elitefts™ Sunday Edition

The dietary supplement industry is a multi-billion dollar a year business. Recent legislation, most notably the passing of the Dietary Supplement Health and Education Act (DHSEA) in 1994, has significantly reduced federal oversight of the supplement industry. The DHSEA makes it impossible for the Food and Drug Administration (FDA) to remove a supplement from the market based solely on lack of evidence or efficacy. Alternatively, a supplement must show an egregious risk to health in order for the FDA to act upon its removal. In light of this fact, a brief review of major supplement classes would be helpful for the average consumer. The most effective supplements are creatine, whey protein, and vitamin D. While others show some effectiveness, data is inconsistent and side effects are present.

The United States has an image problem. No, it does not have to do with the struggling recovery from the recent recession or tensions with Iran and the revolutionary Middle East. In order to see our problem first hand, one only has to walk down a busy street or stop and buy groceries. Maybe all you have to do is wake up and take a glance in the mirror. You are fat, he is fat, she is fat, and we are all fat, most of us anyway.

Recent media reports put nearly two-thirds of the adult U.S. population as either overweight or obese. With obesity comes a myriad of health problems including increased risk of cancer, diabetes, and heart disease. The best part is we want to do something positive about it. According to a recent article, seven out of every ten adults in the U.S. takes some form of dietary supplement be it a vitamin, mineral, or herb(16). The question then is can dietary supplements help us achieve not only a trimmer body but a healthier one as well? Furthermore, what, if any, adverse effects exist? In order to determine whether dietary supplements are effective or even needed, we must start at the beginning.

Dietary supplements are defined as a highly refined food product that should not be confused with a food (4) and have undergone significant regulatory changes in the previous twenty years. Prior to 1994, dietary supplements were treated like drugs in the sense that they needed evidence that showed efficacy and safety of the product. However, in 1994, Congress passed the DSHEA(5), which defines drugs and dietary supplements very differently. Today, the FDA can't regulate dietary supplements unless the product contains a new ingredient [1] or the product is deemed a significant safety risk to the public(5).

According to the DSHEA, a dietary supplement is:

“1. A product (other than tobacco) intended to supplement the diet that contains one or more of the following dietary ingredients:

a. A vitamin
b. A mineral
c. An herb or other botanical
d. An amino acid
e. A dietary substance for use by humans to supplement the diet by increasing the total dietary intake
f. A concentrate, metabolite, constituent, extract, or combination of any ingredient identified in a through e.

2. The product must also be intended for ingestion and cannot be advertised for use as a conventional food or as the sole item within a meal or diet”(3).

The passing of the DSHEA meant that the FDA could not control the dietary supplement industry in the same way that it controls the prescription drug industry. A prescription drug must pass numerous safety and efficacy requirements in order for it to be put into production. A dietary supplement does not have to pass any. Furthermore, prior to 2007, the FDA had no official standard policy regarding manufacturing practices of any supplements (5). A few companies maintained the previous standard General Manufacturing Policy (GMP) that was in place pre-DSHEA and subjected themselves to FDA audits. Others maintained the GMP common with the food industry, which largely dealt with safety of workers and sanitation (5). However, oversight and compliance was inconsistent at best. Finally, in 2007, the FDA passed a set of General Manufacturing Policies solely for the dietary supplement industry. This was based on troubling findings of chemically contaminated material, substituted ingredients, non-food ingredients, introduction of illegal substances, and bacterial contamination, among others (4–5). The hopes are that with the new GMP the FDA can resume some form of the regulation it had prior to 1994.

Because of the outstanding sums of money to be made—estimates exceed 40 billion dollars for the industry as a whole (4)—and the lax and incomplete regulatory standards within the industry, supplement companies are able to make outlandish and unsupported claims. Whether the claim is gaining thirty pounds of muscle in four weeks or losing ten pounds of fat in a week, a supplement is able to be produced and sold to the public as long as the company does not claim to treat, diagnose, or cure a disease (4). Conversely, in order for the FDA to act in removing a supplement, that supplement does not need to be simply ineffective. It must be found to produce a “significant or unreasonable risk of illness or injury when used as directed on the label or under normal conditions of use (if there are no directions)”(4). In light of these details, a general review of supplement efficacy and safety is needed in order for each consumer to make an informed decision about his or her health and the products he or she uses to support it.

