The Evolution of the White Mustache

Ad campaigns proclaim through white-mustachioed celebrities: “Milk: It does a body good.” This bovine-born best friend of cupcakes, this basis of cheese, this bedfellow of cereal is also the bedrock of nutrition in many cultures. Indeed the human love affair with dairy goes back thousands of years to our very dawn as farmers and animal-keepers. Our love of milk is stamped on our genome.

Of course today, in a world bursting with Haagen Dazs, Kraft singles and industrial agriculture, eating dairy may be less survival tool and more dangerous indulgence. To many, the creamy white liquid is a nutritional nightmare: a source of deadly chemicals and the root of allergies, inflammation and behavioral problems. But fount of goodness or drink of the damned, milk and mankind have forged a bond unlikely to break anytime soon.

Cattle were domesticated some 8,000 years ago in the Fertile Crescent of the Near East. While it was originally thought that the practice originated in this area and then spread, there is evidednce that Africans likely independently domesticated cattle. Indeed, the harsh scrublands of Africa were likely ideal climes for dairy drinking to flourish, says anthropologist Diane Gifford-Gonzalez of the University of California, Santa Cruz. “You can’t farm the savanna,” she says. Dairy was just a natural progression of rearing cattle in an area where agriculture was impossible and food scarce.

If water was lacking or polluted, milk was a cleaner alternative. If food was lacking, milk was the perfect energy drink, loaded with fat, protein and carbohydrates.

However grand the benefits of lifelong dairy drinking, it did present the human digestive system with a problem. Babies are born with the right tools for drinking milk – specifically, the enzyme lactase, which breaks down the milky sugar lactose. But as we grow up, lactase production tapers off. An estimated 50–75% of the world’s population cannot easily digest milk, ice cream or cheese. Instead they live on yogurt and other fermented dairy products that have little lactose.

So communities that thrived on milk just had to evolve. According to studies by Mark Thomas of University College London and Sarah Tishkoff at the University of Maryland, when northern Europeans and tribal East Africans settled into cattle rearing, they developed several mutations that kept the lactase gene churning away into adulthood.

Tishkoff found that pastoral African populations developed the mutation between 3,300 and 4,500 years ago. Thomas found that in northern Europeans, mutations conferring lactose tolerance arose about 7,000 years ago.

The mutations conferred a distinct survival advantage – being able to drink milk kept them alive and hydrated, says Tishkoff. And to this day, says Gifford-Gonzalez, many cultures still depend on milk as a primary nutrition source, partially explaining why lactase mutations carry over from generation to generation. “If cows disappeared, folks like us would not be fazed, but other groups would be extinct in no time,” she says.

Our intimate coevolution with dairy suggests there is nothing more natural than a squirt of milk on your breakfast – at least if you have the right genetics to enjoy it. Of course the Western relationship with dairy foods has changed. Water quality and food scarcity are no longer an issue in the West, says Gifford-Gonzalez. So milk may now be more of a supplement than a staple – and its popularity is waning. According to the USDA, per capita consumption of beverage milk in 2000 was down 38% since the 1950s (from 36 gallons per year to 23).

The milk we drink doesn’t look much like the body-temperature beverage enjoyed by our ancestors, fresh from the teat. It’s processed, pasteurized, defatted, dried, sugared and stuffed with chemicals. It can still do a body good – but there’s some bad stuff too.

So while it may have saved our ancestors from famine and disease, what does milk do for us today?

THE GOOD:
Promotes weight loss
A 2004 study by Michael Zemel at the University of Tennessee found that obese people who ate a high-dairy diet lost more weight than those on a low-dairy diet. The authors thought it was the increased calcium that promoted fat loss. However, this study lost a lot of steam when it was revealed that it was sponsored by the National Dairy Council. But just this week, a new study from the UK found that men who drank a least a pint of milk (and also ate lots of cheese and yogurt), were 62% less likely to have metabolic syndrome (short hand for obesity, diabetes and cardiovascular disease).

Fights osteroporosis
Milk is a source of calcium, which is good for the bones. The National Academy of Sciences says healthy adult women aged 19 to 50 should consume 1,000 milligrams of calcium a day. But the Harvard School of Public Health says results of the long-term Nurses Health Study shows no difference in broken bones, regardless of calcium consumed. In Asia and India, calcium intake is lower with no adverse effect on bone health, and now in Britain, the recommended calcium dose has been lowered to 700 milligrams.

Fights PMS
The long-term Harvard University Nurses Health Study suggests that mood swings associated with PMS are lower in women who drink milk. The study was published in 2005 in the Archives of Internal Medicine. Anxiety, irritability and sadness were reported less by women in the study. However, the study was sponsored in part by a pharmaceutical company that makes calcium supplements.

Fights cancer
A meta-analysis published in the Journal of the National Cancer Institute in 2004 showed a link between increased milk and calcium consumption and lowered colon cancer. Another large study of the Netherlands Cohort Group looked specifically at yogurt and colon cancer in 1994, since many studies have suggested bacteria in yogurt is good for health. The study found no link between increased yogurt consumption and decreased colon cancer.

Contains uber-good conjugated linoleic acid
A 1994 study in Cancer Research showed a diet including conjugated linoleic acid (from dairy) reduced mammary tumors in rats. Preliminary work published in 2000 in the Journal of the American College of Nutrition showed conjugated linoleic acid keeps cholesterol from packing up in rabbit arteries. A 2005 study from the University of Wisconsin - Madison also found that CLA fights harmful inflammation and immune response in rodents.

Has lots of vitamins
Vitamin A, a member of the carotenoid family, is found as retinol in milk, and is added to lowfat and skim milk. It helps with things like night vision and healthy skin and teeth. Naturally occurring amounts of vitamin D, plus the 300 to 400 international units usually added, help prevent osteoporosis and may help prevent breast cancer, according to a Brigham and Women’s Hospital study from 2007 in Archives of Internal Medicine.

THE BAD:

High in artery-clogging saturated fat
A cup of whole milk has 5 grams of saturated fat and 66 milligrams of cholesterol; a cup of Ben and Jerry’s ice cream, at least 20 grams of saturated fat and 130 milligrams of cholesterol. The link between saturated fat and heart disease is well established, and accordingly, the U.S. Department of Agriculture recommends no more that 20 grams of saturated fat each day and no more than 300 milligrams of cholesterol.

Has evil chemicals
Modern cattle farming relies on getting as many animals as possible into the smallest space possible. Where there is crowding, there is disease. Antibiotics keep cows healthy but might boost the evolution of resistant superbugs. Hormones, such as bovine growth hormone (BGH) or insulin-like growth factor (IGF-1) encourage cows to produce more milk, but may harm our own delicate hormonal balance. Poisonous pesticides are often residual in cow feed and can be passed through to milk. Organic milk is usually free of all these chemicals, but can cost double the price of “regular” milk.

Causes a common allergy
Milk allergy in infants is often misdiagnosed as gastrointestinal reflux disease or colic, says a 2005 Pediatric Nursing study. Most kids outgrow the allergy, but those that don’t can have diarrhea, vomiting, eczema, runny or stuffy nose, coughing and wheezing, amongst other symptoms. Finding a good diagnostic tool – other than making the kid drink milk and seeing what happens – remains a challenge. And of course, many people are intolerant to the sugar lactose and suffer their love of cheese accordingly.