UC Food Blog
Since the onset of Title IX in 1972, opportunities have dramatically increased for female athletes, largely to their benefit. However, some negative health outcomes such as disordered eating, chronic menstrual disturbances and low bone mass have been associated with high-level competition among some female athletes, particularly in sports such as gymnastics and cross-country running, where a slender physique or lean body build is important.
“Adolescent female athletes, in a rapid growth and development phase, may be at greatest risk,” authors Michelle T. Barrack of UCLA and Marta D. Van Loan of the USDA Agriculture Research Service report in the July-September 2011 issue of California Agriculture journal. Their review article is published in a special issue of the journal, “Food as medicine: Can what we eat help cure what ails us?”
The article identifies athletes at risk in order to understand the origin of possible negative outcomes and recommend behavioral modifications that promote participation in competitive sports while supporting lifetime health.
The “Female Athlete Triad syndrome” is a trio of interlinked negative outcomes that can result from poor nutrition in a small percentage of high-level female athletes:
- Low bone mass in young women can lead to the early onset of osteoporosis and increased risked for bone fractures;
- Menstrual disturbances are caused by inadequate reproductive hormones, especially estrogen, which can in turn inhibit bone mineralization during adolescence and impede bone maintenance thereafter;
- Eating disorders can disrupt the menstrual cycle, resulting in low or no estrogen production; adequate levels of estrogen are needed to increase bone mineralization and, in turn, bone density.
An important question is whether these exercise-related health problems occur from an energy deficit, in which calories consumed do not meet calories needed for the increased level of physical activity, or from excess stress that alters the hormones regulating menstrual function and bone metabolism.
“Several well-controlled animal and human experimental studies have confirmed that as long as energy is available for physiological needs other than exercise, it promotes normal hormone function,” Barrack and Van Loan note. “This suggests that intense exercise does not in itself exert an additional stress that disrupts menstruation and bone metabolism.”
The article details the basic nutritional needs of female athletes.
“Just consuming enough energy (calories) is not enough,” Barrack and Van Loan wrote. “For optimal health and peak performance, it is critical to consume the three primary macronutrients for energy metabolism (carbohydrates, protein and fat) as well as a multitude of micronutrients (vitamins and minerals).” Critical micronutrients include B vitamins, antioxidants, calcium and vitamin D, iron, zinc and magnesium.
“The optimal diet for a young, developing athlete should maximize sport performance, while reducing injury risk and facilitating overall health, growth and maturation,” the authors wrote. “Due to the metabolic and physiologic demands of their sports, the nutrient needs of young athletes can be much higher than their nonathlete peers and higher than the needs of young adult athletes who have reached maturity. It is important to make competitive adolescent athletes aware of their specific needs as well as to identify those athletes at risk of developing deficiencies.”
In hard times, Americans have always turned to gardening. Gardens enable people to improve their food security. Plus gardens have many other benefits.
The Victory Gardens of World War I and World War II - and the garden efforts of the Great Depression - helped Americans increase home and community food security. In addition to helping the family budget and improving nutrition, these gardens helped to save fuel by reducing transportation; provided natural beauty in communities; empowered every citizen to contribute to a national effort; and bridged social, ethnic, class, age and cultural differences during times when cooperation was vital.
We are in the midst of a new cycle of a garden movement. While there are many reasons people are gardening today, there is a growing demand for food that is tasty, nutritious, and economically and environmentally sustainable.
The current resurgence in home and community gardens is similar to previous calls to garden in our country. Using gardens and the food that comes from them, we can profoundly change our lives and our communities. Gardening empowers eaters to take an active role in producing their own food. This simple act can improve nutrition, teach youth about science, reduce health care costs, regenerate the economy, preserve natural resources, strengthen national security, build resilient communities and nourish future generations.
Gardening offers many opportunities to improve one’s life by providing outdoor exercise, and excellent nutrition with home-grown fruits and vegetables. Working outside at home makes it easier to meet and greet neighbors – or make new friends at a community garden. But perhaps most importantly, during these uncertain economic times, gardening can help people be more self-sufficient.
The University of California has many resources for people and communities interested in gardening. The UC ANR Free Publications website and the UC ANR Catalog, which contains both free and priced publications, are great places to start.