Sports nutrition

Sports nutrition supplements account for roughly ten percent, monetarily, of the entire dietary supplement market (4). These products range from weight gainers (basically low quality whey protein with the addition of maltodextrin[2]) to highly processed and very expensive pro hormone supplements.

Creatine: A common misconception about creatine, or creatine monohydrate, is that it is the equivalent of a mild anabolic steroid. By definition, anabolic steroids[3] are synthetic derivatives of the male sex hormone testosterone and are highly effective at increasing lean body mass and strength (4). In contrast, creatine is a nitrogenous compound that is synthesized in the liver by the body but is also obtained through consumption of animal products, most notably meat and fish (4). However, creatine also exists in a purified supplement form, commonly creatine monohydrate.

Creatine is often regarded as the most studied sports supplement in history. This research has shown two instances in which creatine shows a marked effect on sports performance—energy metabolism and strength gain(4).

Creatine’s role in energy metabolism is based on its status as an essential substrate for creatine phosphate (CP) in the process of rapidly making ATP, our cells' form of energy. During high intensity/short duration exercise[4], CP is rapidly depleted in order to continue making ATP at the cellular level. As CP stores are depleted, the ability to perform maximal exercise is reduced (4). Creatine supplementation can lengthen the period of time in which high intensity exercise can be sustained (4). However, it is also noted that these benefits are not indefinite, as creatine can only be loaded to a certain amount within the muscle and eventually those stores will deplete to the point where maximal exercise is no longer possible (4).

Creatine supplementation has also been shown to increase body weight and strength. The increase in body weight is mostly attributable to an increase in lean body mass (LBM). A common misconception about LBM is that it is entirely constituted by muscle mass. However, LBM in relation to the human body includes muscle mass, bone, and fluid, mostly water (4). This increase in LBM in creatine supplemented humans comes on rapidly and in the form of intracellular water retention[5]. However, extended creatine use has been shown to increase protein synthesis with further increases in LBM (4). Increases in strength are attributable to both the increase in fluid retention and the increase in long-term protein synthesis.

The adverse effects of creatine are few and mild. With high doses (>20g/day), some participants reported mild gastrointestinal (GI) issues and bloating (4). Another common side effect considered adverse by those supplementing and trying to lose weight is weight gain (4).

Pro-hormones: Used in sports nutrition and by recreational weightlifters and bodybuilders, pro-hormones represent a class of testosterone precursors (4). Note the difference between pro-hormones and anabolic steroids. Anabolic steroids are actual synthetic versions of testosterone. Most testosterone precursors were officially banned under the Anabolic Steroid Control Act of 2004 (4). However, many supplement companies sell legal pro-hormones or derivatives of the illegal pro-hormones.

Pro-hormone effectiveness is virtually nonexistent. In studies with androstenedione, the testosterone precursor that Mark McGwire was reportedly using, there was no increase in serum testosterone or other androgens following both low and high dosages in men (4). Some studies have shown an increase in serum testosterone levels when supplementing in women, but more research is needed to support this data (4). Conversely, pro-hormones show some of the adverse effects of anabolic steroids, including decreased high density lipoprotein (HDL), without any of the benefits.

Whey protein: Whey protein is a popular method used to increase dietary protein intake for both active and non-active populations. It’s effectiveness across broad ranges of use has been extensively researched.

Whey protein has been primarily used in the sports nutrition circle as a post-workout source of dietary protein (3, 7, 9). The reason for this lies in the way that whey is digested. Whey is separated from the other constituents of milk, including casein and lactose, during its factory processing. When whey is digested, it does not form curds like casein when it contacts acid in the stomach. Because of this, the surface area of the whey is increased allowing for rapid digestion (7, 9). This rapid digestion is theorized to increase protein synthesis after exercise. While some evidence exists for this effect (7), most studies compare a whey protein supplement with a supplement containing only carbohydrates (3, 7, 9). Also, other studies show that total caloric value is more correlated with overall protein synthesis (7). More complete research is needed to conclude that whey protein is superior to other proteins in facilitating LBM gains[6].

