The Dairy Myth
I recently gave a talk on childhood nutrition, specifically addressing milk intake. We know that calcium and vitamin D are critical nutrients for bone health, but is cow’s milk is the best way to get adequate amounts? It may shock you, but I don’t think that cow’s milk is a necessary (or even healthy) part of a child’s diet. My own children have never been offered milk on a regular basis, as we transitioned straight from breastfeeding to filtered water between ages 1 and 2. My holistic approach is sometimes a bit unconventional, but it’s grounded in science. While much of the research presented here is directed toward children, these principles apply to adults as well.
Children in the Unites States Drink Too Much Dairy!
Dairy is a staple in most children’s lives. Although official World Health Organization (WHO) recommendations1 are to breastfeed until age 2 or longer, the general opinion and practice in the U.S. is to switch from formula or breastfeeding to cow’s milk at 12 months of life.
I find that many children don’t do well with dairy, as milk is one of the major contributors to food allergies and sensitivities.2 Beyond that, it is often offered in higher than recommended quantities, even among physicians. I informally polled a group of over 10,000 physician moms, and found that many of them were exceeding the recommendations for milk intake by the American Academy of Pediatrics (AAP).
Calcium and Bone Health
Calcium is especially important during adolescence when bone building peaks between ages 12-15 years of age. Adequate calcium helps prevent osteoporosis. Calcium can also protect against lead toxicity by decreasing the absorption of lead in the gastrointestinal tract.3 It is also very important during pregnancy and breastfeeding, as adequate maternal levels protect a growing baby by preventing mobilization of lead stores from maternal bone.4
Is Dairy the Best Source of Calcium?
First, it’s not clear if dairy products are the best source of calcium for most people. Despite aggressive marketing by the dairy industry, the verdict is still out as to whether or not milk really builds healthy bones.
Second, we don’t truly understand how much calcium we really need.5 Our current recommended intakes are based on short-term studies. Long-term studies are more relevant, but the few we have actually cast doubt on the need for high calcium intake that is currently recommended. Studies in other countries (India, Peru and Japan) where calcium intake is low do not show an increased rate of bone fractures, but other variables make this data hard to interpret.
Recommended Calcium Requirements
The recommended dietary allowance for calcium varies based on who you ask. The healthiest amounts have not yet been established.
The recommendations for calcium that are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies (formerly National Academy of Sciences) are:
- 1-3 years – 700 mg
- 4-8 years – 1000 mg
- 9-18 years – 1300 mg
- 19-50 years – 1000 mg
- 51-70+ years – 1000 to 1200 mg
The UCSF Medical Center has published the following recommendations:
- 1-3 years – 500 mg
- 4-8 years – 800 mg
- 9-18 years – 1300 mg
- 19-50 years – 1000 mg
- 51-70+ years – 1200 mg
Current Recommendations for Milk
The AAP recommends 2 cups (16 oz) of milk or it’s equivalent for children ages 2-8. 16 oz of milk provides about 600 mg calcium and 200 IU Vit D (if fortified). “Milk and water are the healthiest choices, and water is the best option between meals.”
The American Heart Association (AHA) recommendations are similar.
I think there are a few things that are important to point out. First, “or it’s equivalent” means that ~600 mg plant-based calcium would fulfill these same recommendations. Second, AAP is sponsored by Milk Life. America’s Milk Companies have much to gain by perpetuating the myth that drinking a lot of milk is healthy.
Problems With Dairy
Many people do not tolerate dairy. Milk is among only 8 foods that account for 90% of food allergies in the U.S.6 Dairy allergy or sensitivity may be due to milk proteins (casein or whey) or milk sugar (lactose), and depends on several factors including:
- People with gut issues and increased intestinal permeability (aka leaky gut) will tend to react more.
- People with gluten related disorders are often intolerant of casein as well, because its molecular structure is so similar to that of gluten.
- Patients with Small Intestine Bacterial Overgrowth (SIBO) cannot tolerate the sugars in milk because it feeds the bacteria in the small intestine.
