Health Care Professional Information
Common Name
Xanthophyll, dihyroxycarotenoid, nonprovitamin A carotenoid
Clinical Summary
A natural pigment synthesized by plants and microorganisms, lutein is used primarily as an antioxidant and also to prevent and treat cancer, heart disease, and macular degeneration. Lutein has antioxidant (1) (21) and anti-inflammatory (22) effects. It is classified as a nonprovitamin A carotenoid, which also includes lycopene and zeaxanthin. Alpha-carotene, beta-carotene, and beta-cryptoxanthin are classified as provitamin A carotenoids because they can be converted into retinol.
Epidemiologic studies suggest an inverse relationship between increased lutein consumption and decreased incidence of atherosclerosis (2) and cataracts (3) (4) although the effects of dietary lutein on macular degeneration are inconsistent (5) (6) (7). Conclusions from a systematic review and meta-analysis suggest that the current evidence is insufficient to support use of lutein and other dietary antioxidants to prevent early age-related macular degeneration (7) (8).
Inverse associations have been reported between lutein consumption and risk of colon cancer (9), renal cell carcinoma (19) and nonaggressive urothelial cell carcinoma (20). A recent meta-analysis found a modest association between dietary lutein and colorectal cancer (10). Data on the effects of dietary lutein intake and cervical cancer risk are conflicting, (11) (12) whereas no association was found between lutein and lung cancer risk (13).
Food Sources
Kale, spinach, winter squash, cruciferous vegetables, cabbage, green beans, yellow/orange fruits, mangoes, papayas, peaches, oranges (1)
Purported Uses
- Cancer prevention
- Cataracts
- Macular degeneration
- Visual acuity
Mechanism of Action
Lutein is a natural pigment synthesized by plants and microorganisms. Lutein accumulates in the retina and lens, and has been associated with a decreased risk of macular degeneration and cataracts (14). Although the physiologic function of lutein in the macular membranes is not known, it is hypothesized that it may protect the retina from oxidative damage (15) (16). Referred to as a nonprovitamin A carotenoid, it is not known to have any vitamin A activity.
Lutein is associated with reduced risk of atherosclerosis (2).
Carotenoids also have antioxidant, immune enhancing properties, inhibit mutagenesis and transformation, and inhibit premalignant lesions (1). Lutein-mediated AP-1 suppression and anti-inflammatory activity have been shown to be due to its strong antioxidative and p38/c-Jun-N-terminal kinase (JNK) inhibitory activities (22).
Current data suggest an association between lutein and decreased risk of colon cancer (9).
In another study of N-nitrosodiethylamine-induced hepatocellular carcinoma (HCC) in rats, lutein was shown to reduce the activity of γ-glutamyl transpeptidase, a marker of cellular proliferation (21).
Pharmacokinetics
Absorption:
Intestinal absorption of carotenoids, including lutein, is facilitated by the formation of bile acid micelles containing carotenoids. The presence of fat in the small intestine stimulates the secretion of bile acids from the gall bladder and improves the absorption of carotenoids by increasing the size and stability of the micelles, thus allowing more carotenoids to be solubilized. Bioavailability of lutein is affected by the dose and presence of other carotenoids such as Beta carotene. The bioavailability of lutein from vegetables is approximately 70% (16).
Distribution:
The concentrations of various carotenoids in human serum and tissues are highly variable and depend on food sources, efficiency of absorption, and amount of fat in the diet. Lutein is transported by high-density lipoprotein (HDL) and, to a lesser extent, by very low-density lipoprotein. The serum concentration of carotenoids after a single dose peaks at 24 to 48 hours post dose. The average lutein concentration in human serum is 280 nM (1). Lutein is primarily stored in adipose and the liver. Of all the carotenoids circulating in the body, only two polar species, lutein and zeaxanthin, are contained in the macula (17).
Metabolism/Excretion:
It is assumed that lutein is excreted through the bile and kidneys (14).
