Energy Source

Nutrition and exercise feed healthy habits
Melinda Manore

Often getting up before sunrise to attack the hills rimming Corvallis, Professor Melinda Manore has overcome injuries from a skiing mishap and a car accident in her quest to stay active. Exercise, she says, keeps her mentally and physically fit. (Photo: Karl Maasdam)

The mixed messages blare at every grocery checkout: supermodels smiling seductively from magazines that push chocolate-cake recipes and weight-loss tips on the same page. No wonder millions of American females struggle with food and body image, laments OSU Professor Melinda Manore.

The health of women across the age and activity spectrums — from teenage Olympic athletes to middle-aged pre-diabetics to elderly arthritis sufferers — is at the heart of Manore’s research in the dual sciences of nutrition and exercise. The broad question that drives her is, “How can we be healthy women and be happy with our bodies?” For answers, she looks at levels both micro and macro: chemical (micronutrients, hormones), physical (bone density, metabolic efficiency), motivational (lifestyle changes, food choices), even societal (family habits, media messages).

“Thirty years ago, if you saw a glamorous woman on a magazine cover, it was a head shot,” she says. “Now, it’s full-body — with nothing on. These young girls see these photos and think they should look like that, too.”

When she began her career a quarter-century ago, only a handful of researchers were investigating the linkages between eating and exercising. Back then, the two fields were rarely paired. So in 1984, the year she earned her Ph.D. in nutrition at OSU with a minor in exercise science, she was at the forefront of a movement. As obesity and diabetes galloped across America over the next couple of decades, the need for more research became acute. Investigating the interactions of food and movement has, at last, come into its own as a discipline.

“There’s been this whole turnaround,” she says. “Finally, we’ve gotten together.”

Besides coauthoring four top-selling textbooks, publishing 100-plus papers and articles in refereed journals, and holding the associate editorship of the American College of Sports Medicine’s Health and Fitness Journal from 1998 to 2006, Manore works with Oregon Health and Science University’s Department of Medicine through an OSU-OHSU research exchange.

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Good Vibrations

Manore’s studies span vastly different demographics: from elite speed skaters to self-professed couch potatoes; from limber gymnasts to stiff-limbed grandmothers; from athletes with eating disorders to Hispanics with diabetes.

Some of her most notable research is in the “female athlete triad” — how the synergy of sports, hormones and bone growth affects the health of girls and women. The 2002 Winter Olympics were, for Manore and one of her graduate students — Nanna Meyer, a former racer on the Swiss National Ski Team — a rare chance to study this all-important triad in top winter sport athletes. Meyer headed to Salt Lake City, legendary for its dry powder, to compare the bone densities of skiers, bobsledders and skaters against those of ordinary college women. It turned out that all the athletes who rocket down icy mountains at breakneck speeds — whether on skis, boards or sleds — had denser bones than the control subjects.

This first-ever bone study among winter athletes — a collaboration among Manore, Meyer and University of Utah researcher Janet Shaw — suggests that winter sports provide beneficial “loading patterns:” physical forces that stress the skeleton in ways that promote mineral growth. These bone-loading patterns include “mechanical loading” (impact from jumping or pounding) and “vibration loading” (stress from vibrating).

The sliding sports (luge, bobsleigh, skeleton) topped all events for whole-body bone density, the data revealed. It might seem improbable that a luger could build a better set of bones than a speed skater. One rips down the ice, toes-first, while lying flat on her back. The other attacks the ice on her feet, pumping and gliding, pumping and gliding. But the research team wasn’t all that surprised.

“Recent work on animals,” the researchers wrote in the September 2004 issue of Medicine and Science in Sports and Exercise, “has shown that vibration loading, imposing low-magnitude, high-frequency mechanical signals, can increase bone formation.” The Utah Olympics study, along with ongoing studies in OSU’s Biomechanics Laboratory, have added important human-subject evidence to the research base on skeletal vibration.

Hormones are the third prong of the triad. That’s because when young women’s diets are dangerously low in calories, menstruation can stop. “Hormone production goes flat, just as if the women were starving,” Manore explains. “You see this all the time in third-world countries; when there’s not enough food, the women stop menstruating. It’s a protective effect so they don’t get pregnant, because they can’t sustain a child if there’s no food.”

This hormonal shutdown can, along with poor energy and dietary nutrient intakes, suppress bone growth. In developed countries like the U.S., food abundance is a greater problem than shortage. Here, the girls and women most vulnerable to “ammenorhea” (no periods) are typically those who take extreme measures to shed pounds: strenuous dieters, disordered eaters, gymnasts, dancers and other athletes driven to extreme thinness. Over five or six years, a young woman can end up with “bones that look like an old woman’s,” reports Manore, who served on the International Olympic Committee for Gymnastics from 1996 to 2000. “So now, you have a 20-year-old with a hip fracture — or worse. It’s an issue for coaches; it’s an issue for parents. When a girl gets into eating disorders, I’m sorry, but you can lose her.”

