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HPRC Fitness Arena: Nutrition
The Human Performance Resource Center is here to serve Warfighters and their families, commanders, and healthcare providers. If you’ve visited before, you probably know that we focus on “total force fitness.” But do you really know what that means—or how HPRC got started? If you’re curious, check out this PDF that describes HPRC, what we do, and the vast amount of information we cover. In addition, you may have noticed that we use the term “human performance optimization” throughout our site; this article also explains what that means.
The physical demands placed on the Warfighter in training and operational settings can take a toll on joints and bones over time. Following a healthy diet can help reduce your risk of many diseases and maintain healthy joints and bones. A few nutrients have been shown to support joint and bone health, including calcium, vitamin D, vitamin C, and selenium. Consuming too much alcohol has been shown to have a negative effect.
Calcium and vitamin D work together for strong bones and overall bone health, because vitamin D helps your body absorb calcium. Men and women ages 19–50 should try to get 1000 mg of calcium daily; older women need 1200 mg daily. Good sources of calcium include milk, yogurt, fortified orange juice, and green leafy vegetables. Your body produces vitamin D when your skin is exposed to sunlight, but you can also get it in your diet from salmon, tuna, and fortified dairy products. Adults need about 600 IUs of vitamin D daily.
Vitamin C is essential for cartilage—the material that cushions your joints and prevents bones from rubbing together. Men need about 90 mg and women need about 75 mg daily, roughly the amount in a large orange. You can get vitamin C from citrus fruit, broccoli, and tomatoes.
Dietary selenium (a mineral) also may play a role in bone health. Adults need about 55 mcg of selenium daily. Selenium is found in nuts (especially Brazil nuts), tuna, and sunflower seeds.
Drinking too much alcohol negatively affects many of the body’s systems, including the bones and joints. Alcohol can cause weight gain, increase risk for osteoporosis and stress injuries, and damage cartilage. Limit your alcohol consumption to one drink per day for women and two for men. A drink is defined as one 5 oz. glass of wine, one 12 oz. beer, or one 1.5 oz. shot of liquor.
Inflammation can play a role in joint conditions such as arthritis, so a diet that helps reduce inflammation might be beneficial in protecting your joints. Eating plenty of fruits and vegetables, whole grains, and healthy fats (found in nuts and fatty fish such as salmon) not only reduces inflammation, it can also help maintain a healthy weight, which is essential to preserving joint health.
Excess body weight stresses joints and increases wear and tear. Following a diet that is lower in fat and calories can help maintain or reduce body weight, preventing additional joint stress. For more information about healthy joints, read the fact sheet from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Also, Chapter 17 of the Warfighter Nutrition Guide, “The High Mileage Warrior Athlete,” provides more information on maintaining joint and bone health.
The Department of Defense (DoD) Safety Review Panel published their findings on DMAA in a recent report now available through HPRC. The Assistant Secretary of Defense for Health Affairs asked the Safety Review Panel to evaluate the safety of DMAA-containing dietary supplement products. The Panel has recommended that the sale of DMAA-containing products be prohibited in all military exchanges.
HPRC maintains a list of dietary supplement products containing DMAA and periodically updates this list. The most recent version can be found on HPRC’s website. Note that, as of the FDA announcement in April 2013, DMAA is illegal in the U.S. as an ingredient in dietary supplements. For more information, visit the OPSS FAQ about DMAA. Operation Supplement Safety (OPSS) can provide service members and their families with information to make informed decisions about dietary supplement use. For the full DoD Safety Review Panel report, see the link on HPRC's Dietary Supplements web page.
Grapefruit is a tropical fruit known for its lip-puckering flavor. It contains vitamin C and many other nutrients and is a regular feature at the breakfast table. Grapefruit and its extracts also show up as flavoring agents in beverages and are sometimes added to dietary supplements.
Despite its many health benefits, grapefruit can pose a risk for people taking certain drugs. That’s because grapefruit can affect the way drugs are broken down or transported in the body—potentially increasing or decreasing the drugs’ effectiveness.
If you enjoy eating grapefruit or grapefruit-containing products, be aware of potential interactions when taking medication. If you take prescription or over-the-counter drugs, ask your doctor or pharmacist if you should avoid grapefruit. This consumer update from the Food and Drug Administration has more information.