Literature Summary and Critique
Christen WG, et al. Dietary carotenoids, vitamins C and E, and risk of cataract in women: a prospective study. Arch Ophthalmol. Jan 2008;126(1):102-109.
To determine the effects of dietary carotenoids on cataract formation in women, this prospective observational study was undertaken with 35,551 female participants for 10 years. Cataract formation and visual acuity were the primary outcome measures. Reduced risk of cataract formation (18%) was associated with increased dietary lutein/zeaxanthin intake. Randomized, clinical trials of lutein/zeaxanthin in both men and women are necessary to determine if lutein supplementation may also reduce cataract risk.
Ros MM, Bueno-de-Mesquita HB, Kampman E, et al. Plasma carotenoids and vitamin C concentrations and risk of urothelial cell carcinoma in the European Prospective Investigation into Cancer and Nutrition. Am J Clin Nutr. 2012 Oct;96(4):902-10.
This study invovled 856 patients with newly diagnosed urothelial cell carcinoma (UCC) who were were matched with 856 cohort members by sex, age at baseline, study center, date and time of blood collection, and fasting status. Plasma carotenoids including alpha and beta carotenes, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin were measured by using reverse-phase HPLC. The plasma vitamin C was measured by a colorimetric assay. Incidence rate ratios (IRRs) were estimated by using conditional logistic regression with adjustment for smoking status, duration, and intensity. Researchers report that the risk of UCC decreased with greater concentrations of plasma carotenoids (IRR for the highest compared with the lowest quartile: 0.64; 95% CI: 0.44, 0.93; P-trend = 0.04). Plasma lutein was inversely associated with risk of nonaggressive UCC (IRR: 0.56; 95% CI: 0.32, 0.98; P-trend = 0.05). Plasma beta-carotene was also inversely associated with aggressive UCC (IRR: 0.51; 95% CI: 0.30, 0.88; P-trend = 0.02), but no association was observed between plasma vitamin C and risk of UCC.
Plasma lutein and beta-carotene may reduce the risk of UCC.
Dosage (Inside MSKCC Only)
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References
- Khachik F, Beecher GR, Smith JC. Lutein, lycopene, and their oxidative metabolites in chemoprevention of cancer. J Cell Biochem Suppl 1995;22:236-46.
- Dwyer JH, et al. Oxygenated carotenoid lutein and progression of early atherosclerosis: the Los Angeles atherosclerosis study. Circulation 2001;103:2922-7.
- Christen WG, Liu S, Glynn RJ, et al. Dietary carotenoids, vitamins C and E, and risk of cataract in women: a prospective study. Arch Ophthalmol. Jan 2008;126(1):102-109.
- Moeller SM, Voland R, Tinker L, et al. Associations between age-related nuclear cataract and lutein and zeaxanthin in the diet and serum in the Carotenoids in the Age-Related Eye Disease Study, an Ancillary Study of the Women's Health Initiative. Arch Ophthalmol. Mar 2008;126(3):354-364.
- Dagnelie G, Zorge IS, McDonald TM. Lutein improves visual function in some patients with retinal degeneration: a pilot study via the internet. Optometry 2000;71:147-64.
- Tan JS, Wang JJ, Flood V, et al.Dietary antioxidants and the long-term incidence of age-related macular degeneration: the Blue Mountains Eye Study.Ophthalmology. Feb 2008;115(2):334-341.
- Cho E, Hankinson SE, Rosner B, et al. Prospective study of lutein/zeaxanthin intake and risk of age-related macular degeneration. Am J Clin Nutr. Jun 2008;87(6):1837-1843.
- Chong EW, Wong TY, Kreis AJ, et al. Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis. BMJ. Oct 13 2007;335(7623):755.
- Slattery ML, et al. Carotenoids and colon cancer. Am J Clin Nutr 2000;71:575-82.
