The Sunday Times Magazine
July 21, 2002
Cover feature: Is there a time bomb in your diet? Exploding the myths
about milk
MILK: NECTAR OR POISON?
Investigation by Peter Martin
Cow's milk is full of calcium, giving you healthy bones. It contains
the vitamins B12 and riboflavin, and low-fat milk prevents some cancers
and heart disease. Milk can increase the risk of cancer. It can trigger allergies and
osteoporosis. And the saturated fats in whole milk are hazardous for
your heart.
Just 7,000 years ago, the first settled communities, with their new-found
genius for growing crops and domesticating animals, were able to create
a relative heaven on Earth, verily a 'land of milk and honey'.
But dairy culture was largely confined to the Caucasian minority, and
today most of humanity still thinks it a very peculiar practice to consume
milk beyond the end of weaning, and even more peculiar to drink the
milk of another species.
A handy measure here is lactose intolerance. For 7 out of 10 people
worldwide, drinking cow's milk would bloat them uncomfortably, if not
give them the squits.
But we milky few stuck at it, and selective pressure gradually knocked
out the genes responsible for our severest reactions to milk. Not that
everyone approved of the white stuff. Hippocrates, the father of medicine,
swore by milk-exclusion diets for curing all sorts: enfeebled babies,
diarrhoea, skin complaints, wheezing, painful joints.
In the main, however, once it was twigged that putting a cow serially
into calf keeps the milk flowing, her fertile, maternal glamour became
synonymous with tribal good. Today, the New Zealand dairy industry invokes
that same sense of bovine blessing with images of blonde jerseys batting
their soulful eyelashes. For us, of course, dear old Daisy will for
ever be a black-and-white friesian grazing on lush grass.
But there's no Easter bunny, either. In reality, the modern high-yield
dairy cow is a pitiful, ramshackle embodiment of market-driven exploitation.
The new UK model, so help us, is the American holstein battery cow.
A shed-housed fermentation vat on legs, teats dragging on the ground,
it's a sight to frighten children - a giant, 650-kilo, emaciated ectomorph
resembling Frankenstein's goat. Kept hungry by the demands of its genetically
uprated metabolism, it eats more or less round the clock and produces
100 pints of milk a day, twice as much as Daisy ever managed.
Trouble is, after years-long genetic selection for ever-increasing milk
yield, today's holsteins blow up or break down at the slightest glitch
in feeding or welfare. In the larger American herds, they're fit only
for culling, done and busted, by the age of three. They rarely manage
two calves, and the average number of lactations - periods of milk-giving
- is down to 1.8 and dropping.
The holsteinisation of the UK dairy herd is already under way, however.
Farmers have not been able to resist the genetic promise: a 2% compound
increase in milk yield annually. So it is that the Holstein-Friesian
mix is our commonest dairy creature. Welfare wasn't too good when Daisy
was supreme, but fully 80% of UK dairy cows now go for what's called
'involuntary' culling.
'It's not cost-effective and it's cruel,' says Professor John Webster
of Bristol university's veterinary school, and Britain's leading authority
on animal husbandry.
'I'm not going to dissuade farmers from going for genetic improvement,
but going for every improvement just doesn't work. We see farmers already
down to two lactations as an average lifetime performance - as opposed
to five, six, even eight.'
So much for the poor cow. Now to the milk: the current crisis facing
the western dairy industry centres on whether or not the white stuff
is the right stuff for optimising human health. Of all sacred cows,
even milk as the supposed ideal source of calcium for bone health has
come under the stun gun.
As never before, the dairy industry is fighting a pitched battle to
uphold consumer belief in the 'essential goodness' of its products.
Consider some recent exchanges of unfriendly fire:On breast cancer:
'To discover that lifelong milk drinkers have a reduced risk of breast
cancer is an exciting step forward.' Dr Anita Wells, of the UK Dairy
Council, on a recent Norwegian study.
'The contradicting results may indicate that any association between
milk and breast cancer is not a strong one.' Dr Anette Hjartaker, of
a Norwegian research team, commenting on a whole range of studies into
breast cancer and milk consumption.
On heart disease: 'There is no scientific evidence to support the claim
that drinking milk and eating dairy products, per se, which provide
some saturated fat, increases the risk of heart disease.' The UK Dairy
Council.'Women who ate more unsaturated fat instead of saturated fat
had fewer heart problems.'
