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Dietary Supplements in Aircrew

By In Aerospace Medicine, Blog, Civilian Aviation Medicine, Flight Medicine, . . . On September 23, 2014


Dietary Supplements

Dietary Supplements

Ok, I got this nailed- Vitamin M, dip, coffee, Jack & Coke.  That’s what makes a fighter pilot” ~ Anonymous Fighter Pilot

Although this may be the typical formula that fighter pilots from decades past relied on for optimal performance, the modern combat aviator tends to take a much more sophisticated cocktail of performance enhancing supplements.  According to a 2013 article in Forbes Magazine, VMS (Vitamins, Minerals and Supplements) reported revenue of $32 billion from supplements alone in 2012.  Since manufacturers have lobbied for their products to be considered food (supplements to one’s diet) by the FDA, they are free from the strict regulatory oversight required for medications.  Vitamins, minerals, supplements and medications are all essentially chemicals.  They are atoms arranged in particular molecular structures that take part in chemical reactions, some of which react with living cellular tissue in  helpful ways, others in a more destructive manner.  Some of these products’ pure states are found in nature, but many are manufactured synthetically.  All military members including aircrew, purely by their common demographic profile (predominantly young, male, and athletic) and driven by internal and external pressures to improve performance are intensely marketed to by VMS manufacturers and retailers. Any person choosing to put these products into their bodies should ask three main questions regarding each substance.

  1. What are the benefits?
  2. What are the risks?
  3. Are the potential benefits worth the risk?

The answers to these questions may have some individual variation.  Aircrew need to approach these questions with extended caution. Aircrew may also be responsible for complying with particular military or FAA guidance that leaves little room for personal preference to these questions. If you’re a professional pilot or air traffic controller, it is likely the die has already been cast for you.  Below is a table categorizing a variety of common vitamins, minerals and supplements by Benefit and Risk.  This table mostly applies to the general public.  For a specific discussion on VMS use in aircrew, scroll to the bottom of this post.

PARODY ON THE DIETARY SUPPLEMENT INDUSTRY [NOW WORTH > $32 BILLION]

 

Dietary Supplements Classification System –Risks and Benefits

The Dietary Supplements Classification Table was developed to assist military personnel in making informed decisions about supplements. Benefit was ranked on a scale of low, moderate, or high potential benefit. Safety concern was similarly ranked on a scale of minimal, low, moderate, or high concern.  This table has been replicated below from the Human Performance Resource Center, which is a comprehensive online tool for military members or anyone interested in evidence based guidelines for human performance optimization. For an alphabetical list of supplements, see here.

Dietary Supplements Classification Table

Click on the numbered cell in the table to see the Dietary Supplements in that Class and learn more about them.Risk (Safety Concerns)
MinimalLowModerateHigh
Potential BenefitHigh 1279
Moderate34810
Low561112
Disclaimer: This table includes consideration of the safety and potential benefits of dietary supplements based on use at appropriate doses and availability of current data in the literature.  For individual guidance, consult with a designated health professional for your respective service or specific organization. Scores of 1-3 are in the “green zone,” 4-8 in the “yellow zone,” and 9-12 in the “red zone.”

Supplements by Zone

Green ZoneYellow ZoneRed Zone
Branched-Chain Amino AcidsAntioxidantsEphedra
Fish Oil/Omega-3 Fatty AcidsBeta-Alanine (B-Alanine)Melatonin (for flight personnel)
Melatonin*CaffeineBitter Orange (Synephrine)
Multivitamins & MineralsChromiumTestosterone Precursors/Boosters and Anabolic Compounds
ProbioticsCoenzyme Q10 Weight-loss Supplements
Tyrosine Creatine
Vitamin B ComplexGlutamine
L-Arginine
L-Carnitine
Megavitamins & Minerals
Quercetin
Food-based Products
Sports BarsProtein Powder (including whey)**Energy Shots
Sports Drinks*Energy Drinks
Sports Gels
*Excessive consumption is potentially dangerous and could lead to side effects and/or adverse reactions. **Insufficient evidence to support a recommendation for use. Note: Supplements in bold appear in more than one zone.

