High-Protein Diet Factored Into Athlete's Sudden Death

Hockey player unaware of rare enzyme deficiency; ammonia built up in brain.

ByJANE E. ALLEN, ABC News Medical Unit
October 6, 2010, 3:57 PM

Oct. 7, 2010— -- Like many serious athletes his age, 20-year-old Ben Pearson wanted to increase his protein intake to boost his muscle development. And like many others, it appears the 6-foot-2, 240-pound junior hockey defenseman from Cambridge, Ontario, loaded up on protein supplements in the form of shakes and nutrition bars to accomplish that goal.

For most anyone else, such supplementation would have been safe. But in Pearson's case, the additional protein may have been a contributing factor in his death last weekend.

Pearson had a rare genetic disorder that kept his body from properly breaking down the protein in those shakes and bars. No one knew that since birth, his body couldn't make enough of a critical dietary enzyme to process the key nutritional building block.

His father, Stephen Pearson, told a Canadian newspaper, The Record, that his son had been on a high-protein eating plan at the time -- and as a result, the protein boosted ammonia levels in his blood that caused brain swelling and led to his death early Saturday.

Stephen Pearson didn't specify the name of Ben Pearson's diagnosis, and obituaries said he died "after a brief illness." But it appears that he suffered from a condition known as a urea cycle disorder.

A healthy body breaks down protein into several components, including nitrogen. Substances in the body called enzymes then convert that nitrogen into urea, a waste product that leaves the body in the urine.

But in someone lacking the proper enzymes, nitrogen accumulates in the blood as ammonia, which poisons the brain. Brain damage, coma and death can follow.

Urea cycle disorders are incurable. They are thought to occur in about one in 14,000 people and they stem from deficiencies in any of eight enzymes. The most common of the disorders is called ornithine transcarbamylase deficiency (OTC), with a prevalence of around one in 30,000, said Dr. Mark Batshaw, principal investigator of the Urea Cycle Disorders Consortium, part of the NIH's Office of Rare Diseases Research Network.

These conditions usually are inherited, but they also can arise from spontaneous mutations. Those that create problems just after birth or in infancy are most deadly.

The milder forms of the condition, which can begin in childhood or later, frequently lead to an aversion to meat and other protein-rich foods. The condition can be triggered by a number of factors, ranging from severe infections and stress to some prescription drugs such as the anti-seizure medication Depakote.

The symptoms of high ammonia levels in the blood include vomiting, lethargy, disorientation and sleepiness, as well as combativeness, irritability and anorexia.

Hockey Player May Have Suffered From Protein Overload

Ben Pearson began feeling sick a few weeks ago, and was ailing during his last game on Sept. 24, both Jarrett Rose, his assistant coach with the Norwich Merchants, and his father have said.

Although Batshaw said he couldn't comment with any authority on the case, he theorized that "in a situation like this, what may have happened was that for a week or two, the ammonia was getting out of control" because of an illness or the protein in Pearson's diet, "and it just got to a level where it became symptomatic."

Batshaw said urea cycle disorder specialists don't know why people like Pearson are able to survive so long without clinical symptoms. When doctors have gone back into the medical histories of patients, they often have found that protein made them feel sick, or that they had recurrent episodes of vomiting "thought to be of gastric origin when, in fact, they were due to accumulations of ammonia."

Proper treatment depends upon frequent blood monitoring. Some patients simply can follow a low-protein diet. Others must take essential amino acid supplements.

During an acute crisis, doctors use dialysis to remove ammonia from the blood. Many patients take medication that scrubs ammonia from the bloodstream. Typically, it's oral sodium phenylbutyrate called Buphenyl.

Doctors may give Ammonul, an FDA-approved injection of sodium benzoate and sodium phenylacetate. They may administer an intravenous combination of sodium benzoate and sodium phenylbutyrate, Batshaw said. Some require a liver transplant.

