Research would suggest that as little as 2% of infants have a true cow’s milk protein allergy
(CMPA) and for those that do, more than 80% of them will outgrow that cow’s milk
allergy by the time they reach their 5th birthday. This leads to several questions surrounding why many families are recommended to remove cow’s milk from their diet while breastfeeding or to change to a more broken down version or dairy-free cow’s milk formula. It is important to note that there are a number of reasons for infants to be fussy, spit up, etc. outside of CMPA. Latch, positioning, feeding flow, inadequate burping, volume of feed, timings of feeds, activity after feeds, and more should be assessed and optimized prior to removing cow’s milk proteins. Additionally, there are different types of protien and ratios of these proteins in formulas which can be attributing to tolerance issues.
BUT WHY DO WE NEED IT?
Cow’s milk is a top 8 allergen and should be introduced within the first year of life to decrease risk of anaphylactic reactions later on in life. A varied and healthy diet throughout pregnancy, breastfeeding and childhood along with early introduction of top allergen foods not only decreases risk of food allergies but may aid in decreasing risk of the atopic march towards asthma.
WHAT AND HOW MUCH?
From 12-24 months of age it is recommended for toddlers to consume full fat milk at no more than 24 oz/d. If the child is consuming other dairy products such as cheese, yogurt, etc. the consideration for 16 oz/d is highly recommended as more than 3 servings of dairy is associated with increased risk of iron deficiency anemia, constipation, etc. Full fat dairy intake is important for brain development and overall caloric intake at this age as they continue to eat more at meals and expand their palate.
At the age of 3, a transition towards low-fat or skim milk should be considered based on your child’s overall caloric and fat needs. Skim milk is recommended throughout childhood, adolescents and beyond, however full fat dairy takes center stage again in childbearing years.
WHY PRIORITIZE MILK THROUGH CHILDHOOD AND ADOLESCENTS?
Low fat dairy intake has been found to be connected with a leaner body type in the 6-18 year old group. Additionally, dairy is one of the most abundant sources of calcium - a nutrient important to nerve and bone health. It is estimated that bone mass increases by 40-60% during adolescents, however 70-90% of this population is not consuming enough calcium. Adequate calcium intake along with vitamin D, K2, phosphorus and weight baring activity is essential for bone density and preventing risk of osteopenia/osteoporosis later in life. Furthermore, calcium intake may even be associated with decreased height when consumed in quantities of less than 300mg/d.
MILK AND REPRODUCTIVE SYSTEM
An NIH article suggested at one point and time that dairy intake may be associated with early puberty in females OR later puberty. However, low fat dairy intake has since been associated with later onset of puberty. The NIH conclusions of earlier or later puberty onset was likely due to not looking at types of milk intake. We know that high body weight is related to earlier onset of puberty, and therefore the findings of early onset puberty in the NIH study are likely due to a subset of high intake full fat dairy consumption leading to increased calorie intake and weight status which then was associated with early onset puberty. On the other hand, we have seen that low fat dairy intake is correlated with a leaner body type as well as later onset puberty. To note, skim milk is also correlated with a decrease in PMS symptoms and a later onset menopause and may be a great way to help preserve AMH (egg counts) in women of childbearing age who are not yet ready for children.
On the other hand, during childbearing years, full fat dairy is associated with increased fertility and decreased time to conception. One study showed a 66% less occurrence of ovulatory infertility with full fat dairy intake. We also see that progesterone production is increased by 30% with full fat dairy intake.
AND, not to leave out the men, skim milk consumption was correlated with increased fertility in men of child baring age. It was seen that skim milk intake resulted in higher sperm count, motility, and morphology.
BUT WHY?
Outside of protien, fat, carbohydrates and calcium, milk contains a lot of essential vitamins and minerals. Many of which are part of the process of producing progesterone. Milk contains B6, selenium, Omega 3s (when fat containing), and vitamin D which are all essential to progesterone production (Vitamin C is important too! But is not in milk). During the age of 1-2 years old as well as during preconception, it may be worth the money to purchase grass fed dairy products as grass fed milk has been shown to have up to 147% more DHA (a type of Omega 3 fatty acid) compared to non grass fed milk. DHA is important for brain development, fertility and early fetal development.
The correlation in men fertility is likely due to the selenium and zinc in milk.
SO WHAT NOW?
Make milk and other dairy products part of your daily life! Aim for 2-3 servings a day and speak to an outpatient registered dietitian nutritionist if you are concerned about choosing the right type of milk for you! Dairy intake can be in the form of milk, yogurt, cheese, cottage cheese, butter, cream, or ice cream. Find products that you like and will consume regularly. Remember that a standard 8oz cup of milk contains 15g of carbohydrates, 8g protien and varying fat depending on %fat purchased.
Rachel Hutto MS, RD, LD, CNSC Early Life Dietitian
Citations:
2.Kai Kang, Olusola F Sotunde, Hope A Weiler, Effects of Milk and Milk-Product Consumption on Growth among Children and Adolescents Aged 6–18 Years: A Meta-Analysis of Randomized Controlled Trials, Advances in Nutrition, Volume 10, Issue 2, 2019, Pages 250-261.
3.Fang, A., Li, K., Li, H. et al. Low Habitual Dietary Calcium and Linear Growth from Adolescence to Young Adulthood: results from the China Health and Nutrition Survey. Sci Rep 7, 9111 (2017). https://doi.org/10.1038/s41598-017-08943-6
4.Audrey J Gaskins, Ana Pereira, Daiana Quintiliano, John A Shepherd, Ricardo Uauy, Camila Corvalán, Karin B Michels. Dairy intake in relation to breast and pubertal development in Chilean girls1,2. The American Journal of Clinical Nutrition, Volume 105, Issue 5, 2017, Pages 1166-1175.
5.Wiley AS. Milk intake and total dairy consumption: associations with early menarche in NHANES 1999-2004. PLoS One. 2011 Feb 14;6(2):e14685. doi: 10.1371/journal.pone.0014685. PMID: 21347271; PMCID: PMC3038976.
6.Purdue-Smithe AC, Whitcomb BW, Manson JE, Hankinson SE, Rosner BA, Troy LM, Bertone-Johnson ER. A Prospective Study of Dairy-Food Intake and Early Menopause. Am J Epidemiol. 2019 Jan 1;188(1):188-196. doi: 10.1093/aje/kwy212. PMID: 30239575; PMCID: PMC6321800.
7.Chavarro JE, Rich-Edwards JW, Rosner B, Willett WC. A prospective study of dairy foods intake and anovulatory infertility. Hum Reprod. 2007;22(5):1340-1347. doi:10.1093/humrep/dem019
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