As a parent, you do all you can to protect your child – yet this everyday action could be a cause of childhood cancer.

In the 1970s Mel Greaves visited a London hospital’s childhood cancer wing – and, with that, the professor found his calling to become a researcher in the field. And just 40 years later he made his biggest breakthrough in what we know about acute lymphoblastic leukemia. This is the form of the disease that most commonly affects kids aged 15 and younger.

Parents who have faced such a diagnosis know just how scary it can be discovering that their sons or daughters have leukemia. Without the right treatment, after all, the disease can progress rapidly and quickly turn fatal. And even with the proper care, it’s a nightmare knowing that a little one is suffering from such a serious illness.

That’s why so many parents do what they can to prevent their children from getting sick in the first place. They of course take care of their babies so that they can grow up healthily without ever having to face such a terrifying diagnosis. Yet, according to Greaves’ findings, some of the steps that parents take to ensure their children’s well-being can actually be what triggers the cancer in the first place.

Thirty percent of children with cancer suffer from leukemia – an iteration of the disease that attacks the blood and bone marrow. Acute lymphoblastic leukemia proves the most common of such diagnoses too. And although it can affect adults, 85 percent of cases involve children 15 and younger.

Inside of our bones resides marrow, a sponge-like substance that has a vital bodily responsibility: creating blood cells. It can do so because it contains stem cells, which then become any one of three types of blood cells. These are red and white blood cells as well as platelets. Each of these cells also play a vital role in the body.

For instance, red blood cells carry oxygen throughout the body. Platelets, meanwhile, help us to stop bleeding post-injury. And white blood cells ward off infection when we get sick. In a healthy body, then, the bone marrow wouldn’t release any cells until they reached maturation. Acute lymphoblastic leukemia causes this finely tuned system to malfunction, though.

The disease in fact causes the bone marrow to release immature white blood cells, which are also known as blast cells. This is dangerous for multiple reasons. For one, these underdeveloped white blood cells can’t fight infection effectively. And with too many in production, the number of red cells and platelets decreases as well.

All these changes generate the symptoms that help doctors diagnose acute lymphoblastic leukemia. So without a healthy balance of blood cells – and with a weakened immune system – one might feel tired or suffer from regular infections. Some experience fevers or swollen lymph nodes too. And the skin tends to go pale and easily bruise.

Other symptoms of acute lymphoblastic leukemia include night sweats, bleeding from unusual spots, joint pains, abdominal aches, weight loss or a purple skin rash called purpura. Parents who notice a combination of any of these conditions should take their child for a medical evaluation – although in most cases the root cause won’t be leukemia.

If the doctor does diagnose a child with acute lymphoblastic leukemia, though, they tend to follow a standard treatment plan. First, medical professionals begin by targeting the unwanted cells that have started growing in the bone marrow. This step helps to rebalance the number of red and white blood cells and platelets.

Image: KatarzynaBialasiewicz/Getty Images

Next the treatment will focus on leukemia cells that have spread to the central nervous system. This only occurs in some cases of acute lymphoblastic leukemia, and, if it does, it can carry a handful of other symptoms. Some children may experience headaches, vomiting, dizziness, blurry vision or even seizures, for instance.

In most cases, though, doctors use chemotherapy to kill leukemia cells in both the central nervous system and the bone marrow. Yet some patients may require additional treatments, such as blood transfusions or antibiotics. Cures can also come in the form of bone marrow transplants.

Luckily, children diagnosed with acute lymphoblastic leukemia have a great chance of coming out on the other side. Nearly every little one with the disease actually achieves remission – a period in which they no longer have cancer symptoms. Eighty-five percent will walk away fully cured too.

Image: YouTube/The Institute of Cancer Research, London

Professor Sir Melvyn Greaves has played a huge part in the way doctors understand leukemia today. Since 1984, in fact, he has worked at the U.K.’s Institute of Cancer Research, London. And early on, Greaves devised groundbreaking ways to differentiate between different versions of the disease. His findings have therefore allowed medical professionals to better tailor treatments to each type of leukemia and every suffering patient.

