Winter 2017

Rethinking Muscle Cramps

A spicy drink that doesn’t taste good appears to obliterate pain through misdirection of the nervous system.

By Bruce Morgan

Previous Next

Illustration: Sophia Foster-Dimino

Anyone who plays sports, whether as a weekend warrior or a pro, has likely encountered the pain of a muscle cramp. Veteran marathoner Paula Radcliffe cramped up so badly at the 2004 Olympics in Athens that she had to withdraw from the race.

But what underlies the condition, exactly? For a long time now, sports medicine experts have theorized that muscle dehydration or a muscle starved for electrolytes caused the cramp, and treated it accordingly with water and electrolytes.

Rod MacKinnon, M82, H02, winner of the 2003 Nobel Prize in Chemistry, has a different idea. “The primary origin of the cramp is the nerve, not the muscle,” he told the Wall Street Journal last summer. The backstory has the tang of salt air. MacKinnon was kayaking with a friend off Cape Cod a decade ago when his hands and arms cramped up badly. Once back on shore, MacKinnon and his friend, Bruce Bean, a Harvard neurobiologist, hypothesized that the condition might be linked to something gone awry with impulses in the nervous system.

MacKinnon had an edge when it came to understanding nerves; after all, he won the Nobel Prize for uncovering the first atomic structure of protein molecules that generate electrical signals in living organisms. Now he had the idea that he could modify the nervous system—distract it, in a way—by overloading the nervous system through pungent flavors in a person’s mouth. In MacKinnon’s more precise, scientific phrasing, “The strong sensory input causes inhibition of the motor output.”

He has spent the past decade tinkering in his kitchen at home to test his theory, cooking up spicy drinks with varying amount of ginger and cinnamon while also trying to induce cramps using electrical stimulation. He found that his drinks did indeed have the effect of deterring muscle cramps. The results of more controlled subsequent studies done in the laboratory, which he presented last year at meetings of the American Academy of Neurology and the American College of Sports Medicine, further confirmed his hypothesis.

Word has gotten around, and a number of endurance athletes have already started drinking something spicy before their events. In 2015, MacKinnon launched his own concentrated beverage, called “Hotshot,” distributed nationwide. Nobody, not even the inventor, pretends the peppery mix of flavors tastes good. But it apparently delivers such a shock to the body that the body has no time for muscle cramps.

Top Stories

Head in the Clouds

There’s never been a good test for how altitude affects a mountain climber’s mental acuity. But recently one of our students took steps to improve things.

In A New Light

With its latest gift, a $15 million donation, the Jaharis Family Foundation Inc. will move the anatomy lab into modern new space and ease the debt burden on students specializing in family medicine.

A Cancer Cell’s Achilles’ Heel

Cell biologist Michael Forgac targets a mechanism that allows cancer to spread.

Heart Guard

High-tech chest protector thwarts sudden death in young athletes.

Open-and-Shut Case

John Santa, ’76, is leading an effort to make doctors’ notes from office visits readily accessible to patients, but not everyone is so eager to see it happen.

Starting Over Again

How a Tufts residency program is helping a small community of Haitian refugees in Lawrence, Massachusetts.

Editor's Picks

The Alzheimer’s Hope

First, neuroscientist Philip Haydon made himself an expert in a little-known area of brain science. Now he is testing a revolutionary new approach that shows great promise for the treatment of this dread modern disease

Big Road Blues

Living near a highway can be bad for your health in a million small ways

Disease Detective

On the trail of health threats around the globe 

Field Marshal

At the height of the Depression and against all odds, Dorothy Boulding Ferebee, ’24, ventured to Mississippi to blaze a resonant new trail in public health

Resistance Fighter

Longtime faculty member Stuart Levy has spent a lifetime studying mechanisms of antibiotic resistance and crusading to abolish the use of antibiotics in animal feed 

The Gift

Over the past 30 years, the live-donor liver transplant program at Lahey Hospital & Medical Center has treated more patients than any comparable program in the country. One of those patients had his life saved thanks to a donation by his son, a Tufts medical student. Here, in their own words, is the story of that experience