The hope long has been that gene therapy might one day give patients' bodies the ability to make the missing enzyme. However, gene therapy trials suffered an enormous blow with the death of 18-year-old Jesse Gelsinger, a young man from Arizona with partial OTC. Although he was able to control his condition with a low-protein diet and handfuls of daily pills, he was hopeful about taking less medication one day.

He volunteered for a gene therapy safety study at the University of Pennsylvania in 1999, but suffered multiple organ failure that researchers associated with the virus used to deliver copies of the gene for the missing enzyme into his liver.

Most People Have Nothing to Fear From Protein

Batshaw, who was part of the Penn study, is currently chief academic officer at Children's National Medical Center in Washington, D.C. He heads the Longitudinal Study of Urea Cycle Disorders, which is monitoring the health of about 450 patients -- about half of whom have OTC deficiency -- at a dozen sites in the United States, Canada and Switzerland.

He said he was unaware of anyone else with a urea cycle disorder becoming fatally ill after eating a high-protein diet like Pearson's.

Keith Ayoob, director of the nutrition clinic at the Rose R. Kennedy Center at the Albert Einstein College of Medicine in the Bronx, N.Y., said that what happened to Pearson "will not happen to the average person. If you don't have an enzyme disorder, you're not going to get this."

In light of Pearson's death, some people might wonder about the wisdom of a high-protein diet, especially the Atkins plan that initially relies solely on protein and fat but no carbohydrates.

"There have been reported cases of young women who have decided to go on an Atkins diet and it has unmasked a urea cycle disorder. Some survive and some don't," Batshaw said.

However, when healthy people follow high-protein diets, their bodies can handle byproducts of protein metabolism. Much of the ammonia leaves the body in perspiration. Their stomachs will slow down the rate at which they break down food.

Athletes like Pearson need more protein than their sedentary counterparts, said nutritionist Heidi Skolnik, who consults for the New York Giants and the New York Knicks, as well as the Juilliard School and School of American Ballet.

But, she said, "there are a lot of athletes that over-consume protein to build muscle mass. One of the things they don't realize is there's a limit to how much your body can absorb and utilize at once."

When athletes take in too much protein, some gets laid down as fat.

Skolnick shared the story of one athlete who got faulty nutritional advice from his wife's personal trainer. The man ended up consuming twice as much protein as advised for athletes.

"He was eating protein at every meal," Skolnick said. "In between meals, he was pushing the proteins."

Instead of giving him more lean muscle, he put on fat.

How Much Protein Is the Right Amount?

Consuming excessive protein may lead to an upset stomach. Relying on protein and cutting back on carbohydrates may produce headaches and low energy.

Skolnick said the best way for your body to handle protein is in small amounts spread through your day. You might choose eggs, cheese or soy at breakfast; chicken at lunch; fish at dinner; milk or yogurt as a snack.

The general guideline in the current food pyramid for people over the age of 8 is to get 5 to 6 ounces of protein daily from meat and beans, additional protein from two to three daily servings of dairy products, and still more protein from whole grains and vegetables.

An athlete needs at least an additional 3 ounces a day, but a 300-pound athlete may need as much as 26 ounces of daily protein, Skolnik said.

Generally, sedentary people should get .8 to 1.2 grams of protein for every kilogram of their body weight.

"You can easily double it without any trouble, and triple it without any trouble," Ayoob said. "There's a margin of error the body builds in."

Protein bars and shakes usually are made from whey or casein, which are milk products, or from eggs or soy.

"There's nothing wrong with those," said Skolnik. But if you're already eating animal protein, "why do you need a protein shake on top of it?"

As a sports nutritionist, she recommends bars and shakes "as a part of recovery, after a good workout."

Although it's hard to sustain a very high protein diet for a long time, the bigger issue with that kind of eating becomes "what you're pushing out," Ayoob said.

Someone who is eating steak three times a day, or living on protein bars and shakes, probably isn't eating a lot of fruits and vegetables, and may be missing out on all-important fiber.

ABC News Live

ABC News Live

24/7 coverage of breaking news and live events