Cystine Introduction   Cystine is a nonessential, sulfur-containing amino acid that is formed from the oxidation of the amino acid cysteine.  This oxidation process is quite complex, beginning with methionine and ending with cystine.   This nonessential amino acid is concentrated in various protein structures located throughout the body.  It is an important constituent of connective and skeletal tissue, digestive enzymes (chromotrypsinogen A, papain, and trypsinogen), insulin, and hair keratin.  Cystine, in association with N-acetylcysteine (NAC), can be used in place of L-cysteine, and may prevent side effects associated with exposure to certain types of radiation. [1]  Cystine may also aid in the body's natural detoxification processes.   Glutathione is a major antioxidant compound found in living animal and plant tissue. Cystine increases glutathione levels in major organs and bone marrow, providing the body with an anti-aging mechanism.  This has proved especially useful in the reduction and accrual of age spots.     Cystine Food Sources   Nearly all foods contain sufficient amounts of cystine.  Viable sources of cystine include whole grains, soybeans, whey, beans, dairy products, eggs, meat, nuts, and seafood.  Serving sizes below are based upon 100 grams of a given food source and are expressed in milligrams, representing the amount of cystine contained.     Cereal Grains and Pasta mg/100g Food Name 575.9 Oat bran, raw 540.1 Macaroni, protein-fortified, dry, enriched, (n x 5.70)   Breakfast Cereals mg/100g Food Name 575.9 Cereals ready-to-eat, wheat germ, toasted, plain     Vegetables and Vegetable Products mg/100g Food Name 662.1 Seaweed, spirulina, dried     Nut and Seed Products mg/100g Food Name 952.1 Seeds, sunflower seed flour, partially defatted 855 Seeds, cottonseed kernels, roasted (glandless) 814 Seeds, sesame flour, partially defatted 685 Seeds, safflower seed meal, partially defatted 621.1 Seeds, sesame flour, high-fat     Legumes and Legume Products mg/100g Food Name 1150 Soy protein isolate, Protein Technologies International, supro 1100 Soy protein isolate, Protein Technologies International, ProPlus 1046 Soy protein isolate 1046 Soy protein isolate, potassium type 1046 Soy protein isolate, potassium type, crude protein basis 886 Soy protein concentrate, produced by alcohol extraction 886 Soy protein concentrate, produced by acid wash 886 Soy protein concentrate, crude protein basis (N x 6.25), produced by acid wash 757 Soy flour, defatted 757 Soy flour, defatted, crude protein basis (N x 6.25) 750 Soy flour, low-fat 750 Soy flour, low-fat, crude protein basis (N x 6.25) 723.9 Soy meal, defatted, raw 668.9 Peanut flour, defatted 662.9 Tofu, dried-frozen (koyadofu) 662.9 Tofu, dried-frozen (koyadofu), prepared with calcium sulfate 638.1 Soybeans, mature seeds, dry roasted 627.1 Meat extender 588.1 Soybeans, mature seeds, raw 566.9 Soybeans, mature seeds, roasted, salted 566.9 Soybeans, mature seeds, roasted, no salt added 561 Soy flour, full-fat, roasted 555.9 Soy flour, full-fat, raw 545 Winged beans, mature seeds, raw     Finfish and Shellfish Products mg/100g Food Name 673 Fish, cod, Atlantic, dried and salted     Beef Products mg/100g Food Name 727 Beef, variety meats and by-products, spleen, cooked, braised     Pork Products mg/100g Food Name 557 Pork, fresh, variety meats and by-products, kidneys, cooked, braised     Dairy and Egg Products mg/100g Food Name 2102 Egg, white, dried 1099 Egg, whole, dried 613.9 Egg, yolk, dried     Spices and Herbs mg/100g Food Name 582.1 Spices, mustard seed, yellow [2]     Cystine Uses   Information regarding cystine use in human physiology remains limited.   Cystine is an effective detoxification agent, protecting the body against free radicals in the environment.  The effects of assorted oxidants contained in alcohol and cigarette smoke may be lessened as a result of the dietary supplementation of cystine.  It may also prove useful in diminishing the effects of a "hang over" caused by excessive alcohol consumption, as well as preventing liver and even brain damage. Because cystine contains anti-oxidative properties, it may increase immunity by aiding in white blood-cell activity.   Its most practical use may be in its ability to thwart obesity.  Cystine is integral in the production of insulin in the pancreas gland.  Taken in conjunction with vitamin C, cystine may further assist the body in its assimilation of sugars and starches.  Cystine may neutralize excess insulin production, thereby eliminating unwanted fat production and deposition.   Other bodily functions are equally dependant upon this amino acid.  Cysteine is fundamental in providing proper functioning of the largest organ in the human body - the skin.  