Russian homeopathy, hiding in plain sight

It turns out that Russia has its very own brand of bogus medicine:"release-active drugs," or RADs. Dozens of scientific articles have been published claiming that these substances can be used to treat or cure a remarkably broad range of illnesses, including:
"... influenza, hemorrhagic fever, meningococcal meningitis, herpes, HIV, diabetes, erectile dysfunction, sleep disorders, obesity, chronic inflammatory joint diseases, attention deficit hyperactivity disorder, ..., alcoholism, allergies, and many other health problems." 
If this sounds too good to be true, that's because it is.

Thanks to a new report published in the journal BMJ Evidence-Based Medicine (provocatively titled "Drug discovery today: no molecules required") we now know that RADs aren't drugs at all, because they don't actually contain anything. As the new study reveals,
"The problem [with RADs] is that typical dilutions of the active ingredient are so high (from 1:1024 to 1:101991) that no molecules of the initial antibodies should be present in the ‘drug’ itself."
In other words, RADs are simply homeopathy by another name. As I've written many times before, homeopathy is one of the most patently absurd forms of pseudoscience, and although it's been debunked countless times, it remains popular due in part to commercial interests that profit handsomely from selling ineffective but expensive sugar pills.

RADs are produced by a single Russian company, with the odd name "OOO NPF Materia Medica Holding." The papers promoting the benefits of RADs are authored by a variety of Russian authors, but they are nearly all co-authored by or associated with one person, Oleg Epstein, who is also the company's founder.

Epstein and his Russian compatriots have been very clever about disguising the fact that their "release-active drugs" aren't drugs at all. Their papers are full of scientific jargon, which has no doubt helped them get their work past reviewers who (as every scientist who has published papers knows) can sometimes be a bit lazy.

They've also taken advantage of–one might say abused–the U.S. clinical trials system, ClinicalTrials.gov, by registering 22 studies of RADs there, such as this one.

The authors of the BMJ report (Alexander Panchin, Nikita Khromov-Borisov, and Evgenia Dueva, all Russian, though Dueva is based in Canada) are unsparingly blunt in revealing how Epstein has manipulated the scientific system in Russia to gain approval (and lucrative sales) of his so-called drugs. For example, Epstein has published 90 papers on RADs in a single journal, including 48 in a special issue that he edited himself.

Panchin and colleagues also took a closer look at 6 papers about RADs that were published in English-language journals, all co-authored by Epstein. They report that
"the articles contained misleading descriptions of active substance concentrations, severe flaws in study design and methodology, as well as concealed conflict of interests.... the authors did not mention that MMH manufactures and sells RADs and holds the corresponding patents. Epstein was not mentioned as the founder and CEO of MMH."
They contacted all of these journals, and only one journal, PLoS ONE, went so far as to retract the bogus science on RADs. Kudos to PLoS ONE for doing so. The other journals, some of them published by reputable scientific publishers including Elsevier, Wiley, and Springer, either didn't respond or refused to take action.

Fortunately for consumers, RADs haven't yet spread into U.S. and European markets, although their manufacturers are trying. In a recent letter published in a the Journal of Medical Virology, Epstein and his co-authors write that
"Currently we are in the process of approving evaluation requirements for our products, taking into account their peculiarities and allowing their potential authorization in the USA and Europe."
Buyer beware. The Russian quacks are coming.

Don't smack your kids!

Spanking doesn't work. What's more, it may cause long-term harm to children.

With the holidays approaching, families will be spending more time together, and much of that time will be rich and rewarding. But kids being kids, many of them will misbehave. Parents, in their turn, may grow exasperated and frustrated.

There are many ways to discipline kids, but hitting them is a bad idea. The American Academy of Pediatrics just issued a new policy statement, its strongest ever, telling parents that spanking or hitting their kids is not only ineffective, it is harmful. They don't allow for any exceptions, stating that
"corporal punishment is invariably degrading."
This idea has been gaining traction for decades. In 1989, the UN Committee on the Rights of the Child called for all nations to ban corporal punishment of children, and over the years, many countries have heeded that call. Just two months ago, the Global Initiative to End All Corporal Punishment of Children reported that 54 countries around the world have banned spanking in all settings, including the home.

