This presentation is adopted from the review on "Milk and Health" that summarizes the evidence for the benefits and possible risks associated with the consumption of cow’s milk. The authors describe the relationship of milk consumption to the risks of fracture, obesity, cardiovascular disease, allergies, and various cancers.

1. Time to Question EverythingYou Know About Milk
Impact factor: 70.670 (2018)
Massachusetts Medical Society (United States)
1812–present
February 13, 2020
N Engl J Med 2020; 382:644-654
DOI: 10.1056/NEJMra1903547
Compiled by
Dr. Pankaj Dhaka
Assistant Professor
School of Public Health and Zoonoses
GADVASU, Punjab, India

2. For strong bones and overall health, consume
three servings of reduced-fat milk a day
Perhaps the most widely advocated nutrition
recommendation of the last half-century in US:

3. None of this seems to be true…
The most common health reason for drinking milk is to strengthen bones,
to create a “bank” for calcium throughout life and prevent fractures

4. The USDA’s “Choose My Plate” dedicates a corner of their
icon for milk and equivalent dairy products

5. The purpose of animal milk
• The natural purpose of cow, goat, or sheep milk is to help young animals grow quickly
and avoid predators, it contains all essential nutrients, including protein and calcium.
• For this reason, milk can provide a nutritionally balanced alternative to the sugary
drinks, chips, and other low-quality, processed foods that have flooded our diets
• Milk also contains a variety of growth-promoting factors.
• But today, the milk supply has increased levels of hormones like estrogen and
progestins, because industrial dairy cows are pregnant for most of the time they are
milked.
• In fact, children who drink a lot of milk, even those with good overall nutrition, tend to
grow an inch or two taller

6. Is milk really good for bone health and preventing fractures?
• Not seems true → at least for general population
• For > 3 years old,
Suggested intake of Ca in US:
1000-1300 mg/day as a regular dietary supplement
WHO suggests barely half that amount: 500 mg/day
Who’s right?

7. • Systematic reviews show no
relationship between the hip fracture
rates for Ca intakes ranging from
about 500 mg to more than 1000
mg/day
• Milk intake ranging from none to
more than four servings a day
was unrelated to hip fracture in men
or women
Calcium intake and risk of fracture: systematic review
BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h4580

8. • While international comparisons
such as these can be “confounded”
(meaning influenced by other
factors including genetics and
physical activity level)
→Show that high intakes of dairy
products are not required to keep
our bones from crumbling
Relationship between milk intake and hip fracture rate. From N Engl J Med 2020;382:644–54.
!!! countries with the highest milk consumption, like Sweden, tend to have a
higher risk for hip fracture than those with the lowest consumption, like China !!!

9. • Even among the young → No evidence that milk protects against fractures later in life
• Among almost 1,00,000 adults studied in middle age or older, each additional glass of milk a day
consumed in adolescence was associated with a 9% higher risk of hip fracture in men
• Relationship apparently explained by height → Milk may not strengthen bones, but children who drink
lots of it tend to be taller.

11. What about milk and obesity?
• Despite widely advertised claims to the contrary:
• Clinical trials show no overall effect of dairy products on body
weight or the success of obesity treatment
• The amount of fat in dairy products does seem to influence
weight over long-term → just not in the way experts had thought
• In studies involving young children/ adolescents/ adults
consumption of full-fat milk was associated with less weight
gain or a lower risk for obesity compared to the same
amount of reduced-fat milk

12. 1st Food Guide Pyramid?
• During the low-fat diet craze of late 20th century,
we were told that eating fat makes you fat, and
that carbohydrates were the healthiest nutrient.
• Of course, things didn’t turn out well, with
skyrocketing obesity rates over last 40 years
• We now know that many high-fat foods are not
only healthy, but also highly “satiating” →
helping us to feel full after eating.
• Consider a child in the 1960s who, for an after-
school snack, had a glass of whole milk and two
cookies
• Today that typical child might have fat-free
milk and, because she felt less satisfied, 4-5
cookies → A bad trade-off for metabolism,
weight, and general health.

13. The link between milk and heart disease
• In addition to the (mistaken) belief that it would promote weight loss, reduced-fat milk was
recommended out of concern for the high saturated fat content in whole milk
• Saturated fat is known to raise LDL (“bad”) cholesterol and, in population studies, is
associated with heart disease
• However, saturated fat also increases HDL (“good” cholesterol) and lowers triglycerides in
comparison to carbohydrates.
• In addition, all saturated fats are not alike, with those in dairy having some potentially
beneficial effects.
• As with weight, a critical and often overlooked question is:
How dairy foods fit into an overall diet. Specifically, what other foods might be eaten
in place of dairy products, or dairy fat?
• If the replacement is sugar and other processed carbohydrates, the impact on your
waist and heart will probably not be good.

14. What about milk and cancer risk?
• Dairy products contain growth-stimulating factors
• Could high levels of consumption increase risk for cancer, a disease of uncontrolled
cellular growth?
• Despite extensive study, the answer remains… maybe
• Milk consumption is linked to prostate cancer in men and endometrial cancer
(but probably not breast cancer) in women.
• In contrast, milk consumption may protect against colorectal cancer.
• However, as with other studies of associations involving cancer, it can be difficult to
prove cause and effect.
• Furthermore, most studies focus on adults in middle age or later, whereas risk factors
for cancer may extend back to childhood

15. Other issues to consider:
Allergies and environmental risks
• Many populations around the world have lactose intolerance → limiting the
amount of milk that can be consumed.
• For some people without symptoms of intolerance, regular consumption may
predispose to allergies and allergic conditions, such as eczema and asthma
Dairy consumption also impacts the environment in which we all live…
• In contrast to traditional integrated farming methods — with grass-fed animals
that may help recycle carbon into the soil — high-intensity industrial milk
production produces large amounts of greenhouse gasses, water pollution, soil
degradation, antibiotic resistance, and other environmental disruptions

16. In the end…
• There is no human requirement to drink the milk of other animals
• All the nutrients in milk can be obtained in the necessary amounts from other dietary
sources
• For calcium, alternative sources include kale, broccoli, nuts, seeds, beans, sardines,
and other whole foods
• Milk and other dairy products may provide health benefits for those with poor diet
quality, especially children
• For people following a healthy diet, high intakes of dairy might cause harm
• There is no evidence for health benefits of reduced-fat over whole milk

17. Take-home messages
1. The currently recommended three servings a day of milk is excessive.
Consider zero to two servings a day as a reasonable range.
2. Avoid sugar-sweetened milk and dairy products.
3. If you consume dairy, enjoy the full-fat versions!

18. Dr. David Ludwig
Physician, Nutrition Researcher, and Public Health Advocate
#1 NY Times bestselling author of ALWAYS HUNGRY? and ALWAYS DELICIOUS
Reference