This strongly suggests that it would be helpful to find a way to bring
the enzymes into the gut of those who are lactose intolerant. Otherwise milk products are a valuable food
source. Controversy on calcium is also
misplaced only because the industry chose to connect the dots in a way that
suited their marketing.
Otherwise, the dairy economy literally populated the forestlands of
Europe. A burned off clearing became
pasture and easily remained pasture with modest effort. These later became cropping fields.
A small herd provided real food security for a family and it was
naturally conserved. In time game meat
was supplemented by semi wild pigs and chickens of course. This all took place in a biome where plant
foods were generally problematic, taking millennia to establish properly.
Should Humans Drink Cow’s Milk? New Study of Neolithic
Farmers May Have the Answer
Many would remember
the days when a milk trolley would be rolled out during morning recess at
school and all the children would come running for their daily glass of milk,
or the TV images of energetic children racing around the playground with the
message to drink milk for healthy bones. However, new research has
questioned whether drinking cow’s milk is actually good for us at all. The
answer to this question may lie in a new
study of our ancient Neolithic ancestors who
first began the practice of dairy-related animal husbandry.
A multidisciplinary
team of scientists from an EU-funded initiative, which began in 2009, examined
the role played by milk, cheese, and yogurt in the early colonization of Europe
and found that until 8,000 years ago, humans were only able to digest
lactose, a form of sugar present in milk, during childhood and that as
adults they lost the ability to produce endogenous lactase, the enzyme required
to break down lactose.
However, shortly
before the first farmers settled in Europe, a genetic mutation occurred in
humans that resulted in the ability to produce lactase throughout their lives.
Increasing numbers of adults in Central and Northern Europe were since been
able to digest milk.
Just 5,000 years ago,
lactase persistence was almost non-existent among the population but
researchers believe that extensive positive selection and recurrent waves of
migration were responsible for this development.
"To appreciate
the significance of our findings, it is important to realize that a major
proportion of present-day central and northern Europeans descend from just a
small group of Neolithic farmers who happened to be able to digest fresh milk,
even after weaning," explained Anthropologist Professor Joachim Burger of
Johannes Gutenberg University Mainz (JGU). This reveals that far from
being normal, the ability to digest milk is only the result of a strange
genetic adaption.
[ This genetic adaptation just happened to allow actual cattle
husbandry and the populating of Europe. ]
Scientists point out,
however, that 60%
of modern-day people still lack the enzyme for breaking down lactose and
just don’t know it, meaning that they experience a wide range of digestive and
allergy problems which they have never had attributed to their milk-drinking.
Another argument that
has been recently been debunked is that drinking cow’s milk increases bone
strength and prevent osteoporosis. In fact, the skeletons of our Palaeolithic
ancestors, who did not drink milk, reflect great strength and muscularity and a
total absence of advanced osteoporosis, possibly due to the fact that research
has shown we can get as much calcium as we need from grains and vegetables
alone.
Of all the mammals on
earth, human beings are the only ones who continue to drink milk beyond
babyhood. Whether this should be the case or not is now in doubt.
Should Humans Drink Cow’s Milk? Part 2 - Digesting
Milk in Ethiopia
Yesterday we reported on a new study
of our ancient Neolithic ancestors who first began the practice of
dairy-related animal husbandry and discussed the implications this may have
with regards to the controversial questions – should human’s drink cow’s
milk? Now a second study has just been published in The American Journal
of Human Genetics tracing the origins of the ability to digest milk in Ethiopia.
A genetic phenomenon, called ‘soft selective sweep’, which allows for the
selection of multiple genetic mutations that all lead to a similar outcome -
the ability to digest milk - has been characterised for the first time in
humans. The study demonstrated that individuals from the Eastern African
population have adapted to be able to digest milk, but via different mutations
in their genetic material. We need lactase when we are babies to digest our
mother's milk, so in babies large amounts of lactase enzyme are expressed by
our genes. When we are older we no longer rely on our mother's milk for
essential nutrients, so in most humans manufacture of the lactase enzyme stops
through de-activation of the corresponding gene. However, subtle mutations in the
regulatory region of the gene in some individuals cause lactase to carry on
being expressed into adulthood. "Our genetic make-up determines our
ability to digest milk into adulthood. Just over a third of the global
population have inherited genes that allow us to make lactase, the enzyme that
digests milk, as adults,” said Professor Dallas Swallow, from the Department of
Genetics, Evolution and Environment. "This study shows that several
different genetic changes that allow our bodies to make lactase have emerged
independently. Changes to our lifestyle over the past 10,000 years -- including
diet, altitude acclimatisation and infectious disease resistance -- will likely
have caused many genetic adaptations of this kind,” said Swallow. Only in the
last 5,000 to 10,000 years have humans started drinking the milk of other
animals, following advances in our ability to herd animals. In times of plenty,
being able to drink the milk of other animals would not have given a particular
advantage to those with lactase persistence. However, in situations where food
sources became scarce, individuals capable of producing lactase as adults would
be able to drink the milk of their animals, increasing their chances of
survival. Ethiopia has been subject to frequent droughts that contribute to
famine. Individuals who can digest milk are more likely to increase their
chance of survival under these conditions. –
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