Nutrition Chapter 8

superoxide

a molecule with one unpaired electron which makes it a free radical

hydrophilic antioxidants

act in the cytosol of cells or in extracellular fluids such as blood

most notable function of Vitamin A is in the retina of the eye where they...

aid in vision, especially in low light conditions. Insufficient intake over time can cause complete vision loss.

What micronutrient and phytochemical sources are best at protecting against chronic disease?

all of them, together!

Free radicals, unstable molecules with unpaired electrons, are what?

an unavoidable byproduct of cellular metabolism.

lignans

are a group of chemical compounds obtained from many food sources, including grains, nuts, seeds, fruits, and vegetables, and especially flax seed. - some may be helpful in treating hormone dependent cancers like breast and ovarian.

phytochemicals

are chemicals in plants that may provide some health benefits. Many act as antioxidants.

hydrophobic antioxidants

are largely responsible for protecting cell membranes from free radical damage

carotenoids

are pigments synthesized by plants that give them their yellow, orange and red color.

atoms

are the basic building blocks of all matter, living and non-living.

What are the signs and symptoms of Vitamin A toxicity?

dry, itchy skin, loss of appetite, swelling of the brain, and joint pain. In severe cases, may cause liver damage and coma.

superoxide dismutases SOD

during SOD-mediated enzymatic catalysis, 2 superoxides are converted into hydrogen peroxide and oxygen.

electrons contain _________, and this is stored within the _________ and movements of electrons and the bonds atoms make with one another.

energy; charge.

What are free radical detoxifying enzymes responsible for?

for protecting the insides of cells from free radical damage.

lutein and zeaxanthin

found in great leafy veggies, and peppers, corn, and saffron, act as antioxidants in the retina of the eye and protect it from UV light damage

What are the bodies two major defense systems?

free radical detoxifying enzymes and antioxidant chemicals

lipoic acid

free radical scavenger, aids in regeneration of Vitamin C and E

carotenoids

free radical scavengers

phenolic acids

free radical scavengers, protect cellular membranes

atoms and molecules such as superoxide that have unpaired electrons are called this...

free radicals - those containing oxygen are more specifically referred to as reactive oxygen species.

why does the reactivity of free radicals pose a threat to macros like DNA, RNA, proteins, and fatty acids?

free radicals can cause chain reactions that ultimately damage cells and can continue unchecked unless stopped by a defense mechanism.

What are the two antioxidant chemicals that the body synthesizes?

glutathione and uric acid

antioxidants are broadly classified into what two groups?

hydrophilic which is water soluble, and hydrophobic which is lipid soluble. This determines where they act in the body.

catalase

in cells, catalase enzymes are found in high numbers and continuously patrol for hydrogen peroxide molecules.

Overcooking can transform some of the carotenoids into what?

inactive products

What happens when an electron escapes?

instead of completing the cellular respiration cycle, they are transferred to an oxygen molecule.

antioxidant

is any molecule that can block free radicals from stealing electrons; these act both inside and outside of cells.

Can the body synthesize antioxidants?

it can for some but others must be obtained from the diet.

RDA for vitamin A intake for adults over 19 years old?

males is 900mcg/day and females is 700mcg/day

What are 4 essential cofactors for enzymes involved in detoxifying free radicals?

manganese, iron, Cooper, and zinc. - in proper doses they allow for optimal detoxification of free radicals - in excess and when not bound by proteins, they accelerate the production of free radicals.

electrons charge

negative charge

neutrons charge

no charge

protons charge

positive charge

What are some functions of selenium?

protecting endothelial cells that line tissues, converting the inactive thyroid hormone to the active form in cells, and mediating inflammatory and immune system responses.

Vitamin C in the diet

protects DNA, RNA, proteins, and lipids, aid in regenerating vitamin E

vitamin E in the diet

protects cellular membranes, prevents glutathione depletion

vitamin A in the diet

protects cellular membranes, prevents glutathione depletion, maintains free radical detoxifying enzyme systems, reduced inflammation.