- Mannisto S, Yaun SS, Hunter DJ, et al. Dietary carotenoids and risk of colorectal cancer in a pooled analysis of 11 cohort studies. Am J Epidemiol. Feb 1 2007;165(3):246-255.
- VanEenwyk J, Davis FG, Bowen PE. Dietary and serum carotenoids and cervical intraepithelial neoplasia. Int J Cancer. Apr 22 1991;48(1):34-38.
- Ghosh C, Baker JA, Moysich KB, et al. Dietary intakes of selected nutrients and food groups and risk of cervical cancer. Nutr Cancer. May-Jun 2008;60(3):331-341.
- Gallicchio L, Boyd K, Matanoski G, et al. Carotenoids and the risk of developing lung cancer: a systematic review. Am J Clin Nutr. Aug 2008;88(2):372-383.
- Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academy Press; 2000.
- Snodderly DM. Evidence for protection against age-related macular degeneration by carotenoids and antioxidant vitamins.Am J Clin Nutr. Dec 1995;62(6 Suppl):1448S-1461S.
- van het Hof KH, et al. Bioavailability of lutein from vegetables is 5 times higher than that of beta-carotene. Am J Clin Nutr 1999;70:261-8.
- Olmedilla B, et al. A European multicentre, placebo-controlled supplementation study with alpha-tocopherol, carotene-rich palm oil, lutein or lycopene; analysis of serum responses. Clin Sci (Lond) 2002;102:447-56.
- Elinder LS, et al. Probucol treatment decreases serum concentrations of diet-derived antioxidants. Arterioscler Thromb Vasc Biol 1995;15:1057-63.
- Hu J, La Vecchia C, Negri E, et al. Dietary vitamin C, E, and carotenoid intake and risk of renal cell carcinoma. Cancer Causes Control. 2009 Oct;20(8):1451-8.
- Ros MM, Bueno-de-Mesquita HB, Kampman E, et al. Plasma carotenoids and vitamin C concentrations and risk of urothelial cell carcinoma in the European Prospective Investigation into Cancer and Nutrition. Am J Clin Nutr. 2012 Oct;96(4):902-10.
- Sindhu ER, Firdous AP, Ramnath V, Kuttan R. Effect of carotenoid lutein on N-nitrosodiethylamine-induced hepatocellular carcinoma and its mechanism of action. Eur J Cancer Prev. 2012 Nov 25. [Epub ahead of print]
- Oh J, Kim JH, Park JG, et al.Radical Scavenging Activity-Based and AP-1-Targeted Anti-Inflammatory Effects of Lutein in Macrophage-Like and Skin Keratinocytic Cells. Mediators Inflamm. 2013;2013:787042.
Consumer Information
How It Works
Bottom Line: Current evidence is not sufficient to know if lutein is useful in preventing macular degeneration. A diet containing lutein-rich fruits and vegetables may lower the risk of colon cancer.
Lutein is a natural pigment synthesized by plants and microorganisms. Because it is an antioxidant, cancer prevention activity has been proposed, but no studies have proved this. Scientists also think that lutein may stimulate the immune system, inhibit the mutation of DNA, or inhibit the growth of pre-cancerous cells. Lutein has been associated with a decreased risk of macular degeneration and cataracts, although researchers are uncertain how lutein exerts this effect. In addition, studies in animals and human subjects have shown that high lutein intake can prevent the progression of atherosclerosis.
Purported Uses
- As an antioxidant
Laboratory and clinical data support this use.
- To prevent cancer
One population-based study showed that higher intake of foods rich in lutein is associated with a lowered risk of developing colon cancer. but another review of the clinical trials revealed that this effect is small. Dietary lutein does not reduce the risk of lung cancer, and its effects on cervical cancer are mixed. There is no proof that lutein can treat cancer.
- To treat cataracts
Population-based studies in humans found that eating lutein-rich foods was associated with reduced risk of developing cataracts. There is no evidence that lutein can treat cataracts or that lutein supplementation will have the same effect as dietary lutein.
