NUTR 3330 Final Exam (last of the course content) Complete Questions With Accurate Answers Graded A+.

what are phytosterols? what are the 3 most common? - correct answers - plant-derived sterols that are structurally similar to cholesterol - beta-sitosterol, campesterol, stigmasterol 2 subclasses of phytosterols? structure? any characteristics? - correct answers 1. sterols - has a double bond at position 5 2. stanols - has a reduction of the double bond at position 5 - less common than sterols - more a product of sterol bacterial degradation than in food - produced by hydrogenating sterols what foods are cholesterol and phytosterols in? different in atherogenic potential and blood levels? - correct answers - cholesterol = animal foods - phytosterol = plant foods - both are atherogenic (plaque build-up) but phytosterols are less of a concern since only 1-15% is absorbed - phytosterol blood levels are 200x lower than cholesterol highest food sources of phytosterols? how do they affect cholesterol? - correct answers vegetable oils, nuts, seeds, legumes have a cholesterol lowering effect 3 main areas where phytosterols seem to help - correct answers 1. CVD 2. cancer 3. immune health how have phytosterols been shown to help CVD - correct answers - can reduce blood lipids, especially total and LDL cholesterol - have a dose-dependent effect on LDL-cholesterol lowering, but plateaus at 3g/day - no diff btw sterols and stanols mechanism of how sterols lower cholesterol? - correct answers - sterols are more hydrophobic than cholesterol - they compete for space in mixed micelles in the intestine - this causes cholesterol to be displaced and go into feces - sterols are not absorbed so after competition, will also go into feces - has an overall effect of lowering cholesterol by 30-50% factors to consider when determining phytosterol cholesterol lowering efficacy? - correct answers - sterols vs stanols; is one more efficacious? - dose-response relationships; when does response plateau - does form of administration matter; ex. margarine vs orange juice - does diet being consumed matter; work with low and/or high fat diet - one's baseline cholesterol values factors to consider when seeing if phytosterol could replace a lipid-lowering drug? - correct answers - are there more or less side effects - cost - magnitude of effect; effects from sterols could be less - potential additive effect with drug what were results of study looking at additive effect of plant sterol and drug in lowering LDL cholesterol? - correct answers - some additive effect when taking drug and sterol together in lowering LDL cholesterol compared to alone - could mean you could dec the dose of drug to supplement some with phytosterols why is there limited ability to incorporate sterols and stanols in food? ratio of sterol to fatty acid in a 1.6g sterol ester? - correct answers - have low solubility in fats so need to esterify them with a fatty acid to increase their solubility - the FA they're attached to makes them heavier in 1.6 sterol ester = 1.0g plant sterols/stanols anf 0.6g fatty acid types of food phytosterols are incorporated in? affect on taste? typical dose in margarine? since when have these products been allowed in canafa? - correct answers - fatty foods like margarine, cream cheese, salad dressing, yogurt - no affect on taste - 1.7g plant stanol/sterol ester per serving of margarine - since 2010 what are benecol softgels? serving? dose amount to meet health claim? what is minute maid premium heart wide? serving? - correct answers - is a dietary supplement in the US that incorporates phytosterol esters - serving in 3 softgels that contains 1.7g plant stanol esters - need 2 doses (3.4g) to meet health claim - orange juice with added plant sterols - serving is 8oz of juice, contains 1g of plant sterols evidence that phytosterols/stanols can help with prostate and colon cancer? mechanism potential? - correct answers prostate - beta-sitosterol inhibits growth of prostate cancer cells - taking beta-sitosterol in humans improved symptoms associated with benign prostate hyperplasia colon - inhibited colon cell and colon cancer cell proliferation - potential mechanism may include membrane structure, fluidity, integrity, enzymes, signal transduction, apoptosis, and effects on neutral and acidic sterols in the colon how have phytosterols/stanols been shown to improve immunity? - correct answers - BSS and it's glucoside BSSG can be immune modulators - inc proliferation of lymphocytes with anti-inflammatory properties - improved TB recovery, HIV, arthritis biggest safety concern of phytosterols on fat soluble nutrients? evidence? factor to consider? what 2 vitamins does it not affect? - correct answers - they can reduce absorption of fat soluble vitamins - have shown to dec nutrients like beta-carotene, vit e - timing bc would maybe only affect nutrients consumed with the phytosterols, not before or after - doesn't seem to affect vit k or vit d phytosterolemia - what is it - cause - symptoms - correct answers - an inborn error of phytosterol metabolism that causes one to absorb more than normal - inability of intestine to distinguish btw cholesterol and plant sterols and can't excrete sterols rapidly in bile - reduced cholesterol 7a-hydroxylase activity - caused by high conc of phytosterols, 50-60x higher than normal - reduces whole body cholesterol synthesis - causes early onset atherosclerosis what assessments were needed to allow sale of foods containing added plant sterols in canada? what was included in the safety assessment? what did safety assessment conclude? what did health claim assessment study find? what did it conclude? - correct answers - safety assessment - health claim assessment in lowering cholesterol - in safety assessment, did a toxicological assessment for adverse effects at higher doses, included reference safe intakes (3g/day for adults, 1g/day for kids) - concluded that a max of 1g free phytosterols per serving can be added to a list of allowed foods (fat based) - found that with 2g/day of plant sterols, it lowered LDL cholesterol by 8.8% independent of the food matrix - concluded the relationship btw food enriched plant sterol consumption and blood cholesterol lowering and that foods that carry this health claim need to have specific composition criteria what products does the food and drug act include? what is it regulated by? - correct answers - includes products intended for human consumption historically regulated as a food or drug - regulated by health canada and health protection and foods branch (HPFB) 3 branches of the HPFB and what they're for - correct answers 1. therapeutic products programme (TPP) - evaluates safety and effectiveness of drugs, medicinal devices, and biological products 2. food directorate (FD) - evaluates safety and effectiveness of food 3. natural and non-prescription health products directorate (NNHPD) - evaluates safety and effectiveness of products in between foods and drugs aspects that natural health products (NHPs) that need to be regulated - correct answers - product and site licenses - labeling - type of claims - standards of evidence for claims - adverse events reporting - role of healthcare practitioner - distribution and licensing mechanisms - description of the NHP industry infrastructure when was the ONHP/NNHPD created? - correct answers 1999 after release of a report what are the regulatory components of the NHPD? - correct answers - product labeling - product licensing - site licensing - GMPs - reporting on adverse events concerns regarding NHPs? - correct answers - regulations make restrict people's access to NHPs - cost of product licenses and taxes of NHPs could be expensive for manufacturers and thus consumers - GMPs may be too strict, especially with product testing - evidence to support a claim for a schedule a disease should be allowed - claims and standards of evidence need clear guidelines of how they'll be applied - how the NNHPD will develop the framework regarding requirements for products - public and consumers should be able to report adverse effects to the government - need to fit everything on labeling but has limited space, discern what is most important - capacity vs workload of all the applications could cause delays - inc efficiency of the NNHPD response what is schedule a of the food and drugs act - correct answers - the prevention of ads or claims of any food, drug, cosmetic, or device to the public as a treatment or cure of any diseases, disorders, or abnormal physical states included in schedule a - these include arthritis, asthma, prostate cancer, epilepsy, heart disease, liver disease, hypertension, obesity, etc - meant to direct health issues to a medical practitioner what is the main implication of schedule a - correct answers - it delays the advancement of health claim policies what are the 2 concerns about defining NHPs? what are the 2 components of the definition of a NHP? - correct answers - definition needs to draw a line between NHPs and foods and NHPs and drugs - function and substance component what is the function component of the NHP definition? describes substances used for what? what claims can it include? - correct answers - relates to the intent/health effects of the NHP - describes NHPs used in the diagnosis, treatment, or prevention of a disease or its symptoms, restoring function in humans, or maintaining and promoting health/modifying