Dr Walter Willett, on the Harvard Nurses' Health Study involving 78,000
women.
In the almighty propaganda war between the industry and an army of 'anti-milk'
campaigners of the vegetarian and animal-rights persuasion, both sides
are equally ruthless in their selective recourse to the evidence. The
shining exception is the handful of hard-science types working on behalf
of 'the green stuff'.
One such is Dr T Colin Campbell, professor emeritus at Cornell University,
New York state, and a pioneer of dietary epidemiology. 'I see it as
unarguable,' he says. 'For disease prevention, nutrition, and the whole
matter of animal protein, including milk and dairy, is at the very centre
of the plate.'
Another hard-science 'green-stuff' type is Dr Stephen Walsh, lecturer
in advanced process control at Imperial College, London, and the Vegan
Society's accomplished data-buster. It was Walsh who recently nailed
the US and UK dairy councils' specious claim for milk's protective role
in breast cancer. But the councils are unrepentant.
'It's very good news about breast cancer,' the UK DC's Dr Wells told
me, citing just two studies that have shown a protective effect but
none of those describing negative or null effects. 'What these anti-milk
people do is quote the bits that suit them while ignoring the entirety
of the evidence.' Oh dear.
Back to Walsh: 'If there is a beneficial effect of milk in relation
to breast cancer, it is most likely due to the calcium and vitamin D
content. And if there is an adverse effect, it's most likely to be from
milk's effect on the IGF-1 insulin growth factor.' (Background: IGF-1
naturally occurs in human and in cow's milk. Once genetic protection
has been breached, IGF-1 accelerates malignant cell growth, and is one
of the targets of the anti-cancer drug tamoxifen.) 'On balance,' says
Walsh, stun gun cocked, 'the best course is to get your calcium and
vitamin D from somewhere other than milk, and skip the potential hazards
of IGF-1.'
You can see why cow's milk might upset anyone who has never drunk it
before. It's not just because people with no dairy tradition lose the
metabolic ability to process the lactose in their own mother's milk
by the age of four. Every kind of milk - human, elephant's, camel's
or dog's - is formulated to meet the different growth needs of its young.
In the cow's case, that of a herbivore with four stomachs, a huge bone
mass and a tremendously hormone-charged growth rate. But although we
milky few have genetically adjusted to some of milk's 'alien' elements,
there are others we appear not to have accommodated, and which inevitably
seek out unintended biochemical roles for themselves.
As Hippocrates suspected, the white stuff is the commonest cause of
childhood allergies. Standard medical advice is that such allergies
usually desist by the age of three. But in a recent Finnish study, two-thirds
of a group of 56 infants diagnosed with cow's-milk allergy were still
allergic and highly symptomatic at the age of 10. Other studies show
that many children are milk-allergic but don't know it. Reactions include
runny noses, wheezing, coughing, ear infections, rashes and stomach
upsets. When milk is withdrawn from their diet, symptoms improve or
clear altogether, and reintroducing it leads to relapse in the majority.
The chief culprits appear to be lactose and bovine protein.
More serious is the evidence that frequent milk and dairy consumption
can more than double the risk of prostate cancer. It appears that milk,
by raising IGF-1 levels, promotes cancer growth; at the same time, excessive
calcium suppresses vital vitamin-D activity, which reinforces malignant
cell growth. Two years ago, after the then mayor of New York, Rudolph
Giuliani, had been diagnosed with prostate cancer, Peta (People for
the Ethical Treatment of Animals) ran billboard images of him with a
'milk moustache' and the line, spoofing US 'Got milk?' ads, 'Got prostate
cancer?'
Zero for taste, but scientifically spot on.
The most notorious of the anti-milk advocates is the American Robert
Cohen, author of Milk: The Deadly Poison, and slash-and-burn boss of
www.notmilk.com. To start with, Cohen looked like a good guy,
not least for his campaign against Monsanto's genetically engineered
cattle hormone, bovine somatotropin (BST). When injected into cows,
it boosts milk yield by 20%. But it also increases mastitis and antibiotic
crossover into humans, as well as upping IGF-1 levels in the cow and
in the milk.