Nonetheless, the average American still thinks spanking is a good idea. A few years ago, FiveThirtyEight reported that 70% of U.S. adults still agreed that "it is sometimes necessary to discipline a child with a good, hard spanking." This was an improvement over 1986, when 84% of adults agreed with that sentiment, but we obviously have a long way to go.

Even worse, corporal punishment in school is still permitted in 19 states, as described in a study by Elizabeth Gershoff and Sarah Font earlier this year. These states are primarily in the southern U.S., with the top offenders being Arkansas, Mississippi, and Alabama, where over 50% of the schools still use corporal punishment. In these schools, as Gershoff and Font write,
“a teacher or administrator typically administers corporal punishment by using a large wooden board or 'paddle' to strike the buttocks of a child.”
Perhaps it's no coincidence that the schools in those states rank among the 10 worst in the nation: Arkansas is 42nd, Alabama is 43rd, and Mississippi is 48th.

The American Academy of Pediatrics (AAP) report warns of multiple harms that come from corporal punishment, including:

  • "spanking ... is associated with outcomes similar to those in children who experience physical abuse;
  • experiencing corporal punishment makes it more, not less, likely that children will be defiant and aggressive in the future;
  • corporal punishment is associated with an increased risk of mental health disorders and cognition problems."

The AAP report also includes warns that verbal abuse, including any language "that causes shame or humiliation," can be as harmful to children as physical punishment.

Why would violence against a child ever be a good idea? The answer is simple: it never is. Children, especially younger children, cannot understand that a thrashing is intended to send a message about their behavior. Instead, they often think that their parent is angry at them (and sometimes they're right), which in turn makes them fear their own parents.

Parents do need to discipline their children at times, as anyone who's had kids will know. Parents who want guidance can visit the AAP's parent-focused website, healthychildren.org, where they offer alternatives to spanking, for both younger and older children.

Many parents think that spanking works, because they were spanked and turned out okay. That might be true for some, but it's not true for everyone. The AAP report cites nearly 100 studies showing that spanking doesn't work.

So don't hit your kids–and if you're in one of the 16 states that allow schools to hit them, contact your local school district and ask them to change this outdated and abusive practice.

The problem with our democracy isn't gerrymandering. It's integers

(This week, in the wake of the recent U.S. elections, I take a detour from my usual topics to apply a little math to our election system.)

As everyone knows, the U.S. Congress has grown increasingly un-representative. We have states where the population is evenly split among Democrats and Republications, but where–thanks to partisan gerrymandering–the number of House members is grossly skewed in favor of one party. Even without gerrymandering, voters for the losing side in many House districts feel, justifiably, that they have no representation in Congress.

The solution is surprisingly simple. We can save it with a little math. It's not even that complicated. The problem, as I explain below, is integers.

The New York Times just published an argument that the House of Representatives is too small. They point out that the House grew every decade until 1911, when its size was frozen at 435. The Times says that after 100 years of population growth, "America needs a bigger House."

Fair enough, but how do we fix it? The Times argues, oddly enough, that the right number is 593 representatives. Why? Because 593 is the cube root of the total U.S. population. Curiously, many other democracies follow a cube root rule, first described in this 1972 paper by Rein Taagepera. The legislature of Denmark, for instance, has 179 representatives for a population of 5.77 million, and 179 cubed is 5,375,339. Canada has 37 million people and 333 members of their House of Commons, a near-perfect example of this rule, if you ignore their 105 senators.

The first thing to point out is that the NY Times got the math a little bit wrong. The current U.S. population is 329 million, for which the cube root is 690. So if we keep the Senate at 100 members, then we need 590 Representatives in the House, not 593. But the Canadian model doesn't count their senate, so perhaps we need 690 Representatives. But that's a small quibble.