Whey protein is also effective in areas outside sports nutrition. Most notably, it is effective in immune function (3, 7, 9). This property seems to be related to two aspects of whey. First, two of the constituents of whey, lactoferrin and immunoglobulins, have direct effects on both infectious agents, viruses and bacteria, and the human immune system (9). Lactoferrin is inherently antimicrobial. That is it can limit the growth and replication of microbes and viruses alone (9) while immunoglobulins positively increase human immune response to the same organisms (9). Furthermore, lactoferrin detoxifies potential carcinogens and inhibits metastasis[7] of primary cancerous tumors in mice (9).

Secondly, whey protein is a beneficial antioxidant[8] (9). This is important both in disease states and in exercising states. The primary antioxidant in whey, glutathione, is implicated in both HIV and cancer. While whey’s ability to increase glutathione to therapeutic levels is debatable, it possibly demonstrates the need for more research (9). Furthermore, whey, via glutathione, decreases oxidative stress caused by intense training (9).

While whey has positive effects on the body, it has few side effects. The most common side effect, especially with higher doses, is GI discomfort and gas (3, 7, 9). Whey can usually be consumed by those who are lactose intolerant, as lactose is often removed during the manufacturing process[9]. However, this usually depends on the quality of the protein supplement (7).

Stimulants

Stimulants, often referred to as “fat burners” by popular media (6), are nutrition supplements that affect the central nervous system (CNS) and are reportedly able to increase fat metabolism during exercising and at rest or cause long-term effects that increase fat metabolism by the body (6). Many different compounds are considered to be stimulants, from the everyday compounds of caffeine and green tea extract (GTE) to the recently illegal compound of ephedra.

Caffeine: Caffeine, found and consumed mostly in coffee, cocoa, and advertised energy drinks, has for years been theorized to increase fat metabolism. It is also one of the most widely used drugs on the planet (4). Caffeine, in aerobically trained athletes, increases the use of fatty acids for fuel and thus acts as a glycogen saver and increases time to exhaustion in exercise (4, 6, 10). This is also shown in untrained populations. Additionally, caffeine has a short-term thermogenic effect, increasing the resting metabolic rate (RMR) for up to three hours after ingestion (6). When combined with other sympathetic nervous system (SNS)[10] stimulants like ephedrine, there appears to be an additive effect (6).

Evidence has been presented to support caffeine's effectiveness on the peak power of athletes. It decreases sprint times and increases power in swimming and running sprint times (4, 10). Furthermore, caffeine increases the volume of training sessions, increases bench press strength, and increases peak torque (10). However, other studies show insignificant evidence on the same criteria (4). The method of ingestion seems to have an effect on strength, power, and aerobic performance. Concentrated pills produce the best effects while classic sources of caffeine like coffee and sodas are less effective (4).

Caffeine does have the ability to produce adverse effects, though most are mild. The most common effects are GI distress, anxiety, restlessness, and insomnia (4). However, more serious side effects like heart arrhythmia can become life-threatening in susceptible individuals[11] (4). Caffeine is also a mild diuretic, so overuse in hot climates can lead to dehydration and heat related illnesses (4).

L-carnitine and taurine: These compounds are commonly included in energy drinks in conjunction with caffeine. L-carnitine is found naturally in meats, and body levels are easily replenished by the consumption of meat products (6). It also plays an important role in fatty acid metabolism, as it transports fatty acids to the mitochondria to be broken down for energy (6). Consequently, it is hypothesized that supplementation will increase this process. However, studies show that this is unlikely because intramuscular stores of l-carnitine are already very high and need high insulin levels in order to be increased (6). High insulin values can be achieved through consumption of a large amount of carbohydrates or through insulin injections. Thus, the practical use of l-carnitine as a fat burner has been dismissed[12].

