Nutrition Part 3

*1880-1920, 90% of children in parts of Europe and in Boston had rickets (industrialization era)

- smoke from coal-burning fires absorbed much of UV portion of sunlight which was needed to produce vitamin D in the skin

**In 1921 it was discovered that if you exposed children to UV light, symptoms of rickets disappeared.

Beri beri

- 1st medical link to this dietary deficiency was made by a Japanese doctor who observed the symptoms in Japanese navy crew who ate only polished white rice but not in crew who got meat, beans and barley

- Polished rice with husk, bran and germ removed = strips nutrients

- Fatigue, together with complications affecting the cardiovascular, nervous, muscular, and GI systems

Pellagra- three ‘D’s: dermatitis, diarrhea, dementia

- early 1900’s in the southeastern USA, cotton economy failed, and people ate corn as a staple

- niacin in corn is tightly bound and not very available for absorption

- 1907-1940 in USA (3 million cases, 100,000 deaths)

- Leading cause of preventable childhood blindness and increases the risk of death from common childhood illnesses such as diarrhea

-Night blindness is one of the first signs of vitamin A deficiency

- Beta-Carotene (precursor to vitamin A – plant foods)

- Retinol (pre-formed vitamin A – animal foods)

(precursor to vitamin A – plant foods)

• Dark green vegetables

• Deep orange fruits and vegetables

• No upper tolerable limit but high intakes may turn skin yellow-orange

(pre-formed vitamin A – animal foods)

• Animal products with fat (meat, fish, etc.)

• Vitamin A derivative (retinoids) used in some acne medications (dangerous for developing fetus

– miscarriage, severe birth defects, death). Avoid getting pregnant for 4 weeks after use

Goiter

- Iodine is an element that is needed for production of thyroid hormone

- If deficient, leads to hypothyroidism = weight gain, inability to tolerate cold, fatigue

- Can lead to intellectual disabilities in children if mother was deficient during pregnancy

- Approximately 30% of the world’s population remains at risk for iodine deficiency

• The B vitamins and vitamin C

• Due to water solubility, they “wash out” of the body in one to several days

– Except for B 12 as it can be stored up to one year in the liver

– This does not make them safe in high doses...

• Vitamin B 6, niacin and C can be toxic in high doses

• “Megadoses” stress the kidney

• Water soluble vitamins are easily destroyed during food storage and preparation

1. Refrigerate fruits & vegetables

2. To minimize oxidation, reduce contact with air

3. Wash fruits & vegetables before cutting

4. To minimize cooking losses, steam or stir-fry vegetables. Avoid high temperature for long time.

• Leafy green vegetables

• Legumes

• Liver

• Lentils

• Fortified grain products

*Most common food source is enriched or fortified food products.

*Synthetic folic acid more bioavailable than naturally occurring food folate.

1. DNA stability

2. Heart health

3. Fetal health

- folate deficiency induces and accelerates carcinogenesis

- structure of cell’s genetic material becomes disrupted --> accumulate abnormalities --> cancer

- lack of folate causes homocysteine to accumulate in blood

- high homocysteine --> heart attacks, strokes

- Almost complete absence of spinal cord and brain deformities (neural tube defects) in babies born to mothers consuming inadequate folate.

- The two most common neural tube defects are spina bifida (treatable) and anencephaly (fatal – portion of brain and skull missing).

- Intakes should be:

400 μg all females600 μg pregnant4 mg previous neural tube defect

***WHY THEY ADDED FOLIATE IN BREAD

- protects tissues from oxidative stress

- oxidative stress is caused by free radicals that are produced in response to normal metabolism using oxygen; UV radiation; air pollution; tobacco smoke

- over time lead to increased risk of cancer, heart disease and arthritis

- Vitamin C along with vitamin E and other phytochemical found in fruits and vegetables neutralize free radicals

They donate electrons to unstable molecule to stabilize them, to dampen the damage of free radicals

- helps form collagen

- fibrous structural protein of connective tissues (bones, teeth, blood vessels, wounds)- assists in preventing bruising