The real problem, though, is that expanding the House by 35% won't address the fundamental problems of our democracy. The Times observed, correctly, that a single representative can't stay in touch with 750,000 people. Increasing the size of the House to 593 will reduce that number to 550,000, which will hardly help. The framers of the Constitution wanted one representative for every 30,000 people, by the way, but that would yield a ridiculously large House today.

The real solution is to get rid of our reliance on integers. Let me explain.

The root of our problem is that each Congressional district elects just one person, in a winner-take-all election where you only need to win by one vote. This means that the losers end up with a Representative who simply doesn't represent them. This means that, in a close election, 49.9% of the voters can be effectively disenfranchised. Even in lopsided victories, where 70% of the voters support the winner, the remaining 30% are stuck with someone who doesn't represent them.

The solution: elect TWO representatives from each Congressional district, and award them each a fractional vote in Congress. Each of the top two vote-getters would have a Congressional vote that is proportional to the number of voters who supported them. Thus if a district elects a Democrat (D) with 55% of the vote, and the losing Republican (R) gets 45%, both of them go to Congress, and D gets 0.55 votes while R gets 0.45 votes.

This will double the size of the House, to 830 members. It will also completely fix partisan gerrymandering. Here's why: imagine a state that is 50-50 Democrat and Republican, but that has packed one district so that 80% of its voters are Republican, allowing it to create three majority-Democratic districts that are 60-40 in favor of D's. Under the current system, that state has 3 Democrats and 1 Republican in Congress. (We have many states that look just like this under our current system.)

Under my new system, our hypothetical state would send 4 D's and 4 R's to Congress. The R from the "packed" district would get 0.8 votes, and the R's from the other three districts would get 0.4 votes each. The entire state delegation would therefore have 0.8 + 0.4 + 0.4 + 0.4 = 2 Republican votes, and 0.2 + 0.6 + 0.6 + 0.6 = 2 Democratic votes, accurately reflecting the overall population of the state.

Gerrymandering is nearly impossible in this system. Packing voters into one district would simply increase the voting power of the majority member for that district, while reducing the voting power of other members of the same party by a corresponding amount.

My system is perfectly legal, and Congress could create it with a simple bill, just as they increased the size of the House in the past. No Constitutional amendment is necessary.

What if more than two people are running for a House seat, as is often the case? We could divide the single House vote proportionally among the top two vote-getters, ignoring the third parties. (States could also use ranked-choice voting to re-apportion the votes of the losing candidates.) A nice side effect is that "protest" votes for third parties wouldn't have such a devastating effect on either of the top candidates. What if only one person ran for a seat? Easy: he or she would get a full vote in Congress rather than a fractional vote. What if the top two vote-getters were from the same party? No problem there, they would both go to Congress, and their party would get a full vote from that district.

Of course, this would make counting votes in the House a bit more complicated. The majority and minority whips wouldn't be able to simply count integers; instead, they'd have to add up the fractional votes of their 435 members. But why should we limit ourselves to a voting system that only uses first grade math? In the U.S., fractions and decimals are covered by the fourth grade. I think Congress can handle that.

There. I've now fixed our democracy. Time to get back to science.

Football has corrupted our universities. Time for it to leave.

The University of Maryland, College Park began their first
game of the season by honoring their teammate Jordan
McNair, number 79, who died during a May 2018 practice.
The University of Maryland, where I was a professor for six years, is embroiled in a football scandal that started with the tragic death of a young player, Jordan McNair, who died of heat stroke during practice. On an especially hot day in late May, the coaches were driving the players too hard, and when McNair collapsed, they failed to immerse him in cold water, which might have saved his life.

This past week, as the results of a 192-page inquiry were being leaked to the press, the university's Board of Regents has been meeting this weekend to decide what actions to take. According to the Washington Post and the Baltimore Sun, the board is considering whether to fire the coach, DJ Durkin (who has been on administrative leave since early September), the president of U. Maryland, Wallace Loh, and the athletic director, Damon Evans.