Taurine, used mainly in energy drinks such as Monster ™, is also purported to have fat burning effects. One study reports an increase in fat oxidation during exercise with supplemented taurine. However, other studies show no effect (6). In total, the research is inconclusive, and more research is needed before a consensus can be reached.

There have been no instances of side effects concerning l-carnitine at doses of three grams daily (6). However, that does not mean that adverse side effects will not arise with higher intake. Taurine side effects alone have been inconclusive, as it is almost always consumed in tandem with other stimulants. Research is needed on taurine alone to determine any side effects.

Green tea extract: Green tea extract (GTE) is a compound found in green tea that can also be converted to pill form and sold as a dietary supplement. It is linked to increased fat metabolism. Current research shows that GTE can affect fat metabolism, specifically when combined with other CNS stimulants (6). When combined with caffeine, GTE is shown to increase fat metabolism by up to sixteen percent above RMR (6). Another study shows that 24-hour fat metabolism increased by twenty percent when GTE was used in conjunction with caffeine versus caffeine alone, suggesting an additive effect (6). Other studies show that long-term supplementation with GTE can help reduce or maintain body weight as well as cause advantageous adaptations in fatty acid metabolism (6). Although a research consensus is lacking, GTE has potential as a possible weight loss aid.

Fatty acids

Dietary fat has been a hot topic in health and nutrition since the 1990s when the so called “war on fat” started. This period of time saw the demonization of all fats as a causative agent of chronic disease and premature death. Today, continuing research shows that some fats are essential to human health and can contribute beneficially to a variety of diseases.

Fats can be broken down into three categories—saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) (14). SFA contain no double bonds and thus are tightly packed while MUFA contain one double bond and PUFA contain multiple double bonds. The topic of this section will concentrate on two supplemental PUFA—n-3 omega fatty acids (omega-3) and conjugated linoleic acid (CLA).

Omega-3s: Omega-3 fatty acids are commonly found in cold water fish, most notably cod and salmon, though they are present in smaller quantities in other species. However, our industrial diet consists of little naturally found omega-3[13], thus supplementation has become a popular method for increasing intake. These supplements are commonly concentrated oils from the above fish, although krill and oils derived from algae are also used (15). Can supplementing these fatty acids along with other PUFA and MUFA in the diet instead of SFA have beneficial effects on health and disease?

Omega-3 fatty acids have been extensively studied in diseases ranging from heart disease to diseases of inflammation like Crohn’s and arthritis. Many studies show a cardio-protective benefit of omega-3 supplementation (2). These benefits are attributed to lowering total cholesterol, especially LDL, which assists in the prevention of atherosclerosis. Recent research shows that these fatty acids lower levels of inflammation, which is now seen as a major contributor to heart disease (2, 8). The greatest benefit would likely be seen with a replacement of SFA with omega-3 fatty acids.

Inflammatory diseases are another major class of diseases that omega-3 fatty acid supplementation improves. Supplementation has positive effects in Crohn’s disease, inflammatory bowel disease (IBD), psoriasis, eczema, and arthritis (2). The improvements in these disease states is thought to be mediated by a lowering of the immune system, mostly through inhibition of pro-inflammatory cytokines (2). The fatty acid composition of cell membranes is also altered and is hypothesized to be partially responsible for improvements in disease symptoms. The mechanisms involved are unknown and current research is investigating these areas (8).

Omega-3 supplementation is beneficial in certain types of cancers, notably colon, breast, and prostate cancers (8). Unfortunately, these findings have been deemed as insufficient evidence by the World Health Organization (WHO) as well as other health organizations[14]. Current research also shows a connection between dietary omega-3 fatty acids and brain function and fetal development (2, 8). Most importantly, proper intake of these fatty acids supports growth and neurological and cognitive development of the fetus (2). However, further research is needed in these areas before a consensus can be made.