Yet Greaves found his way into the field in a roundabout way. The professor actually first studied both zoology and immunology in the 1960s – and didn’t dedicate himself to cancer research until a decade later. At that time, you see, Greaves found himself in a London hospital’s cancer wing. And seeing children suffering from leukemia sparked his years of work to better understand the disease.

Image: YouTube/The Institute of Cancer Research, London

Since then, Greaves has, of course, worked to crystallize the differences between types of leukemia. But he has also delved into the disease’s origins too. In the 1990s, for instance, Greaves and his team studied mutations that could cause leukemia before a child is born. His research continues to explore the disease’s triggers in kids aged two to five as well.

Image: YouTube/The Institute of Cancer Research, London

Greaves has also spent decades gathering evidence to prove another one of his theories about childhood leukemia. And in 2018 he released his findings to the public – and they made serious waves. Greaves revealed, after all, that some steps that parents take to protect their children from illness could in fact be what cause their little ones to get cancer.

Before Greaves embarked on his long-term study, though, only one factor had been solidly linked to acute lymphoblastic leukemia. So experts knew that an exposure to elevated amounts of radiation could lead to a later cancer diagnosis. Yet the level would have to be high to cause leukemia; those exposed to post-atomic bomb radiation in Japan could have developed the disease, for example.

Experts had researched a slew of other possible contributing factors in the past too. And many of them included elements that appear in the average person’s environment. However, those studies had failed to find any strong evidence linking such factors to childhood cancer – until Greaves completed his research.

Greaves had long believed that children exposed to illness and infection at early ages develop strong immune systems. These kids therefore gain the fortifications they need in order to ward off future ailments. But some children don’t have this experience, and, Greaves says, it’s all because their parents try to raise them in extra-clean environments.

Image: Images By Tang Ming Tung/Getty Images

Yes, sterility and sanitization shouldn’t be parents’ main concerns anymore, Greaves revealed. That’s because it can exacerbate pre-existing conditions in some children – leading to their leukemia diagnoses. It all starts in the womb, Greaves stated, when some babies develop genetic mutations. Some call this a “pre-leukemia” change in the DNA, and 5 percent of children come into the world with it written in their genetic codes.

One out of every 100 children born with this mutation will then go on to develop leukemia. And, according to Greaves, this result becomes more probable when parents keep their children in environments that are too sterile. Without exposure to normal infections, then, their immune systems don’t have the chance to shore up against future illnesses.

So when these little ones finally face infections, they don’t have the ability to ward them off. Instead, the viruses can trigger further changes in their genetics. These mutations can then go on to cause acute lymphoblastic leukemia. Therefore, according to Greaves, cultivating an environment that’s too clean can do more harm than good.

Greaves and his team also found that children raised in particular socioeconomic situations tended to experience cancer more often than their counterparts. The research in fact posited that those raised in industrialized or otherwise wealthy countries had suffered from leukemia more often than those in poorer nations. The study concluded that this was because more developed areas have a tendency for less large families and more sterile households – thus reducing exposure to illnesses.

To reiterate their hypothesis, Greaves and his team performed an experiment on mice. They in fact gathered rodents born with the genetic mutation that could later cause leukemia. Then the experts kept the baby mice in an extra-clean environment. Later, when the young creatures came in contact with respiratory bacteria, these rodents developed leukemia much more frequently than mice raised in other conditions.

Image: YouTube/The Institute of Cancer Research, London

Greaves spoke about his research in May 2018, according to the Daily Mirror. He said, “I have spent more than 40 years researching childhood leukemia. It has always struck me that something was missing, a gap in our knowledge, why otherwise healthy children develop leukemia and whether this cancer is preventable.”

Greaves went on to debunk a long-standing myth about childhood illness and its lasting effects. He said, “Infection was first suspected of causing this cancer around 100 years ago. The problem is not infection; the problem is lack of infection.” And knowing such information could prove to be a huge medical breakthrough.

