Nutrition Midterm #3 (NST10 UC Berkeley), Nutrition Midterm #2 (NST10 UC Berkeley), Nutrition Midterm #1 (NST10 UC Berkeley)

FAT SOLUBLE VITAMINS LECTURE

what are the four major fat soluble vitamins?

A, D, E, K

where are fat soluble vitamins stored?

in fat cells, hard to run out of them if you have them in your body although deficiencies can happen

can you make fat soluble vitamins?

no, need to be in your diet

how do you absorb fat soluble vitamins?

fat soluble vitamins require bile acid for absorption, the small intestine absorbs fat-soluble vitamins similarly to fat absorption (packaged into chylomicrons)

what forms does vitamin A come in?

retinal or retinoic acid

retinal is involved in the visual cycle

retinoic acid regulates expression of hundreds of genes to control cell function

how do you get vitamin a?

you have to eat it in things that contain carotenoids like carrots

what does vitamin A deficiency lead to?

- night blindness

- visual issues

- skin health - retinoic acid can treat severe acne

- reproductive health

- if super severe, testes degeneration

how do you get vitamin D?

with enough sunlight, you do not need dietary vitamin D - you can either eat it or convert in your skin the pre-form of vitamin D (7-dehydrocholesterol)

what parts of your body convert the pre-form of vitamin D to be used effectively?

converted first by the liver and then by the kidney to the active form

calcitriol is the active form

if you have a kidney disease or liver disease you will have low vitamin D bc it is not being converted properly

what does vitamin D help you absorb?

calcium from the diet

what does vitamin D deficiency lead to?

infections (influenza, tuberculosis, respiratory tract infections), lung disease, autoimmune diseases, various kinds of cancer

what is vitamin K?

a cofactor in enzymes that activates proteins required for: blood clotting, blood vessel repair, modulating bone density, preventing soft-tissue calcification

what happens when you bleed if you run out of vitamin K?

you will not stop bleeding

how do you fix vitamin K deficiency?

supplementing it can fix deficiency really quickly

what is vitamin E and what does it do?

vitamin E is the most potent lipid-soluble anti-oxidant known

protects polyunsaturated fatty acids, low density lipoproteins, and membranes from oxidative damage

which fat-soluble vitamin is most common to have a deficiency for?

D

PROTEIN DISCUSSION

what are the most important functions of proteins?

structure: connective tissues require collagen and keratin

enzymes: facilitate biochemical reactions

transport: transporting substances into and out of cells

protection: antibodies, immune system, barrier against injury and infection

contractile proteins: allow muscles to move

also peptide hormones, fluid balance, and pH balance

how many grams on average does an adult need per day?

40-80g

what are the times in your life where you need more protein?

infancy, pregnancy, breastfeeding, injury/illness

how do protein needs differ for active people?

most active people need .8g/kg/day for their body weight

for the general population, consuming additional protein does not enhance performance if exercise is not present

can too much protein cause problems?

too much protein can lead to dehydration and kidney damage and can also be really expensive

what do complete proteins have?

all 9 amino acids

what do incomplete proteins have and what are complementary proteins?

incomplete are missing at least 1 essential amino acid

complementary proteins are foods that if you eat them together you cover all 9 amino acids

what are the pros and cons of vegetarianism?

Pro:

Lower body weight

Reduced risk of type 2 diabetes

Reduced risk of heart disease

Lower blood pressure

Better digestive health

Reduced risk of some cancers

economic/environmentally friendly

Vegetarian protein souces are generally cheaper!!

Cons:

Easy to be deficient in some nutrients such as protein, vitamin B12, calcium, vitamin D, iron, zinc, omega 3 fatty acids

Difficult to eat in certain social situations

Junk food can be vegetarian

WATER SOLUBLE VITAMINS LECTURE

what are the classifications of water soluble vitamins?

dissolve in water, no real stores, readily excreted, absorbed by portal system, not required daily, high doses can be toxic, subject to cooking and food storage losses

what are the functions of water soluble vitamins?

coenzymes and antioxidants

what are the main water soluble vitamins?

