Survival traits that are killing us

The Biblical admonition that “the meek will inherit the earth,” said cardiologist Lee Goldman, M.D. ’73, M.P.H. ’73, is just not true. “We’re not the descendants of people who got killed; we’re the descendants of people who killed other people.”

Knowing how to survive violence was one of four bedrock traits that allowed our ancestors to pass on their genes for more than 200,000 years. The others are appetite, which leads to gorging and storing fat; craving water and salt, which staves off dehydration; and the ability to clot, which minimizes blood loss after injury or childbirth. These traits distinguish the lineages of people alive today from those that perished, said Goldman, dean of the faculties of health sciences and medicine at Columbia University Medical Center.

And yet in the 21st century, Goldman argues, our lives are increasingly threatened by those very traits. That is the central argument of his new book, Too Much of a Good Thing: How Four Key Survival Traits Are Now Killing Us. “Now each of those traits is overprotective, doing more than we need.”

The problem is recent. For millennia, rates of random genetic change arising from mutations, combined with natural selection, matched the generally slow rate of change in the natural environment. But during the past two centuries, Goldman said, labor-saving technologies like cars and elevators have made us sedentary. We sweat less but still crave salt; we burn fewer calories but can’t resist calorie-dense foods.

As for clotting, Goldman writes, “veins were built for constant motion,” and if we sit and sit, our life-saving clotting ability can turn on us. Video-game addict Chris Staniforth, Goldman notes, died at age 20 after a long session at the computer. A clot that formed in his leg migrated to cause a fatal blockage in his lungs.

Vigilance against danger once protected us, but can now cause anxiety or even post-traumatic stress disorder, and the ancient ability to act submissive to avoid aggression can lead to depression. Whereas archeologists estimate that violence killed about one in six hunter-gatherers, Americans are now twice as likely to commit suicide as to be killed by a fellow human.

“Our genes just can’t keep up,” Goldman writes. “And as long as modern killers [such as chronic disease] afflict us after we bear children, who will in turn have their own children, there’s no natural selection process to give an advantage to genes that hypothetically could help us catch up.”

Goldman has little hope that willpower or shaming can overcome our attraction to potato chips or M&Ms. Policy measures will serve us better than attempts at self-control, he said. In Finland, for example, efforts to cut sodium consumption through nutrition labeling and lowering the salt content of foods have reduced deaths from heart attack and stroke among middle-aged Finns. Goldman also believes that medications will become more effective as they are increasingly tailored to individuals’ genes and biomarkers.

Goldman’s 284-page book, packed with science, is his first for a lay audience. He is well known for his landmark Goldman Index. Developed with colleagues in 1977 and revised in 1999, the index predicts the likelihood that a person undergoing non-cardiac surgery will suffer postoperative heart problems. Goldman is also the lead editor of the 3,000-page internal medicine textbook, Goldman-Cecil Medicine.

Too Much of a Good Thing grew partly out of questions from patients—“questions like, Why is it so hard to lose weight? Do I really have to take my blood pressure medication? Should I take an aspirin every day?”

Goldman chose to write for “a well-informed public interested in medical science,” he said. “I decided it was going to be a serious read, not a watered-down self-help book.”