The University of Maryland has made one mistake after another with its football program, as I've pointed out again and again. Let's look at a timeline:

2010: in virtually his very first major decision as president, Wallace Loh approved the hiring of a new coach (Randy Edsall) and a $2 million payout to the old coach (Ralph Friedgen), who was pushed out a year early. This was at a time when the entire university system was in the midst of a 3-year hiring and salary freeze, which included unpaid furloughs (basically, pay cuts) for almost all employees. Not for football, though.

2011: UMD doubled down: in order to invest more in football, the university eliminated 8 other varsity sports, all of them sports that are healthy for students and that don't carry any risk of permanent brain damage. Here's what they cut: men’s cross-country, indoor track, outdoor track, men’s swimming and diving, men’s tennis, women’s acrobatics and tumbling, women’s swimming and diving, and women’s water polo. Loh's argument at the time: "should we have fewer programs so that they can be better supported and, hence, more likely to be successful at the highest level? Or, should we keep the large number of programs that are undersupported compared to their conference peers?"

It pains me to read these words again. Is this what "successful" means for a major university? That its football team wins a few more games? Meanwhile, hundreds of students who played those other sports, all of which likely enriched their lives and their health, were left without teams.

2012: Maryland left the ACC, to which it had belonged for over 50 years, and joined the Big Ten conference, a move that was supposed to make more money. Never mind that it would require the players to travel much longer distances for games at other schools in the Big Ten. Never mind the $50 million exit fee to leave the ACC.

2015: Deja vu! Maryland football was still losing, so they fired the coach again, giving him a $4.7 million payout from state funds, to hire another new coach, DJ Durkin. The coach they fired, Randy Edsall, was the guy who was supposed to take the Terrapins "from good to great." That worked out well, didn't it?

2017: How is that team doing, anyway? Overall record 4-8, tied for dead last in the Big Ten's eastern division. What was it that president Loh said again about being successful at the highest level?

2018: Under coach DJ Durkin, a team practice on a very hot day causes the tragic death of a young player, Jordan McNair.

This slow-moving disaster illustrates what I've pointed out before:


The bottom line: football is corrupting our universities, and it needs to go. This doesn't necessarily mean that fans must lose their favorite college teams. Here's one possible solution.

Football fans, including state legislators and university administrators, like to claim that football makes a profit. Let's suppose that's true: then it will do just fine as an independent business. Get football out of the universities, and make it a privately-run minor league for the NFL (which it already is, in effect). Let each team pay fees for use of the university's name, the stadium, practice fields, and parking on game days. Then the football club can pay its coaches whatever it wants, and it will have to pay the athletes, who are disgracefully paid nothing right now. And the university will still have its team, but without the corrupting influence of money. Even better, universities won't have to pretend that they are providing a first-class education to the players, while padding their coffers at the players' expense.

Let's end the farce of having university presidents try to manage large, commercial sports programs. Let them get back to focusing on research and education, topics on which they actually have some expertise.

I'm not naive: I don't think any major university is going to get rid of football any time soon, despite the growing evidence that football carries a major risk of brain damage to the players. This has only happened once, when the University of Chicago eliminated its football program in 1939, and brought it back in decades later as much-reduced program, now in NCAA Division III. The university itself has remained a powerhouse, routinely ranked in the top universities in the country academically.

Meanwhile, the Maryland Board of Regents is trying to decide what to do. If they read the timeline above, they'll know what I think: get rid of the whole lot, including the football program, and get the university back to its real mission.

A dubious homeopathy study made its way into a scientific journal. Will it be retracted?

Homeopaths did it again–they snuck a dubious study into a respectable journal. Well, sort of. Let's quickly look at the study, and then look at the journal that published it.

The paper has a very science-y sounding title, which likely helped it sneak under the radar: "Ultra-diluted Toxicodendron pubescens attenuates pro-inflammatory cytokines and ROS-mediated neuropathic pain in rats." It seems they were studying pain in rats, but what else is hiding inside this title?

