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Nine Nutrients to Know

Originally Published May 2010


As anyone who has spent time walking the dietary supplement aisle of their neighborhood drugstore, health food store, or even club store might suspect, the number of Americans using dietary supplements is rising. Likewise, the supplement choices for these customers are expanding.

Dietary supplements are also poised for growth in mainstream medicine. Our nation's healthcare reform turns an eye to complementary and alternative medicine, including the use of dietary supplements in preventive care. The concept of preventive healthcare is one that many Americans are now wrapping their minds—and healthcare dollars—around.

Preventive care was also the focus of the recent Congressional Dietary Supplement Caucus Briefing on Capitol Hill, initiated by the Council for Responsible Nutrition (CRN) and the Natural Products Association.

At the briefing, Mark Hyman, MD, medical director of The UltraWellness Center in Massachusetts, and an authority on prevention and wellness, discussed why we should turn to preventive care, including dietary supplements, in maintaining good health—instead of only treating symptoms of illness when they occur. "As a nation, we are overfed but undernourished," said Hyman. "Dietary supplements play an important role in functional and preventive medicine."

Those at the briefing spent time discussing the notion of "functional" medicine—a future model for healthcare that marries conventional and alternative therapies.

As more Americans make supplements part of their healthcare regimens, so are medical practitioners. The Life...supplemented Healthcare Professionals Impact Study from CRN, in which healthcare professionals shared information about their own supplement use, as well as about the supplements they prescribe to patients, reported in 2007 that 79% of physicians surveyed and 82% of nurses surveyed indicated that they recommend dietary supplements to patients. In a more recent version of the survey, 85% of nurse practitioners agreed that one of the roles of healthcare professionals is to provide their patients with information about dietary supplements.

Our 5th annual Practitioner's Guide to Dietary Supplements shines the spotlight on a selection of dietary supplements. Some have been purchased by consumers for years; others have more recently gained ground. This year's guide includes information from NHI OnDemand, an online resource that offers natural health information—including a full library of health conditions and dietary supplements—to providers, researchers, government agencies, manufacturers, and consumers. Visit www.nhiondemand.com for more information.

Resources such as NHI OnDemand and this guide are designed to bring healthcare practitioners the latest updates and science about dietary supplements, so that when patients need that information, their doctors can provide it.

"I hope that patients know how open we are to hearing about their supplement use...At the same time, nurse practitioners, doctors, and all healthcare professionals have to do a better job being open to listening to patients when it comes to supplements. These are mainstream products, and it's our job to help our patients figure out which supplements best meet their individual needs."

— Barbara Dehn, RN, MS, NP, Women's Physicians (Mountain View, CA), in the latest Life...supplemented Healthcare Professionals Impact Study

Chondroitin Sulfate

Supplementation with chondroitin sulfate is often undertaken to support the repair and maintenance of strong, healthy cartilage and joints. Thanks to its antiinflammatory effects, chondroitin sulfate helps to inhibit enzymes that damage the joints.2

Chondroitin sulfate is found in the walls of blood vessels. Because it attracts water, it is an important factor in keeping cartilage fluid and elastic—crucial to maintaining healthy joints. With aging, the water content of cartilage decreases, causing problems in joint mobility. Acute traumatic injury, arthritis, malnutrition, and other conditions can also damage cartilage.

Chondroitin sulfate is a glycosaminoglycan, generally able to inhibit enzymes that are present in the synovial fluid that may damage or inflame joint cartilage (elastase, hyaluronidase). Chondroitin sulfate's role in halting or reversing joint degeneration appears to be due to its ability to stimulate the synthesis of glycosaminoglycans and hyaluronic acid.

Chondroitin sulfate has been reported to act synergistically with glucosamine and galactosamine1, although studies are not conclusive.

Humans can synthesize chondroitin sulfate. However, endogenous production of chondroitin sulfate tends to decrease with age.9 As a dietary supplement, chondroitin sulfate is manufactured from shark, porcine, and bovine cartilage.

