Seven thousand steps is the new magic number

 If, like me, you've been trying for years to fit those widely recommended 10,000 steps per day into your schedule without great success, you may be able to breathe a sigh of relief. New research published in the prestigious Journal of the American Medical Association (JAMA) shows that just 7,000 steps per day significantly reduces deaths from all causes among middle-aged Americans, regardless of race or gender. 

It's not that taking more than 7,000 steps per day would be bad for you--increasing benefits were found up to 10,000 steps per day. However, the benefits of moderate walking--just 7000 to 9000 steps per day--were massive, a 50 to 70 percent reduction in the risk of dying over the years of the study.

Credit: MabelAmber

"You see this gradual risk reduction in mortality as you get more steps," says Amanda Paluch, an assistant professor of kinesiology at the University of Massachusetts, Amherst, and corresponding author for the JAMA study. "There were substantial health benefits between 7,000 and 10,000 steps but we didn't see an additional benefit from going beyond 10,000 steps."

(It turns out that 10,000 steps per day was not a scientifically determined goal, but a catchy number that gained traction because of an advertising campaign for a Japanese pedometer!)

Paluch and her colleagues utilized data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. The study started in 1983 and is still continuing. It involved over 5,000 men and women from four US states, and is notable for both its duration--now approaching 40 years--and for its racial balance. 

Participants activity levels were measured over the course of one year, and they were re-assessed ten years later. Overall, participants who walked 7,000 to 9,000 steps per day at the start of the study were just 28 percent as likely to die as those who walked fewer than 7,000 steps per day--a more than 70 percent risk reduction. Women and Blacks showed the greatest benefits of higher activity levels, but men and Whites still showed a 60 percent reduction in mortality risk over 7,000 steps per day.

Interestingly, walking faster was not associated with decreased mortality. The number of steps turned out to be much more important than the minute-by-minute intensity of the exercize.

The clear implication is that no matter who you are, you can increase your odds of living a longer and healthier life simply by taking 7,000 or more steps per day. 

"Showing that steps per day could be associated with premature mortality is a new contribution to the field," says Paluch. "Preventing those deaths before average life expectancy--that is a big deal."

Let's all make Professor Paluch happy, and click off those 7,000 steps starting today!

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REA 9/30/21

Is there a Republican death wish? Check out this link.

In the social sciences it's  rare to see a simple, clear, unequivocal relationship between two variables. People are complex, issues are multi-faceted, categories are often fuzzy, good data hard to come by.

That's what makes the graph in this article from The Daily Kos, "A Simple Actuarial Analysis" so mind-blowing.

The x-axis is the county-by-county percentage of Trump voters in the 2020 election.

The y-axis is the number of Covid deaths per 100,000 residents in those counties between 7/10/21 and 9/7/21.

Please take a look and come to your own conclusion.

US Capitol, January 6, 2021

Credit: Brett Davis/Flickr

Best data yet on the actual risks of the Pfizer mRNA vaccine

Many people don't trust even repeated assurances from official sources that mRNA vaccines like the Pfizer/BioNTech Covid shots are safe. In fact it's not unusual for opinion leaders opposed to these vaccines, and their followers, to warn that the Covid vaccines are extremely dangerous and have already caused high levels of serious illness and thousands of deaths. Millions of Americans appear to be far more afraid of the vaccines than of the Covid virus itself, and continue to refuse vaccination.

                                                                 Anti-vaccine protester

Credit: Fibonnaci Blue/Flickr

A new, peer-reviewed study appearing in the New England Journal of Medicine injects solid data into this fraught debate. The study provides an accounting and analysis of adverse events that occurred among more than 800,000 people within 42 days of receiving the Pfizer vaccine in Israel between December 20, 2020 and May 24, 2021, compared to an equal number of carefully matched peers who remained un-vaccinated, and to 173,000 peers who were diagnosed with Covid during the same time period. All the data came directly from anonymized medical records.

It's the largest controlled, peer-reviewed study of the side-effects of the Pfizer vaccine to date--nearly 40 times larger than Pfizer's phase III study--and provides the most accurate and detailed evidence to date of its risks when administered to large numbers of people on a national basis.

Anyone interested in reading the full research paper, carried out by researchers at the Clalit Institute in Israel and Harvard Medical School, can find it here.

The study evaluated 25 potentially serious adverse effects that earlier studies and clinical experience since the vaccines were released had identified as possibly linked to the Pfizer or other Covid vaccines, or to Covid itself. It did not look at mild, short-lived symptoms that typically accompany many vaccinations, such as fever, tiredness, or soreness near the injection site. It also did not attempt to evaluate any potential long-term effects.