B complex and vitamin C

how do you get these key water soluble vitamins?

required in diet

deficiencies used to be common but are rare now at least in the US because of mixed diets and enrichments of food supply

how can water soluble vitamins be lost?

natural vitamins are the tissue or food forms, often less bio-available than synthetic vitamins because synthetic vitamins are usually the transport form

losses can occur in food preparation, storage, and cooking

ex: removing husks to make grain/cereal products takes away a lot of the vitamins

can you store water soluble vitamins?

no you can't store them in your body which is why large doses can be really toxic

what are the four reference key values of a Dietary Reference Intake value?

estimated average requirement (EAR)

recommended dietary allowance (RDA - satisfies 97.5% of healthy ppl)

adequate intake (AI)

tolerable upper-intake level (UL)

what does vitamin C (ascorbic acid) do?

forms collagen which is the framework of bone, skin, and gums

anti-oxidant

helps with immune function

hormone and neurotransmitter synthesis

what are good sources of vitamin C?

fruit juices, fruit, spinach, asparagus

what does vitamin C deficiency lead to?

scurvy, loss of appetite, retarded wound healing, bleeding gums and capillaries

what is folate, what does it do, and what are the potential impacts of deficiency?

helps with the synthesis of nucleotides involved in RNA and DNA synthesis and DNA repair

causes macrocytic anemia if deficient and can also be associated with increased cancer risk

sources: fortification/enrichment, liver, spinach, lentils, oatmeal, asparagus, leafy green veg.

what is the key birth defect that comes from folate deficiency?

spina biffada - incomplete closure of the neural tube in the lower back

what is B12, what does it do, and what are the potential impacts of deficiency?

B12 is a coenzyme for amino acid catabolism and maintains myelin sheath of nerve fibers

deficiency causes pernicious anemia and demyelination of the spinal cord, can also cause vascular disease

sources: only available in animal sources, algae, and bacteria - normal diets usually don't have an issue, vegans need to supplement

what is niacin/vitamin B3, what does it do, and what are the potential impacts of deficiency?

comes in two forms - nicotinamide and nicotinic acid - it is a coenzyme that helps with the metabolism of carbs, proteins, and fats

deficiency leads to pellagra, diarrhea, dermatitis, dementia, and potentially death

tryptophan is a supplement that can help reduce the need for niacin

coffee contains high levels of niacin

what is vitamin B6 (pyridoxine), what does it do, and what are the potential impacts of deficiency?

it is a coenzyme for over 100 enzymes in amino acid metabolism and is required for removing nitrogen to form amino acids

deficiency leads to dermatitis, anemia, or convulsions if severe because you can have impaired neurotransmitter synthesis from amino acids

good sources: enriched cereals, meat, fish, poultry, starchy veg

what is thiamin (B1), what does it do, and what are the potential impacts of deficiency?

required for metabolism of carbohydrate and branched-chain amino acids and production of DNA and RNA

deficiency leads to Beriberi - damage to nervous system, heart, and muscle weakness

what is riboflavin (B2), what does it do, and what are the potential impacts of deficiency?

helps in oxidation-reduction reactions in metabolism

good sources: milk, enriched foods, meat

deficiency: sore throat, swollen mucous membranes, dermatitis, stunted growth

what is biotin, what does it do, and what are the potential impacts of deficiency?

important for gluconeogenesis and fatty acid synthesis

deficiency only seen with large consumption of raw egg yolks over time

what is pantothenic, what does it do, and what are the potential impacts of deficiency?

required for synthesizing cholesterol, steroids

good sources: chicken, beef, egg, potatoes, oat cereals, tomato

deficiencies are very rare

MUSCLE BIOLOGY & THE PHYSIOLOGY OF EXERCISE & SPORT LECTURE

what does resistance exercise entail?

duration of seconds not minutes, power athletes have large muscle mass, fat is variable

power activities are highly dependent on effort, difficult to assess clinically

what does aerobic exercise entail?

duration longer than seconds, intensity less than VO2 max

improved "fitness" which is measurable by oxygen use

what are the metabolic alterations associated with fitness?

improved insulin-mediated glucose utilization, reduced blood TG, higher HDLc, altered clotting factors, lower resting pulse, reduced body fat, reduced weight, higher ratio lean body to fat mass, reduced visceral fat mass

what are some factors that increase muscle ANABOLISM?

amino acids, carbs, insulin effects, testosterone, muscle tension, genetics - some have higher stretch, protein, hormones etc.

what are some factors that increase muscle CATABOLISM?