The US Food and Drug Administration passed BST for use in 1993, since
when Monsanto has successfully prosecuted US producers that presumed
to put 'BST-free' on their milk cartons. Although we import some US
dairy products from BST-treated herds, BST's use - if only for the moment
- is still banned in Europe.But Cohen has lately assumed the role of
messianic propagandist. At an EarthSave conference last year, he claimed
that if children in the initial stages of type-1 diabetes were put on
a milk-exclusion diet, the diabetes would stop developing. Challenged
by EarthSave to produce attested cases, he flounced off. Cohen's next
outrage was to label the Norwegian paper on milk and breast cancer 'the
most fraudulent study of the century', and insisted that milk drinkers
had 6.4 times the risk of breast cancer.
'Complete rubbish,' says Walsh. 'But because Cohen was bringing all
of us into disrepute, I challenged him on the data, and gave him a month
to reply or I'd go public. He didn't, so I did.' The American VegSource
website has since disowned him with an electronic valediction entitled
The Sad Truth about Robert Cohen.
For the 'green stuff', less dismissible is the Washington, DC-based
Physicians Committee for Responsible Medicine (PCRM). Recently, it posted
a well-balanced update of milk's role in prostate cancer. But such is
its anti-milk bias, you'll hear nothing from the PCRM about milk's equally
probable protective role in colorectal cancer. Never has consumer choice
been so gritty. Drink milk and 'win' on colorectal cancer but 'lose'
on prostate; or get adequate calcium from other sources.But while the
brazenly anti-milk campaigners are a serious nuisance to the dairy industry,
the hard-science green groups are a much more formidable enemy. One
such is the Vegetarian Nutrition Dietetic Practice Group (VNDPG).
In January, the US National Dairy Council called a 'calcium crisis'
summit. Ostensibly an open debate, the security arrangements were specifically
designed to exclude any member of the VNDPG - and you could see why.
The VNDPG's science-solid party piece consists of demonstrating that
all the recommended dietary allowances - for protein, fats and nutrients,
including calcium - can easily be met within a plant-based diet and,
by extension, that nobody has need of milk or dairy.
The industry's most successful propaganda coup, of course, has been
to equate essential calcium with dairy products. Which is why the cow-flop
hit the fan when the Harvard Nurses' Health Study delivered its first
results on milk consumption and bone health in 1997. Bottom line: those
women who got the most calcium from dairy appeared to be at twice the
risk of hip fracture of those who got very little. The PCRM ran billboard
and newspaper ads across America - 'Milk Does Not Protect against Bone
Breaks' - while Peta still goes so far as to claim that milk and dairy
actually cause osteoporosis.
But they're both wrong. For it now appears that the nurses' study had
been confounded on two counts. One centred on the vitamin A, in the
form of retinol, that US milk-producers put into low-fat milk. Most
studies involving retinol-free milk show a neutral or bone-protective
effect. But a recent US investigation found that retinol is strongly
associated with increased fracture risk, confirming a similar study
in Sweden. It seems the nurses had been drinking from a poisoned chalice.
The other catch-22 was the nurses' own health savvy. As shown by an
Australian study, people with a family history of fractures deliberately
increase their calcium intake by way of self-defence. So, although it
looked as if the nurses' high milk intake caused more fractures, this
may be illusory owing to at-risk individuals consuming more milk in
unsuccessful attempts to protect their bones.
So what's the whole picture? Milk is protective of bone health, but
protection diminishes dramatically in older people. As The American
Journal of Clinical Nutrition recently concluded, 'Age-related bone
loss may be more attributable to excess calcium loss than to inadequate
calcium intake.' (Our italics.)
That's the bone breaker: excess calcium loss. Where the dairy industry
and public policy get it wrong is in placing undue importance on calcium
intake. For one thing, other dietary factors operate like bone thieves.
Salt and animal protein - most notably chicken, fish and eggs - all
result in net calcium losses through urine. Conversely, extra potassium
from a diet rich in fruit and vegetables buttresses retained calcium
by limiting losses. Walsh puts it well: 'Relying on calcium alone to
prevent osteoporosis is like fielding a football team with only strikers
and no defenders.'