Results:

Of the 25 adverse effects studied, 5 appeared more frequently following vaccination than they did in the same time period in the group of matched, but un-vaccinated peers:

Myocarditis--inflammation of the heart muscle--was 3.24 times more frequent in the vaccinated vs. un-vaccinated groups. However, since the incidence was low overall, that meant just 2.7 extra events per 100,000 people. In this study 91 percent of cases occurred in young men.

Lymphadenopathy--swollen lymph nodes--were 2.43 times more frequent among vaccinated compared to un-vaccinated people, appearing in 78.4 more cases than expected per 100,000. Swollen lymph nodes can be a sign of a serious condition such as cancer, but usually are simply an indication that the body is mounting an immune response.

Herpes zoster--shingles--was 1.43 times more frequent in the vaccinated group, and accounted for 15.8 additional cases per 100,000 vaccinated individuals.

Appendicitis occurred 1.4 times more often in vaccinated than unvaccinated individuals, adding 5 cases for every 100,000 people.

Bell's palsy--dysfunction of a facial nerve--occurred 1.3 times as often among the vaccinated group, but was also rare, accounting for 3.5 extra cases per 100,000 vaccinated individuals.

An unexpected finding was that vaccination lowered the risk of some of the adverse effects being studied, compared to the un-vaccinated group. Those included acute kidney injury, intracranial bleeding, anemia, and lymphopenia--low levels of white blood cells. The researchers suspect that those benefits appeared because of un-diagnosed Covid cases among the 800,000 un-vaccinated participants, which raised the incidence of those conditions--known complications of Covid-- in the un-vaccinated group.

As is true of almost any medical intervention, this study shows that the Pfizer/BioNTech mRNA vaccine is not risk-free. More importantly, the study gives us a clear measure of just what the vaccine's short- to medium-term risks are. Out of 25 potential side effects, 5 appeared at higher rates in the vaccinated vs. un-vaccinated groups. Of those, the most most serious was myocarditis, which added just 2.7 cases per 100,000, and the most frequent, which added 78 cases per 100,000, was not particularly serious--swollen lymph nodes.

In order to provide further context for those risks, the researchers looked at the same 25 potential adverse effects among 173,000 un-vaccinated study participants in the 42 days after they were diagnosed with Covid. The results reflect many of the all-too-well-known risks of Covid infection:

Cardiac arrythmia--3.8 times more frequent; 166 extra cases per 100,000

Acute kidney injury--14.8 times more frequent; 125.4 extra cases per 100,000

Pulmonary embolism--blood clot in the lungs--12.4 times more frequent; 61.7 extra cases per 100,000

Myocardial infarction--heart attack4.47 times more frequent; 25 extra cases per 100,000

Deep-vein thrombosis--3.78 times more frequent; 43 extra cases per 100,000

Myocarditis--18.3 times more frequent; 11 extra cases per 100,000

Pericarditis--5.39 times more frequent; 10.9 extra cases per 100,000

Intracranial bleeding--6.89 times more frequent; 7.6 extra cases per 100,000

Relative risks from Pfizer vaccination vs Covid infection

Credit: Noam Barda et al./NEJM

The vaccine is not risk free, but equally clearly, it does not cause anything like the degree or kinds of risk that anti-vaccination advocates and believers warn of. And the risks from the vaccine pale in comparison to the far higher risks from a Covid infection.

Here's what Dr. Ran Balicer, the study's lead author, concludes:

"These results show convincingly that this mRNA vaccine is very safe and that the alternative of 'natural' morbidity caused by the coronavirus puts a person at significant, higher and much more common risk of serious adverse events. These data should facilitate informed individual risk-benefit decision-making, and, in our view, make a strong argument in favor of opting-in to get vaccinated, especially in countries where the virus is currently widespread."

I'd add that the United States, which leads the world in Covid cases and deaths, qualifies as one of those countries.

If you want to compare your own risks from the vaccine with your risks from Covid, here's an approach:

If you're in the US and you're not vaccinated, as a rough approximation you have about a one percent chance--1000 out of 100,000 people--of getting Covid in any given six-week period. 

If you're vaccinated, your odds are somewhere between 10 and 20 times better, depending on where and with whom you live, work and recreate.

Six weeks is the same length of time used in the above study, so you can get an idea of your chance of developing any or all of the Covid complications that the study quantified.

To those conditions you can add yet another risk. Over the course of the pandemic in the US, 1.6 percent--1600 out of every 100,000 people--who were diagnosed with Covid died from it.

So, as a first approximation, your chance of coming down with Covid during a given six-week period--and dying from it--is about the same as your chance of getting a case of shingles within six weeks of a Covid vaccination.

From what I hear, shingles isn't fun, but dying is worse.

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REA 9/8/21