functions in humans - claims can include nutrient function, therapeutic use, and disease risk-reduction what types of substances can be included in the substance component of the NHP definition? what could be an example of what is or isn't an NHP? what else does substance component include? - correct answers - a plant or plant material, fungus, non-human animal material - an extract or isolate of a primary molecular structure which was the same prior to extraction - a vitamin or its salts/derivatives - amino acid or its salts - essential fatty acid - synthetic duplicate of any of the above - a mineral - a probiotic ex. vit d in a supplement is an NHP but vit d in orange juice isn't an NHP - also includes an exclusion list forms or administration of NHPs? what isn't (in the past) considered an NHP? - correct answers - capsule, pill, or tablet - didn't include things in conventional foods what are the 4 contents of the NHP regulatory framework document? - correct answers NHP licenses (product and site), GMPs, labeling and packaging, and adverse reaction report and analysis what are the NHP regulations responsible for? - correct answers - take into consideration existing food and drug regulations - make necessary amendments - ensure that the food and drug regulations won't apply to NHPs what is the licensed NHP database? what does it include? - correct answers - is an inventory of all NHPs that have a license from health canada - includes a products natural product number or homeopathic medicine number, medicinal and non-medicinal ingredients, dosage form, recommended use, and risk info assoc with use what framework are NHPs now under after recent revision? what else is included in this framework other than NHPs? what approach to regulation does this framework take? - correct answers consumer health product framework. includes cosmetics, non-prescription drugs, disinfectant products - takes a risk based regulation approach what are supplemented foods? what can be added to the food? what are the 3 components of the SE regulations? - correct answers prepackaged foods with added supplemental ingredients, has a list of categories included - vitamins, minerals, and amino acids added to form (not an NHP since in food and not a medicinal form - components to regulate are labelling, cautionary statements, and health claims what are phytoestrogens? 3 classes? what are they structurally similar to? - correct answers - non-steroidal plant compounds able to exert estrogenic effects - contains isoflavones, lignans, and coumestans - similar to endogenous and synthetic/anti-estrogren isoflavones - significant food source? - 3 major forms in their glycoside - aglycone forms? - proportion of these in food? - what types of foods could have the aglycone form in it? - correct answers - highest source in soybeans, then legumes, clover - genistin - genistein - daidzin - daidzein - glycitin - glycitein - proportions 60/30/10% - fermented foods like miso could have aglycone instead of glycoside what are isoflavone precursors of daidzein and genistein in clover? where in the body are these precursors converted to isoflavones? - correct answers - daidzein = formononetin - genistein = biochanin A - converted in the intestine since precursors aren't absorbed intakes of isoflavones in asian vs western populations? - correct answers - asian intake about 24-40mg/day while western has 1mg/day what are important concepts for intake estimates? would estimate in glycoside units under or overestimate true isoflavone intake? - correct answers - units, glycoside or aglycone form - would overestimate bc weight of the sugar would make it seem like there's more of the biologically active molecule that in reality what does the isoflavone database aid in? what's one limitation? - correct answers - provides accuracy of intake estimates and related isoflavone intake to disease risk - doesn't give indication about bioavailability absorption and metabolism of isoflavones - correct answers - isoflavone glycosides genistin, daidzin, and glycitin are consumed - in the intestine, glycosides are converted by bacterial enzymes into aglycones genistein, daidzein, and glycitein - aglycones can absorbed or continue on in the intestine - if still in intestine, bacterial enzymes with further break them down into isoflavone metabolites p-ethylphenol, equol, and O-DMA - metabolites can also be absorbed or be excreted what happens to the aglycones when they are absorbed? what form is found in the urine? what must be done when analyzing biological fluids for isoflavones? - correct answers - enter portal circulation to the liver - conjugate with glucuronic acid or sulfate - then travel back into circulation to exert biological