Pets and your child’s immune system

Posted on July 9, 2012 by Michael

I’ve said time and time again that solid science does not come from individual studies sitting all by their lonesome. Rather, it comes about as a result of a body of evidence. That isn’t to discredit any individual study that may be released, but instead to point out that the very nature of science is to discover and expose and correct for flaws. That cannot possibly be accomplished if one person or group comes up with a finding and everyone says, ‘Oh, good. Let’s just go with that.’ And that brings me to this recent study on children who live with dogs in their first year of life:

The study of nearly 400 children found that dogs were especially protective, and the babies who lived with dogs during their first year were about one-third more likely to be healthy during their first year, compared to babies who didn’t have a pet in the home. Babies with dogs in the home were 44 percent less likely to develop an ear infection, and 29 percent less likely to need antibiotics than their petless peers.

“Children who had dog contacts at home were healthier and had less frequent ear infections and needed fewer courses of antibiotics than children who had no dog contacts,” said the study’s lead author, Dr. Eija Bergroth, a pediatrician who worked at Kuopio University Hospital, in Finland, at the time of the study.

There is no reason to doubt the methodology of this study, as far as I know. There is no reason to doubt its integrity. This isn’t a highly complicated paper about kin selection or something of that nature where the logic can get quite counter-intuitive. This is a relatively straight-forward study, by all accounts. However, that does not mean it actually is better to have dogs around infants:

Previous research on pets in the home has suggested that animals, and dogs in particular, may provide some protection against the development of asthma and allergies. But, other studies have found that household pets may increase the number of respiratory infections in children, according to background information in the study.

Yet, on the flip side once again, this doesn’t mean it’s bad to have dogs (unless the child has allergies, of course). What this means is that there are some interesting results, both of which fit well into independent theories. For the previous studies, we know that animals carry plenty of germs and disease, so it wouldn’t be surprising to learn that they tend to transmit that sort of stuff to babies – basic germ theory. However, for this recent study, we also know that the immune system tends to do better when exposed to diverse environments early in life. That gives it a chance to build a working ‘knowledge’ of what it must resist. So which is the correct model?

We don’t yet know.

I personally lean towards it being better to have pets in the home, in part because dogs and cats are linked to greater happiness, which in turn is linked to a healthier body, but I’m not staking a claim to anything one way or another. The scientifically responsible thing to do here is to wait for a more robust body of evidence.

That’s how this whole thing works.

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Promising skin cancer news

Posted on June 6, 2010 by Michael

One of the oldest treatments for cancer in the modern era is to stimulate the immune system. William Coley was one of the pioneers in this technique, coming up with Coley’s Toxin in the late 19th century. This was a mixture that basically involved infecting patients with the bacteria Streptococcus pyogenes. Coley claimed fantastic results, but he kept his records poorly. I don’t know if he ever lied – there is no direct evidence which says he did – but his results were almost always questionable. Besides that, he tended to lose patients to bacterial infections from time to time.

Cancer research lost some of its focus on the immune system in the early part of the 20th century, Coley’s toxin was reclassified into oblivion by the FDA, and governments really didn’t supply the funds for research they should have. Research, however, has long come back around to looking at the immune system and how it can help fight cancerous cells. One of the most recent results has to do with a new drug, Ipilimumab, which is for patients with melanoma

The results, reported Saturday at a cancer conference, left doctors elated.

“We have not had any therapy that has prolonged survival” until now, said Dr. Lynn Schuchter of the Abramson Cancer Center at the University of Pennsylvania, a skin cancer specialist with no role in the study or ties to the drug’s maker.

The drug, ipilimumab, (ip-ee-LIM-uh-mab), works by helping the immune system fight tumors. The federal Food and Drug Administration has pledged a quick review, and doctors think the drug could be available by the end of this year.

Ipilimumab is a T-cell potentiator. T-cells basically have antigens which help to regulate immune responses. These antigens inhibit ‘overreactions’ within the immune system. What ipilimumab does is block this inhibition. It says to the immune system, ‘Run wild, you’re free!’

The increased survival rate is great when measured by percentage – 67% – but the practical numbers only mean a few more months of life. That’s how a lot of cancer research goes, unfortunately, and it makes it all so much less of an elation. But this is still hopeful. It’s good progress on the cancer front. (But do keep in mind, this is just one study for one type of cancer, interesting and promising as it may be.)

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