Clinical Applications

Osteoarthritis: Chondroitin sulfate has shown to reduce symptoms of osteoarthritis over an extended period of use.3,4,5 Positive results occur when used together with glucosamine.6

Snoring: Results of a small placebo-controlled pilot study on snoring using chondroitin sulfate as a nasal spray were encouraging. Seven individuals were evaluated during sleep, and the time spent snoring was shown to be reduced by a statistically significant percentage.8

Sports Injury: Animal research suggests chondroitin sulfate supplementation may be useful in healing joint-related injuries in athletes.7

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Coenzyme Q10

Necessary for basic cell function, coenzyme Q10 (CoQ10) levels can decrease with age. Prescription drugs, such as statins, can further deplete CoQ10 levels.

Clinical Applications

Angina: CoQ10 was associated with a 50% decrease in the frequency of angina episodes and the use of nitroglycerin, along with significant increase in exercise capacity.28

Atherosclerosis: CoQ10 may aid against atherosclerosis due to its ability to prevent the oxidation of LDL cholesterol.19,20

Breast Cancer: CoQ10 therapy may have played a role in some cases of advanced metastasized breast cancer that went into remission.29

Cardiomyopathy: CoQ10 strengthens the heart and may be safe and effective in long-term therapy for chronic cardiomyopathy.14

Chemotherapy Support: CoQ10 may help to protect against cardiac damage in patients receiving either of the anthracycline agents doxorubicin or daunorubicin. The incidence of diarrhea and mouth ulcers may also be reduced.30

Chronic Fatigue Syndrome: CoQ10 may be beneficial.33

Congestive Heart Failure: CoQ10 is a complementary therapy for patients with congestive heart failure.15 A review of studies reported that CoQ10 improves ejection fraction, exercise tolerance, cardiac output, and stroke volume in patients with CHF.16

Diabetes: Many diabetic individuals have a deficiency of CoQ10-synthesizing enzymes. CoQ10 deficiency may hinder the ability of the pancreas to produce insulin.31

Hypertension: A CoQ10 dose of 225 mg/day resulted in a lowering of blood pressure, and 56 of 109 patients discontinued use of between one to three antihypertensive medications within six months.17 A study found that pregnant women at high risk for preeclampsia, when supplemented with CoQ10, may reduce the risk of developing preeclampsia by 10%.18

Infertility: One study reported an inverse correlation between CoQ10 content and sperm count.26 Supplementation resulted in improved rates of fertilization.27

Migraine: CoQ10 deficiency may play a role in pediatric and adolescent migraine.9

Muscle Injuries: Supplementation may decrease risk of exercise-induced muscle injury.10

Muscular Dystrophy: Patients had increased cardiac function, exercise tolerance, and limb control; and reduced leg pain and fatigue.12

Obesity: 50% of obese patients were found to be CoQ10 deficient. Those taking CoQ10 lost more than twice as much weight as controls.13

Parkinson's Disease: CoQ10 may play a role in preventing much of the MPTP-induced loss of striatal dopaminergic neurons.21 PD patients have lower platelet mitochondrial CoQ10 levels.22 An 80-patient clinical trial on early-stage PD patients concluded that the greatest benefit was seen in those taking the highest dosage of CoQ10 (1200 mg/day).25

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Fiber

Generally, Americans should strive for a fiber intake of 25 to 30 g/day, preferably from foods, not supplements. However, surveys indicate that dietary fiber intake among U.S. adults averages about 15 g/day,10 which may warrant supplementation.

Clinical Applications

Chronic Respiratory Diseases: Higher fiber intake may improve lung function and reduce the prevalence of chronic obstructive pulmonary disease.16

Constipation: Low-fiber diets are associated with constipation in children24 and the elderly.25 Additional fiber is one of the most important natural treatment recommendations, along with extra hydration and exercise.26

Diabetes Type 1: High fiber may improve glycemic control; reduce hypoglycemic events.21

Diabetes Type 2: Fiber intake has been associated with a lower risk of type 2 diabetes.18 Increased dietary fiber intake improved blood glucose and lipid values.19,20

Diverticulosis: Low-fiber diets may increase the risk of developing diverticular disease.22

