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Health

Cheese offers nutrition benefits, less lactose than you expect

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Cheese is rich and creamy, and it’s irresistible on a cracker, paired with a selection of fresh fruit or sprinkled over a bowl of chili. Americans really do love it. The per capita consumption is 40 pounds a year, or a little over 1.5 ounces a day.

But when people talk about their fondness for cheese, it’s often in a guilty way, as in, “Cheese is my weakness.”

“Cheese is packed with nutrients like protein, calcium and phosphorus, and can serve a healthy purpose in the diet,” says Lisa Young, an adjunct professor of nutrition at New York University­. Research shows that even full-fat cheese ­won’t necessarily make you gain weight or give you a heart attack. It seems that cheese doesn’t raise or reduce your risk for chronic diseases, such as heart disease and Type 2 diabetes, and some studies show it might even be protective.

Good bacteria, lower saturated fat risks

It’s easy to see why people might feel conflicted about cheese. For years, the U.S. dietary guidelines have said eating low-fat dairy is best because whole-milk products, such as full-fat cheese, have saturated fat, which can raise LDL (bad) cholesterol levels, a known risk for heart disease. Cheese has also been blamed for weight gain and digestive issues such as bloating. It turns out, though, that cheese may have been misunderstood.

Yes, it’s high in calories: Some types have 100 calories or more per ounce. And it’s rich in saturated fat. So why is it okay for most people to eat it? “Cheese is more than its saturated fat content,” says Emma Feeney, an assistant professor at the Institute of Food and Health at University College Dublin who studies the effect cheese has on health.

Old-school thinking on nutrition has been focused on individual nutrients — such as fats or protein — that either promote or prevent disease. It’s not clear that this is the wrong approach, but nutrition experts are now putting more emphasis on the entire food and how its structure, nutrients, enzymes and other components interact with one another.

When milk is transformed into cheese, the process changes the way the nutrients and other components in it are chemically arranged. This has an effect on how it’s digested and processed by the body, which can lead to health effects that are different from the effects of eating the same nutrients in another form, such as butter.

In 2018, Feeney led a six-week clinical trial in which 164 people each ate an equal amount of dairy fat either in the form of butter or cheese and then switched partway through the study. “We found that the saturated fat in cheese did not raise LDL cholesterol levels to the same degree as butter did,” she says.

Experts have varying theories about why the saturated fat in cheese is less harmful. “Some studies show that the mineral content in cheese, particularly calcium, may bind with fatty acids in the intestine and flush them out of the body,” Feeney says. Other studies suggest that fatty acids called sphingolipids in cheese may increase the activity of genes that help with the body’s breakdown of cholesterol.

When cheese is made, it gains some beneficial compounds, too. “Vitamin K can form during the fermentation process,” says Sarah Booth, director of the Vitamin K Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. The vitamin is important for blood clotting, and bone and blood vessel health.

And as a fermented food, “both raw and pasteurized cheeses contain good bacteria that can be beneficial to human gut microbiota,” says Adam Brock, vice president of food safety, quality and regulatory compliance for Dairy Farmers of Wisconsin. This good bacteria, found mostly in aged cheeses such as cheddar and Gouda, help break down food, synthesize vitamins, prevent bacteria that cause illness from getting a foothold, and bolster immunity.

Weight gain, lactose misunderstandings

Cheese also seems to reduce the risk of weight gain and several chronic diseases.

Weight gain: Cheese is a concentrated source of calories. But studies suggest that you don’t need to skip cheese to keep the scale steady. In one, published in the New England Journal of Medicine, researchers set out to determine which foods were linked to weight gain by following 120,877 men and women in the United States for 20 years, looking at their weight every four years. Cheese wasn’t associated with either gain or loss, even for people who increased the amount of it they ate during the study.

One reason cheese may help control weight is that it may reduce appetite more than other dairy products.

Cardiovascular disease: A large meta-analysis of 15 studies published in the European Journal of Nutrition that looked at cheese’s effect on cardiovascular disease found that people eating the most (1.5 ounces per day) had a 10 percent lower risk than those who didn’t eat any. Other analyses have found that cheese doesn’t seem to affect heart disease risk either way.