What are the structural elements of an atom?

protons, neutrons, and electrons.

oxidative stress

refers to an imbalance in any cell, tissue, or organ between the amount of free radicals and the capabilities of the detoxifying and repair systems.

Both males and females require vitamin A in the diet to effectively _____________.

reproduce

AI for Vitamin E intake

- 0-6 months= 4mg/day - 7-12 months= 5mg/day - 1-3 years old= 6mg/day - 4-8 years old= 7mg/day - 9-13 years old= 11mg/day - 14-18 years old= 15mg/day - over 19- 15mg/day

What are some good sources of carotenoids?

- 1 cup of pumpkin canned - 1 cup of carrot juice - 1 cup of cooked carrots or collards

What are some good sources of selenium?

- 1 ounce of Brazil nuts - 3 ounces of shrimp - 3 ounces of crab meat - 1 cup of ricotta cheese - 3 ounces of salmon

What are some good sources of Vitamin A?

- 3 ounces of beef liver - 3 ounces of chicken liver - 1 cup of skim milk - 1 cup of whole milk - 1 ounce of cheddar cheese

What are some good sources of Vitamin C?

- 6 ounces of orange juice and grapefruit juice - a medium sized orange - 1/2 a raw sweet red pepper - a cup of boiled kale or cauliflower

health benefits of Mediterranean diet?

- 9% decrease in overall deaths - 9% decrease in heart death - 6% decrease in cancer deaths - 13% reduced incidence of Parkinson's disease and Alzheimers

Vitamin C functions and health benefits

- also called ascorbic acid, is a water soluble micronutrient essential in the diet for humans. - effective in scavenging reactive oxygen species, reactive nitrogen species, and many other free radicals. - required part of several enzymes involved in the synthesis of collagen, signaling molecules in the brain, some hormones, and amino acids.

flavonoids

- are a large class of chemicals including anthocyanidins, flavanols, and isoflavones. - are very effective free radical scavengers, and there is some evidence that higher intakes of flavonoid-rich foods and/or beverages reduce the risk of cardiovascular disease.

organosulfur compounds

- are predominantly found in garlic, but can also be found in onions and leeks. - Studies suggest these found in garlic reduce cholesterol, are anti-inflammatory, stimulate synthesis of glutathione, and cause death of cancer cells.

What is the DRI for Vitamin C for adults over 19?

90 for mals and 75 for females

High doses of vitamin C have demonstrated what side effects consistently?

GI upset and diarrhea

DASH diet

- eating plan low in saturated fat, cholesterol, and total fat. - fruits, veggies, low fat dairy foods, whole grains fish, poultry, and nut are emphasized in this. - red meats, sweets, and sugar containing beverages are mostly avoided. - the low sodium version of this diet reduces oxidative stress which may have contributed to improved blood vessel function in salt sensitive people

Vitamin E health benefits

- eight chemically similar substances, of which alpha-tocopherol appears to be the most potent antioxidant. - can change function of proteins in cells, plays a role in the operations of the immune system, enhances dilation of blood vessels, and inhibits blood clot formation.

mediterranean diet

- fresh fruit and veggies abundant in this diet - cultural identity of the diet involves multiple herbs and spices - olive oil is main source of fat - fish and poultry consumed in low amounts - red meat intake in very low amounts

While our bodies have acquired multiple defenses against free radicals, we also use free radicals to support its functions like:

- immune system using cell-damaging properties to kill pathogens - thyroid gland synthesizes its own hydrogen peroxide which is required for production of thyroid hormone - Reactive oxygen species and reactive nitrogen species, which are free radicals containing nitrogen, have been found to interact with proteins in cells to produce signaling molecules. - nitric oxide has bene found to help dilate blood vessels and act as a chemical messenger in the brain

Vitamin A deficiency in children

- linked to growth retardation - important for limb, heart, eye, and ear development in fetal stages of life - too little or excess can cause birth defects

What are some important functions of Vitamin A in the body?