– with vit.C deficiency tissue hemorrhage or bleeding is a major symptom

- conversion of tryptophan --> serotonin (controls mood) & norepinephrine (increase heart rate)

- fatty acid transport into mitochondria for energy metabolism

- making of hormones (e.g. thyroxine)

- adrenal glands contain more vitamin C than any other organ

- released with stress hormones during stress reaction

- stresses: infections, burns, toxic heavy metals, chronic aspirin, barbiturates (sedatives), oral contraceptives, cigarette smoking (also B6, B12, folate)

- 1 g/day of vitamin C led to 1 day shorter cold & reduced severity of symptoms (by 23%)

- vitamin C reduces blood histamine but at a dose of 2 g daily for 2 wks

- body’s need: 10 mg prevent scurvy

- DRI: females 75 mg/d; males 90 mg/d

- excess: nausea, diarrhea, abdominal cramps, excessive gas

- raises blood concentrations of Ca & phosphorus

1) increases absorption from intestine

2) increases reabsorption from kidneys

3) mobilization from bones into blood

- recent research: breast, prostate, colon decreases with increased vitamin D intake

- living higher than 37º latitude increases MS risk >100%

- 400 IU supplement decreases risk by 40%

* Production in the skin needs 10-15 min sunlight (UVB) on arms & face 2-3x per wk (dark pigment may require up to 3 hr)

• Fortified dairy foods

• Fortified margarine

• Fish oils

• Egg yolk

* fluid milk is most reliable source

1) 70 years and older - vitamin D production is only 30% of younger adults

2) institutionalized individuals at high risk

3) sunscreen - reduce or block vit. D synthesis, but not completely

* 15 min exposure early morning or late afternoon without sunscreen produces all that is required for a day

Biologically active compounds of plants believed to confer resistance to chronic disease

– Give pigmentation and flavor

– Promote chemical reactions/used in metabolism

– Protect them from bacteria, fungi, animals and environmental oxidants

• None of the phytochemicals are essential

• Deficiency symptoms are not observed if we do not consume them

• Many have protective and antioxidant properties that make them useful to our tissues

– Via antioxidant or anti-inflammatory effects

• Others are toxic to us– Too much is not better!

– Cancer

– Heart disease

– High blood pressure

– Other chronic diseases

– Follow the advice in Canada’s Food Guide and

– Eat a variety: don’t eat the exact same foods every day

Cause:

- sun

- air pollution

- ionizing radiation

- metabolism

- smoking

protect cells against oxidative damage and reduce the risk of developing certain types of cancer. Phytochemicals with antioxidant activity: allyl sulfides (onions, garlic), carotenoids (carrots, tomatoes), flavonoids (berries), polyphenols (tea, grapes).

• Hormonal action - Isoflavones, found in soy, imitate human estrogens and help to reduce menopausal symptoms and osteoporosis.

• Stimulation of enzymes - Indoles, which are found in cabbages & broccoli, stimulate enzymes that make estrogen less effective and could reduce the risk for breast cancer.

Interference with DNA replication - Saponins found in beans interfere with the replication of cell DNA, thereby preventing the multiplication of cancer cells. Capsaicin, found in hot peppers, protects DNA from carcinogens.

Some phytochemicals bind physically to cell walls thereby preventing the adhesion of pathogens to human cell walls. Proanthocyanidins are responsible for the anti-adhesion properties of cranberry. Consumption of cranberries will reduce the risk of urinary tract infections and will improve dental health.

1. In large doses, phytochemicals may be toxic.

2. Up to 10,000 phytochemicals identified. Cannot all be isolated and put into supplement.

3. Health benefits are associated with foods and often not supplements.

4. Many supplements are untested and some phytochemical supplements may actually harm health (e.g. beta-carotene).

- isolation may worsen rather than benefit, without other substances

Solanine – when potatoes are exposed to light, they turn green = natural defense against insects eating them (bitter)– diarrhea, vomiting, headache, paralysis

Aflatoxins from Aspergillus fungi growing on nuts/peanuts, dried foods, grains, and spices, which can cause liver cancer with chronic exposure. Testing done by CFIA. Discard nuts/peanuts that look moldy, discolored or shriveled.