effects - aglycones that have been absorbed with appear attached to GA or sulfate in the urine - when analyzing, first need to deconjugate the isoflavone what is equol? why is it unique? - correct answers - a metabolite of daidzein - only 30-40% of the population excretes in/makes it - most potent of the metabolites, binds estrogen receptor with higher affinity - longer half life - inversely assoc with breast cancer - ability to produce or not produce it could impact how one reacts to soy potential health effects of soy isoflavones? - correct answers - cancer, specifically hormone-dependent cancers like breast and prostate - CVD - osteoporosis - menopause - cognitive function what is clover disease? attributed to? - correct answers - fertility problems in female sheep that ate a lot of clover - due to amount of isoflavone precursors present in clover, interferes with ability to reproduce what are some hormonal and anti-hormonal effects reported in humans by isoflavone use? - correct answers - doesn't interfere with fertility - don't exert feminizing effects on men that eat intake similar to asian diet - most effects related to risk of hormone-dependent diseases what receptor do isoflavones bind to? what is their potency compared to endogenous estrogen? how are they able to have an effect? - correct answers - bind to estrogen receptor, are 1/1000 less potent - but have effects since their quantities are much higher, 1000x greater than estrogen so will be able to bind sometimes hypothesis of whether isoflavones have estrogenic or anti-estrogenic effects? what happens with high endogenous estrogen? low? - correct answers - depends on the level of endogenous estrogen already present high - isoflavones compete with estrogen for receptor, but isoflavones are weaker estrogens - would exert a net anti-estrogenic effect bc there's less potency of estrogen low - isoflavones don't need to compete for receptor bc not any estrogen - would had a net estrogrenic effect bc anything is more than nothing how are isoflavones thought to aid in breast cancer prevention? evidence? how does age of exposure link to health benefits of isoflavones? what stages of life do isoflavone exposure show the most protection of cancer? - correct answers - anti-estrogenic effect could reduce risk evidence - lower rates of hormone-dependent cancers in asian population maybe due to higher soy consumption - are bioavailable and can reach the breast milk - early like events contribute toward breast cancer risk so timing/age of exposure to isoflavones may be important - in a study, exposure to isoflavones in prepubertal and adulthood show less tumours than individual stages or no exposure when induced with tumour causing chemical - therefore, combo of exposure in adolescence and adulthood gives the most protection against cancer link btw isoflavone exposure and breast cancer survival and recurrence - correct answers - no assoc/no inc risk or inverse assoc evidence of isoflavone exposure and prostate cancer? what models can be used to study this? - correct answers - tofu intake assoc with 65-70% reduction in prostate cancer risk - can use epidemiological studies, ecological studies, animal models, human studies, meta analyses mechanism of how isoflavones can reduce cancer (risk)? - correct answers - reduces concentrations of reproductive hormones in many ways - antioxidant effects - inhibit tyrosine kinase, angiogenesis, DNA topoisomerases - increase apoptosis how do isoflavones help with CVD? what happens when isoflavones are extracted from soy protein in regards to this? - correct answers - soy protein, not the phytochemical, shown to reduce total chol, LDL chol, and TAGs - isoflavones alone don't affect blood lipid levels, therefore need to be in soy protein in order to exert effects how have isoflavones been shown to help with osteoporosis? population most benefited? - correct answers - bind to estrogen receptor which is a bind component of bone building and breakdown - increases bone formation and decreases bone resorption, ex VKDP osteocalcin - post-menopausal women most at risk bc decline in estrogen leads to osteoporosis - evidence that asian women have lower amount of hip fractures than white women links to soy isoflavones helping with menopausal symptoms. potential issues? - correct answers - alternative to HRT - decreases hot flash requency and severity - issue of the placebo effect - time, since age can change things - subjectivity what are the pharmokinetics of isoflavone bioavailability with food intake? - correct answers - blood levels inc with consumption - then reaches a plateau - means absorption may be a saturable process effects on soy-fed children later in life? - correct