The critical factor, then, is calcium balance - and on that score, the
white stuff falls down badly. Several substances in milk, particularly
protein, contribute to calcium losses. Result: a third of the calcium
initially absorbed by the body from milk is then wasted, through urine,
in losses caused by the milk itself; from cheese, more than two-thirds
is wasted. Bad news for those with poor calcium absorption, as among
many elderly people, and the genetically prone.
So which are the best bone foods? Granny was right: eat your greens!
They're unbeatable for calcium absorption, while minimising losses (excluding
spinach, which has too-high oxalate levels). The superstar of bone health
is vitamin K, staple of green, leafy vegetables - the darker the leaf
the better; 100 grams per day of such vegetables provides enough vitamin
K to halve the risk of fracture.
Better still, greens provide other minerals that improve calcium balance.
Although a pint of milk contains twice as much calcium as 200 grams
of spring greens, because of lower protein and higher potassium the
greens pack the same punch on retained calcium. And other vegetables
and fruits, such as peppers, oranges and bananas, although low in calcium,
reduce calcium losses by virtue of their richness in potassium.
Of course, diet is not the sole key to bone health. Top of the must-have
list is enough vitamin D to convert dietary calcium into bone - via
sunshine (ideally 15 minutes a day) or, in winter, vitamin supplements.
With bones, it's also a case of use 'em or lose 'em. Key here are impact
exercises like jogging, ball games, step exercises or walking - which,
even in the elderly, strengthens bones. But very, very old bones tell
their own story. According to the fossil evidence, pre-dairy hunter-gatherers
were so well blessed with calcium, potassium and vitamin K from plant
sources, plus sunshine D from so much outdoor trekking, that they had
bones like rhinos'.
Wary of the dangers of saturated fats, most of us have switched to lower-fat
milk over the past 20 years. Even while charging the same price for
low-fat as for whole milk, however, the dairy industry now recycles
much of that skimmed-off saturated fat into upwardly aspirant foodstuffs:
greater ranges of cheese and cream products, biscuits, pastries, cakes,
pizzas, ice cream, sauces, dips and ready meals. As the Harvard epidemiologist
Dr Walter Willett says, 'Once a cow is milked, the fat from that milk
is in the food supply, and someone ends up drinking or eating it.'
The recommended intake of calories from saturated fat consistent with
good health is 10%. But the national figure is 14%, and dairy fat is
the single source for more than a third of them. The consequences are
disastrous.
'Individuals make their informed dietary choices,' says Dr Mike Rayner,
a nutrition and heart specialist at Oxford university. 'But you have
to look at what's happening at the population level and, as far as cardiovascular
disease and strokes are concerned, the very top of the danger hierarchy
is saturated dairy fat, including the stuff that's found its way back
into the food chain.'
The UK Dairy Council's website - much of it harping on the scary theme
of 'Is your child missing out?' - has nothing to say about its recycled
saturated fats. But its offerings on milk and dairy amount to revisionism
of a sort to beggar belief: 'There is no scientific evidence to support
the claim that drinking milk and eating dairy products, per se, which
provide some saturated fat, increases the risk of heart disease.'
No scientific evidence? Consider the 1950s trial of the 'sippy diet',
which compared patients who had been put on a milk-sipping treatment
for ulcers with those who hadn't. Autopsy results showed that sippy-dieters
had had more than double the heart attacks. More recently, the Harvard
nurses' study showed that women drinking two glasses a day had 67% more
risk of heart disease than those drinking no whole milk.
Only low-fat milk is exonerated. Indeed, the Harvard nurses who drank
it showed a modestly reduced risk of heart disease. In sum, the results
separated the cardiovascular hazard of saturated fat from the cardio-protective
effect of calcium. So let's be clear. Low-fat milk doesn't hurt the
heart; it can lower blood pressure. But the dairy industry insists on
making the same claim for the entirety of dairy products and for whole
milk - and it's just not on.
Up in arms, the Vegan Society has just formally challenged both the
US and UK dairy councils to substantiate their 'wishful thinking' and
'selective citation' of the scientific evidence on the core issue of
saturated dairy fats. Walsh has planted his battle standard on several
internet sites. 'But our intention,' he says, 'is to challenge them
on a whole range of health claims. If someone continues to use dairy,
that's their choice, but we'd like it to be an informed choice.'