from spinach, turnip greens, rhubarb, and other foods can bind to calcium and irritate the stomach; cause kidney stones

found in whole grains and legumes

– bind minerals (iron and zinc); cooking, baking, sprouting, fermentation can reduce phytates

A. Selective BreedingB. Genetic Engineering

* selectively breeding crops & animals for centuries

* examples: wild corn = 5 kernels/stalk: super-sweet corn: leaner animals: chickens used to lay 50 eggs/year today they lay 245 eggs/year

* modifying genetic material of living cells so they produce newsubstances or perform new functions* insert gene from one organism into another

1. extend shelf life

2. efficient food processing

3. biopharming

4. improved nutrient composition

5. genetically assisted agriculture

* tomatoes stay firm & ripe longer

* “antisense” (mirror image) gene* binds to native gene and prevents synthesis of softening protein (in tomatoes)

* harvested at more flavorful, nutritious vine-ripe stage

* rennin - coagulate milk in cheese production

* traditionally from calf stomach

* today mass produced in bacteria

* save time, money & space

* in the future : lactose free milk?: decaf coffee bean?

* use animals & plants to produce drugs:

- cow produce vaccine in milk

- use bananas to make edible vaccine

- hydroponically grow tomato plants to secrete desired protein through roots into water

* soybeans: upgrade protein quality

* canola: increase monounsaturated fatty acids

* “golden rice”: genes from daffodil & bacteria to make beta-carotene

• 1.15 million child deaths are precipitated by vitamin A deficiency each year.

• One cup could supply 50% of the RDA of vitamin A for an adult

* 90-95% of canola crops in Canada are GM to withstand herbicides (not just for food also lip gloss, soap, others)

* farmer can spray whole field, kill weeds & not harm canola

* Canada = soy, corn, canola, sugar beets, alfalfa (imports = USA squash and 80% of Hawaiian papayas)

* hypoallergenic peanuts are being researched

• Allergenicity: In principle, the transfer of genes from commonly allergenic organisms to non-allergic organisms is discouraged in the science of GM. No allergic effects have been found relative to GM foods currently on the market.

• Gene transfer: Gene transfer from GM foods to cells of the body or to bacteria in the GI tract is of concern if the transferred genetic material adversely affects human health (e.g. antibiotic resistance genes)

• Outcrossing: The migration of genes from GM plants into conventional crops. Cases have been reported where GM crops approved for animal feed or industrial use were detected at low levels in the products intended for human consumption. Several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM crops and conventional crops are grown.

Both sexes: lung cancer is the #1 cancer that causes death

Men: prostate

Women: breast

Leading cause of death in Canada

1. Initiation – carcinogen permanent genetic change in a cell (carries mutation until it’s death)

2. Promotion - compounds cause the initiated cells to divide and accumulate – large number of daughter cells with the mutation

3. Progression – transformation from benign tumor to neoplasm, cells can undergo further mutations with metastatic potential

4. Metastasis - invade surrounding tissues and/or spread

A. Genetic factors: affects riskB. Immune factors

C. Environmental factors

D. Dietary factors (initiators, promoters, antipromoters)

ineffective immune system may not recognize tumor as foreign

- aging decreases immune function- immunosuppressive drugs & viral infections

* exposure to radiation & sun

* water & air pollution

* smoking

* lack of physical activity

- carcinogens initiate cancer

- some pesticides at high doses are carcinogenic

- nitrosamines – strong carcinogens

- naturally occurring or formed during processing

* alcohol (beer & scotch)

* processed meats (ham, bacon, deli meats, hot dogs)

- in the stomach, nitrates added as preservative, can combine with amines to form nitrosamines

- linked to stomach, esophagus, liver and bladder cancer

• Group 1: Carcinogenic to humans

• Group 2A: Probably carcinogenic to humans

• Group 2B: Possibly carcinogenic to humans

• Group 3: Unclassifiable as to carcinogenicity in humans

• Group 4: Probably not carcinogenic to humans

Processed meat (Group 1) refers to meat that has been transformed through salting, curing, fermentation, smoking, or other processes