- To prevent and treat macular degeneration
A few clinical trials support this use, but others have found no effect of lutein consumption on macular degeneration. Also, there is not enough evidence that lutein can treat macular degeneration.
- For increased visual acuity
Clinical trials support this use in patients with degenerative diseases of the retina.
Research Evidence
Cataracts:
In this large study, 35,551 female participants were followed for 10 years to compare the intake of dietary lutein and cataract. Women who reported high dietary consumption of lutein were less likely to develop cataract, indicating that eating lutein-rich foods may reduce risk of cataract. Further clinical studies of patients taking lutein supplements or placebo are needed to determine if these protective effects were due to dietary lutein alone.
Cancer Prevention:
This study invovled 856 patients with newly diagnosed urothelial cell carcinoma (UCC) who were were matched with 856 members by sex, age at baseline, study center, date and time of blood collection, and fasting status. Plasma carotenoids that were measured included alpha and beta carotenes, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin. Researchers report that the risk of UCC decreased with greater concentrations of plasma lutein and beta-carotene.
Last updated: April 23, 2013
absorption (ub-SORP-shun)
The process of taking nutrients from the digestive system into the blood so they can be used in the body.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)acid (A-sid)
A chemical that gives off hydrogen ions in water and forms salts by combining with certain metals. Acids have a sour taste and turn certain dyes red. Some acids made by the body, such as gastric acid, can help organs work the way they should. An example of an acid is hydrochloric acid. Acidity is measured on a scale called the pH scale. On this scale, a value of 7 is neutral, and a pH value of less than 7 to 0 shows increasing acidity.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)affected
Individuals in a pedigree who exhibit the specific phenotype under study.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)age-related macular degeneration (ayj-ree-LAY-ted MA-kyoo-ler dee-JEH-neh-RAY-shun)
A condition in which there is a slow breakdown of cells in the center of the retina (the light-sensitive layers of nerve tissue at the back of the eye). This blocks vision in the center of the eye and can cause problems with activities such as reading and driving. Age-related macular degeneration is most often seen in people who are over the age of 50. Also called AMD, ARMD, and macular degeneration.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)aggressive (uh-GREH-siv)
In medicine, describes a tumor or disease that forms, grows, or spreads quickly. It may also describe treatment that is more severe or intense than usual.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)anti-inflammatory (AN-tee-in-FLA-muh-TOR-ee)
Having to do with reducing inflammation.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)antioxidant (AN-tee-OK-sih-dent)
A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, vitamins A, C, and E, and other natural and manufactured substances.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)assay (A-say)
A laboratory test to find and measure the amount of a specific substance.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)baseline (BAYS-line)
An initial measurement that is taken at an early time point to represent a beginning condition, and is used for comparison over time to look for changes. For example, the size of a tumor will be measured before treatment (baseline) and then afterwards to see if the treatment had an effect.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)beta carotene (BAY-tuh KAYR-uh-teen)
A substance found in yellow and orange fruits and vegetables and in dark green, leafy vegetables. The body can make vitamin A from beta carotene. Beta carotene is being studied in the prevention of some types of cancer. It is a type of antioxidant.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)bile (bile)
A fluid made by the liver and stored in the gallbladder. Bile is excreted into the small intestine, where it helps digest fat.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)bladder (BLA-der)
The organ that stores urine.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)blood (blud)
A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cancer (KAN-ser)
A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)carcinoma (KAR-sih-NOH-muh)
Cancer that begins in the skin or in tissues that line or cover internal organs.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)carotenoid (kuh-RAH-teh-noyd)
A yellow, red, or orange substance found mostly in plants, including carrots, sweet potatoes, dark green leafy vegetables, and many fruits, grains, and oils. Some carotenoids are changed into vitamin A in the body and some are being studied in the prevention of cancer. A carotenoid is a type of antioxidant and a type of provitamin.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cataract (KA-tuh-RAKT)
A condition in which the lens of the eye becomes cloudy. Symptoms include blurred, cloudy, or double vision; sensitivity to light; and difficulty seeing at night. Without treatment, cataracts can cause blindness. There are many different types and causes of cataracts. They may occur in people of all ages, but are most common in the elderly.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cell (sel)
The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cervical (SER-vih-kul)
