Ricki Lewis

I stopped eating beef 5 years ago, following a trip to Costa Rica just days after being diagnosed with breast cancer. Our daughter had been urging us to give up red meat for more than a decade, but a lecture and slide show on the effect of cattle ranching on Costa Rica's spectacular biodiversity, right after my diagnosis, finally did the trick. So compelling were the environmental and human health reasons to no longer eat beef that I barely dwelled on the obvious animal cruelty aspect.

Back home, I wrote about another anti-beef argument here at DNA Science: a sugar (a type of sialic acid) on our cell surfaces that is slightly different than versions on muscle cells of cattle and pigs. The cells of these animals make an enzyme that dismantles their form of sialic acid, but our cells don't. As a result, the human immune system reacts to cow and pig muscle cells bearing sialic acid with its inflammatory response. Over time, thanks to hamburgers and steaks and ribs, risks of cardiovascular disease, arthritis, and cancer rise.

A few days ago, my husband and I returned from a second trip to Costa Rica. This time, we saw firsthand the stark difference between cattle grazing land and the plants-upon-plants-upon-plants that make up natural ecosystems.

To continue reading, go to DNA Science, where this post first appeared.

When a headline in the Washington Post dubbed COVID "A Plague of the Elderly," I cringed, envisioning Logan's Run, the sci-fi classic in which people past a certain age voluntarily die. The film came out in 1976, the year I graduated college.

That would make me, well, elderly.

Yes, older folks are over-represented among those who get very sick or die from COVID, with "nearly 9 out of 10 deaths now in people 65 or older," WaPo reminds us. That is striking for an age group that makes up only 16 percent of the population. But while media reports trumpet the damning statistics, few delve into the biology behind the elevated risk: it could be that our shorter chromosomes hamper the immune response.

The WaPo article, like others, states the obvious:

"The vulnerability of older people to viruses is neither surprising nor new. The more we age, the more we accumulate scars from previous illness and chronic conditions that put us at higher risk of severe illness."

Yes, a 75-year-old with COPD is less likely to survive COVID pneumonia than a 75-year-old with healthy lungs. And developing COPD is more likely after decades of exposure to irritants. But number of years by itself may be a surrogate for some other factor.

Might the culprit be telomeres, the tips of chromosomes? They shrink as time passes, like candles burning down.

To continue reading, go to DNA Science, where this post first appeared.