Diabetes and hypertension: Cheese and full-fat dairy also seem to be linked to a lower risk of both. In a study of more than 145,000 people in 21 countries, the researchers found that eating two daily servings of full-fat dairy or a mix of full-fat and low-fat was linked to a 24 and 11 percent reduced risk of both conditions compared with eating none. Eating only low-fat dairy slightly raised the risk. And among people who didn’t have diabetes or hypertension at the start of the nine-year study, those who ate two servings of dairy each day were less likely to develop the diseases during the study.

Lactose intolerance: Lactose, a sugar in milk, can be difficult for some people to digest, leading to diarrhea, bloating and other gastrointestinal symptoms. But the bacteria used to make cheese digests most of the lactose in the milk, says Jamie Png of the American Cheese Society. Much of the lactose that remains is found in the whey, which gets separated from the curds toward the end of the cheesemaking process and is drained off. If you’re sensitive to lactose, stick to hard or aged cheese such as cheddar, provolone, Parmesan, blue, Camembert and Gouda, and minimize fresh soft cheese like ricotta and cottage cheese.

Even though cheese itself doesn’t appear to have negative effects on health, how you incorporate it into your overall diet matters.

In much of the research suggesting a neutral or beneficial effect, the highest amount of cheese people ate each day, on average, was about 1.5 ounces, but in some cases it was up to 3 ounces. (An ounce of cheese is about the size of your outstretched thumb.)

In some studies, the health benefits of cheese were found to be the greatest when it replaced a less healthful food like red or processed meats. So there’s a big difference between crumbling some blue cheese over a salad and serving up a pepperoni pizza with double cheese. “Incorporating cheese into a Mediterranean-style diet where you also include fruits, veggies, whole grains and other foods known to lower disease risk is going to be the most beneficial to your overall health,” Young says.

For those watching their sodium intake, cheese can be pretty salty. (The salt acts as a preservative.) If you’re eating about an ounce a day, it’s not a huge concern. Most types give you between 150 and 300 milligrams of sodium per ounce. (The daily value is no more than 2,300 mg.) Eat more, though, and the sodium can add up.

The form cheese takes may also influence how it affects health. “Many of the studies on cheese and health use cheese in a nonmelted form,” Feeney says. “We still don’t know how melting or cooking affects the health outcomes, for example, eating cheese on pizza or in cooked dishes like casseroles.”

Copyright 2022, Consumer Reports Inc.

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Health

Ancient Europeans were lactose intolerant but drank milk, study finds

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A group of scientists has concluded that ancient Europeans drank milk for millennia despite the digestive problems it may have caused, casting doubt on theories on how humans evolved to tolerate it.

Scientists have long speculated that an enzyme needed to avoid any gastrointestinal discomfort developed rapidly in populations where domesticating dairy animals was prevalent.

People who could tolerate milk, that theory goes, gained a new source of calories and protein and passed on their genes to more healthy offspring than those without the genetic trait — known as lactase persistence — that allows them to digest the sugar in milk into adulthood.

But a new study has offered a radically different theory, arguing that side effects such as gas, bloating and intestinal cramps weren’t enough on their own to move the evolutionary needle on the genetic mutation.

“Prehistoric people in Europe may have started consuming milk from domesticated animals thousands of years before they evolved the gene to digest it,” the study’s authors said.

The study, published in the journal Nature, was produced in collaboration with more than 100 scientists across a range of fields including genetics, archaeology and epidemiology. The scientists mapped out estimated milk consumption in Europe from approximately 9,000 years ago to 500 years ago.

By analyzing animal fat residues in pottery from hundreds of archaeological sites, alongside DNA samples harvested from ancient skeletons, the researchers concluded that lactase persistence was not common until around 1,000 B.C., nearly 4,000 years after it was first detected.

And, rather than in times of abundance, they argue that it was during famine and epidemics that having the mutation became critical to survival: when undigested lactose could lead to serious intestinal illnesses and death.

Using archaeological records to identify periods where populations shrank, they concluded that people were more likely to drink milk when all other food sources had been exhausted, and that during those periods, diarrhea was more likely to escalate from a mild to a deadly condition.

George Davey Smith, an epidemiologist at the University of Bristol, who teamed up with the researchers on an analysis of contemporary data on milk and lactase persistence in current populations, said the study raises “fascinating questions” about whether some people who believe they are lactose intolerant “might actually be fine if they drank milk.”