The first warning here is the phrase "ultra-diluted." In the world of homeopathy, substances are diluted until there is literally nothing left, not a single molecule. Some of the dilutions in this paper were indeed extremely dilute, down to 10-30, which means that they were just water. So they can't possibly have any therapeutic effect, at least no more effect than plain water.

You might also be wondering what Toxicodendron pubescens is. That's poison oak! Here's what homeopaths claim about poison oak: that if you dilute it down sufficiently, it reduces itching and pain. This is one of the basic principals of homeopathy, that "like cures like"–that if you want to treat a symptom, using a substance that causes the same symptom, only dilute it way down. Feeling itchy? Rub some poison oak on that! I'm not kidding–here's a link to a product you can buy that really makes this claim.

Of course this is utter nonsense, as I and many others have written before. Homeopathy doesn't work for anything at all, as a massive Australian study concluded back in 2015.

Now let's look at where this dubious study appeared: in a journal called Scientific Reports. Scientific Reports is a mega-journal that publishes 25,000 papers per year, making it the largest journal in the world. What's also interesting is that it is published by the Nature publishing group, which also publishes the highly prestigious journal Nature and many other related, high-quality journals. (Full disclosure: I've published many papers in those journals.) PLoS ONE was the first mega-journal, and it was so successful (i.e., it made so much money for its publishers) that Nature decided to imitate it. They've managed to steal a lot of the "customers" from PLoS ONE because the Nature brand is, apparently, more appealing to many authors.

It's tempting to argue that everything in Scientific Reports is just low-quality stuff, so one more bad paper doesn't mean anything. But it's not so simple. Scientific Reports is trying to be a decent journal, one that has a very high acceptance rate (59%, according to their website) but that nonetheless publishes only valid science. Last year I was involved in a kerfuffle with them over a plagiarized paper, and after lots of pressure, we did get them to retract the paper. It wasn't easy, but the Editor in Chief corresponded with me at the time, and he really does seem to be trying to enforce some decent standards.

When you publish 25,000 papers a year, though, some garbage is going to slip through. To their credit, Scientific Reports has now issued a note of concern on this homeopathy paper, as reported by the alert team at Retraction Watch. Here's the note in its entirety:
"Editors’ Note: Readers are alerted that the conclusions of this paper are subject to criticisms that are being considered by the editors. Appropriate editorial action will be taken once this matter is resolved."
The right thing to do would be to retract this paper, because its results are simply not valid. We'll see if that happens.

Meanwhile, when reading the paper, I noticed that no less than eight of its references are to a journal called Homeopathy, published by Elsevier, one of the biggest and most profitable academic publishers in the world. Unlike Scientific Reports, Homeopathy is not even trying to publish valid science; its entire existence is premised on a nonsensical set of beliefs.

The good folks over at Retraction Watch wrote about this journal two years ago, in an article called "Does a journal of homeopathy belong in science?" Spoiler alert: it doesn't. As Ivan Oransky and Adam Marcus wrote then:
"the issue is that science publishers, even legitimate global corporations like Elsevier, will accept something patently unscientific if it might make them money."
So while Nature does deserve criticism for letting bad science slip into its mega-journal, Elsevier has a lot more explaining to do. At least Nature is trying.

World Health Organization endorses TCM. Expect deaths to rise.

Mother and young rhinoceros killed for their horns.
Image credit: Wikipedia
A few days ago, a news story in the journal Nature reported that the World Health Organization, which is supposed to be devoted to improving the health and medical care of people around the globe, will for the first time endorse a belief system called "traditional Chinese medicine." I'm labeling TCM a belief system because that's what it is–but the WHO will be endorsing it as a set of medical practices.