 

DIETARY SUPPLEMENT USE IN AIRCREW

Any of the medications found in the ‘Red Zone‘ above should definitely be avoided.  All of the substances in the ‘Green Zone‘ can be used with confidence that in most cases the risk is low and the benefit has either been demonstrated or exists theoretically.  The exception to this is the light-sensitive hormone produced by the pineal gland known as Melatonin, which helps regulate our natural circadian rhythm.  This substance may be useful in the general public, but is not authorized for unrestricted use by aviators.  Melatonin is covered in detail below.

*** Substances that should be absolutely avoided by aircrew are those supplements containing Ephedra, Bitter Orange (Synephrine), Testosterone Precursors of Anabolic Compounds, and Melatonin.  The U.S. Navy also categorizes Energy Drinks/Shots, Ginkgo Balboa, Echinacea, and Ginseng as Category C (prohibited in aircrew and requiring at minimum 24 hours removal from flying duties).***

 

GENERAL GUIDANCE ON SUPPLEMENT USE

  • Dietary Supplements are regulated like food by the FDA.  They can be marketed and sold with limited or no research on effectiveness.
  • Dietary supplement ingredients are poorly regulated and labels may or may not represent actual substances or amounts of each substance.
  • Dietary supplements may have adverse effects, trigger allergic reactions, or interact with medications or other supplements.
  • If using an approved supplement, ensure it has the United States Pharmacopeia (USP) Verified Dietary Supplement Ingredient Mark, Consumer Lab (CL) seal of approval, or comes from a reputable manufacturer.  DO NOT PURCHASE SUPPLEMENTS FROM EXCLUSIVELY INTERNET COMPANIES!
  • In the Department of Defense; flyers, special operational personnel, and those members on the Personnel Reliability Program (PRP) program are required to report use of nutritional supplements to their flight surgeon or medical provider.

 

POWERTHIRST – THE ORIGINAL

 

COMMONLY USED DIETARY SUPPLEMENTS

Essential Multivitamins & Minerals

These substances and other essential nutrients are required for metabolic processes, but cannot be synthesized by the body and therefore are derived exclusively from one’s diet.  Most healthy adults with a diverse diet will meet the minimum needs for these substances, but supplementation may be required in particular populations.  It is important to note that some vitamins (K,A,D, & E) can actually result in dangerous overdose.  Intake should not exceed tolerable upper intake level (UL) as determined by the Institute of Medicine (IOM).  UL represents total intake from food, beverages, and supplements.

  • Aeromedical Recommendation:  Probably no appreciable benefit for a large majority of aircrew, unless specifically recommended by flight surgeon or AME.  Though, very low risk unless taken in large amounts.  Biggest cost is one’s financial investment in vitamin-enriched urine.

 

Sports Drinks (not ‘Energy’ Drinks)

Effective for rehydration and replenishing electrolytes for training or sports that exceed one hour.  These drinks also contain small amounts of carbohydrates.  Shoot for drinks containing 4-8% carbs (14-19 grams/8 oz serving).  Any higher amounts of sugar will delay your stomach from emptying its contents and absorption will be inadequate.

  • Aeromedical Recommendation:  Useful for aircrew who double as endurance athletes.  No harm for in-flight use and may provide quick and easy source of energy to help maintain blood sugar levels for high-performance pilots (especially long duration sorties).

 

Sports Gels

Sports gels are used to deliver substantial energy resources in a small, easily carried packet for endurance athletes.  These products are usually high in carbohydrates (typically 20-30 grams per serving) and sometimes contain caffeine or other supplements.  These products have been shown to maintain blood sugar during exercise and generally improve performance.  It is important for users of these gels to drink adequate water to provide dilution.  Not doing so will delay the stomach from emptying and can cause GI upset as a consequence.  For this reason, water is preferred over sports drinks in combination with sports gels.

  • Aeromedical Recommendation:  Small risk for gastrointestinal upset if used in-flight, but may provide quick access to nutrition in order to replenish glycogen stores and maintain blood sugar levels for high-performance pilots (especially long duration sorties).  Recommend ground-testing prior to in-flight use.  Increasing water intake is critical to dilute the sugar content and aid with absorption.

