Milk is touted to build strong bones, but a compilation of all the best studies found
no association between milk consumption and hip fracture risk; so,
drinking milk as an adult might not help bones, but what about in
adolescence? Harvard researchers decided to put it to the test.
Studies have shown
that greater milk consumption during childhood and adolescence
contributes to peak bone mass, and is therefore expected to help avoid
osteoporosis and bone fractures in later life. But that’s not what
researchers have found (as you can see in my video Is Milk Good for Our Bones?).
Milk consumption during teenage years was not associated with a lower
risk of hip fracture, and if anything, milk consumption was associated
with a borderline increase in fracture risk in men.
It appears
that the extra boost in total body bone mineral density from getting
extra calcium is lost within a few years, even if you keep the calcium
supplementation up. This suggests a partial explanation for the
long-standing enigma
that hip fracture rates are highest in populations with the greatest
milk consumption. This may be an explanation for why they’re not lower,
but why would they be higher?
This enigma irked a Swedish research team, puzzled because studies again and again had shown a tendency of a higher risk of fracture with a higher intake of milk. Well, there is a rare birth defect called
galactosemia, where babies are born without the enzymes needed to
detoxify the galactose found in milk; so, they end up with elevated
levels of galactose in their blood, which can cause bone loss even as
kids. So maybe, the Swedish researchers figured, even in normal people that can detoxify the stuff, it might not be good for the bones to be drinking it every day.
And galactose doesn’t just hurt the bones. Galactose is what
scientists use to cause premature aging in lab animals—it can shorten
their lifespan, cause oxidative stress, inflammation, and brain
degeneration—just with the equivalent of like one to two glasses of
milk’s worth of galactose a day. We’re not rats, though. But given the
high amount of galactose in milk, recommendations to increase milk
intake for prevention of fractures could be a conceivable contradiction.
So, the researchers decided to put it to the test, looking at milk
intake and mortality as well as fracture risk to test their theory.
A hundred thousand men and women were followed
for up to 20 years. Researchers found that milk-drinking women had
higher rates of death, more heart disease, and significantly more cancer
for each glass of milk. Three glasses a day was associated with nearly
twice the risk of premature death, and they had significantly more bone and hip fractures. More milk, more fractures.
Men in a separate study also had a higher rate of death with higher
milk consumption, but at least they didn’t have higher fracture rates.
So, the researchers found a dose dependent higher rate of both mortality
and fracture in women, and a higher rate of mortality in men with milk
intake, but the opposite for other dairy products like soured milk and
yogurt, which would go along with the galactose theory, since bacteria
can ferment away some of the lactose. To prove it though, we need a
randomized controlled trial to examine the effect of milk intake on
mortality and fractures. As the accompanying editorial pointed out, we better find this out soon, since milk consumption is on the rise around the world.
What can we do for our bones, then? Weight-bearing exercise such as
jumping, weight-lifting, and walking with a weighted vest or backpack
may help, along with getting enough calcium (Alkaline Diets, Animal Protein, & Calcium Loss) and vitamin D (Resolving the Vitamin D-Bate). Eating beans (Phytates for the Prevention of Osteoporosis) and avoiding phosphate additives (Phosphate Additives in Meat Purge and Cola) may also help.
Maybe the galactose angle can help explain the findings on prostate cancer (Prostate Cancer and Organic Milk vs. Almond Milk) and Parkinson’s disease (Preventing Parkinson’s Disease With Diet).
Galactose is a milk sugar. There’s also concern about milk proteins (see my casomorphin series) and fats (The Saturated Fat Studies: Buttering Up the Public and Trans Fat in Meat and Dairy) as well as the hormones (Dairy Estrogen and Male Fertility, Estrogen in Meat, Dairy, and Eggs and Why Do Vegan Women Have 5x Fewer Twins?).
Milk might also play a role in diabetes (Does Casein in Milk Trigger Type 1 Diabetes, Does Bovine Insulin in Milk Trigger Type 1 Diabetes?) and breast cancer (Is Bovine Leukemia in Milk Infectious?, The Role of Bovine Leukemia Virus in Breast Cancer, and Industry Response to Bovine Leukemia Virus in Breast Cancer). Nutrition Facts
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