PERSONAL HEALTH : The USDA’s Clean-Plate Contingent
Confined for up to a year in a locked ward, they are unable to smoke, drink alcohol, or have conjugal visits. Visiting hours with relatives and friends are limited to a few hours one day a week, and chaperons lurk at their elbows on all trips beyond the locked door to make sure they ingest nothing they aren’t allowed to eat. Under orders to devour every last speck of food in their regimented diet, they lick their plates and mumble about deteriorating table manners.
This isn’t a minimum-security prison for wayward junk bond kings. It’s a metabolic ward for human guinea pigs who eat special diets to test the impact of different nutritional regimens. At the U.S. Department of Agriculture’s human nutrition centers, the only advantage people may have over prisoners is the prerogative to leave if they just can’t stand it any longer.
Despite the restrictions, most volunteers derive a great sense of satisfaction in “doing something for science.” Proponents of preventive medicine, the USDA researchers debunk nutrition myths and discover important dietary requirements that animal studies will not resolve. We--the taxpaying, eating public for whom these studies are done--glean information about how a different diet can make us healthier.
Some examples of what we as eaters have learned from human guinea pigs:
* A high-fiber diet, including five times more fiber than usual, cannot significantly reduce cholesterol in a high-fat diet.
* Women who don’t consume enough copper and iron sleep longer, but feel less rested.
* High doses of aluminum, which people ingest when they use antacids regularly, leads to poor quality sleep.
* Women with low iron have less energy during an aerobic workout, tire faster, and aren’t able to maintain their body temperature in a cold room.
* Increased doses of Vitamin E improve the immune responses of senior citizens, but Vitamin A derived from supplements instead of natural foods may lead to toxic buildups.
Dozens of healthy humans, ranging from newborn to 93 years old, can be found in metabolic wards in the USDA’s five Agricultural Research Service human nutrition centers in Boston, Houston, Grand Forks, N.D., Beltsville, Md., and San Francisco. Although universities also conduct human nutrition studies, the five federal centers do the bulk of the long-term research, mostly because such studies are so costly.
This year, $45.7 million will be spent at the centers. Some of that money is spent on animal research, as well as non-residential studies of human volunteers who take food home or visit the ward only to eat their meals. The most expensive research, however, involves experiments on the metabolic ward, where about a dozen people at a time live under what could politely be called house arrest, eating a strict diet.
During a 100-day San Francisco study of how fish oils affect blood clotting and cholesterol levels that are major factors in heart attacks, six of the 12 volunteers ate salmon for 40 days and 40 nights after a 20-day stabilization diet, while the other six ate a varied diet. Then the two groups switched.
Broiled salmon salad, salmon and sour cream sandwiches, salmon-cucumber salad, seasoned salmon spread on a bagel, and broiled salmon filet were served for lunch. Dinner consisted of baked salmon with dill weed, salmon teriyaki, baked salmon in tomato sauce, baked salmon with tarragon, and salmon lasagna.
Once the volunteers had eaten the five variations, they began again at the top of the list; they ate each meal eight times. The worst dish, according to popular consensus was the salmon lasagna. The best part of the diet was that they didn’t have to face salmon for breakfast.
What kind of people subject themselves to such a strict regimen?
There are college graduates who haven’t figured out what they want to do next, people who have retired and want something interesting to do, housemakers whose children are gone, and people between jobs.
Rodger O’Brien, 54, a retired contractor who manages rental houses in San Jose says he volunteered for the fish oil study because “I had a hard time getting my cholesterol down below 250. Besides, it’s a good study. This is something worthwhile.”
Roy Elder, 59, from San Jose, joined the same study because he was between jobs. James Yamaguchi, a 62-year-old retired Santa Clara city worker, volunteered because “eating salmon appealed to me. I love to eat salmon.” He hesitated. “Although, I don’t know about 40 days in a row.”
“We look for people who have a sense of adventure,” said James Penland, research psychologist at the ARS Grand Forks Nutrition Research Center. “But not someone who is sensation-seeking.”
Beyond that, selection of participants is “certainly an art, not a science,” he said.
Advertisements are placed in the media. The first screening takes place by telephone. Participants must be healthy. Unlike some studies administered by the National Institutes of Health in which sick humans are given experimental drugs, human nutrition studies aren’t designed to affect health one way or the other. Participants must be able and willing to eat the diet provided. They must be the appropriate sex: males and females do not live on metabolic wards at the same time.