- maintaining vision and healthy immune system - healthy skin - linings and coverings of tissues - regulates growth and development

Most of the marketed advertisements for antioxidants are...

- not supported by scientific evidence

tea

- physiological, mental, and social benefits. - more than 700 different phytochemicals - drinking this associated with decreased risk of heart disease, cancer, and diabetes.

What are the 3 major enzyme systems of free radicals?

- superoxide dismutases SOD - catalase - glutathione peroxidases

The CDC has developed seven strategies to increase American's intake of fruits and vegetables including:

- support implementation of Food Policy Council by government - increase availability and affordability of high quality fruits and veggies in poor areas - promote farm to where are programs - encourage public places to serve more fruits and veggies - support schools in developing healthy food messages for kids - encourage the development and support of community and home gardens - emergency food programs like food banks increase supply of veggies and fruits.

The Who estimates that, overall, how many million deaths could be avoided annually by increasing fruit and veggie intake?

2.7 million

Study reported that for every increased serving of fruits or vegetables per day, especially green leafy vegetables and vitamin C-rich fruits, there was a ___________________ lower risk for heart disease.

4%

What is the RDA of selenium for adults over 19?

55mcg for males and females

herbs and spices

They are an additional dietary source of phytochemicals, and many have exceptional antioxidant capacity.

What is the number 1 cause of preventable blindness worldwide?

Vitamin A deficiency

What are some antioxidant chemicals obtained from the diet?

Vitamin A, E, C, and carotenoids, lipoid acid, phenolic acids and selenium.

What is essential in the human diet but most other mammals can readily synthesize it?

Vitamin C

What is the recommended amount of fruits and veggies per day?

between 5-13 servings per day - fewer than 1 in 10 achieve this - orange juice was highest fruit intake and potatoes highest veggie intake

Vitamin A supplementation is a relatively common practice in treating some types of ___________ ____________.

cancer patients; and is thought to improve the effectiveness of some anticancer drugs. However, some can inhibit the actions of some anticancer drugs.

Oxidative stress has been implicated as a contributing factor to...

cancer, atherosclerosis, arthritis, diabetes, kidney disease, Alzheimers, Parkinson's, schizophrenia, bipolar, emphysema and cataracts.

What are examples of phytochemicals?

carotenoids, indoles, lignans, phytoestrogens, stanols, saponins, terpenes, flavonoids, carotenoids, anthocyanidins, phenolic acids, and many more.

selenium

cofactor of free radical detoxifying enzymes, maintains glutathione levels, aids in regeneration of vitamins C and E

Around 25 known proteins require this to function including some enzymes that are involved in detoxifying free radicals.

selenium

Vitamin A is a generic term for a group of...

similar compounds called retinoids

Glutathione Peroxidases

similar to catalase, these enzymes convert hydrogen peroxide to water and oxygen.

What can accelerate the production of free radicals within the body?

substances and energy sources from the environment can add and accelerate these including: - excessive sunlight - ozone - smoke - heavy metals - ionizing radiation - asbestos

The antioxidant hypothesis

the educated guess that antioxidant chemicals protect against chronic disease- has existed for decades. - it is the combination of these, phytochemicals, and nutrient rich foods that achieves these end goals.

Many people take Vitamin C supplements routinely to prevent colds, however...

there is no good evidence that vitamin C prevents a cold

uric acid

this molecule is a metabolic intermediate in the breakdown of nucleotides such as adenine, which is found in DNA and RNA, among other macromolecules.

glutathione

this molecule is composed of three amino acids and is found in high concentrations in cells.

carotenoid bioavailability

unlike micros, this is actually increased by the cooking process because cooking, along with chopping and homogenizing, releases these from the plant matrix. - also increased by cooking in oil

What is the best dietary source of vitamin E with 20.3 mg?

wheat germ oil