About a quarter of Americans are lactose intolerant. In a lawsuit filed last year, a group of American doctors asked why the U.S. Department of Agriculture’s dietary guidelines recommend so much dairy — suggesting that the federal agency is looking out for the interests of the meat and dairy industries rather than the health of Americans.

USDA dietary guidelines are driven by milk marketing concerns — not nutrition — lawsuit alleges

Previous studies have suggested that populations had to rely heavily on dairy before individuals adapted to tolerate it in abundance. A smaller study in 2014 found the variation that allows humans to digest lactose didn’t appear in Hungarian DNA samples until 3,000 years ago, whereas it may have cropped up as far back as 7,000 years in places such as Ireland where cheesemaking became abundant.

Amber Milan, an expert in dairy intolerance at the University of Auckland, said the idea that the lactase mutation became important to survival only when Europeans began enduring epidemics and famines is a “sound theory” and “supported by previous research of drivers of genetic selection.”

She added, however, that she is not sure the new study “entirely rules out that widespread milk consumption was the evolutionary force behind lactose tolerance” — partly because the genetic data was collected from Biobank, a British biomedical database of genetic and health information from some 500,000 people.

The authors have also focused on the major European genetic variant for lactase persistence — which, while appropriate for this study, “does potentially miss other genetic variants that result in lactase persistence,” Milan said.

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Science

Russian scientists clone cow and edit her genes to remove protein that causes lactose intolerance

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Researchers in Russia announced they have produced the country’s first viable cloned cow – and are now editing her genes in the hope of producing hypoallergenic milk. 

The unnamed calf weighed about 140 pounds when she was born in April 2020. 

For her first year, she was kept in a separate enclosure with her mother. Now, 14 months, she’s up to nearly a half-ton and appears healthy with a normal reproductive cycle.

‘Since May, she has been on daily pasture with the other cows of the Institute,’ said  Galina Singina, a researcher at the Ernst Federal Science Center for Animal Husbandry and lead author of a new study published in the journal Doklady Biochemistry and Biophysics. 

‘It required some adaptation, but that happened quickly,’ she said.

The experiment was a double win, according to the report from Moscow’s Skoltech Institute of Science and Technology, because the researchers also successfully altered her genes to not produce the protein that causes lactose intolerance in humans.   

Singina worked with colleagues at Skoltech Institute and Moscow State University to ‘knock out’ the genes responsible for beta-lactoglobulin,  the protein that causes ‘lactose malabsorption,’ often called lactose intolerance, in humans.   

The researchers used CRISPR/Cas9 technology to remove PAEP and LOC100848610, two genes representing beta-lactoglobulin in the bovine genome. 

They managed to clone the calf using somatic cell nuclear transfer (SCNT), with the nucleus from a regular cell of a donor transferred into an egg with its nucleus removed.

The resulting embryo was then implanted into the uterus of a cow and carried to term.  

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The cloned calf was born in April 2020 and appears healthy. The first cloned cow in Russia, the unnamed bovine has had her genes altered to not produce the protein that causes lactose malabsorption or intolerance  

While genetically modified mice are a fairly common phenomenon, modifying other species is exponentially harder, due to higher costs and difficulties in breeding and husbandry, said co-author Petr Sergiev, a professor at Skoltech Institute.

‘Thus, a methodology leading to cattle with hypoallergenic milk is not only a necessity for agriculture of the future, but also a cool project,’ Sergiev added.

Nearly 70 percent of the world’s population has some form of lactose malabsorption, according to the National Institute of Diabetes and Digestive and Kidney Diseases, making it difficult for them to digest milk and other dairy products derived from cattle.

Cloning a single cow is really just a test run, Sergiev explained. The next is impregnating a herd of several dozen cows with embryos with the edited genes.   

The clone was created via somatic cell nuclear transfer (SCNT), with the nucleus from a regular cell of a donor transferred into an egg with its nucleus removed

The ultimate goal is to develop a breed of cows that naturally produces hypoallergenic milk. 

‘Since it is not a 100% certain process, you have to roll the dice a lot, and it’s quite expensive,’ Sergiev says. 

Elsewhere, researchers are cloning cows for their own health rather than human’s: a team in New Zealand used CRISPR genome editing to create cows with gray patches instead of the traditional black, to decrease the amount of heat the animal absorbs while in pasture.   