amino acid deficiency, insulin deficiency, carb deficiency, thyroid hormone, glucocorticoids

what increases aerobic capacity?

endurance exercise training, high altitude, increased hematocrit (erythropoetin), genetics

what is the debate around the efficacy of nutritional supplements for exercise performance?

mostly cannot be shown to have any advantage in proper controlled studies, that said creatine is the most well-proven one that has minimal adverse affects

caffeine can also help with some activities

what are some consequences of performance enhancing drugs?

very low HDLc, mood liability, acne, hair growth, breast shrinkage, liver tumors, loss of endogenous sex hormones, changes in libido, premature stop of bone growth, permanent changes in female vocal chords

what is the objective of blood doping - how does it work and what are the consequences?

objective is to increase oxygen carrying capacity of blood to exercising muscles

can be achieved legitimately by training at altitude

erythroprotein is the hormone used

consequences: blood sludging, strokes

what is another use of some performance-enhancing drugs?

there can be therapeutic uses for erythropoetin

NUTRITION & EXERCISE - FUELS FOR ATHLETIC PERFORMANCE LECTURE

what are the three fuels for energy production?

carbohydrate, fat, amino acids

how does the rate of glycogen utilization change with exercise intensity?

glycogen utilization by muscle increases with exercise intensity

muscle glycogen depletion results in fatigue

brief summary of glycogen depletion:

glycogen is a long strain of glucose molecules

even the leanest marathon runners have enough fat to run from berkeley to LA but we only have 2500 calories as carbohydrate and once we run out of that despite fat fuel we cannot exercise any longer

how does caffeine impact exercise?

it decreases reliance on glycogen as fuel

decreases rated percieved exertion at the same absolute exercise intensity

enhances prolonged endurance performance and high-intensity short-duration exercise

how does creatine impact exercise?

can help short term and long term improvement

short term it can improve strength and power by 5-15%

long term there are greater gains in strength, sprint performance, and FFM during training

side effect = weight gain

CARCINOGENESIS LECTURE

what are the two driving forces in carcinogenesis?

mutagenesis - genetic mutation (initiation phase)

mitogenesis - cell division (promotion or progression) increases the likelihood of mutated cells becoming cancer

what is the recommendation for carcinogenesis prevention?

the pathogenic goal is to prevent genetic damage (the initiation phase) and or slow cell division (promotional phase)

how does a tumor grow?

repeated rounds of mutation - fixation - expansion

one cell can accumulate many mutations by growth advantage and clonal expansion of cells with initial mutations - the daughter cells are then targets of new mutation

what is the leading risk factor of cancer?

age - it takes a long time for carcinogenesis to develop

how was gastric cancer defeated?

electricity led to refrigerators which led to more access to fresh fruit and then also refrigerated trucks allowed us to transport it all over

carcinogenesis was reduced in the stomach because of better diet

how was cervical cancer defeated?

gradually figured out that cervical cancer is an STD via HPV

big breakthrough was the pap smear - you could see atypical cells from cervical scrapings and treat pre-cancer which is very effective

what is responsible for the reduction in lung cancer deaths?

still by far leading cause of cancer deaths in US

fall in smoking rates almost exactly parallels the fall in lung cancer rates

what is dietary chemoprevention?

pathogenic goal to modify dietary intake to prevent genetic damage and or slow cell division (initiation or promotion phases of carcinogenesis)

how do carcinogenic mechanisms work in nutrients?

chemicals in food can generate free radicals or otherwise cause genetic damage - increases cell division by providing a growth stimulus

a key example of this is cooking meat at high temperatures - searing it and making it black

what are some chemoprevention mechanisms?

anything that increases proliferation rate of epithelial cells can be a tumor promotor

examples:

estrogens and mammary epithelial cells

androgens and prostate epithelial cells

inflamation and colon cancer etc.

what are dietary chemopreventitives?

soy is a powerful cancer supressor

cruciferous vegetables (broccoli, brussel sprouts, cabbage, cauliflower)

green and black tea

calorie restriction

what happens when humans metabolize ethanol?

When humans metabolize ethanol, the process primarily occurs in the liver through a series of enzymatic reactions. The main enzyme involved in ethanol metabolism is alcohol dehydrogenase (ADH), which converts ethanol to acetaldehyde. Acetaldehyde is then further metabolized to acetate by the enzyme aldehyde dehydrogenase (ALDH). Finally, acetate is converted to carbon dioxide and water, which can be easily eliminated from the body.

is ethanol energy converted to fat in the human liver?