answers - high levels of isoflavones but no effect on reproductive abilities - no equol production how do isoflavones impact thyroid function? what populations might be affected by this? - correct answers - they inhibit thyroid peroxidase which is important in making thyroid hormones - competes for iodine, but with fortified products this isn't an issue - can interfere with people without a healthy functioning thyroid and are on thyroid medication - isoflavone interfere with absorption of medication; certain foods also interfere with absorption so need to take in morning on empty stomach lignans - type of phytochemical? - highest food source? - correct answers - phytoestrogen - highest in flaxseed, then whole grains, fruits, vegetables, seeds types of plant lignans? types of mammalian lignans? what is the link btw these? - correct answers plant- in lignan-rish foods - SECO - matairesinol mammalian- in biological fluids - enterodiol - enterolactone - link is that plant lignans are precursors for mammalian lignans absorption and metabolism of lignans? - correct answers - plant lignans in glucoside form like SECO-DG are consumed - in intestine, glucosidases convert them into plant lignan aglycones SECO or matairesinol; these can be absorbed or continue in intestine - lignans still in intestin can be further metabolized by bacterial enzymes into mammalian lignans enterodiol or enterolactone, respectively, and these can be absorbed or excreted potential health benefits of lignans? - correct answers lower breast cancer risk - inverse relationships with dietary intake of plant lignans and urinary excretion of mammalian lignans - related to hormonal and anti-hormonal effects lower cvd risk - flaxseed consumption may lower serum lipid levels coumestans - what type of phytochemical? - food sources? - main form? - correct answers - phytoestrogen - found in sprouts and clover - coumestrol characteristics of glucosinolates - correct answers - sulfur-containing phytochemicals - includes brassica family - chemically stable and biologically inactive - kept in all parts of the plant characteristics of glucosinolate structure? - correct answers - has a thioglycosidic link = glucose attached to a sulfur - has a sulfate group responsible for imparting acidic properties and is counterbalanced by a cation - R group that can be any amino acid 3 classifications of glucosinolates? what are these based on? how many types are there in total? - correct answers - classification based on amino acid precursor attached to R group 1. aliphatic; derived from alanine, leucine, isoleucine, valine, or methionine 2. aromatic; derived from phenylalanine or tyrosine 3. indole; derived from tryptophan - over 100 types exist food sources of glucosinolates? - correct answers - cruciferous vegetables - brassica family (broccoli, cabbage, cauliflower, brussel sprouts, kale) what is the importance of the glucosinolate food composition database? - correct answers - advances knowledge of phytochemicals in relation to disease risk - can get more accurate count of intake how do glucosinolates get absorbed and metabolized? where is this enzyme located in the plant? how is the enzyme and glucosinolate brought into contact? - correct answers - glucosinolates are ingested, some can get absorbed - in the stomach and small intestine, enzyme myrosinase from plant can come into contact and cleave glycosinolate at the thioglycosidic bond - makes the aglycone form - aglycone form is unstable and degrades spontaneously to make biologically active breakdown products called isothiocyanates; sulfate group is released - isothiocyanates can get absorbed or continue through intestine and be absorbed in colon - if reaches the colon and not absorbed, bacterial myrosinase can turn product into metabolites which are absorbed - anything left gets excreted in feces - plant myrosinase located in diff area than glucosinolate - brought into contact by cooking, chopping, harvesting, etc what are isothiocyanates? what are 3 naturally occuring types? - correct answers - breakdown products of glucosinolates - PEITC, BITC, and sulforaphane what factors can affect glucosinolate bioavailabilty? how does this related to supplements? - correct answers - loss during cooking - myrosinase inactivated by cooking or heat or stomach acid - inc by bacterial produce myrosinase - therefore cooked vegetables could have less isothiocyanates than raw - supplements often don't contain active myrosinase, therefore can't do conversion what roles do glucosinolate breakdown products have? what factor could alter their health benefits? - correct answers - toxicological effects - plant defence system - gives sensory quality like taste and flavour to product