Elevated Cholesterol Levels: Soluble fiber resulted in relatively small but significant lowering of total cholesterol and LDL cholesterol.27 A meta-analysis of 10 trials found that adding 3 g or more of soluble fiber to the daily diet enabled those with hypercholesterolemia to achieve a modest lowering of plasma cholesterol levels.28 In a larger meta-analysis, 88% of reviewed studies found that soluble fiber results in a lowering of total cholesterol, and 84% of studies reported significant reductions in LDL cholesterol.29

Hemorrhoids: Increasing the intake of dietary fiber is one of the primary lifestyle recommendations for patients with hemorrhoids.30 In one study, patients with internal bleeding hemorrhoids who were treated with a commercially available fiber supplement for 15 days experienced a substantial reduction in the frequency of bleeding episodes and the number of congested hemorrhoids present, compared to controls. Also, additional improvements were noted at an evaluation 15 days after the fiber supplementation ended.31

Irritable Bowel Syndrome: A meta-analysis deemed fiber effective and safe.17

Weight Management: High-fiber diets may help protect against obesity, according to the results of a study that followed young adults for a period of 10 years. Individuals who consumed the least dietary fiber gained eight pounds more over the 10-year period, compared to individuals who consumed at least 21 g of fiber daily.32

View article references at http://alpha.nhiondemand.com/ViewContent.aspx?mgid=541

Glucosamine

Glucosamine is found in healthy cartilage. When naturally synthesized, glucosamine may be insufficient in quantity to offer sufficient repair. Supplementation with glucosamine is often promoted for its role in joint health and aiding those suffering from osteoarthritis, helping to make the synovial fluid thick and elastic. Supplemental sources of glucosamine are derived from chitin, which is the processed exoskeleton of shrimp, lobster, and crab shells.

In dietary supplements, glucosamine is often partnered with chondroitin sulfate. Glucosamine appears to act synergistically with chondroitin sulfate, without side effects. Chondroitin sulfate inhibits the deleterious effect of degradative enzymes on critical joint components. Manganese, vitamin C, and bromelain may improve the effectiveness of glucosamine, without the side effects typical of nonsteroidal antiinflammatory drugs.

Reports of rapid symptomatic response to glucosamine in osteoarthritis may be attributed to the promotion of synthesis of cartilage proteoglycans. Glucosamine also stimulates synovial production of hyaluronic acid (HA). HA has antiinflammatory and analgesic properties, and promotes anabolic behavior in chondrocytes. Concentration and molecular weight is decreased in osteoarthritis; glucosamine supplementation may provide long-term benefits for repair of joint structures.1

Clinical Applications

Gonarthritis: A 12-month study demonstrated that glucosamine sulfate may have chondroprotective activity, with significant improvement shown in subjects after the first three months of therapy.6 Various studies report that glucosamine sulfate may lead to long-lasting pain reduction by means of increasing anabolic mechanisms, reducing the activity of proteolytic enzymes, and by its antiinflammatory effect.7

Kidney Stones: A study involving a mixture of glycosaminoglycans, including glucosamine, administered to 40 patients with idiopathic calcium-oxalate nephrolithiasis, reported a significant reduction in oxalate stone formation.9

Osteoarthritis: Studies indicate that supplementation with glucosamine reduced inflammation.11,12,13,14 Researchers found that glucosamine sulfate supplementation in patients improved symptoms of osteoarthritis, and the arthritis did not progress as rapidly as it did in the placebo group.15,16 Glucosamine combined with physical training may be beneficial to patients suffering from osteoarthritis.17,18

Temporomandibular Joint Dysfunction: Studies report decreased joint noises, pain, and swelling after the administration of glucosamine and chondroitin sulfate in the treatment of TMJ.8

Wound Healing: Glucosamine availability appears to be rate-limiting for HA synthesis. Administration of glucosamine during the first few days after surgery or trauma may enhance HA production in the wound, promoting swifter healing with potentially diminishing complications related to scarring.10

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Lutein

Lutein, one of the 600 known naturally occurring carotenoids, is also found in plants—largely, leafy green vegetables such as spinach and kale. Lutein is also highly concentrated in marigolds, which is the source for most of the lutein supplements currently marketed to support eye health.