The Nature writer, David Cyranoski, presents this news in a classic two-sides-of-the-story format, describing the "endless hours" that TCM proponents spent on such important topics as the "correct location of acupuncture points and less commonly known concepts such as ‘triple energizer meridian’ syndrome." Later in the article (but much later), he points out that scientists have argued that qi and meridians simply don't exist.

Cyranoski also falls into the trap of using the phrase "Western medicine" as if it were just an alternative point of view. An apt response is this comment from a biology Ph.D. student, who goes by @astrelaps on Twitter:
"What a weak, equivocal article from the world's preeminent scientific journal. "For those steeped in Western medicine..." is like writing "For those steeped in climate science" or "For those steeped in evolutionary biology" when reporting on climate change denial or creationism."
Well put. On the other hand, Cyranoski does point out that the major motivation for TCM is money:
"[China] has been aggressively promoting TCM on the international stage both for expanding its global influence and for a share of the estimated US$50-billion global market."
Were you thinking this was about health care? Afraid not. Cyranoski goes on to point out some serious problems with TCM, for example:
"Critics view TCM practices as unscientific, unsupported by clinical trials, and sometimes dangerous: China’s drug regulator gets more than 230,000 reports of adverse effects from TCM each year."
Actually, it's much worse than this.  Here's what TCM really looks like: the horrific slaughter of the last remaining rhinoceroses in Africa in order to hack off their horns, which are sold to become part of elixirs that some people mistakenly think confer strength or virility. Last year, National Geographic ran a heart-wrenching photo essay showing some of the awful results of rhinoceros poaching in Africa; take a look at these photos here.

TCM also looks like this: black bears kept in grotesquely cruel "farms" with a permanent tube inserted into their abdomens so that their bile can be harvested. Despite a growing movement to end this inhumane practice (see this NY Times story), it persists today, with thousands of bears kept in cages so small they can barely move. No one can view photos such as these and say that TCM is a good thing.

And TCM is behind the slaughter of the last remaining wild tigers, which are virtually extinct now in Asia, so that men can foolishly eat their bones, claws, and genitals in the mistaken belief that tiger parts will make them virile. Here too, National Geographic has details and photographs that are almost too painful to look at.

And don't get me started on pangolins, the beautiful, peaceful mammal that's now perilously endangered because TCM practitioners think its scales have some sort of medicinal value. (They don't.) For more on these gentle creatures, see the article I wrote last year.

I can almost hear the counter argument: but what about artemisinin? That's a plant extract derived from Artimisia annua, an herb that was traditionally used in China to treat malaria. Turns out that it really works, and artemisinin is now the basis of a number of modern malaria treatments.

Well, great. If an herb has the potential to treat disease, we should (and can, and do) study it, figure out what the active ingredient is, develop a controlled process for delivering effective doses, and use it. That's what happened with artemisia, and it also happened with taxol, an effective cancer chemotherapy derived from the Pacific yew tree, and common aspirin, derived from the willow tree.

But one success doesn't excuse hundreds of bogus claims that are based on little more than magical thinking.

There's no legitimate reason to use terms such as "Chinese" medicine, or American, Italian, Spanish, Indian, or [insert your favorite nationality] medicine. There's just medicine–if a treatment works, then it's medicine. If something doesn't work, then it's not medicine and we shouldn't sell it to people with false claims. The same is true for alternative, holistic, integrative, and functional medicine: these are all just marketing terms, with no scientific meaning. They merely serve to disguise sloppy, unscientific thinking at best, and in a less charitable interpretation, outright fraud.

As the Nature article points out, TCM has been a scam for decades: it was revived and heavily promoted in China by former dictator Mao Zedong, who didn't believe in it himself, but pushed it as a cheap alternative to real medicine. I won't go over that again here, but see these stories from Alan Levinovitz in Slate and David Gorski at Science-based Medicine.

Finally, why would the World Health Organization start pushing a set of unscientific practices that are likely to harm people's health? Support for TCM grew during the tenure of former WHO director Margaret Chan, who ran the WHO until 2017 and who had close ties to China. When Nature tried to contact Dr. Chan, the WHO responded that Chan "is not answering questions on matters related to the WHO."

