Nutritional and Toxicity Flashcards
When is AREDS useful?
moderate to late stage AMD
What effect does AREDS supplementation have?
25% risk reduction of progression to advanced AMD; or 20% risk reduction over 5 years
What was the probability of progression to advanced AMD with placebo vs antioxidants + zinc?
placebo 28% and antioxidant + zinc 20%
What is category 1 from the original AREDS study?
no AMD or small drusen <63 um or drusen collectively < 120 um
What is category 3 from the original AREDS study?
concern intermediate drusen < 125 um = 1/2 diameter of retinal vessel at ONH per Dr. Wolfe
When should you start AREDS supplementation based on category?
category 3
What is category 4 from the original AREDS study?
wet AMD in one eye w/ any stage of AMD in the fellow eye
Drusen vs RPE drop out
drusen have shadow around it since it’s sub-RPE while RPE dropout is sharply demarcated
With drusen in one eye and geographic atrophy in the other, do you recommend AREDS?
yes
When is it hard to visualize geographic atrophy?
with blonde fundus, utilize AF or red-free
With geographic atrophy in both eyes do you recommend AREDS?
No, refer to low vision
What color is a sub-retinal heme?
gray-green per Dr. Wolfe
What color is the breakthrough heme?
red
What technology should you order with a sub-retinal heme?
OCT and IVFA
With drusen in one eye and unremarkable findings in the other do you recommend AREDS?
yes
What is the difference between AREDS 1 and 2?
2 removed vit A and added lutein and zeaxanthin
What is culinary medicine?
evidence-based field in medicine that blends the art of food and cooking with the science of medicine
What is the goal of culinary medicine?
help people reach good personal medical decisions about accessing and eating high-quality meals that help prevent and treat disease and restore well-being
Culinary medicine does not..
have a single dietary philosophy, reject prescription medication
What might an anti-inflammatory diet be good for?
rheumatologic disease
What is a ketogenic diet good for?
neurological disease
What is a mediterranean diet good for?
cardiovascular and metabolic disease
What condition is legumes good for?
hyperlipidemia
What condition is soy nuts good for?
hypertension
What condition are tree nuts good for?
metabolic syndrome
What condition is baked fish good for?
heart failure
What condition is honey and milk good for?
acute cough
What was the first medical school with culinary medicine?
Tulane
What 2 genes are associated with AMD?
CFH and ARMS2
What is CFH?
a gene dealing with complement and immune response/inflammation
What is ARMS2?
a gene dealing with oxidative stress
What is a healthy diet for prevention of AMD?
carotenoids, fish and nuts, supplements, normal weight, no smoking, exercise
High total fat intake leads to
3 fold higher risk for progression of AMD
High saturated and trans fat leads to
2 fold increase in AMD progression
High Omega 3 leads to
reduced AMD progression by 25-40%
What were the nutritional differences between the discordant twins?
lower intake of vit D, betaine and methionine
T/F omega 3 intake is associated with lower risk of progression to geographic atrophy
true, mostly in those with ARMS2
What is a mediterranean diet and when is it beneficial?
high intake omega 3 and low saturated fats, benefit if one non-risk CFH allele (no benefit for CFH homozygous risk genotype
T/F vitamin D intake had significantly lower risk of progression
true
When does AREDS hurt you?
patients with high CFH and no ARMS2 risk alleles increased progression to NV compared to placebo
When does AREDS help you?
those with low CFH and high ARMS2 risk had decreased risk of progression with AREDS
T/F vitamins are cofactors (coenzymes) essential for many biochemical reactions necessary for cell survival
true
How many vitamins are universally recognized?
13
What are vitamins classified based on?
biological and chemical activity (function), not structure
Where are water-soluble vitamins stored?
not stored in the body, can be depleted within a number of days during starvation
Where are fat-soluble vitamins stored?
carried in fat and stored in liver, excess storage may lead to toxicity
What are water-soluble vitamins?
Bs, C, and folic acid
What are fat-soluble vitamins?