According to Dr. Trevlor Suslow, a plant pathologist and Cooperative Extension specialist at UC Davis, “Americans consume more than six billion servings of uncooked fresh fruits and vegetables every year, versus a very small number of illnesses that are clearly linked to foodborne pathogens.”
The take-home message is that the food supply in the U.S. is generally very safe, particularly when everyone in the food supply chain (including consumers) does their part to assure food safety.
The U.S. Food and Drug Administration (FDA) recently released the following information for home consumers:
Nearly 48 million people (1 in 6 people) are sickened by food contaminated with harmful germs each year, and some of the causes might surprise you.
Although most people know animal products must be handled carefully to prevent illness, many don’t realize that produce can also be the culprit in foodborne illness. In recent years, the U.S. has had several outbreaks of illness caused by contaminated fruits and vegetables — including spinach, tomatoes, and lettuce.
Fresh produce can become contaminated in many ways. During the growing phase, fruits and veggies may be contaminated by animals, harmful substances in the soil or water, and poor worker hygiene. After produce is harvested, it passes through many hands, increasing the contamination risk. Contamination can even occur after the produce has been purchased, during food preparation, or through inadequate storage.
The FDA says to choose produce that isn’t bruised or damaged, and make sure that pre-cut items — such as bags of lettuce or watermelon slices — are either refrigerated or on ice both in the store and at home. In addition, follow these recommendations:
- Wash your hands for 20 seconds with water and soap before and after preparing fresh produce.
- Cut away any damaged or bruised areas before preparing or eating.
- Gently rub produce while holding under plain running water. There’s no need to use soap or a produce wash.
- Wash produce BEFORE you peel it, so dirt and bacteria aren’t transferred from the knife onto the fruit or vegetable.
- Use a clean vegetable brush to scrub firm produce, such as melons and cucumbers.
- Dry produce with a clean cloth or paper towel to further reduce bacteria that may be present.
- Throw away the outermost leaves of a head of lettuce or cabbage.
Store perishable produce in the refrigerator at 40 degrees or below.
(Condensed from an FDA news release. The site has an interesting video and useful links to other sites with food safety information.)
For more on what UC Davis and UC Cooperative Extension are doing to assure the safety of fresh produce:
- UC Food Safety website
- Postharvest Technology Center website
- Center for Produce Safety website
- UC publications
I have two active young sons. They get plenty of exercise. Their diets, however, can be a challenge. They have different tastes – one could eat breakfast items all day; the other could eat dinner items all day. One likes sugary sweet foods; the other likes salty, fatty foods. My wife is a great cook who makes balanced, nutritious meals, but it’s not easy pleasing everybody. There is one thing we all can agree on: We love fruit.
We can eat fruit throughout the day. It might go with breakfast, with lunch, as a snack or mixed in with a salad at dinner. I think my kids like fruit not only because we make it available and encourage them to eat it, but because they have sampled fresh fruit at farmers markets, watched it grow in our backyard and harvested it themselves at U-pick farms.
The federal government’s new MyPlate nutrition guidelines emphasize fruits and vegetables – they’re half the plate. But it’s not enough to try to force-feed your children canned carrots. Food can be fun. Giving kids a hands-on experience with fresh fruit can help them appreciate its importance. I’m no dietitian, but as a parent, I offer three tips for helping children to eat more fruits (and vegetables).
- Go to a farmers market. California has more farmers markets than any other state in the country. Find one near you at www.cafarmersmarkets.com. At a farmers market, the food and the farmers are the stars. You can sample the goods. You can ask a farmer questions. You can learn about the difference between a blood orange and a Cara Cara orange. It’s an event, but a short one. And the price is moderate.
- Grow your own produce. We’ve had mixed results with this one. Tomatoes came out great one year, were poached by animals another. We have a couple of fruit trees in our yard, but they don’t get much sun and the fruit isn’t sweet. We have had success with herbs, though, and find that our sons will munch on a mint leaf or point out the plants to friends and family. On a recent visit to their aunt and uncle’s house, they picked giant lemons and enjoyed homemade lemonade. No matter how small the effort, it shows children the life cycle of a plant, the anticipation of healthy food and, hopefully, the payoff of plentiful produce for a low cost.