Lutein specifically concentrates in the macula, located in the center of the eye's retina. The macula lies directly behind the lens and is the area of the eye that receives the most light. Lutein protects the macula by filtering out potentially damaging forms of light (blue light) and neutralizing oxygen free radicals and singlet oxygen. In humans, small amounts of lutein are also converted into zeaxanthin in the macula of the eye.12

Lutein is associated with a number of eye diseases—in particular, age-related macular degeneration, a leading cause of blindness in older adults. In the United States, the National Eye Institute is currently conducting its second-stage large-scale Age-Related Eye Disease Study, known as AREDS2. The five-year, 4000-participant trial is testing the effects of lutein, zeaxanthin, and omega-3 fatty acids on age-related macular degeneration.

Although lutein is a star in the eye health realm, a growing body of evidence suggests that it may also provide protective effects against the development of breast, colon, lung, skin, cervical and ovarian cancers.3,4 Recent research also indicates that lutein may help in the prevention of cardiovascular disease. For example, mice supplemented with lutein were found to have significantly less atherosclerosis than controls. In humans, serum lutein levels have been found to be inversely related to arterial wall thickness.5 Also, two epidemiologic studies have reported an inverse relationship between lutein levels and the incidence of stroke.6,7

Animal studies also suggest that lutein may enhance immune function. In both dogs and cats, supplementation increased lymphocyte and antibody production after vaccinations, compared to animals on control diets.8,9

Finally, lutein is now also being employed by the skincare industry. Published studies with lutein and zeaxanthin on skin health began emerging in the 1990s, when scientists first discovered its presence in human skin. Recent science has determined that lutein can improve skin hydration and elasticity, prevent oxidative stress, and, just as it protects the eye, protect the skin from the sun's damaging blue light.

Because many people don't get enough lutein in their diet, they take lutein supplements, especially to increase macular pigment density.1,2 The most common dosage of lutein in a dietary supplement is between 2 and 6 mg; however, in the dietary supplements industry, there has been a trend toward even higher doses of lutein, such as up to 10 mg. In supplements for eye health, lutein is being combined with ingredients such as omega-3 and vitamins A, C, and E—all purported to be beneficial to eye health.

Clinical Applications

Cataracts: Individuals found to be in the highest quintile (20%) of dietary lutein intake were only half as likely to develop cataracts as those in the lowest quintile of lutein intake.14

Macular Degeneration: In a four-week study, participants consuming diets high in lutein showed increases in macular density.20 In the first round of the National Eye Institute's Age-Related Eye Disease Study (AREDS), results involving 4519 participants found that higher dietary intake of lutein and zeaxanthin lowered the risk of developing neovascular age-related macular degeneration.22

Note: Recently, the third National Health and Nutrition Examination Survey (NHANES) evaluated the relationship between dietary lutein and zeaxanthin, and the presence of age-related maculopathy. No overall observations could be made regarding inverse relations between these carotenoids and age-related maculopathy. However, pigment abnormalities are generally early signs of age-related maculopathy, and the study did find that higher levels of lutein and zeaxanthin in the diet were associated with lower rates of pigmentary abnormalities.23

Retinitis Pigmentosa: In one study, supplementation resulted in increased serum lutein levels in all patients. However, only half of the patients registered increases in macular pigment density.15 Another study noted that patients with retinitis pigmentosa who took 40 mg/day of lutein for nine weeks exhibited significant improvement in visual acuity.16

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Omega-3

In the late 1970s, scientists learned that the native Inuits of Greenland who consumed a diet very high in omega-3 fatty acids had surprisingly low rates of heart attacks. Since that time, more than 4500 studies have been conducted in an attempt to understand the beneficial role that the omega-3 fatty acids—which are deficient in the diets of Americans—play in human metabolism and health.

The most common forms of omega-3 for nutrition supplementation are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). All are polyunsaturated. In the human body, ALA gets converted into longer-chain omega-3 fatty acids such as EPA and DHA.

There are both marine- and plant-based sources of omega-3 for nutritional applications. Marine plants such as plankton are the primary source of omega-3 fatty acids in the aquatic food chain. Fish and other ocean animals that feed on plankton incorporate the omega-3 fatty acids in their tissues, and are the most common sources for DHA and EPA omega-3 supplementation today. Krill and algae are other marine sources of omega-3 gaining interest.

