What's Wrong With Milk?

Summary:

There is a lot of controversy surrounding dairy, but most of the "facts" being thrown around are not grounded in truth. Learn about the pros and cons of milk, how the hormones in milk might affect you, and whether or not it is related to breast cancer.

Transcript:

Hi everyone!  It’s Dr. Lisa Schwartz and today I want to talk about the controversies around dairy –how it relates to breast cancer and other issues.

There’s something about cow’s milk that ignites a passion on the order of religious zealotry as to whether it is a protein and calcium filled goodness that has been consumed as a healthy beverage for centuries or the one animal product that for sure will give you cancer, heart disease, Alzheimer’s, and cause you to grow extra limbs where they shouldn’t be. 

 Usually, neither side of that debate is well equipped with facts in these discussions.  So, let’s start with some facts…

1.     Milk is a mixture of fat globules in a water-based fluid that contains carbohydrates, proteins, and minerals. All of this makes it an ideal fuel for growth. Which is why mammalian babies are fed milk.

2.     The carbohydrate or sugar in milk is called lactose.

3.     Whole milk contains about 3.4% total fat.  The fats found in milk are predominantly saturated and monounsaturated.  

4.     The protein in cow’s milk is about 82% casein and 18% whey.  These particular proteins contain all 9 essential amino acids.  Amino acids that are “essential” cannot be made in the body and therefore must be consumed in the diet. 

5.     Milk also contains a host of vitamins and minerals not the least of which are vitamin D and calcium. 

Those are the background facts on milk and now let’s get to the good things about  milk first.  What are the benefits attributed to milk consumption?

One, it’s a great source of protein, vitamins, and minerals as I mentioned above. 

And two, it contributes to general bone health by supplying calcium and vitamin D.  In fact it is a great source of calcium and adequate consumption of calcium  throughout life is important. 

 You see, most of the body’s calcium is stored in the bones, but there is a certain amount of calcium that needs to remain in the bloodstream so that cells function properly. When the blood calcium runs low, the bone storage provides the needed calcium and releases some of its store to the bloodstream.  This can lead to weaker bones in the long run.  But if you consume adequate amounts of calcium and vitamin D, then the calcium in the bones is left in storage.  The exception may be postmenopausal women where bone loss from lack of estrogen exceeds intake. 

 In some studies involving older populations, dietary supplementation with calcium and vitamin D has led to fewer fractures.  You could take supplements or even eat other foods containing calcium, but the calcium found in milk has a greater bioavailability (meaning it is more easily absorbed) than calcium from vegetable sources and fortified foods.

 And now we get to the part you’ve really been waiting for…What are some of the concerns with milk?

 First of all, should you be drinking whole milk or skim milk?  Current thinking is… whole milk. The fats that are in milk are predominantly saturated fats, which have gotten a bum wrap over the years.  However, we now know that not all saturated fats increase your risk of cardiovascular disease. 

 In skim milk, most of the fat has been “skimmed” off the top (although the process is more complicated than just letting the cream rise to the top) and then you need to add back vitamins A and D because they are fat soluble vitamins and get skimmed away with the fat.  Producers also add some “milk solids” that give it a thicker consistency so that it’s thicker than water.   Sounds yummy, right?

 The fat that is in whole milk leaves you feeling more sated and less hungry than with skim milk.  There is some research that folks who consume whole fat dairy, actually weigh less and are less likely to develop diabetes. So in most cases, whole milk is going to be the better choice.

 Now, some people avoid milk because of an allergy or sensitivity to it.  A true allergy to milk proteins occurs in about 1% of the population, it is a little more common in children, and it can be outgrown.  But it does indeed exist, and if you have a true allergy then you need to avoid milk.

 The thing that is more common is a sensitivity to milk or lactose intolerance. The sugar in milk is lactose, and you need the enzyme lactase to break it down.  As some people age, they produce less lactase so they can’t break down the sugar in milk  and end up with GI symptoms such as gas and diarrhea. 

 Other factors can play a role, too.  For example, the proportion of the population that is lactose intolerant is dependent on ethnicity to some extent with it being more common in those of Asian and African descent.

 Also, symptoms may not occur unless you consume more lactose than the lactase produced by your body can handle.  This means that most people with lactose intolerance can actually consume up to 8 ounces of milk without problems and more if they consume the milk with other food.  Cheeses and yogurt have lower levels of lactose and those can be tolerated as well.

 Now, let’s talk about hormones. Again time for more facts:

·      Cows produce growth hormone naturally but some dairy producers administer extra growth hormone to cows to increase milk production.  So far, the US Food and Drug Administration, the World Health Organization, and National Institutes of Health have reported that the supplemental hormones given to cows are safe for human consumption at the amounts present in milk. 

·      The hormone known as recombinant bovine growth hormone has been banned in the EU, Canada, Australia, Japan, and New Zealand because it increases the risk that a cow will develop mastitis. Not because of health risks to humans.

·      Organic milk in the US is produced from cows who have not received supplemental growth hormones.  In fact, only about 17% of dairy cows in the US receive the supplemental growth hormones. 

·      All milk contains miniscule amounts of the naturally occurring female hormones estradiol and progesterone (but much, much less than women have in their bodies naturally).

·      Consumption of milk does not appear to affect blood levels of hormones.

·      And, drum roll please…Milk consumption has not been linked to breast cancer.  In fact in one recent review there was an inverse relationship between dairy consumption and breast cancer.

 And, for another big misconception:  there are no antibiotics in milk.  Dairy cows are treated with antibiotics only when they are sick.  They are separated from the herd and their milk is discarded until the antibiotics have cleared.  All milk must test negative for antibiotics.  Antibiotic use in animals used for meat production is a different story

So what have we learned?

 ·      Cow milk is a great source of protein, vitamins, and minerals, especially calcium and vitamin D.

·      Organic milk in the US comes only from cows that have not received supplemental hormones.

·      There are no antibiotics in milk. 

·      The estrogen and progesterone levels in milk are very minor and don’t effect blood levels of hormones.

I hope this has cleared up some of the controversy with dairy.  If you are interested in more information about breast cancer, nutrition, and healthy lifestyle changes, be sure to visit my website and blog at LisaSchwartzMD.com or subscribe to my You Tube channel at Lisa Schwartz, MD.  Thanks for your time and attention.  See you next week.