of soy milk is that it has only about a quarter of the calcium as cow's milk. Many soy milk manufacturers are adding calcium to their products, but studies show that it is not as beneficial as naturally-occurring calcium.  It is also important to point out that while research suggests that isoflavins in soy milk can help reduce and prevent osteoporosis, the recommended amount for dietary intake has not yet been established.

Almond and Coconut Milks

  • Both Almond and Coconut milk are both lactose and cholesterol free milk alternatives. However, both varieties are lacking in nutrition compared to cow’s milk. They provide only 1 gram of protein per cup verses the grams found in regular milk. 
  • The positive press surrounding coconut milk has to do with the content of lauric acid and other medium-chain fatty acids (MCFAs). MCFAs promote weight maintenance without raising cholesterol levels and may be helpful in preventing weight gain (6).  Some research suggestions that lauric acid may have favorable effects on HDL cholesterol (7), but these studies are not conclusive.
  • While they serve as great low calorie alternatives that are fortified with many of the same vitamins and minerals, most experts agree that both Almond and Coconut Milk are inferior sources of nutrients for children (8).

The Takeaway…

Either soy or cow’s milk can have the same beneficial effect when consistently consumed as part of a regular healthy diet.  The push for no dairy products seems like another diet fad that Americans may or may not choose embrace. The science behind milk consumption in combination with weight bearing exercise for the preservation of bone mineral density and prevention of osteoporosis is well established.  If you are worried about extra chemicals and hormones added to cow’s milk, I suggest you buy Organic. Horizon, Organic Valley, and Stoneyfield Farms are just a few brand you can find at most supermarkets.   

 References:

1)      Baars AJ, Bakker MI, Baumann RA, et al. Dioxins, dioxin-like PCBs and non-dioxin-like
       PCBs in foodstuffs: occurrence and dietary intake in the Netherlands. Toxicol Lett.          
        2004;151:51-61.
2)      Voskuil DW, Vrieling A, van’t Veer LJ, Kampman E, Rookus MA. The insulin-lik growth factor system in cancer prevention: potential of dietary intervention strategies. Cancer Epidemiol Biomarkers Prev. 2005;14:195-203.
3)      Cramer DW, Greenberg ER, Titus-Ernstoff L, et al. A case-control study of galactose
       consumption and metabolism in relation to ovarian cancer. Cancer Epidemiol  Biomarkers  Prev.   
       2000;9:95-101.
4)      Lydeking, E, Jens, O, Beck, E, and  Jenson, K.  (2004). Soymilk or progesterone for prevention of bone loss. European Journal of Nutrition, 43(497), 246-257

5)      Newton, K., LaCroix, A., & Levy, L. (2006). Soy protein and bone mineral density in lder men and women: a randomized trial. Maturitas, 55(3) 270-277.

6)      Aoyama, T., Nosaka, N., & Kasai, M. (2007). Research on the nutritional characterisitics of medium-chain fatty acids. Journal of Medical Investigation, 54(3-4), 385-388.

7)      Amarasiri, W. & Dissanayake, A. (2006). Coconut fats. The Ceylon medical journal, 51(2)47-51.

8)      Appold, K. (2011). Cucckoo for coconut products. Today’s Dietitian. <http://www.todaysdietitian.com/news/exclusive1011.shtml>



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