Sodium—a component of table salt—is an essential element. It helps your muscles and nerves function correctly and maintains the proper balance of your body’s fluids. However, too much sodium in your diet may increase your risk of high blood pressure, heart attack, stroke, and certain types of cancer.
The average American consumes about 3,400 milligrams (mg) of sodium every day, mostly in the form of salt. But the current Dietary Guidelines for Americans recommends that adults limit their sodium intake to just 2,300 milligrams per day—roughly the amount in one teaspoon of table salt.
The guidelines also recommend that certain “at-risk” groups limit their sodium intake to about 1,500 mg per day: adults over the age of 51, African Americans, and people who have high blood pressure, diabetes, or kidney disease.
Recently, the Institute of Medicine (IOM) looked at the evidence supporting the current recommendations regarding sodium intake. IOM concluded:
- Research supports current recommendations to reduce sodium intake to about 2,300 mg daily.
- More research is needed to support the recommendation that those “at risk” should cut back to 1,500 mg or less a day.
Bottom line? If you’re in an at-risk group, speak to your doctor or registered dietitian about whether you should reduce your salt intake. For just about everyone else: Cut back on the salt.
How? Most of the sodium Americans consume comes from processed foods—tomato sauce, soups, canned foods, bread, and prepared mixes—but it can also come from foods naturally high in sodium—cheese and some types of seafood. Also, many restaurant foods are high in sodium, but sometimes you can request low sodium items. The best way to ensure a low sodium diet is to eat whole foods such as fresh or frozen fruits and vegetables; lean, unprocessed poultry and fish; unsalted nuts; whole grains; and low-fat dairy products such as skim milk or yogurt. For more information, check out this CDC web page.
For additional information and other conclusions from the study, see the news release (which includes a link to the full study) from the National Academies.
Operation Supplement Safety (OPSS) has added even more questions and answers to its FAQs section on HPRC’s website. Be sure to check back often as we add more answers to questions about supplement ingredients, performance and dietary supplements, weight loss and supplements, and choosing supplements safely. Didn’t find what you were looking for? Use our Ask the Expert button located on the OPSS home page.
Sugar can be present in foods even when we don’t know it. Some hidden sources of sugar on listed food labels are high-fructose corn syrup, brown rice syrup, brown sugar, honey, maple syrup, glucose, (or dextrose), lactose, sucrose, and the sugar alcohols sorbitol, zylitol, mannitol, and maltitol. Those people watching their sugar intake should read labels carefully to spot hidden sources.
Have you heard of Total Force Fitness, but you aren’t sure what it is? It’s a framework for building and maintaining health, readiness, and performance in the Department of Defense. It views health, wellness, and resilience as a holistic concept that recognizes “total fitness” as a “state in which the individual, family and organization can sustain optimal well-being and performance under all conditions”—a connection between mind, body, spirit, and family/social relationships. Total fitness shifts the perspective from treatment to wellness and focuses on prevention and strengths.
The Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury created a slide presentation for units and groups on Total Force Fitness: A Brief Overview that describes what TFF is, its core components, and each of its eight “domains” (behavioral, social, physical, environmental, medical and dental, spiritual, nutritional, and psychological). For more in-depth reading, check out the original Military Medicine Supplement that started it all, including a scholarly chapter for each domain.
Tribulus terrestris is used as an ingredient in some dietary supplement products marketed as testosterone “boosters” and/or to enhance muscle strength. What is it and does it work? Read this OPSS FAQ about Tribulus terrestris to find out. Also, be sure to check the OPSS section often, as we add answers to other questions about ingredients in performance-enhancing and bodybuilding supplements. OPSS can help you learn how to choose supplements safely.
If you have a question about a particular dietary supplement ingredient or product, and you can’t find the answer on our website, please use our “Ask the Expert” button located on the OPSS home page.
Do you know that many kinds of chewing gum—including the gum in MREs—contains a sugar sweetener called “xylitol”? This natural sweetener can be good for your teeth and gums! Xylitol has been found to offer preventive dental benefits, including reduced bacteria and acids that cause cavities and significant decreases in plaque. Most studies have shown that the use of chewing gum or mints with xylitol three to five times a day, especially after eating, result in the greatest benefits. Other sugar-free sweeteners used in gum and mints offer some oral health benefits, but for maximal benefits use products with xylitol. For more information, read this health fact sheet xylitol and how it can protect your teeth. Although chewing gum or mints with xylitol helps reduce cavities, they do not replace the benefits of regular brushing and flossing.