Safety concerns over omega-3 supplementation are few. Mega doses can cause a blood thinning effect by blocking clotting factors, increasing the likelihood of fatal bleeding (2). Another concern is while omega-3s reduce inflammation, they increase the rate of oxidation. It is recommended that an antioxidant be taken in conjunction when supplementing with omega-3s (2). Finally, contamination is a concern, as source fishes can potentially be high in heavy metals such as mercury (2, 8).

CLA[15]: Conjugated linoleic acid (CLA) is an unsaturated fatty acid found naturally in beef and dairy products like cheese, yogurt, and milk (17). It is available in pill form as a purified product in nutrition stores. Recently, supplement companies have argued that CLA can help reduce body weight and body fat (6, 17). The proposed mechanism of this weight and body fat loss is a decrease in food intake and lipogenesis[16] and an increase of fat oxidation and fat burning. Research done on animal studies, largely mice, has shown that CLA supplementation does lead to a decrease in body weight and body fat through the above mechanisms. However, research on human subjects has shown little positive evidence. Long-term studies greater than three months have shown no reduction in body composition outside of what the caloric deficit demonstrated (15). Other studies have shown similar results (17).

While CLA may not help human subjects, its safety has negative evidence. Most symptoms of CLA supplementation are gastrointestinal and mild. Research recently showed that in both humans and rats, long-term CLA use lowers insulin sensitivity up to fifteen percent (6, 15). This is significant because research hypothesizes that insulin sensitivity is a contributing factor to the ongoing obesity epidemic (15).

Vitamins

Multivitamins are the most used dietary supplements by volume and across age groups. While other supplements may be particular to one group, such as whey protein for athletes, vitamins encompass the spectrum of occupations. Vitamins are essential for many cellular processes, including body growth, blood clotting, eye health, and metabolic health[17] (14). Today, most processed foods have been “enriched” with what basically amounts to a multivitamin supplement. What role, if any, do multivitamins along with specific vitamins have in human health?

Multivitamins are composed of several, sometimes over twenty, individual vitamins. The most common ingredients are vitamins A, all the B vitamins, C, E, and minerals like calcium and iron. Recently, most companies have begun to include vitamin D (1). The efficacy of a multivitamin has been argued for decades, and some studies show beneficial effects while others show none.

One specific study marked the changes in blood markers over a 24-week study period while diet and exercise were controlled. The results of this study show a decrease in blood homocysteine levels, a marker for cardiovascular disease (1). This was likely caused by the presence of folate, a B vitamin, in the supplement. Interestingly, this decrease was only seen in individuals with low blood folate before supplementation (1). Normal and above normal blood folate levels pre-supplementation showed no improvement post-supplementation (1). A second finding was a decrease in the oxidation rates of LDL cholesterol, the bad cholesterol (1). Theoretically, this decrease would decrease the risk of cardiovascular disease and is most likely mediated by vitamin E, which research shows can reduce death rates in patients with coronary heart disease (1). However, other studies with different variables show no change in pre- and post-supplement levels of blood markers.

While research is contradictory over the overall efficacy of multivitamins, one thing is certain—if an individual has a legitimate deficiency or even a low blood level of certain vitamins, like B vitamins and vitamin E, multivitamins can assist overall health (1). However, one must remember that a multivitamin is not a “cure all” or a substitute to a sensible and comprehensive diet. Also, legitimate deficiency is very rare in the developed world.

The safety of multivitamin supplements is high. While overdose is theoretically possible, actual cases are few. One must note the difference between fat soluble (e.g. vitamins A, D, and E) and water soluble vitamins[18]. Overall, vitamins are the safest of all dietary supplements.

Outside of multivitamins, vitamin D and vitamin C alone have garnered an increased look from researchers for their roles in treatment of disease and overall health. Vitamin D levels are chronically low across the world, due to a number of factors including increasing age, obesity, and decreased exposure to sunlight (12). The only natural sources of vitamin D are seafood, mushrooms, egg yolks, and exposure to UV radiation, which, through a complicated process, synthesizes vitamin D from cholesterol (12). One should notice that milk is not a natural source but is rather fortified with vitamin D during processing. Recent studies challenge whether this fortification process is effective (12).

