Science, despite its limitations, is pretty amazing

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Reflections from my Notebook

The discipline of science often gets disparaged when it becomes intertwined with politics, such as the case with climate change or even the number of deaths from a hurricane, as well as when theories change, such as the newest advice that taking aspirin daily to prevent heart attacks isn’t really helpful.

Yet, the marvels of the modern world are built on the certainties of science — from the technology that brings us instant communications on our cellular phones to the intricacies of rockets that blast off into outer space for exploration. We are comfortable enough with that certainty to risk our lives traveling 60 miles an hour down highways in automobiles that work in ways most of us don’t truly understand.

Still, the uncertainty of science is also fascinating. There are many things even scientists don’t understand and theories are constantly evolving, making last year’s recommendations mute.

A phenomenon this year is the bumper crop of acorns many people are finding throughout Minnesota. The Department of Natural Resources notes that a single mature oak tree can drop as many as 10,000 acorns in a single year. The larger amounts — up to 10 times the normal crop — happen every two to five years.

Some people may think the bumper crop this year is a prediction of a brutal winter, but scientists doubt trees can predict the weather. Rather the trees are reacting to a good spring and summer for oak trees.

However, there is more to the story as this bumper crop happens cyclically no matter what the weather brings. The reason is due to something called masting. Angela Gupta, a forestry expert for University of Minnesota Extension, explained to the Star Tribune that without masting years, oak trees would eventually die out.

Many animals eat acorns and if a tree produced the same number of acorns every year, the animal population would grow to match the food supply, meaning all the acorns would be eaten each year.

“By producing a bumper crop, a tree is producing more acorns than can be eaten and ensuring that some of them will survive to germinate new trees,” Gupta told the Star Tribune.

The fascinating part is that masting happens in unison. How do the individual trees that don’t share root systems like some trees, such as aspens, know how and when to do it?

Scientists don’t know.

Few would claim there is a secret life of plants, as was the basis of a popular book decades ago, or that they communicate among themselves. Rather, there is likely some trigger in nature that prompts masting every few years.

Not only are there natural occurrences that scientists can’t exactly explain, scientific knowledge is continually evolving, with new studies that may contradict previous studies. For example, it was always thought that drinking a glass of wine a day was good for people, but an update to that theory made headlines recently when it was determined that there is no safe amount of alcohol.

Experts point out that the increased mortality rate associated with light drinking is tiny — almost negligible — so there isn’t any reason to panic. Yet, previously it was thought that a glass of wine with dinner was actually good, even healthy, for us.

Many studies on human health change over time. That’s because it is difficult to pin down a control group since population groups vary in ways unrelated to the variable scientists are trying to study.

Scientists originally accounted for factors, such as obesity or smoking, in studying the relation of alcohol to health. However, a less obvious, but still confounding issue, is why people who don’t drink choose to abstain from alcohol.

The magazine Popular Science had an interesting report of why that matters. An analysis by an international group of alcohol epidemiologists and addiction researchers, published in the Annals of Epidemiology, notes that  “as people progress into late middle and old age, their consumption of alcohol declines in tandem with ill health, frailty, dementia, and/or use of medications.”

Popular Science noted that the decline means that, as people become less well—even if they’re not elderly — they will also tend to stop drinking. So when they enroll in a study on drinking and get lumped into the group of non-drinkers, they’ll artificially inflate the mortality risk — even though their deaths have nothing to do with alcohol abstention.

Tim Naimi, a physician and epidemiologist at Boston University School of Medicine and Public Health who’s studied this subject for many years, explained to Popular Science that there is another factor: “People who in their teens or 20s begin to drink, don’t die or become alcoholics, and are able to maintain drinking at low levels—that’s a select group of drinkers.”

Most people begin as light drinkers, but since alcohol is an addictive substance, a proportion of the population becomes alcoholics.

The remaining moderate drinkers haven’t devolved into alcoholics and haven’t quit due to health problems, leaving an unusually healthy population that has nothing to do with drinking.

Popular Science notes that individuals may look at the statistics and decide having a glass of wine at dinner is fine since the health problems associated with light drinking are tiny. That’s not an awful decision and it is highly unlikely to lead to alcohol-related health problems.

Some headlines focused on the harmful effects of drinking, but the main takeaway is that public health officials shouldn’t be promoting alcohol as a healthy choice, not necessarily that people shouldn’t ever drink in moderation.

Science is important to our modern lives since we depend on scientific knowledge as the basis for much of what have become necessities, leading to convenience and comfort. However people expecting absolutes in all of science will be disappointed because human knowledge, even among the most learned, is limited and constantly subject to revision.

The upside is that the studies being revised usually focus on slight risks that likely won’t affect most people. We already know that heavy or binge drinking, for example, is bad and no study will ever reverse that determination.

So, raise a glass, just a glass, of wine that won’t make you healthier to the amazing, yet mysterious, bumper crop of acorns in Minnesota this year.