Red meat (Group 2) refers to beef, veal, pork, lamb, mutton, horse, and goat

- accelerate tumor development once initiating step has occurred

- “lag time” of 10-30 years

- excess dietary fat by contributing to obesity

- omega-6 fatty acids promoters in some animals

- fat can oxidize at high cooking temperatures (restaurant deep-frying – not so much at home)

------> may produce oxidative stress in body

- more important is time – oils become oxidized over time so buy small bottles and if it smells off – throw away

- fat stimulates bile secretion - bacteria can convert bile to cancer-causing compounds

- high fruits & vegetables and decrease cancer risk

- fiber protective against colon cancer

- phytochemicals

- cruciferous vegetables

• Choose diet rich in a variety of plant-based foods- >7 servings of whole grains, legumes, starchy vegetables; 5-10 servings of other vegetables & fruit; limit processed foods & refined sugar

• Maintain healthy weight and be active- avoid under & overweight; 1 hour of exercise daily

• Drink alcohol in moderation, if at all- for cancer prevention, it’s best not to drink alcohol

• Select foods low in fat and salt- limit fatty foods especially of animal origin; limit red meat to 3 portions per week; modest amount of vegetable oil; limit salted foods & table salt (salt-preserved foods damage stomach lining)

• Prepare and store foods safely- do not eat charred food; consume meat/fish grilled in direct flame only occasionally

And most important of all: • Do not smoke or use tobacco in any form

• Charring, burning or grilling meat, poultry and fish over high temperatures causes chemicals to form that are mutagenic (damage DNA).

– HCAs form when amino acids, sugars, creatine in muscle meats react at high temperature

– PAHs form when fat or juices from meat grilled over a heated surface or open fire drip onto the surface or fire and cause flames and smoke. Smoke contains the PAHs and thatsticks to the surface of the meat. Also formed during smoking of food.

– Well done more than rare/medium

– High temp (grilling, pan fry) or cooked longer

• do not burn food when cooking by any method and remove charred portions

• marinating meats can help reduce carcinogen formation

• continuously turning meat over on a high heat source rather than leaving it without flipping often

• trim the fat (fat dripping into heat produces harmful smoke that coats the food)

• lower the temperature – “low and slow”; indirect-heat methods like stewing, steaming or poaching produce less than frying or grilling

1. Stomach: salt-preserved foods; possibly grilling & BBQ-ing

2. Colorectal: saturated fat, red meat, alcohol; possibly grilling

3. Liver: alcohol; hepatitis B

4. Lung: smoking; possibly alcohol, saturated fat, cholesterol

5. Breast: obesity, early puberty, alcohol; possibly meat & fat

6. Prostate: high fat intake (especially from meat)

- hundreds of diseases related to single gene defects

* PKU (phenylketonuria)

* cystic fibrosis

* sickle cell anemia

* hemochromatosis

- but most diseases are a combination of multiple genes and environment

1. Heart disease

2, Cancer

3. Hypertension

4. Obesity

- high cholesterol diets --> plaque in some people- low folate & vegetable diets increase risk

- differs by site- endometrial [environment = 90%]- stomach [72% environment]- prostate [42% environment]

- salt sensitivity = eating too much salt usually increases BP but not in everyone- salt sensitive or salt resistant

- Over 120 genes associated with development

• An autoimmune disease that damages the small intestine• People with celiac disease have an immune reaction to a protein called gluten• Gluten is in wheat, barley, and rye• When people with celiac disease consume gluten, the immune system attacks and destroys the villi

• Celiac disease occurs in genetically predisposed people

• HLA genes (human leukocyte antigen)

• Responsible for how the immune system distinguishes between the body’s proteins and foreign proteins

• ~99% of people with celiac disease and 60% with non- celiac gluten sensitivity have DQ2 or DQ8 risk version of HLA (but 30% of the general population have the risk version so development of the disease is dependent on the combination of risk variants)

Classical: signs malabsorption, including diarrhea, steatorrhea (pale, foul-smelling, fatty stools), and weight loss or growth failure in children.