These low blood values of vitamin D have been linked to chronic diseases including cancer, diabetes, and cardiovascular disease (12). Thus, recent urging by researchers to increase the recommended dietary intake (RDI) from 400 IUs to 800–1000 IUs[19] a day are being considered (12). This intake is only possible through supplementation or unprotected exposure to UV radiation.

Contrary to vitamin D, vitamin C has become known more recently not as a preventative of disease, but as a treatment option in various forms of cancer. Studies show that high doses of vitamin C, usually applied intravenously, can stunt and kill cancer cells while leaving normal cells intact (13). The action of this treatment is through production of hydrogen peroxide from high levels of vitamin C in the tissue[20] (13).

The safety of both vitamin D supplementation and high dose vitamin C are high. There have been no documented cases of overdose in vitamin D supplementation even with long-term high dosages (12). The most common side effect for high dose vitamin C was fatigue and malaise (13). It should be noted, however, that a recent study in mice showed that vitamin C treatment can cause decreased effectiveness of chemotherapy agents when the two are used in conjunction for treatment of cancer (13).

In conclusion, it appears that the safety of dietary supplements varies widely. The most dangerous supplements to use, by a wide margin, are stimulants. Not only has ephedra been linked to numerous deaths and thus been deemed illegal for sale, but recent news reports show that energy drinks like MonsterTM are implicated in deaths around the country. One would be wise to deeply consider any type of stimulant supplement before using them. Outside of stimulants, the side effects of supplements appear to be mild and infrequent.

Usefulness also varies widely among supplements. Whey protein shows benefits across the spectrum of health and in sports nutrition and its efficacy is the most proven. Keeping with the sports nutrition theme, creatine supplementation is also very effective. Omega-3 fatty acids are an interesting supplement because of the volume of research supporting both its use and its uselessness. It is also interesting that an omega-3 drug has recently been released on to the market. Considering the provisions drugs must pass in order to be released, this can be seen as an endorsement of omega-3s to help fight disease. Vitamins also show use in a variety of conditions. Based on their price and lack of side effects, a daily multivitamin and vitamin D supplementation could be encouraged.

Personally, the only supplement I use is whey protein, and I use it to replace fatty meats in my diet. In light of the above research, I would strongly consider both vitamin D and omega-3 fatty acid supplementation. If my training goals were to increase both strength and body weight, I would supplement with creatine. Multivitamins present a more vague answer, and I have never taken nor am I considering supplementing with these. All other supplements, in my opinion, are not worth the price, both in cost and in side effects. It would be preferable to consult a doctor or nutritionist and discuss the advantages and disadvantages of a supplement before implementing it into your diet. Finally, it is important for a consumer to be vigilant with current research while considering any supplement and realize that a poor diet supplemented is still a poor diet.