By endorsing TCM, the WHO is taking a big step backwards. Let's hope that the current leaders of the WHO will realize that this step undermines their core mission. The WHO should not advocate treatments that not only have no evidence to support them and that can cause real harm to patients, but also are the primary reason that humans are hunting rhinoceroses, tigers, pangolins, and other animals to extinction.

Play Tennis For A Longer Life. Science Proves It.

Chris Evert and former President George H.W. Bush playing
tennis at Camp David during Bush's presidency.
Tennis might just be the best thing you can do to extend your life.

A new study from Denmark, published just last week by Peter Schnohr and colleagues, shows that playing tennis may extend your life by nearly 10 years. That's a remarkably big benefit, one that even the study authors were surprised at.

It's been well-established for a while now that exercise helps you live longer. For example, the Cardiovascular Health Study found that people over the age of 75 can expect to gain 1 to 1.5 years of healthy living by being active rather than sedentary. Others studies have looked at the effects of running or walking and found similar positive benefits.

The authors of the new study wanted to look at other sports activities, not just running. Using a large cohort of 20,000 healthy people in the Copenhagen City Heart Study, they identified 8,577 who were in the study from the early 1990s until 2017 and who met a variety of other criteria for inclusion. This gave them 25 years of followup, long enough to ask the question: how does participation in sports affect life expectancy?

In particular, they looked at tennis, badminton, soccer, jogging, cycling, calisthenics, swimming, and health club activities (which included treadmills, ellipticals, and weights).

The bottom line: compared to a sedentary lifestyle, playing tennis extends one's life expectancy by 9.7 years. The other sports all provided benefits too, though tennis was the clear winner. Here's a summary:

  • Tennis: 9.7 years gain in life expectancy
  • Badminton: 6.2 years
  • Soccer: 4.7 years
  • Cycling: 3.7 years
  • Swimming: 3.4 years
  • Jogging: 3.2 years
  • Calisthenics: 3.1 years
  • Health club activities: 1.5 years

The authors didn't expect tennis to do so well, as you can see in this quote:
"Surprisingly, we found that tennis players had the longest expected lifetime among the 8 different sports."
For those who don't read scientific papers regularly, I should point out that the word "surprisingly" rarely gets past the editors unless the result truly is surprising. One part of the surprise is that spending more time exercising did not correlate with the greatest benefits. In fact, the cohort of people who spent the longest time on their exercise was the health club group, who showed the smallest increase in longevity.

One possible reason for tennis, badminton, and soccer doing so well is that out of the 8 sports studied, these are the ones that require 2 or more people and involve social interaction. As the authors explain,
"Belonging to a group that meets regularly promotes a sense of support, trust, and commonality, which has been shown to contribute to a sense of well-being and improved long-term health."
Or it might be that the type of exercise you get in tennis – short bursts of activity rather than slow, steady plodding exercise – might be better for you. The authors noted that
"short repeated intervals of higher intensity exercise appear to be superior to continuous moderate intensity physical activity for improving health outcomes."
If you're still skeptical, the only other study similar to this one, a very large study from Britain published last year, came to the same conclusion: racquet sports had the greatest benefit on all-cause mortality, followed by swimming and aerobics.

So if you're not doing it already, take up tennis! It's easy to find clinics and teams at almost any level (in the U.S., that is), thanks to the thousands of local clubs and to the huge network of USTA leagues, with play ranging from beginners on up, and age groups up to 85 and even 90.

That's right, there are tennis leagues for the 90-and-over set. Maybe tennis players really do live longer.

(Caveats: this was an observational study, based on surveys of people's behavior over a 25-year time span. The scientists tried to take into account all the other variables that might affect life expectancy, but humans are complicated and surveys are never entirely reliable. We don't know that tennis, badminton, and the other sports were the cause of longer life–it might be that people who play sports are generally healthier, and that both leads to longer life and allows them to play more sports.)