The richest land source of omega-3 oil comes from flaxseed, and omega-3 oil can also be found in chia, rapeseed, soybeans, alfalfa, and walnuts.

In the United States, associations such as the Global Organization for EPA and DHA Omega-3s have been petitioning the Institute of Medicine to set clear dietary reference intake values for omega-3 fatty acids, particularly DHA and EPA.

As far as health claims, the Food and Drug Administration has only approved an omega-3 health claim for DHA and EPA related to reducing the risk of heart disease. However, omega-3 is one of the fastest-growing categories in nutritional supplements, and as such, researchers have been studying omega-3s for numerous other health benefits.

Clinical Applications

Allergies: Individuals with allergic conditions were found to have a defect in the enzyme responsible for synthesizing the longer-chain omega-3 fatty acids.19

Asthma: Supplementation with omega-3 may help prevent and alleviate symptoms of asthma.24,25,26,27

Attention Deficit Hyperactivity Disorder: Studies have found that subjects with ADHD had significantly lower concentrations of omega-3 fatty acids.22,23

Autism: Children with verbal apraxia (neurologically based motor planning speech disorder common in autism spectrum disorders) were treated with vitamin E and omega-3. All of the families involved reported significant improvements in many areas, including speech, imitation, coordination, eye contact, behavior, sensory issues, and development of pain sensation.6

Cancer: Dietary intake of omega-3 may play a role in the prevention and healing process of several types of cancers.28,29,30,31 Postoperative cancer patients were supplemented with omega-3 and were reported to experience improved liver and pancreas function.32

Cardiovascular Disease: Cardiovascular health may be supported by omega-3 fatty acids by lowering blood pressure, relaxing blood vessels, and lowering cholesterol levels.9,10,11 Researchers found that dietary intake of omega-3 lowered levels of inflammation and endothelial activation, which might explain in part the effect of these fatty acids in helping to prevent cardiovascular disease.12,13 A study performed in Italy reported that patients supplementing their diets with omega-3 fatty acids had a lower death rate from heart conditions than patients who did not supplement their diets.14 Evidence from a study showed that marine-derived omega-3 protected against telomere deterioration, which could reduce the risk of coronary heart failure.15

Congestive Heart Failure: Researchers found that EPA plus DHA may have a protective effect against heart failure in specific groups such as diabetics and women.7

Depression: People with omega-3 deficiency in the United States, as well as in other countries, may be vulnerable to depression.33,34 Because omega-3s have few side effects and are also beneficial to cardiovascular health, women experiencing psychological distress and depressive symptoms commonly observed during menopausal transition may benefit from omega-3 fatty acid intake.35 Pregnant women who consumed more fish (omega-3 fatty acids) had fewer depressive symptoms in comparison to pregnant women who consumed less fish.36

Elevated Cholesterol: Dietary ALA was reported to lower cholesterol levels in the blood and in liver tissues.20

Elevated Triglycerides: Supplementation with 3 to 5 g daily of omega-3 fatty acids can result in a 30 to 50% reduction in elevated serum triglycerides.16

Hypertension: Supplementation with longer-chain omega-3 fatty acids provides a slight lowering of blood pressure. Reductions range between 3 and 10 mm Hg for both systolic and diastolic pressure.21

Macular Degeneration: It has been reported that higher dietary intake of omega-3 fatty acids and fish reduces the risk of developing age-related macular degeneration.39,40,41

Rheumatoid Arthritis: Several studies indicate that omega-3 may reduce the symptoms of rheumatoid arthritis.37,38

Skin Conditions: Abnormalities in fatty acid metabolism were found in people with problems such as psoriasis and eczema.17,18

Ulcerative Colitis: Based on food-frequency questionnaires from more than 200,000 subjects, researchers found that the highest intake of omega-3 fatty acid may have reduced the risk of developing ulcerative colitis by 77%.5

Weight Management: A study found that a diet rich in omega-3 obtained by eating linseed-fed animals may be effective in weight management, and was also effective in maintaining EPA and DHA levels without fish consumption.8

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Probiotics: L. acidophilus and Bifidobacteria

Probiotics, or "good bacteria," continue to rise to prominence in both conventional dietary supplements and functional foods. Two common probiotic genuses are Bifidobacteria and Lactobacillus.