Relating to the neck, or to the neck of any organ or structure. Cervical lymph nodes are located in the neck. Cervical cancer refers to cancer of the uterine cervix, which is the lower, narrow end (the “neck”) of the uterus.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cervical cancer (SER-vih-kul KAN-ser)
Cancer that forms in tissues of the cervix (the organ connecting the uterus and vagina). It is usually a slow-growing cancer that may not have symptoms but can be found with regular Pap tests (a procedure in which cells are scraped from the cervix and looked at under a microscope). Cervical cancer is almost always caused by human papillomavirus (HPV) infection.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)clinical (KLIH-nih-kul)
Having to do with the examination and treatment of patients.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)cohort (KOH-hort)
A group of individuals who share a common trait, such as birth year. In medicine, a cohort is a group that is part of a clinical trial or study and is observed over a period of time.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)colon (KOH-lun)
The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)colon cancer (KOH-lun KAN-ser)
Cancer that forms in the tissues of the colon (the longest part of the large intestine). Most colon cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids).
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)colorectal (KOH-loh-REK-tul)
Having to do with the colon or the rectum.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)concentration (KON-sen-TRAY-shun)
In science, the amount of a substance, such as a salt, that is in a certain amount of tissue or liquid, such as blood. A substance becomes more concentrated when less water is present. For example, the salt in urine may become more concentrated when a person doesn’t drink enough water.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)diet (DY-et)
The things a person eats and drinks.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)DNA
The molecules inside cells that carry genetic information and pass it from one generation to the next. Also called deoxyribonucleic acid.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)dose (dose)
The amount of medicine taken, or radiation given, at one time.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)hepatocellular carcinoma (heh-PA-toh-SEL-yoo-ler KAR-sih-NOH-muh)
A type of adenocarcinoma and the most common type of liver tumor.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)immune system (ih-MYOON SIS-tem)
The complex group of organs and cells that defends the body against infections and other diseases.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)incidence (IN-sih-dents)
The number of new cases of a disease diagnosed each year.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)intestinal (in-TES-tih-nul)
Having to do with the intestines.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)intestine (in-TES-tin)
The long, tube-shaped organ in the abdomen that completes the process of digestion. The intestine has two parts, the small intestine and the large intestine. Also called bowel.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)kinase (KY-nays)
A type of enzyme that causes other molecules in the cell to become active. Some kinases work by adding chemicals called phosphates to other molecules, such as sugars or proteins. Kinases are a part of many cell processes. Some cancer treatments target certain kinases that are linked to cancer.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)liver (LIH-ver)
A large organ located in the upper abdomen. The liver cleanses the blood and aids in digestion by secreting bile.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)lung (lung)
One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)lung cancer (lung KAN-ser)
Cancer that forms in tissues of the lung, usually in the cells lining air passages. The two main types are small cell lung cancer and non-small cell lung cancer. These types are diagnosed based on how the cells look under a microscope.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)lycopene (LY-kuh-peen)
A red pigment found in tomatoes and some fruits. It is an antioxidant and may help prevent some types of cancer.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)macular degeneration (MA-kyoo-ler dee-JEH-neh-RAY-shun)
A condition in which there is a slow breakdown of cells in the center of the retina (the light-sensitive layers of nerve tissue at the back of the eye). This blocks vision in the center of the eye and can cause problems with activities such as reading and driving. Macular degeneration is most often seen in people who are over the age of 50. Also called age-related macular degeneration, AMD, and ARMD.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)marker (MAR-ker)
A diagnostic indication that disease may develop.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)meta-analysis (meh-tuh-uh-NA-lih-sis)
A process that analyzes data from different studies done about the same subject. The results of a meta-analysis are usually stronger than the results of any study by itself.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)mutation (myoo-TAY-shun)
Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)nM
The amount of a substance equal to a billionth of a mole (a measure of the amount of a substance). Also called nanomole.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)observational study (OB-ser-VAY-shuh-nul STUH-dee)
A type of study in which individuals are observed or certain outcomes are measured. No attempt is made to affect the outcome (for example, no treatment is given).