- Raw vs pasteurized milk are tolerated differently, because raw milk contains the enzymes and lactase to facilitate better digestion.
Some people who do not tolerate cow’s milk do fine with sheep or goat’s milk because the casein components are different.
Consumption of cow’s milk has been associated with a number of chronic issues, including:
- iron deficiency anemia7
- chronic acute otitis media8
- behavioral issues
- sleep disorders9
- type 1 diabetes10
Also, milk has a lot of sugar! Many people think of milk as a protein source, but it’s mostly carbohydrates. Did you know that 1 cup of 2% milk has 12 grams of sugar?
Last but not least, conventional dairy factories expose our children to hormones and antibiotics. Bovine growth hormone (rBGH) has long been used to increase milk production, but its use also causes mastitis and calls for increased antibiotics. Thus, both hormones and antibiotics are passed into the milk supply, which raises concern for precocious puberty and antibiotic-resistance. Remember, milk usually comes from a factory full of cows, not green pastures.
Raw vs Pasteurized?
For those who do tolerate milk and dairy, consuming raw vs pasteurized products is a big debate.
Most mainstream organizations, including the FDA and the AAP, are strongly opposed to raw milk.11 This is based on a concern for food-borne illness and the premise that raw milk can have unsafe levels of bacteria like E. Coli and Listeria.
Opponents also argue that raw milk is not more nutritious. However, at least two large studies demonstrate the protective effects of raw milk. The GABRIELA study12 demonstrates the protective effect of raw milk consumption on childhood asthma and atopy. The PASTURE study[efn_ntoe]http://www.ncbi.nlm.nih.gov/pubmed/25441645[/efn_note] demonstrates the protective effect of raw milk from common respiratory infections.
I would argue that conventional milk factories have their own list of significant issues, like the hormones and antibiotics mentioned above.
Alternative Sources of Dietary Calcium
In general, I recommend minimizing or avoiding cow’s milk, depending on your child. A better option might be organic goat or sheep’s milk products if they are well tolerated. If your child has a diverse diet, I think it is best to focus on calcium from non-dairy foods. The USDA provides a helpful database of foods and nutrients if you want to learn more.
There are plenty of non-dairy sources of calcium. For comparison, 1 cup of milk has about 300 mg of calcium. Some alternative plant-based calcium sources include:
- ½ cup tofu – 350 mg
- 1 cup non-dairy fortified milk (nut, hemp, flax) – 200-300 mg
- 1 oz (~2 Tb) Sesame Seeds – 280 mg
- 1 cup collard greens, cooked – 268 mg
- 1 cup spinach, cooked – 245 mg
- 1 cups kale, raw – 200 mg
- 1 cup white beans – 191 mg
- 1 oz (~3 Tb) chia seeds – 179 mg
- 1 cup pinto beans – 175 mg
- 1 cup navy beans – 123 mg
- 5 figs – 112 mg
- ¼ cup almonds – 96 mg
- 1 orange – 60 mg
The Role of Vitamin D in Calcium Absorption and Bone Health
Vitamin D plays an important role in the absorption of calcium and phosphorus, and is essential for healthy bones and teeth.
The RDI of Vitamin D for children and adolescents was recently increased. AAP published the following recommendations in February 2011:
- 0-12 months – 400 IU/ day
- 1-18 years – 600 IU/ day
There are two sources of vitamin D.13 One source is sun exposure, which is negated by sunscreens and sunglasses. Another source is dietary, including:
- fortified milk and yogurt
- fortified milk substitutes
- cod liver oil
- shiitake mushrooms
- fortified cereals
- fortified juices
Vitamin D intake is important to consider. Breastfed infants and most children need to supplement with Vitamin D, but these levels should be monitored periodically. Adequate levels are complicated by genetic factors, as the Vitamin D Receptor (VDR) polymorphism is relatively common. While it is a simple blood test, most physicians do not routinely test for Vitamin D levels in children. I encourage parents to talk to their child’s healthcare provider about checking serum levels of Vitamin D (25-OH Vitamin D).