Researchers in New Zealand revealed last year they managed to clone Holstein calves (pictured) with silvery gray markings instead of black, to better cope with the heat

‘Compared to a light coat color, black absorbs more solar radiation translating into radiative heat gain which is a contributing factor to heat stress in cattle, negatively impacting on their production levels, fertility and welfare,’ according to their study, published on the preprint site biorxiv.

The researchers see the effort as helping cattle to adapt to climate change, ‘with predictions for more frequent and prolonged hot temperature patterns, we aimed to lighten their coat color by genome editing.’

Heat stress among dairy cows is one of the leading causes of decreased fertility and milk production in the summer months.

The bovines thrive between 25 and 65 degrees Fahrenheit, but anything above 80 degrees and they start reducing their food intake— resulting in less milk.

 Announced in October 2020, the gene-splicing was performed on fetal skin cells from a Holstein Friesian bull cultivated in a petri dish.

The researchers successfully eliminated the pre-melanosomal protein 17 gene, which causes the black coloring, and instead produced ‘a strong color dilution effect’ of a gray and white coat.  

The team from New Zealand used a cloning method to create embryos set to be genetically modified and applied the gRNA/Cas9-mediation, the CRISPR tool, to mutate the pre-melanosomal (PMEL) gene, as first reported by New Scientist.

Once the two calves were born, the team confirmed the silvery gray markings, with the white areas remaining unaffected.

While the calves showed no signs of potential off-target mutations at birth, both were dead with several weeks—one had to be put down and the other died of an infection due to the cloning process.

Goetz Laible with the Ruakura Research Center in Hamilton, New Zealand, said the team will look at more traditional breeding practices to cultivate the  mutation.

The study looked at dairy cows, but Laible believes the same method could be applied to beef breeds, such as Black Angus cattle.

‘Projected onto a global scale, even modest improvements of eco-productivity from color-diluted cattle would translate into substantial environmental benefits,’ according to the study.

WHAT IS CLONING AND COULD WE ONE DAY CLONE HUMANS?

What is cloning?

Cloning describes several different processes that can be used to produce genetically identical copies of a plant or animal.

In its most basic form, cloning works by taking an organism’s DNA and copying it to another place.

There are three different types of artificial cloning: Gene cloning, reproductive cloning and therapeutic cloning.

Gene cloning creates copies of genes or parts of DNA. Reproductive cloning creates copies of whole animals.

Therapeutic cloning produces embryonic stem cells for tests aimed at creating tissues to replace injured or diseased tissues.

To create somatic cell nuclear transfer (SCNT) clones, scientists take DNA (red circle) from tissue and insert it into egg cells (yellow) with their DNA (green) removed. The scientists then switch on or off certain genes to help the cells replicate (right)

Dolly the Sheep was cloned in 1996 using a reproductive cloning process known as somatic cell nuclear transfer (SCNT).

This takes a somatic cell, such as a skin cell, and moves its DNA to an egg cell with its nucleus removed. 

Another more recent method of cloning uses Induced pluripotent stem cells (iPSC).

iPSCs are skin or blood cells that have been reprogrammed back into an embryonic-like state.

This allows scientists to design them into any type of cell needed.

Could we ever clone a human? 

Currently there is no scientific evidence that human embryos can be cloned.  

In 1998, South Korean scientists claimed to have successfully cloned a human embryo, but said the experiment was interrupted when the clone was just a group of four cells. 

In 2002, Clonaid, part of a religious group that believes humans were created by extraterrestrials, held a news conference to announce the birth of what it claimed to be the first cloned human, a girl named Eve.

This was widely dismissed as a publicity stunt.  

In 2004, a group led by Woo-Suk Hwang of Seoul National University in South Korea published a paper in the journal Science in which it claimed to have created a cloned human embryo in a test tube. 

Gene cloning creates copies of genes or parts of DNA. Reproductive cloning creates copies of whole animals (stock image)

In 2006 that paper was retracted. 

According to the National Human Genome Research Institute, from a technical perspective cloning humans is extremley difficult.

‘One reason is that two proteins essential to cell division, known as spindle proteins, are located very close to the chromosomes in primate eggs,’ it writes.

‘Consequently, removal of the egg’s nucleus to make room for the donor nucleus also removes the spindle proteins, interfering with cell division.’

The group explains that in other mammals, such as cats, rabbits and mice, the two spindle proteins are spread throughout the egg. 

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