In the news

            EVALI is an acronym that likely does not affect a single reader of this blog but you might know someone who would benefit from this news item.

            Dr. Jeannie Huang of Rady Children’s Hospital penned an article in the San Diego Union-Tribune on November 27th, 2020 entitled Commentary: I’m a doctor in San Diego. Smoking and vaping put youth at risk for COVID-19.  EVALI (E-cigarette or Vaping use-Associated Lung Injury) arose from the recognition that lung damage is more prevalent among e-cigarette users than had been recognized when the fad began. Even before the onset of the COVID-19 pandemic the CDC reported that as of January 7, 2020 there was a total of 2558 hospitalized patients with vaping lung injury and 60 deaths.

            Tobacco use is also a risk factor in this pandemic. It wasn’t long before healthcare workers observed that smokers were more likely to be severely affected by SARS-CoV-2 and were more likely to die. That of course is in addition to the long-recognized fact that 50 percent of smokers will die of an illness caused directly by that habit!

            As we enter the flu season the risk is magnified: tobacco smokers are five times more likely to contract influenza than non-smokers. The e-cigarette picture is more complicated and the data connecting vaping to COVID-19 will take some time to sort out. There are literally thousands of different chemical ingredients in those little electronic sticks.

            If someone that you care about is a user of tobacco or a vaping device, consider forwarding this blog to them.

Lifestyle

            In the last Carvings I discussed intermittent fasting, actually time-limited fasting, eating nothing between about 7:00 p.m. and 7:00 a.m. My recommendation is a little more user-friendly than the original article, which described a 14-hour fast.

            Only a few days after that post an article in the Journal of the American Medical Association (JAMA), Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men with Overweight and Obesity appeared that contradicted the findings in the first article. The JAMA article, in turn, was skewered by reviewers for a variety of reasons, most of them logical and justified.

            This topic is going to be around for a while, generating lots of argument, and more studies will have to be done on many more patients, with better controls than were done in both studies. Here is the argument in support of my version of time-limited fasting, i.e., no food between 7 p.m. and 7 a.m.

            When vexing medical/biological issues arise I often revert to the fact that our bodies evolved over a couple of million years in conditions that were vastly different from today’s environment and especially our lifestyle. We can’t undo that in the few generations that brought us refined grains, refined sugars, processed foods and a dramatic decrease in physical activity.

            Consider: Until about 150,000 years ago humans lived in the equatorial region of Africa, where day and night are of equal duration. (In Kenya, each phase lasts about 12 hours and 6 minutes; with little variation throughout the year the sun rises at about 6:20 a.m. and sets at about 6:30 p.m.) Our Stone Age ancestors probably only ate during 12 hours of daylight. That is what our bodies have adapted to. It was only with the “advances” of civilization that we are able to enjoy dinner by candlelight in the evening and midnight snacks. By interrupting our circadian rhythm we brought on a myriad of  medical problems such as increased rates of obesity, cardiovascular disease and cancer. 

            The fasting period in the JAMA study lasted from 8 p.m. until noon the next day. The subjects ate three meals of their own choosing during the remaining eight-hour period that began at noon. They were all overweight or obese, including an unreported number, one or more, who were morbidly obese (BMI 43). I find it hard to believe that they ate fewer calories during those eight hours than the amount that made them fat. And although it’s somewhat controversial, skipping breakfast, in a number of studies, is likely to lead to weight gain, not weight loss. Further, eating a late meal on a regular basis also leads to weight gain.

            Having your final meal of the day no later than 7:00 p.m. will probably help you to sleep better, as reported in the first study. Eliminating late night snacks will improve your handling of blood sugar since there will be no spikes for at least 12 hours.

            At the end of the first study more than half of the participants said that they would continue to follow the fasting pattern. I wonder how many subjects in the JAMA study felt that way about their program.