ADEK
What is vitamin A?
retinol, fat soluble, found in animal products
What are the vitamin A vitamer compounds?
retinol, retinal, and four carotenoids
What is the precursor for vitamin A in carrots and other orange vegetables?
beta-carotene
What are vitamin A roles?
develop and maintain epithelial tissue, component of goblet cells, prevents keratinization and squamous metaplasia by controlling rate of ocular surface cell proliferation and differentiation, antioxidant
Where ocularly is vitamin A stored?
within the lacrimal gland
How is vitamin A secreted from the lacrimal gland?
reflexively through aqueous layer of the tear film as all trans-retinol
T/F vitamin A is an antioxidant
true, but studies show carotenoids may undergo oxidation leaving byproducts in the lungs and arterial blood
Vitamin A and smoking
caused oxidative damage and tumor growth in smokers and those exposed to second-hand smoke; vit A removed after AREDS 1
What are free radical examples?
superoxide, peroxide, singlet oxygen and hydroxyl radicals
Where are free radicals found?
in tissues with high metabolic demands ex: lens
What cell produces oxygen species as a defense?
neutrophils
T/F free radicals are in hypoxic or hyperoxic cellular conditions
true
How do antioxidants help?
donate an electron to free radicals neutralizing it
3 additional functions of vitamin A
mediator for gene transcription, component in bone metabolism and hematopoiesis, component of rhodopsin and iodopsin
What are visual pigments made of?
opsin (membrane apoprotein) + chromophore (11-cis retinal)
Where is vitamin A oxidized?
diffuses through the choriocapillaris to the RPE where it is oxidized to 11-cis retinal
What happens when 11-cis retinal absorbs a photon of light?
phototransduction is initiated
Vitamin A deficiency causes
inadequate intake, fat malabsorption or liver disorders
What is recommended daily dose of Vitamin A?
900 micrograms aka 3000 IU for men and 700 micrograms aka 2300 IU for women
Systemic vitamin A deficiency
immunity impairment, impairment to hematopoiesis with potential for anemia, rash
What is a major cause of blindness in underdeveloped countries?
vitamin A deficiency
What is xerophthalmia?
cornea and conjunctiva become keratinized from excessive dryness
What are signs of xerophthalmia?
conj looseness, folds, pigmentation, decreased luster, poor wetting, mucin-secreting goblet cells affected
What is nyctalopia?
night blindness from vitamin A deficiency, rods affected before cones
What is an initial sign of nyctalopia?
lengthened dark adaptation time, once cones are affected: loss of central acuity and color vision
What is a bitot’s spot?
clump of keratin debris within the conjunctiva as a result from dryness
What is keratomalacia?
secondary to chronic dryness that leads to necrosis and ulceration of the cornea, need corneal graft surgery
T/F a severely dry cornea can perforate w/in 24 hours
true
Vitamin A excess systemically
dizziness, HA, hypercalcemia, liver damage, nausea, hair loss, oily skin, joint pain, sore throat, yellow discoloration of the skin (aurantiasis cutis)
Vitamin A excess ocularly
blurred vision, diplopia, nystagmus, nerve palsies, papilledema
What is vitamin C?
ascorbic acid, water soluble, must be ingested, potent antioxidant
What vitamin is a cofactor in collagen synthesis?
vitamin C
Functions of vitamin C
formation of connective tissue, protect capillaries, minimizing hemorrhages, enhances iron absorption, promotes wound healing, healthy gums/teeth/bones
Why do you want good collagen in Bruch’s?
prevent formation of drusen
What vitamin does vitamin C recycle?
E
Where is the highest concentration of vitamin C found in food?
citrus fruits, green vegetables, tomatoes, potatoes, cantaloupe
What are early systemic signs of vitamin C deficiency?
bruising, petechial hemorrhages, weakened hair or nails, low resistance to infection
What are advanced signs of vitamin C deficiency?
scurvy: collagen defects, impaired healing, bleeding into joints, swollen and bleeding gums, impaired digestion, brittle bones, psychological changes
What can decreased vitamin C intake result in?
anemia, decreased ability to fight infection, decreased wound healing rate, swollen painful joints, weakened tooth enamel
What are ocular signs of vitamin C deficiency?
hemorrhagic conjunctivitis, petechial hemorrhages, hyphema
What is vitamin E?
fat soluble, antioxidant, must be absorbed from diet
What is the least toxic vitamin?
E
What vitamin protects vitamin A?