Greaves went on, “[The findings] offer hope of preventing the disease simply by exposing infants to ‘common and harmless bugs.’” Other studies have looked into the link between infection and acute lymphoblastic leukemia too. And some have only corroborated Greaves’ findings around the ties that they found between a patient’s childhood and their development of cancer.

For instance, children who suffer from acute lymphoblastic leukemia are apparently less likely to have attended daycare or have older siblings. Socializing exposes little ones to one another’s germs and infections, after all. And without such interactions – and perhaps without suffering from a resulting illness or two – children might become more susceptible to develop cancer down the line.

Beyond that, babies born via cesarean section have been found to suffer from acute lymphoblastic leukemia more often than infants delivered vaginally. This is because the birth canal contains microorganisms that can bolster a baby’s health; babies who come into the world via surgery do not have exposure to such bacteria. Similarly, it seems that little ones who breastfeed for fewer than six months suffer from the disease more frequently.

However, some research may negate Greaves’ findings. For instance, a similar study compared healthy children’s medical records with those of kids who had suffered from acute lymphoblastic leukemia. Through that process, researchers discovered that those with the disease had more infections than those with the all-clear. The study’s author admitted that some mild infections may not have been recorded in the healthy children’s files, though.

As the U.K.’s National Health Service notes on its website, “It is also worth bearing in mind that these types of observational studies can suggest a link, but cannot conclusively prove on their own that lack of infection causes acute lymphoblastic leukemia.” So parents shouldn’t feel obligated to send children to daycare to prevent the disease, for example.

And, as the NHS website states, this information shouldn’t encourage parents to throw all sanitizing habits to the wind – especially because some infections can be dangerous to young children. The healthcare organization warns against “ditch[ing] important methods of infection prevention, such as frequent hand-washing and making sure your child’s vaccinations are up to date.”

Image: YouTube/The Institute of Cancer Research, London

Indeed, Greaves said something similar at the London press conference in 2018, during which he shared his findings. He began by telling moms and dads that they shouldn’t feel guilty if their child has developed acute lymphoblastic leukemia. He said, “Parents are in no way to blame as they have been doing nothing different to other parents.”

Image: Steve Debenport/Getty Images — Image: SDI Productions/Getty Images

However, Greaves warned against overly cautious parenting tactics. He said, “We should stop worrying about infection so much and encourage social interactions. They pick up priming infections from other children by sharing toys and so on.” The childhood cancer expert then said society’s advancements played an unexpected part in acute lymphoblastic leukemia’s continued presence in today’s world.

Greaves said, “Acute lymphoblastic leukemia is a paradox of progress in society. Progress has seen the eradication of lethal diseases. I think [it] is an accidental consequence of this. The research strongly suggests it has clear biological cause and is triggered by a variety of infections in predisposed children whose immune systems have not been properly primed.”

So parents can make a point of socializing their children more often to expose them to particular germs and benign infections, Greaves said. The professor detailed potential preventions in a YouTube video shared by the Institute of Cancer Research, London. He stated, “Encouraging children to mix with other children, particularly older children, would be good.”

Greaves also said that parents should not “be overzealous about hygiene and over worried about it.” And, as previously mentioned, the professor suggested prolonged breast-feeding for at least three to six months of a child’s life. He noted that it “is beneficial, as it is for many other things in child health.”

Perhaps most importantly, though, Greaves said he sees a light at the end of the tunnel as far as childhood leukemia is concerned. He claimed, “What all of this research points to for me very powerfully is that childhood acute lymphoblastic leukemia is probably a preventable disease. So the challenge is, how could you possibly do that?”

Greaves has an idea. He concluded, “We think the way to do this is to give to infants in the first year of life some form of microbial exposure that’s benign and safe. I’m reasonably optimistic in perhaps a five-to-ten-year timeframe we’ll see this translated into some real benefit.”