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)outcome (OWT-kum)
A specific result or effect that can be measured. Examples of outcomes include decreased pain, reduced tumor size, and improvement of disease.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)physiologic (FIH-zee-uh-LAH-jik)
Having to do with the functions of the body. When used in the phrase "physiologic age," it refers to an age assigned by general health, as opposed to calendar age.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)pigment (PIG-ment)
A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)placebo (pluh-SEE-boh)
An inactive substance or treatment that looks the same as, and is given the same way as, an active drug or treatment being tested. The effects of the active drug or treatment are compared to the effects of the placebo.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)plasma (PLAZ-muh)
The clear, yellowish, fluid part of the blood that carries the blood cells. The proteins that form blood clots are in plasma.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)premalignant (pree-muh-LIG-nunt)
A term used to describe a condition that may (or is likely to) become cancer. Also called precancerous.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)prevention (pree-VEN-shun)
In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors (such as smoking, obesity, lack of exercise, and radiation exposure) and increasing protective factors (such as getting regular physical activity, staying at a healthy weight, and having a healthy diet).
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)progression (pruh-GREH-shun)
In medicine, the course of a disease, such as cancer, as it becomes worse or spreads in the body.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)prospective (pruh-SPEK-tiv)
In medicine, a study or clinical trial in which participants are identified and then followed forward in time.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)randomized
Describes an experiment or clinical trial in which animal or human subjects are assigned by chance to separate groups that compare different treatments.
(http://www.cancer.gov/dictionary)regression (reh-GREH-shun)
A decrease in the size of a tumor or in the extent of cancer in the body.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)retina (REH-tih-nuh)
The light-sensitive layers of nerve tissue at the back of the eye that receive images and sends them as electric signals through the optic nerve to the brain.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)retinol (REH-tih-nol)
A nutrient that the body needs in small amounts to function and stay healthy. Retinol helps in vision, bone growth, reproduction, growth of epithelium (cells that line the internal and external surfaces of the body), and fighting infections. It is fat-soluble (can dissolve in fats and oils). Retinol is found in liver, egg yolks, and whole milk dairy products from animals and in fish oils. It can also be made in the body from a substance found in some fruits and vegetables, such as cantaloupes, carrots, spinach, and sweet potatoes. Retinol is being studied in the prevention and treatment of some types of cancer. Also called vitamin A.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)serum (SEER-um)
The clear liquid part of the blood that remains after blood cells and clotting proteins have been removed.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)supplementation (SUH-pleh-men-TAY-shun)
Adding nutrients to the diet.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)transformation (TRANZ-for-MAY-shun)
In medicine, the change that a normal cell undergoes as it becomes malignant.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)vitamin (VY-tuh-min)
A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)vitamin C (VY-tuh-min…)
A nutrient that the body needs in small amounts to function and stay healthy. Vitamin C helps fight infections, heal wounds, and keep tissues healthy. It is an antioxidant that helps prevent cell damage caused by free radicals (highly reactive chemicals). Vitamin C is found in all fruits and vegetables, especially citrus fruits, strawberries, cantaloupe, green peppers, tomatoes, broccoli, leafy greens, and potatoes. It is water-soluble (can dissolve in water) and must be taken in every day. Vitamin C is being studied in the prevention and treatment of some types of cancer. Also called ascorbic acid.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)will (wil)
A legal document in which a person states what is to be done with his or her property after death, who is to carry out the terms of the will, and who is to care for any minor children.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)