Selection techniques--and the psychological support that volunteers obtain on the wards--have lowered the dropout rate from 33% to 11% in the 10 years that the centers have conducted studies on metabolic wards.
Only one man left the San Francisco salmon-eating ward. The first sign that he wasn’t too happy with the arrangement was that he complained about being cold, noted his roommate, Harry Nelson, a 62-year-old tree farmer from Birch Bay, Wash. With the thermostat turned all the way up and bundled under the blankets, he still complained. Not even the prospect of 100 days of free room and board, and 40 days of salmon dinners, prevented him from packing up his bag and walking out one morning, without a word to anyone.
The pay volunteers receive for putting their lives on hold ranges from little to meager. At the Children’s Nutrition Research Center in Houston, where most of the participants--women with small infants--stay only a night or two, volunteers are paid traveling expenses. At other centers, the pay ranges from $20 to $30 a day, in addition to free room and board.
“We want people who are highly motivated,” said Gary Nelson, a research chemist at the Western Nutritional Research Center in San Francisco. “That’s why money isn’t an incentive.”
Volunteers on the metabolic ward live two to a room and share a bathroom complete with shower, sink and nonfunctional toilet. They give researchers their saliva and their blood. Their urine and feces are also collected.
They have access to a day room equipped with a television, VCR, Ping-Pong, pool table, pay phone, newspapers and magazines, and to a library with typewriters, music tapes and books. Their rooms and living areas are cleaned for them. The only chore they have is to wash their own clothes.
They can leave the ward for long walks along routes that avoid food stores. They can visit a gym for workouts, and go to movie theaters. At all times they are under the eye of chaperons who make sure they don’t sneak a candy bar or a handful of popcorn.
Said Sal Vorja, 62, a retired Spanish teacher from Saratoga, Calif.: “The first time I went to the movies, a person next to me had a tub filled with popcorn that he ate through the whole movie. It was very trying.”
Perhaps because access to eating is so controlled, the volunteers say the high points of the day are the meals.
During the salmon test, several volunteers made a mad dash to be first in line for lunch when the dining room doors opened. At lunch they ate everything on their plates.
O’Brien spilled some juice on his tray and slurped it up with a straw.
“Disgusting,” said Vorja, laughing.
“Well, I have to drink it all,” O’Brien protested.
The men, in fine spirits because they had only 10 days remaining on the ward, had just posted their last breakfast requests on the wall. Brian Garner, 35, a musician between gigs, asked for a guacamole, cheese and sour cream omelet with home fries. “I’m gonna make up for all the cholesterol lost,” he explained.
Life on the ward has its ups and downs. At the top of the complaint list are noise, confinement and bland food. Even Nelson, the scientist who headed the study, had to grit his teeth at times as he stepped into the uncomfortable role of mediator when arguments arose.
“I have a lot of responsibility for their day-to-day life that they would ordinarily have themselves. I become a de facto father figure. It’s a nuisance, but inevitable,” he said. At times, he longed to go back to rats. “You’re less likely to get emotionally attached to them, particularly if you kill them at the end of the study.”
After a study is complete, volunteers are given certificates and payment. Their medical files are sent to their physicians. Their collected specimens are farmed out to researchers around the country. When the studies are completed and published, the volunteers receive copies.
“Some question the validity of human studies because of their limitations,” said Nelson. “They can’t be physically invasive, and the relatively small number of people in each study limits its statistical validity.”
But results do occur. Leslie M. Klevay, a physician and research leader for the ARS Grand Forks Human Nutrition Center, determined that lack of copper in the diet can lead to heart disease. From his research, and others who duplicated it, copper requirements have been written into the RDAs--the Recommended Daily Allowances of vitamins and minerals. From research on cholesterol and heart attacks, physicians now prescribe a change in diet to accompany medication.
The Human Nutrition Center on Aging in Boston is doing research on Vitamin K requirements, the beneficial effects of yogurt, and the effects of calcium supplements on preventing osteoporosis. In Houston, researchers are pioneering the understanding of nutrition in infants, nursing mothers, and pregnant women.
For most volunteers who participate in the studies, the metabolic ward is a once-in-a-lifetime experience, an interesting diversion. That was the attitude of the salmon eaters who lived on the metabolic ward in San Francisco. After he left, Vorja planned to pursue a job as a cruise-line host. Garner intended to visit his family before returning to music. O’Brien’s wife told him that she’d be waiting out front with the car motor running.