E
What is the role of vitamin E?
critical in cell membranes, boosts immune system, widens blood vessels/reduces thrombin formation, reproductive/neurologic/muscular systems
What medication should you be careful with when taking vitamin E?
anticoagulants like Warfarin
What foods contain vitamin E?
vegetable oils, nuts, seeds, and green leafy veggies
What disease is vitamin E deficiency linked to?
diseases where fat is not properly digested or store, ex: crohn’s disease, cystic fibrosis, genetic disease like abetalipoproteinemia
T/F vitamin E deficiency is more common in premature babies
true, low plasma levels of vitamin E leading to levels decreasing rapidly due to lack of adipose tissue
What is the recommended dietary allowance of vitamin E?
15 mg/day for adults
What are signs of ocular vitamin E deficiency?
night blindness (vit A not protected), lipofuscin formation, drusen, increased risk for AMD, lens opacification
What is lipofuscin?
waste product when rods/cones die; forms within RPE cell, damaging the RPE cell membrane
What is zinc for?
antioxidant; metabolism of nucleic acids, proteins, carbs, alcohol; required for DNA/RNA synthesis and vitamin A use
What mineral is used in axoplasmic flow throughout neurons?
zinc
What are sources for zinc?
milk, eggs, poultry, seafood, red meat, onions, peas, soybeans, mushrooms, whole grains, nuts, seeds
What are systemic signs of zinc deficiency?
lack of taste or smell, dry irritated skin, poor appetite, fatigue, infections, hypogonadism, loss of hair, slow growth, problems with wound healing
What are systemic signs of excess zinc?
diarrhea, abdominal cramps, vomiting
What are ocular signs of zinc deficiency?
AMD, optic neuropathy, symptoms of vit A deficiency, low IOP
T/F zinc metabolizes retinal byproducts by the RPE cells
true
How can zinc deficiency optic neuropathy occur?
many drugs are zinc chelators
Why might you have symptoms of vit A deficiency with a zinc deficiency?
zinc metabolizes vit A, maintains normal serum vit A by mobilizing it from liver, transforms retinol to retinaldehyde for use by rods
How are IOP and zinc related?
zinc involved in aqueous production, coenzyme of carbonic anhydrase
Why was copper added to the AREDS formula?
zinc chelates copper, so copper was added to replenish the copper supply
How many naturally occurring carotenoids are there?
600, ~50 in a western diet, and 14 in vivo (human serum)
Macular pigment is the collective name for…
isomeric carotenoids lutein and zeaxanthin
T/F carotenoids are accumulated within the sensory retina at levels 1000x higher than found in serum to the exclusion of all other carotenoids
true
What factors affect serum levels of carotenoids?
serum level decreased by body fat, oxidative stress/smoking, female gender, dietary fat
What are carotenoids transported on?
circulating lipoproteins, slightly higher affinity for HDL
What are the 3 theories of carotenoids?
optical, protection and neuro efficiency
What is the optical hypothesis of carotenoids?
halo found around fovea because it absorbs stray blue light that gives you clarity of vision
What is the protection hypothesis of carotenoids?
reduces oxidative stress, carotenoids span the lipid bilayer and help maintain structure and integrity of the cell membrane
What is the neuro efficiency hypothesis of carotenoids?
unknown moa
What does research on mediterranean diet and AMD show?
no significant association with early AMD, but associated with reduced odds of neovascular AMD
What are 2 main nutritional optic atrophy etiologies?
excess vitamin A and avitaminosis B
What is ethambutol etiology?
toxic optic neuropathy that is dose dependent and duration related, chelating properties, symptoms appear 4 months- 1 year, 25 mg/kg/d, test color vision
What is isoniazid etiology?
toxic optic neuropathy, higher risk with hepatic or renal disease, vision loss, central or cecocentral scotoma, dyschromatopsias
What is amiodarone etiology?
treatment for arrhythmias, unclear moa maybe lipidosis, insidious visual loss, bilateral, persistent ONH edema
B Vitamin overview
water soluble, cannot be stored in the body, important role in cell metabolism, rarely leads to toxicity
What is the role of b1?
thiamine, co-enzyme that converts carbohydrates into glucose, used in heart muscle digestion and nervous sytem, synthesis of acetylcholine
What are sources of b1?