 

Protein & Individual Amino Acid Supplements

This category of supplements includes whey protein and individual amino acids.  These latter variants are often labeled essential amino acids (EAAs) or branched-chain amino acids (BCAAs). Whey is a natural byproduct from cheese production and serves a high quality source of protein since it contains all 20 amino acids.  These supplements can be consumed as powders (usually used to make protein shakes), capsules, or protein bars.   Protein supplements are usually used by athletes attempting to gain muscle mass.  The CDC estimates a daily need of 46 grams of protein for adult females and 56 grams for adult males.  When using protein supplements, it is important to do the math and determine the supplemental need after adding up average protein gained from diet alone.  An additional 10-15 grams of protein per day is all that is needed to gain a pound of muscle mass.  Too much protein will unnecessarily stress the kidneys and liver, and ultimately becomes stored as fat.  For recreational athletes, calculate your desired protein intake using 0.5 grams per pound of body weight daily.  For athletes trying to maximize muscle mass, ingest no more than 0.9 grams per pound daily.

  • Aeromedical Recommendation: Protein is a form of nutrition, needed for energy and metabolic processes.  Getting your nutrition from natural food sources rather than a plastic container from GNC is preferable.  In the past, trace amounts of heavy metals and even contamination from harmful bacteria have provoked recalls of protein supplements.  Gaining muscle mass should not provide significant effect on flying performance, but if this is your aim, protein supplementation will likely help.  Calculate how much you need using info above and don’t overdo it!  For more info consult HPRC.

 

Creatine

The US Navy considers creatine a class B supplement (use is permitted, but information required prior to use and flight surgeon must be notified) for flyers.  Creatine is converted to creatinine in muscles, filtered by the kidneys, and excreted at a maximum daily limit in the urine.  Creatine reacts with phosphate to participate directly in cellular energy production.  Multiple studies have documented improved performance with use for short bursts of high-intensity activities and increased muscle mass.  There is little to no evidence of improvements in aerobic activities.  Some of the short-term adverse effects from this common supplement are increased cramping, discomfort in the lower leg muscles, and predisposition to dehydration.  Medical studies have only demonstrated safety in 5 years of use.

  • Aeromedical Recommendation: Creatine has a good track record for optimization of performance for short-duration, high-intensity activities.  The Anti-G Straining Maneuver (AGSM) meets this definition.  Therefore although not directly studied,  the AGSM could theoretically be strengthened from creatine use.  Many people do not tolerate creatine and have GI discomfort.  I recommend a ground trial of this item for a few weeks when not flying prior to consistent use.  And increase your water intake accordingly- the USN recommends a total of 64 fluid ounces daily with creatine use.

 

Caffeine

This supplement is most commonly ingested in coffees, teas, chocolates or energy drinks, but is now being added to a huge array of dietary or workout supplements.  Caffeine is a stimulant known for improving alertness, vigilance, cognition, and physical performance.  One’s individual sensitivity and total dose are the two biggest considerations when using this substance.  The lethal dose of caffeine has been estimated to be 10 grams, but doses of less than 1 gram have led to sleep loss over multiple nights in some studies.  The FDA recently issued a warning about use of powdered versions in which high doses of 100% caffeine can be quickly consumed at lethal doses.  At least one death by a teenager has been documented.  Recommended dose to gain all of the benefits of coffee is no more than 200 mg (1-2 cups of coffee).  Most authorities recommend no more than twice this amount (400 mg) in a 24 hour period.  A commonly held belief is that caffeine causes significant dehydration.  Although it does have a mild diuretic effect, recent studies demonstrate no long-term impact on  hydration or work performance in the heat. 

  • Aeromedical Recommendation: Higher doses of caffeine may induce mild tremor that need be considered by an aviator.  Finding the individual dose that causes maximum benefit without any performance degradation is advised.  Specific recommendations for fighter pilots to combat fatigue, including use of caffeine, are covered on Fighter Pilot Fatigue.