The flexibility and texture of skin are directly influenced by adequate cystine intake.  Cystine also aids in the formation of carotene which is an agent of hair growth and health.  The health of collagen, a connective tissue protein, is also dependant upon cystine.     Cystine Dosages   Because cystine is considered a nonessential amino acid, a Recommended Daily Allowance (RDA) has not been established.  The U.S. National Academy of Sciences recommends that healthy people achieve .36 grams of highly bioavailable protein for each pound of bodyweight - equaling 0.8 grams of protein per kilogram of bodyweight.     Cystine Toxicities and Deficiencies   Cystine Deficiency A deficiency of cystine is very unlikely, however, certain chronic diseases inhibit the formation of cysteine from methionine and may result in a cystine deficiency.  Choline, a key component of phospholipids, may assist individuals suffering from the  hereditary disorder, Cystinuria; where vast amounts of cystine are lost in urine.   Cystine Toxicity Prolonged and excessive intakes of cystine may result in the formation of cystine kidney stones.  To eliminate this possibility, it is recommended that adequate amounts of ascorbic acid are consumed in concurrence with cystine.   Individuals suffering from diabetes mellitus should not use supplemental cystine due to its ability to inactivate certain disulphidedbrids of insulin, which are critical in determining this hormone's structure.         Return to Supplements Index

Search by Health Condition: --- Select a Condition --- Acid Reflux Acne AIDS and HIV Aging Allergies Alzheimers Anemia Angina Arthritis (OA) Arthritis (RA) Asthma ADHD Autism Bad Breath Breast Cancer Burns Candidiasis Carpal Tunnel Celiac Disease Cellulitis Cerebral Palsy Cervical Dysplasia Cholesterol Chronic Bronchitis CFS Cognitive Function Colds and Flu Cold Sores CHF Constipation Chronic Cough Crohns Disease Cystic Fibrosis Depression Diabetes Type 1 Diabetes Type 2 Diarrhea Diverticular Disease Downs Syndrome Eating Disorders Eczema Emphysema Endometriosis Epilepsy Erectile Dysfunction Fatigue Fibroids Fibromyalgia FLU Gallstones Glaucoma Gout Halitosis Hair Loss Heartburn Hemorrhoids Herpes Simplex Herpes Zoster Hyperlipidemia Hypertension Hyperthyroidism Hypoglycemia Hypothyroidism Impotence Influenza Insomnia IBS Kidney Stones Liver Disease Lupus Macular Degeneration Menopause Migraines Mononucleosis Multiple Sclerosis Obesity Ocular Health Osteoarthritis Osteoporosis Otitis Media Pancreatitis Pain Parkinsons PID PUD Periodontal Disease PMS Pneumonia Prostate Health Psoriasis Raynauds disease RLS RA SAD Shingles Sinusitis Stress TMJD Tuberculosis Ulcerative Colitis UTI Vaginitis Varicose veins Vertigo Vitiligo Search by Supplement: --- Select a Supplement--- 5-HTP ALC Alanine Aloe Vera Alpha GPC ALA American Ginseng Amino Acids Androstenedione Arabinoxylane Arginine Arnica Artichoke Ashwagandha Asparagine Aspartic Acid Astragalus Bacopa Barberry Bee Pollen Bee Propolis Beta Glucan Beta Carotene Betaine HCL Bifidobacterium Bilberry Biotin Bitter Melon Black Cohosh Bladderwrack Boron Boswellia BCAAs Brewers Yeast Bromelain Burdock Calcium Calendula Carnosine Cartilage Cascara Sagrada Cats Claw Cayenne CMO Chamomile Chasteberry Chitosan Chloride Choline Chondroitin Chromium Citrulline Coenzyme Q10 Coleus Colostrum Comfrey CLA Copper Cordyceps Cranberry Creatine Cyclo Cysteine Cystine Dandelion Leaf Dandelion Root Deer Antler Velvet DHEA Devils Claw Digestive Enzymes DMAE DMG DHA Dong Quai Echinacea EPA Elder Eleuthero English Ivy Ephedra Eucalyptus Evening Primrose Feverfew Fiber Fish Oil Flaxseed Fluoride Folic Acid FOS GABA GLA Gamma oryzanol Garcinia Garlic Ginger Gingko Glucosamine Glutamic Acid Glutamine Glutathione Glycine Goldenseal Gotu Kola Grapefruit Seed Grape Seed Extract Green Tea Guggul Gymnema Hawthorn Histidine Hops Horse Chestnut Horsetail Huperzine A Inositol Iodine Iron Isoleucine Kava Lactobacillus Acidophilus Larch Arabinogalactan L-Carnitine L Dopa Lemon Balm Leucine Lecithin Licorice Lutein Lycopene Lysine Magnesium Malic acid Manganese Mastic Melatonin Methionine MSM Milk Thistle Minerals Molybdenum NAC NADH Noni Olive Leaf Omega 3 Omega 6 Oregano Panax ginseng Passion Flower Pau Darco Peppermint Oil Phellodendron Phenylalanine Phosphatidylcholine Phosphatidylserine Phosphorus Phyllanthus Picrorrhiza Policosanol Potassium Proline Psyllium Pygeum Pyruvate Quercetin Red Clover Reshi Rhodiola Rosacea SAM-E Saw Palmetto Schisandra Selenium Serine Shiitake Silicon Sodium Soy Isoflavones Spirulina Sterols Stinging Nettle St Johns Wort Sulfur Taurine Tea Tree Oil Theanine Threonine Tocotrienols Tryptophan Turmeric Tylophora Tyrosine Uva Ursi Valerian Valine Vanadium Vinpocetine Vitamin A Vitamin B1 Vitamin B2 Vitamin B3 Vitamin B5