whole grain cereals, beans, nuts, peas, oranges, brewer’s yeast
Where is b1 deficiency endemic?
east asia, due to large consumption of refined white rice
Who gets b1 deficiencies?
poor dietary intake, alcoholics, institutionalized, GI syndromes
What are signs of early b1 deficiency?
impaired digestion of carbs and constipation
What are signs of chronic b1 (thiamine) deficiency?
beriberi, wernicke encephalopathy, Korsakoff’s psychosis, death
What is beriberi?
anorexia, cardiac enlargement, tachycardia, muscular weakness, ataxia, paresthesia , dyspnea upon exertion
What is Wernicke encephalopathy?
severe, acute deficiency, chronic alcoholism or malnutrition, dementia, ataxia, ophthalmoplegia with nystagmus, mild confusion to coma
What is Korsakoff’s psychosis?
cerebral cortex damage
What are ocular signs of deficiency of b1?
restricted EOM motility, anterior or retrobulbar optic neuropathy, nystagmus, toxic optic neuropathy, ophthalmoplegia
What is vitamin b2 for?
riboflavin, essential for metabolism of carbs, fatty acids and amino acids; tissue repair, formation of antibodies, mucous membranes, enhancing efficacy of vitamin D,
Who gets deficiencies of b2?
low socioeconomic status, elderly recluse, alcoholic, oral contraceptive and diuretic use, hemodialysis, processed foods, exposure to UV light, stressed
What are sources of b2?
milk, whole grain cereals, daily, liver, beef, eggs
What are signs of systemic deficiency of b2?
rare, nonfatal symptoms after 3-4 months, angular stomatitis, seborrheic dermatitis, glossitis
What are signs of ocular deficiency of b2?
conj injection, corneal vascularization, keratitis sicca, SPK, interstitial infiltrates, ulceration, decreased light adaptation, cataracts
What are 3 ocular conditions from low b2?
phlyctenular keratoconjunctivits, rosacea keratitis, angular blepharoconjunctivitis
What are two things that cause angular blepharoconjunctivitis?
vitamin b2 deficiency and moraxella infection
What is the treatment of vit b2 deficiency?
single IM injection or daily oral dose until resolution, maintenance doses
What is vit b3?
niacin, coenzyme for oxidoreductase, used for carbohydrate/amino acid/lipid metabolism, able to synthesize in vivo from tryptophan
What are sources of b3?
brewer’s yeast, meats, brain, liver, legumes, corn
What is a chronic deficiency of b3?
pellagra– skin lesions, diarrhea, dementia
What are signs of b3 excess?
elevated HDL levels, niacin flush, niacin maculopathy (1-3 g)
What are functions of b6?
pyridoxine, amino acid metabolism, synthesis of neurotransmitter (serotonin, melatonin, dopamine, NE, GABA)
What are sources of b6?
high protein: meats, nuts, whole grains, cabbage, peas, bananas, pears
What are ocular b6 deficiencies?
gyrate atrophy, seborrheic dermatosis, angular blepharoconjunctivitis
What is vitamin b12?
cobalamin, synthesized by microorganisms in fermented foods, absorbed with intrinsic factor
What are functions of vitamin b12?
active in all cells, essential for cellular replication, bone marrow and GI tract; metabolism of folate, myelin sheath formation, DNA synthesis
What are sources of b12?
meat (liver)
What deficiency are vegans at a higher risk for?
b12
T/F a gastrectomy can lead to deficiency in b12
true
What are systemic signs of deficiency of b12?
pernicious anemia, neurological dysfunction
What is pernicious anemia?
macrocytic normochromic, characterized by megaloblastic anemia (impaired DNA synthesis) + folate deficiency
What are ocular signs of b12 deficiency?
can precede systemic findings, hemorrhages, CW spots, tortuous blood vessels, ON damage, palor or neuropathy
What is treatment of b12 deficiency?
enhanced diet/supplements, increase iron and folic acid intake; b12 injections w/ pernicious anemia
What is treatment of b12 deficiency if optic neuropathy present?
supplement entire b complex not just b12
Why is temporal pallor often first?
propensity for papulomacular bundle since most metabolically active
What is the acronym for optic neuritis involvement?
VIN DITTCH, MD