 

Energy Drinks & Shots  

Caffeine Content in Energy Drinks

Caffeine Content in Energy Drinks

The US Navy categorizes Energy Drinks and Energy Shots as Class C (prohibited in aircrew and mandating a 24 hour removal from flying duties).  On a related note, the use of tightly regulated pharmaceutical stimulants (Go-Pills) by aircrew has been proven highly effective and covered in another post.  Similar in composition, the difference between energy drink or shot is the volume with any beverage packaged under 250 mL considered a ‘shot’.  Energy drinks claim to offer athletic-performance-enhancing effects, improved concentration, weight loss, increased libido and an array of other desirable effects. Most contain caffeine in varying amounts, as well as small amounts of herbals such as taurine, guarana, ginseng, sucrose, B vitamins, glucuronolactone, inositol, and/or other ingredients.  Some of these products have caffeine levels equivalent to 5 cups of coffee.  The jury is still out on the effectiveness of these products.  One noteworthy USAF study of eight airmen in a centrifuge who consumed a commercial caffeine-carbohydrate drink showed enhanced acceleration tolerance and improved cognitive reaction time.  The size of this study in addition to a lack of consistent findings from other studies make clear guidance elusive.  The large combination of ingredients in these beverages make it even more difficult to determine which individual and combined substances confer benefits and which confer risks.  A large number of individual reports of both mild and serious side effects have been associated with energy drinks.  Some of these reports include stories of platelet dysfunction, increased heart rate, cardiac arrest, stroke and seizures after heavy consumption of energy drinks/shots.  The FDA has been investigating alleged deaths from energy drinks since 2012.

  • Aeromedical Recommendation: Given the unproven effectiveness and high concern for serious side effects, these highly-caffeinated herbal soups are not recommended.  It is much more advisable to use substances in a pure form at a known quantifiable dose than in a poorly-regulated combination with potential for serious adverse outcomes.  Definitely do not use during flight operations.  More information can be found at a previous post on Fighter Pilot Fatigue.

 

Melatonin in Aircrew

Melatonin is a substance often used as a sleep aid or to assist with circadian rhythm disturbances.  But use of this substance is not permitted by any flyer, controller, or missile operator in the USAF due to its significant side effect profile.  This supplement often causes drowsiness, fatigue, and measurable performance decrements- especially if used incorrectly.  The U.S. Navy includes melatonin among its “Class C supplements,” which are described as “not authorized for use by any aviation personnel”.  Use of melatonin by US Navy aircrew requires a 24 hour suspension from all flying duties.

Here is the position of the FAA on this substance:  “Recently, the use of melatonin has been promoted, through the media, as a way to assist with circadian fatigue and jet lag. While studies have demonstrated some benefit from its use, they have also indicated drawbacks from the sedative and hypnotic effects. Additionally, melatonin ingested at the incorrect time may further desynchronize an already troubled circadian rhythm through the addition of another cue. Therefore, it is cautioned that melatonin should not be taken within 24 hours of flying, and professional guidance in the proper use of this neurohormone sought to achieve maximum benefit without adverse reaction.

 

Summary

It is critical that all consumers, but definitely military professionals and all aviators, ask themselves a few important questions. Why are they taking a particular supplement, what is the benefit, and what is the risk?  Finally, is the benefit worthy of  the risk? There are many people, and almost every aviator I know that uses dietary supplements, who would avoid taking a prescription medication at all costs, yet willingly spends hundreds to thousands of dollars annually on supplements with little or no evidence of benefit.  Some of these supplements carry real risk to one’s health.  The difference for these two approaches to similar products is really one of successful marketing.  So my challenge to you:  Be a smart & critical consumer.  Don’t believe the hype. If you have further questions, ask your local flight doc or aerospace physiologist.

 

References

  1. Sather TE, Woosley CL.  Nutritional and Ergogenic Supplements:  Aircrew Guidance and Policy.  Naval Aerospace Medical Institute.
  2. Sanders DC, Chaturvedi AK, Hordinsky JR (1998). Aeromedical Aspects of Melatonin-An Overview. Washington DC: DOT/FAA/AM-98/10
  3. Human Performance Resource Center – Online

  • Vanya

    Great article! Well written and I like the mention of what other services give considerations to.