Lecture 21 - Malnutrition and Alcohol: the Good(?), the Bad, and the Ugly

Carotenoids food sources

fruits: apricots, cantaloupe, tomatoes

vegetables: broccoli, carrots, peppers, spinach, sweet potatoes, squash

Carotenoids biological activities and possible effects

some are converted to vitamin a, provide antioxidant protection, some decrease risk of macular degeneration

Flavonoid

inhibit inflammation, can reduce cardiovascular disease; ability to inhibit reactive oxygen

Flavonoids food sources

berries, citrus fruits, onions, margarine, purple grapes, green tea, red wine, and chocolate

Flavonoids biological activities and possible effects

make capillary blood vessels stronger, block carcinogens and slow the growth of cancer cells

Phytoestrogens

dietary estrogens

Phytoestrogens food sources

flax seed, rye bread, soy milk, soybeans, and tofu

Phytoestrogens biological activities and possible effects

mimic effect of estrogen, induce cancer cell death, slow the growth of cancer cells, reduce blood cholesterol, may reduce risk of osteoporosis

Nitrites can either turn into

nitric oxide (beneficial for body for vasodilation)

nitrosamines (harmful)

Caffeine inhibits...

the breakdown of cAMP

lactose

glucose + galactose

maltose

glucose + glucose

sucrose

glucose + fructose

ethanol

small 2-carbon alcohol
soluble in water and lipid environment (bc of small size and alcoholic hydroxyl group)

allows ethanol to freely pass from bodily fluids into cells

2 main enzymatic pathways for ethanol oxidation

most significant pathway: alcohol dehydrogenase

second major pathway: microsomal ethanol oxidizing system (MEOS)

lipogenesis

making fat from nonfat substances

mostly occurs in liver cells

Alcohol dehydrogenase

main location:

alcohol intake to activate:

extent of participation:

main location: stomach, liver (mostly)

alcohol intake to activate: low to moderate intake

extent of participation: major role (metabolizes about 90% of alcohol)

Microsomal ethanol oxidizing system (MEOS)

main location:

alcohol intake to activate:

extent of participation:

main location: liver

alcohol intake to activate: moderate to excessive intake

extent of participation: role increases in importance with increasing alcohol intake levels

Alcoholic cirrhosis

irreversible condition in which fibrous scar tissue replaces normal liver tissue and interferes with liver function

alcohol dramatically raises

insulin levels

Why alcohol abuse contributes to malnutrition

- causes mucosal damage, which increases ability of large molecules to cross mucosa; allows toxins from the gut lumen to enter portal blood, increasing liver exposure to toxins and thus, increases the risk of liver injury

- damages the lining of the small intestine, decreasing the absorption of several B vitamins and vitamin C

- inflammation of stomach, pancreas, intestine, impairing digestion and nutrient absorption

- less consumption of essential micronutrients

- replace more nutrient-dense energy sources in diet

alcohol consumption might be related to obesity

- liquids less satiating than solid foods; promoting consumption of additional energy sources

- calories consumed as alcohol more likely to be deposited as fat in abdominal region

Fetal Alcohol Syndrome

range of neurological and behavioral disorders that can occur when a pregnant woman drinks alcohol

Fetal alcohol syndrome signs

- head circumference < 10th percentile

- intellectual impairment

problems with reasoning and judgment

- learning disabilities

- attention deficit disorder

- impared visual/spatial skills

- memory problem

- impaired motor skills

- hyperactivity

- neurosensory hearing loss

- inability to appreciate consequences

- delayed development

- attachment concerns

Alcohol consumption is moderate...

beneficial for cardiovascular health:

increase in HDL cholesterol

decrease in LDL cholesterol oxidation

decrease in blood clotting

decrease in platelet aggregation

decrease in homocysteine

decrease in cell aggregation

Alcohol consumption is excessive...

detrimental to cardiovascular health:

increase in acetaldehyde

increase in oxidative stress

increase in triglycerides

decrease in HDL cholesterol

increase in cell aggregation

increase in reactive species

malnutrition

deficiency or excess of nutrients causes measurable adverse effects on tissue/body form and function, and clinical outcome

general effects of semi-starvation: initial stage

no visible clinical signs, may affect reproductive capacity, weakened immune system

general effect of semi-starvation: continued undernourishment...

blood tests reveal depleted nutrient stores and functions

general effects of semistarvation: consequence of weight loss

- decrease in heart rate and muscle tone

- fatigue, muscle soreness, irritability, hunger pains

- poor concentration and lack of ambition

effects of undernutrition during childhood

- stunted growth, impaired motor skills

- low resistance to infection

- often lead to permanent brain impairment

- period of rapid growth rate, especially in the brain and CNS

effect of undernutrition during later years

- require nutrient dense food

- many with fixed income

- many forced to choose between medication and food

- low resistance to infection

wasting

loss of lean body tissue, lean mass lost even with calories

Sarcopenia

loss of muscle mass, muscle strength

Normal response to infection

- changes in trace elements, anemia

- failure of ketosis with starvation

- fever

- loss of appetite

- nitrogen loss

- sleep, lethargy

What happens when you refeed a starving person with infection

- only gains fat back, not lean body mass

- anabolic block

anabolic block

need alternative strategies for inducing synthesis of lean tissue (ex. growth hormone, testosterone, anabolic steroids, resistance exercise, combination therapies)

Starvation: Issue with protein

no storage form

- use of protein as glucose source

- loss of protein means loss of essential functions