Some protection against skeletal damage is provided by intense, bone-loading exercise, the Utah study suggests. In the short term, denser bones mean fewer fractures. In the long term, they fend off postmenopausal osteoporosis.

Getting enough of the B-vitamins, which are important for energy metabolism and blood formation, is another pitfall for women. Healthy levels of vitamin B-6 and riboflavin — essential nutrients found in the so-called “B-complex” — can succumb to the quest for a svelte physique. As with the female triad, athletes who shun calories are at risk, as are those who avoid meat or dairy foods, Manore and former doctoral student Kathleen Woolf reported in the International Journal of Sport Nutrition and Exercise Metabolism in October 2006. For her doctoral research Woolf, who is now at Arizona State University, examined the B-vitamin status and requirements of older active women with rheumatoid arthritis, a disease that compounds the risk of B-vitamin deficiency in later years.

The deep complexity of the exercise/nutrition/health dynamic was highlighted yet again in a 2006 OSU study centered on a compound unfamiliar to most Americans: homocysteine. Its cousin, cholesterol, has become a household word. Fretting over one’s ratio of LDL-cholesterol to HDL-cholesterol is practically a national pastime. Yet few Americans are versed in homocysteine, even though the compound was discovered decades ago, and scientists have long since linked high levels to cardiovascular disease.

Scientists are still unraveling homocysteine’s secrets. Manore and her Ph.D. student Lanae Joubert have found that blood levels vary in surprising ways. For example, it appears that some types of exercise, especially high-intensity exercise like running a marathon, increase blood levels of homocysteine, while others do not. Joubert’s research was designed to decipher how physical activity and diet interact to alter blood homocysteine levels. She wanted to find out, too, if individuals who exercise hard need more B-vitamins, which help to keep blood homocysteine low.

“Being physically active does not necessarily equate to a healthier nutritional status,” the OSU researchers warn in the international journal. Active individuals may, they caution, lack essential nutrients right along with sedentary people — a deficit that “may influence homocysteine levels independent of the amount, intensity or type of exercise.”

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Melinda Manore
Melinda Manore

Manore’s research on diet and exercise holds important clues for combating the growing epidemic of obesity and chronic disease. (Photo: Karl Maasdam)

Zealot for Health

Watching people make unhealthy lifestyle choices clearly pains Manore. From her previous office in Milam Hall, she had a direct view of the elevator. “I cannot tell you how many people, including students, used that elevator instead of walking up the stairs,” she reports. “I wanted to put up a big sign: ‘for disabled and delivery only.’ Or, because it was a really creaky old elevator, ‘use at your own risk.’”

As she tells this story, the frustration in her voice leaves no doubt: For her, healthy living goes deeper than professional interest. Hard work, whole foods and fresh air are in her blood. She was raised on a farm in the shadow of the Rockies. Getting up with the roosters to help gather eggs in the 5,000-chicken barn was her task as far back as she can remember. On the family’s Montana acreage, the lowing of cows, the bleating of sheep and the clucking of hens were the sounds of self-sufficiency. “Where I grew up, you raised your own food, you baked your own bread, you churned your own butter,” she says. “You didn’t go to the store. You didn’t eat out. Everything you did for activity — skiing, hiking, riding horses, gardening — was outdoors.”

Manore’s salt-of-the-earth Montana girlhood is intact even today. Her salad bowls and pasta platters brim with the tomatoes, peppers and basil she grows in her Corvallis garden. Her kitchen is a lab, of sorts, where she experiments with maximizing the fiber content in her home-baked muffins and with cooking dishes that typically veer in creative (but always nutritious) directions. And she panics when the grainy breads baked weekly by her husband are getting low. Her approach toward commercial bread — toward any processed food, in fact — is to leave it in the supermarket along with those airbrushed magazine covers. She’s careful, however, to avoid sounding extreme.

“I’m not the food police,” she insists. “I like chocolate and desserts, just like anyone else. I just think you need to eat them in moderation.”

Making healthy choices doesn’t need to mean self-deprivation and sacrifice, Manore argues. Rather, those choices can become preferences. You might find that you prefer the grilled chicken on whole wheat instead of the double-stack cheeseburger. You might enjoy a hike in the forest over a trek through the mall. “Instead of forcing you to give up your favorite things,” she says, “a healthy lifestyle can become your favorite thing.”

Bridging the gap between scientists and the public — between laboratories and living rooms, kitchens, playgrounds, malls, parks, workplaces — is Manore’s main focus these days. With her doctoral students, she is studying ordinary people facing ordinary problems: middle-aged moms who care for young children and elder parents but forget to care for themselves; Hispanic pre-diabetics in need of culturally appropriate interventions; active 40-something women whose nutrient status is poor despite regular exercise; elderly arthritis sufferers, some active, some not.

“The question is, How do you change your lifestyle for the rest of your life?” Manore says. “You don’t have to become a marathon runner. You just have to start moving more and making better food selections.”

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