Yes, excess ethanol consumption can lead to the conversion of ethanol-derived energy into fat in the human liver. When you consume alcohol, the body prioritizes the metabolism of ethanol over other nutrients. The primary pathway for ethanol metabolism occurs in the liver, where alcohol dehydrogenase (ADH) converts ethanol to acetaldehyde, which is then further metabolized to acetate by aldehyde dehydrogenase (ALDH).

short: fatty acids can then be incorporated into triglycerides which leads to the accumulation of fat in the liver

can animals metabolize ethanol? why?

yes, enzymes that metabolize ethanol are found in almost all mammals

alcohol is produced by yeast under low oxygen conditions and allows animals to metabolize glucose and get some energy while disposing of excess reducing equivalents

how long does it take to reduce blood alcohol content?

if you start with a blood alcohol content of 0.100%, you will fall linearly to ~0.070% after 4 hours

what are the global health consequences of alcohol intake?

estimated 3 million alcohol attributed deaths and 131.4 million disability adjusted life years

CALCIUM AND BONE DENSITY LECTURE

what are cells mostly made of?

water

the body is also mostly made of water

what are the most abundant proteins in the body?

actin-myosin in skeletal muscle and collagen in bone

how do calcium and phosphate contribute to bone?

calcium and phosphate form calcified bone around the primary structural protein, collagen

calcium balances in the body can influence bone mass and strength and the risk of fractures

What is osteoporosis?

the most prevalent modern disease of bone and reflects reduction in bone mass (both collagen and calcium)

osteoporosis increases in prevalence with age and is much more common in women - result is increased risk for bone fractures

what are some of the key functions of calcium in the body?

nerve conduction involves calcium fluxes across cell membranes

many intracellular signaling pathways involve calcium

can also play an essential role in protein structure and action - contraction too

what is the parathyroid hormone?

A hormone that is secreted if Ca+2 levels fall. PTH gene is turned on and more is secreted from the gland. Osteoblast activity also increases and the kidneys produce calcitriol.

what is the relationship between calcium homeostasis and vitamin D?

active vitamin D stimulates calcium and phosphate absorption by the intestine - vitamin D can be obtained from diet or synthesized by the skin, using UV in sunlight

what is the daily recommended calcium intake for adults?

1,000 mg a day

for adolescents: 1300

for older than 51: 1200

what foods contain calcium?

dairy, beans, some green veg

what is the paradox of bone density and athletics in female athletes?

the loss of bone mass in some female athletes is paradoxical because despite the weight bearing activity of something like running, amenorrhea/estrogen deficiency due to underweight greatly reduces bone mass

how does weight bearing activity impact bone?

weight bearing stimulates deposition of bone - heavier people tend to have greater bone mass than lighter people

what are the medical consequences of too high or low levels of calcium or phosphorus?

hypercalcemia = fatigue, coma, death

hypocalcemia = muscle spasms, seizures

hyperphosphatemia = diseases due to excess intake of P

hypophosphatemia = muscle weakness, pain from too low phosphorus intake

YAY GO TEAM

MIDTERM 2 KEY CONCEPTS

I am just turning the study guide into a quizlet, I think last time I focused on too many of the little details and the bigger ideas so we can apply them would be more helpful :)

SECTION 1: Hellerstein's Lectures & his study guide (section 2 will be more random with all the guest lectures on pregnancy etc.)

how long can we starve and stay alive?

very long, we are super good at starving. you can usually survive 60-90 days or more if hydration and electrolytes are maintained

this has been shown in hunger strikes in prison, people stranded without food etc. newspapers show up after 30-45 days

how is it possible to starve for so long?

you can reduce nitrogen losses to 20g/protein a day (3gN)

this means that you would only lose 100g of lean tissue each day instead of 500 which is the usual

how does growth factor get compromised when starving?

you can't produce as much because growing is super energy intensive so you can get stunted if you are consistently starving -- this is also part of why population height average has continually increased as we have more consistent food availability and less war, famine etc.

how is the reproductive system impacted by starving? (gonadotropins, gonadal function)

especially prominent for females and female athletes

menarche - first period delayed

anorexia nerviosa

breast cancer