References

  1. Earnest C, Cooper K, Marks A, Mitchell T (2002) Efficacy of a complex multivitamin supplement. Nutrition 18(9):738–42.
  2. Gogus U, Smith C (2010) n-3 Omega fatty acids: a review of current knowledge. International Journal of Food Science and Technology 45(3):417–36.
  3. Ha E, Zemer M (2003) Functional properties of whey, whey components, and essential amino acids: underlying health benefits for active people (review). Nutritional Biochemistry 14(5):251–58.
  4. Hoffman J, Stout J (2008) Performance enhancing substances. In: Baechle T, Earle R (editors). Essentials of strength training and conditioning. Third ed. Human Kinetics.
  5. Jasques J (2010) Professional’s guide to nutritional supplements: understanding quality and regulatory issues. Bariatric Times 7(10):1–19.
  6. Jeuendrup A, Randell R (2011) Fat burners: nutrition supplements that increase fat metabolism. Obesity Reviews 12:841–51.
  7. Lowery L, Edel J, McBride I (2012) Dietary protein and strength athletes. Strength and Conditioning 34(4):26–32.
  8. Lunn J, Theobald H (2006) The health effects of dietary unsaturated fatty acids. British Nutrition Foundation, Nutrition Bulletin 31(3):178–224.
  9. Marshall K (2004) Therapeutic applications of whey protein. Alternative Medicine Review 9(2):136–56.
  10. McCormack W, Hoffman J (2012) Caffeine, energy drinks, and strength-power performance. Strength and Conditioning 34(4):11–16.
  11. Morton A (2011) Why bother to take vitamins? Journal of the Royal Society of Medicine 104(1):S19–S29.
  12. Moyad M (2009) Vitamin D: a rapid review. Dermatology Nursing 21(1):25–55.
  13. Padayatty S, Sun A, Chen Q, Espey M, Drisko J, Levine M (2010) Vitamin C: intravenous use by complementary and alternative medicine practitioners and adverse affects. Plos One [Internet] 5(7):1–8. Available from: http://ehis.ebscohost.com.proxybz.lib.montana.edu/ehost/pdfviewer/pdfviewer?sid=fa1b89f1-6184-48a8-b981-34edde16a421%40sessionmgr111&vid=2&hid=116.
  14. Reimers K (2008) Nutritional factors in health and performance. In: Baechle T, Earle R (editors). Essentials of strength training and conditioning. Third ed. Human Kinetics.
  15. Salas-Salvado J, Marquez-Sandoval F, Bullo M (2006) Conjugated linoleic acid intake in humans: a systemic review focusing on its effect on body composition, glucose, and lipid metabolism. Critical Reviews in Food Science and Nutrition 46(6):479–88.
  16. Schardt D (2001) Are your supplements safe? Nutrition Action 30(9):1–7.
  17. Wood G (2001) Early findings raise questions about popular CLA supplement. Agricultural Research 49(8):22.

Footnotes

  • [1] A new dietary ingredient is defined as dietary ingredients that were not marketed in the United States in a dietary supplement prior to October 15, 1994 (5).
  • [2] Maltodextrin is a corn-based carbohydrate powder comparable to the corn starch purchased in grocery stores.
  • [3] Anabolic steroids deserve an honest review. However, because of ethical reasons, research is lacking.
  • [4] High intensity exercise can be described as >90 percent of maximal intensity (4).
  • [5] An increase in creatine content of the muscle is thought to effect the intracellular osmotic gradient of muscle cells, which causes more water to enter (4).
  • [6] Research is needed that compares equal protein intakes across controls and experimental groups as compared to the experimental whey protein group receiving more dietary protein than the control group. All that proves is that increased dietary protein causes LBM gains, which already has sufficient evidence.
  • [7] Metastasis is the spreading of cancer from the origin to other organs or systems of the body (7).
  • [8] An antioxidant is a molecule that prevents the oxidation of other molecules (8).
  • [9] Choose a high quality whey protein if you are lactose intolerant, as lower quality options in general contain more lactose (7).
  • [10] The central nervous system (CNS) is divided into two parts—the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). They are responsible for the “fight or flight” and “rest and digest” responses of the body, respectively.
  • [11] This property can be seen in the recent news reports showing multiple deaths from energy drinks where caffeine is the main stimulant involved.
  • [12] The reason for this is high insulin levels are associated with a cessation of fatty acid metabolism in the body. So a high blood insulin level would be counterproductive to fat burning.
  • [13] The general consensus is that an ideal omega-6:omega-3 fatty acid ratio should be 3:1. Estimates put the actual ratio at >20:1 (8).
  • [14] They were deemed insufficient because there is not a large number of studies that have shown similar evidence. This is a current research focus (8).
  • [15] I have previously supplemented with CLA and found no positive benefits. I did not include this in the report because it was anecdotal.
  • [16] Lipogenesis is the process of storing body fat.
  • [17] See Appendix A, located after the reference page, for a comprehensive review on vitamin roles in the body.
  • [18] Excess water soluble vitamins are passed in urine while fat soluble vitamins can accumulate in fat tissue, possibly leading to toxicity.
  • [19] An IU is an international unit of measure for vitamins.
  • [20] This method is common among alternative practitioner of medicine, such as a naturopathic doctor (12).