L. acidophilus

Lactobacillus acidophilus is one of the most prominent probiotic strains that predominantly reside in the small intestine. They provide a number of beneficial functions and effects, such as prevention of bacterial infections, enhancement of digestion and absorption of nutrients, metabolism of cholesterol, and strengthening of the immune system. Maintaining a healthy colonization of intestinal microflora with beneficial bacteria such as L. acidophilus is a key factor in an individual's overall health.

Small amounts of L. acidophilus occur in cultured food products such as yogurt and milk. However, in order to be effective, larger quantities may need to be consumed in the form of supplements.

Clinical Applications

Antibiotic Therapy: Researchers report that ingestion of lactic acid–producing bacteria substantially reduced the incidence of antibiotic-induced diarrhea.8,9

Cancer: Researchers found that administration of L. acidophilus reduced DNA damage in colon cells, indicating a possible role in reduced risk of colon cancer.6

Colds and Flu: A daily probiotic supplement containing Bifidobacteria and L. acidophilus was found to reduce the incidence of cold- and flu-like symptoms in children by 50%.2

Eczema: Researchers found that L. acidophilus and Bifidobacteria were beneficial in preventing eczema in infants who were at high risk for allergies.3

Elevated Cholesterol: Ingestion of L. acidophilus-containing yogurt resulted in approximately a 2 to 3% lowering of cholesterol.4

Enhanced Immunity: Volunteers taking an L. acidophilus supplement for three weeks recorded a doubling of their phagocytic index. Six weeks after discontinued use of the supplement, the activity of the subjects' phagocytes was still 50% higher than it was at the start of the experiment.10

Infantile Diarrhea: Infants treated with L. acidophilus plus rehydration therapy were found to recover more quickly than those treated with other protocols that did not contain L. acidophilus.7

Lactose Intolerance: Ingestion of L. acidophilus by lactose-intolerant humans results in improved lactose digestion, as evidenced by improved symptoms and a decrease in hydrogen excreted in their breath.11

Vaginal Candidiasis: L. acidophilus therapy has been reported to be helpful in the prevention and treatment of vaginal candidiasis infections.5

Bifidobacteria

Bifidobacteria are bacteria that exist primarily in the large intestine—although some also inhabit the lower part of the small intestine. To date, 28 species of Bifidobacteria have been isolated from the intestines of humans and animals.

The following five are the predominant species of Bifidobacteria that occur in humans: B. bifidum, B. infantis, B. breve, B. adolescentis, and B. longum. Bifidobacteria metabolize sugar to produce lactate and acetate. This creates a slightly acidic pH, which is an environment that is unfavorable for the growth of pathologic organisms.

Clinical Applications

Antibiotic Therapy: In a randomized, placebo-controlled trial with erythromycin, volunteers ingesting yogurt with B. longum had a significant reduction in diarrhea and intestinal complaints compared to controls taking plain yogurt.9

Constipation: Children with constipation symptoms were given a probiotic supplement including B. bifidum, B. infantis, B. longum, and Lactobacillus. As a result, the children's bowel movements increased from two per week to 4.2 per week after two weeks, and 3.8 per week after four weeks. Also, abdominal pain reported by the children went from 45% at the beginning of the study to only 20% after four weeks.3

Diarrhea: In a double-blind, placebo-controlled trial, infants with diarrhea were given either a standard infant formula or the same formula supplemented with B. bifidum and S. thermophilus organisms. Infants receiving the supplemented formulas had a substantial reduction in the incidence of diarrhea.6

Elevated Cholesterol: Bifidobacteria are able to remove cholesterol from the intestinal tract by two mechanisms: one is by metabolic assimilation of cholesterol, and the other is precipitation of cholesterol by converting it to a less soluble substance known as coprostanol.7

Enhanced Immunity: Volunteers taking a Bifidobacteria supplement for three weeks recorded a doubling of their phagocytic index. Six weeks after discontinuing the supplement, the activity of the subjects' phagocytes was still 50% higher than it was at the start of the experiment.8

Intestinal Gas: Supplementation with B. longum resulted in the production of significantly less hydrogen gas in the intestines, as well as a corresponding decrease in flatulence.5