- Visit a U-pick farm. We get an early start to summer by visiting U-pick farms in Brentwood. One son prefers cherries; the other prefers strawberries. Between the two, we have a daylong excursion that provides a weeklong supply of delicious bite-sized fruit for a reasonable price. Brentwood’s cherry season typically lasts from May to June. You can still find peaches, strawberries and other crops there in July. We also went apple picking in September in Sonoma County. U-picking is part of the broader field of agritourism, which also can include farm stands, tours, fairs and festivals. The University of California maintains a statewide agricultural tourism directory at http://calagtour.org. Check it out and may your efforts be fruitful.
Can what we eat help fix what ails us? Research increasingly suggests the answer is “yes.” Many foods contain biofactors — biologically active compounds — that may prevent and treat illnesses including asthma, diabetes and heart disease, according to new studies from the UC Davis Center for Health and Nutrition Research (CHNR).
The upcoming July-September California Agriculture journal (to be posted by July 11) reports UC research into plant compounds (phytochemicals) that can help prevent or treat disease. The findings stem from pilot projects at the center, as well as other UC research. Articles focus on how micronutrients, biofactors and phytochemicals (plant compounds) can help reduce the risk of chronic diseases.
Phytochemicals and health. Epidemiological studies link particular diets to less risk of chronic diseases. Notably, the traditional Mediterranean diet — mostly vegetables, fruits and whole grains, with moderate amounts of nuts, olive oil and red wine — is associated with lower rates of heart disease, cancer, and Parkinson's and Alzheimer's diseases. However, it has yet to be firmly established that specific phytochemicals in our diets can protect against diseases. Nutritionists therefore advise eating a wide variety of plant-based foods rather than taking supplements.
Mitochondrial nutrients and aging. The Mediterranean diet is rich in plant compounds that boost mitochondria (organelles in our cells that convert glucose and other nutrients into energy) and so are known as mitochondrial nutrients. When mitochondria are scarce or have genetic defects that keep them from working properly, this can generate toxic metabolites and damaging free radicals.
“Mitochondria are central to aging,” says UC Irvine aging expert Edward Sharman. “Improving their function may modulate or delay the onset of diseases related to aging, such as type 2 diabetes and age-related macular degeneration.” Mitochondrial dysfunction also plays a key role in chronic illnesses such as heart disease, type 2 diabetes and inflammatory diseases such as arthritis.
A new essential nutrient? Another promising mitochondrial nutrient is pyrroloquinoline quinone (PQQ), which was first found in nitrogen-fixing soil bacteria and is now known to be ubiquitous.
“We’re exposed to PQQ all the time at low levels,” says CHNR co-director Robert Rucker, a UC Davis nutrition professor. “It can be derived from amino acids found in stellar dust, and stellar dust is what the earth is made of.”
While Escherichia coli and other common gut bacteria do not make PQQ, the soil bacteria provide it to the plants in our diet. Good sources include fermented soybeans, wine, tea and cocoa.
Animal studies show that PQQ affects health markedly. Rucker and his colleagues found that depriving rats of PQQ compromised their immune systems, and retarded their growth and reproductive rates. In contrast, restoring PQQ to their diets reversed these effects and returned them to good health. Moreover, PQQ stimulated nerve growth and counteracted aging in cultured cells.
Rucker and his colleagues found that, like hydroxytyrosol, PQQ increases the number of mitochondria in cells. “It’s also an extremely good antioxidant and anti-inflammatory agent,” he says.
Personalized medicine. Understanding what biofactors do in our bodies could ultimately lead to personalized medicine, where nutrition-based treatments are tailored to the particulars of each person’s biochemistry. This individual variation at the biochemical level may help explain the inconsistent outcomes of research on omega-3 fatty acids and inflammation.
“The studies are mixed,” says UC Davis pulmonologist Nicolas Kenyon. “Some have shown little effect and others have shown that omega-3 fatty acids can reduce arthritis and inflammation in blood vessels.”
This genotyping is targeted to DNA sequences associated with asthma and so is not comprehensive.
“Some people are nervous about genome-wide analysis, which is scary because none of us is perfect,” Kenyon says. “But people are more interested when the focus is specific screening that could increase their chances of treatment.”