But it gets weirder. Not content to claim saturated fats as harmless,
the industry now wishes to cite them as a boon to good health. Take
this recent UK DC claim: 'A natural fat found in milk, cheese, yogurts
and butter may soon prove to contain anti-cancer properties.'
The magic fat is actually a group of conjugated linoleic acids (CLAs).
But contrary to the council's implicit message, there's a good reason
why eating more dairy will not confer any of CLAs' thus far theoretical
benefits. Their proportion is only 1 in 120 parts of saturated fat;
ergo, to come by a significant amount of CLAs, you'd have to eat artery-choking
amounts of the fat stuff.
'The existence of CLAs is not a health boost for dairy products as we
know them,' explains Professor Philip Calder, in charge of Southampton
university's CLA research project, which is co-funded by the Milk Development
Council. As well, he says:'While CLA animal experiments looked promising,
the human results have been disappointing.' Calder is now running a
volunteer trial using single forms of CLA, to discover if their micro-components
can switch on, or off, genes relating to anti-cancer function in humans.
Concurrently, agricultural boffins at Reading university are seeking
to manipulate the types and composition of CLAs at source - in the dairy
cow. 'Ultimately, the intention is to make new dairy products containing
more CLAs and less saturated fats per serving,' says Calder.
Of course, commercial science will look to where it's paid. 'CLA research
was actually got going by the American meat and dairy industry,' says
Dr Campbell, 'and it's very depressing when people start looking into
little components of this and that. Let's face it, if dairy products
contained all the good things that fruit and vegetables do, we'd be
tired of hearing about them by now.' Indeed, for evidence-backed protection
against a whole range of cancers - breast, ovarian, prostate and colon
- you have only to look at the combination of folate, as found in green
vegetables, and lycopene, as in red produce: peppers, strawberries,
watermelon and cooked tomatoes especially. Plus the entire 'rainbow'
of fruit and vegetables contains tens, if not hundreds, of thousands
of cancer-fighting antioxidants.
As for heart disease, even cholesterol-jammed sufferers can reverse
the damage done by saturated fats by switching to unsaturated ones.
Evidence first emerged from a 1960s study which found that people in
Crete, who consumed 40% fat mostly from olive oil, were the longest-living
population. Then a 1990s French study put heart-attack survivors on
a Cretan-like diet, including plenty of plant monounsaturated and omega-3
fatty acids. Their heart-attack rate dropped by 70% compared with those
on a standard 'prudent' diet.
Even so, the industry is probably right to warn that cutting out milk
and dairy might be hazardous. But that's because the national way of
eating is so awful that creating a 'menu for good health' would entail
a complete dietary overhaul. Modern children, for example, as established
in a 1999 UK study, eat far less healthily than those of the 1950s,
despite the food rationing and shortages of the time. The UK DC gives
the game away with the desperate argument that a glass of milk contains
'less fat than a packet of crisps or a regular-sized bar of chocolate'.
And what, pray, is the chief constituent of a chocolate bar?
Dr Rayner estimates that cutting out saturated fat would more than halve
the risk of heart disease. 'Another Dairy Council argument,' he says,
'is that you need the protein from dairy products. You don't. There's
no evidence of protein deficiency in the UK. Well, yes, we all need
calcium. But osteoporosis is nothing like as large a public-health problem
as cardiovascular disease and stroke. So they can't really argue that
the [bone] benefits of milk and dairy override the dangers of saturated
fats.'
Meantime, the animal-protein industries continue to colonise the globe
with animal-based 'diets of affluence', usually starting with a Big
Mac and a milk shake. As it happens, standard industry advice to the
unconverted on overcoming their lactose intolerance is to persist with
taking a little milk with meals. At the back of all this, lest we forget,
is the modern grotesque of the high-yield battery cow. Has the claim
for milk and dairy as natural foods ever been so tenuous?
'Taken all together - the welfare and environmental issues, and the
adverse health evidence - it posits a fundamental change in British
agriculture,' says Rayner. 'But there's huge reluctance on the part
of the farming community, and the Food Standards Agency doesn't even
have it on its agenda to move us away from an animal-dependent system
to a more plant-based agriculture. It makes no sense.'
© Copyright 2002 Times Newspapers Ltd.
Reproduced with permission