Non-classical: mild gastrointestinal symptoms without clear signs of malabsorption or may have seemingly unrelated symptoms.

Silent: Patients do not complain of any symptoms, but still experience villous atrophy damage to their small intestine.

• In Canada, about 1% of population is affected

– Genetic component: if a 1st degree relative has celiac disease, 1 in 10 chance family member will develop it

• Many people go undiagnosed but testing can involve:

– Blood test: tTG-IgA (tissue transglutaminase antibodies)

**must be on gluten-containing diet – how long?

– Small intestine biopsy

– Genetic screening

• Commonly misdiagnosed as:

– IBS (irritable bowel syndrome)

– Crohn’s disease

Develop symptoms when they consume gluten-containing foods and feel better on a gluten-free diet but do NOT have celiac disease.

- There are no biomarkers for diagnosis- Autoantibodies (TTG, EMA, DGP) are absent

- There is no villous atrophy (although newer work suggests there may be intestinal damage)

- you may pass it on

- so you know if you should avoid gluten

- uncontrolled = 2x more likely to get heart disease, 4x more likely to get colon cancer

Other compounds in wheat, barley and rye may trigger symptoms (e.g. proteins called amylase/trypsin inhibitors or fermentable carbohydrates).

NO

• The study of how genes and diet interact to increase or decrease someone’s risk for disease

• Gene × Environment interactions

• Play a role in “personalized nutrition”

- muscle composition

- Type 2 diabetes

- ancestry composition

- Cilantro taste aversion

- 23andme

- nutrigenomic (canadian)

* food preferences largely learned

* 80 genes that help taste bitter foods

* some are highly sensitive

* vegetables taste bitter --> eat less

* individualized dietary prescriptions

* complete profile with genetic risks, gut microbiota profiles, etc.

ADULTS:

- 150 min. of moderate to vigorous physical activity per week (bouts of 10 min. or more)

- 2 sessions of strength-training per week

CHILDREN:

- 60 min. of moderate to vigorous physical activity everyday

-vigorous at least 3 days per week

-activities that strengthen muscle and bone 3 days per week

85% from fat, 10% from CHO, 5% from protein

• During Exercise:

1. Muscle glycogen

2. Blood glucose

3. Plasma fatty acids

4. Intramuscular triglycerides

1. Intensity & duration of exercise

2. Level of exercise training

3. Initial muscle glycogen stores

4. Supplementation with CHO during exercise

• ATP-Phosphocreatine system

- immediate energy source

- short term, explosive power activities up to 10 sec

• Lactic acid system

- anaerobic breakdown of glucose to lactic acid (glycolysis)

- any intense effort lasting up to 2 min

• Oxygen system

- after 2 min during low to moderate intensity exercise

- glycogen provides 60-70% of fuel during first 20 min of low to moderate intensity exercise

- after 20 min fat increasingly used

• Depletion of muscle & liver glycogen levels --> extreme fatigue

• Some carbohydrate is needed by muscles to generate energy from fat breakdown

• Water & glucose ingestion at point of fatigue may prolong exercise but severe limitations exist for high level of energy production needed for exercise

• Inability to maintain current level of activity; perception of effort greatly increased

- increases with increased exercise

Light = 3-5g/kg

High = 6-10g/kg

***TEAM sports: 5-7g/kg (moderate)

1-4 h pre-exercise : 1-4 g/kg body weight

<1 h pre-exercise : If desired, a small amount of easily digested CHO in an amount and form the athlete prefers

During exercise : Team Sports: 30-60 g/hEndurance: depends on duration, up to 90 g/h

< 8 h to recover : 1– 1.2 g/kg/h for 4 hours

> 8 h to recover : Daily fueling plan adequate to restore muscleglycogen

Timing of protein intake– Before, During or After?

– “longitudinal training studies currently suggest that increases in strength and muscle mass are greatest with immediate post-exercise provision of protein.”

– Evidence from systematic review & meta-analysis

– No further performance benefits (strength, muscle mass) when >1.62 g protein/kg/day BUT 95% CI (1.03-2.20 g pro/kg/d)

Maximize muscle & liver glycogen - endurance