What were people told to eat in the 1980's and 1990's?
High carbohydrate, low cholesterol, low fat
(USDA makes food pyramid and has grain lobbyers)
What did the advice to eat lots of carbohydrates do?
Caused people to become obese and thus get Type 2 Diabetes
What is the Mediterranean diet?
38% fat (but monounsaturated)
Associated with lower risk of CAD than typical Western diet or low fat diet
What happened when an Israeli study compared a low fat diet, Mediterranean diet, and low carb diet?
The low carb diet (Atkins) had the most weight loss, lowest TGs, lower LDL, highest HDL
Low fat diet was the worst
TGs containing fatty acids with one double bond
Associated with low LDL and high HDL
Get it from olive oil, canola oil
Omega-6 fatty acids: lower LDL and HDL, but controversial because may cause CVD if higher omega 6 to omega 3 ratio; in nuts, avocados, olives, soybeans
Omega-3 fatty acids: little effect on LDL, HDL but reduce TGs, suppress cardiac arrhythmias, lower BP, reduce cardiovascular mortality; in fish oil, plants
What determines your cholesterol levels?
More intake of fatty acids than dietary cholesterol
Essential fatty acids
Linoleic acid (omega-6 fatty acid; precursor to prostaglandins, leukotrienes, thromboxane)
Alpha-linolenic acid (omega-3 fatty acid)
Make sure these are in formula for babies or parenteral IV nutrition for people in hospital
Are there essential carbohydrates?
We only need glucose (and this can be made from AAs, other things?)
What does fiber do?
Soluble fiber forms viscous gel when mixed with liquid so delays gastric emptying
Lowers LDL by increasing fecal bile acid excretion and interfering with bile acid reabsorption
Absorbs 10-15 times its weight in water, decreases risk of constipation, hemorrhoids
What does it mean to have a high glycemic index?
Means once you eat it, your blood sugar level spikes higher and faster ("gusher"), as opposed to lower and longer ("trickler")
What type of diet caused people to gain LESS weight?
Low glycemic index
When do we tend to see severe nutritional problems?
If you eat only one type of food
Alcoholics who don't eat because get calories from alcohol
Athletes or body builders on high protein and very low carb diet will have what problem?
Brain needs glucose so will deaminate AAs to get glucose and will degrade tissue proteins to get it
Water soluble vitamins
B complex necessary for energy release
Folic acid and B12 necessary for hematopoesis
B6 necessary for AA metabolism and other enzymatic reactions
Vitamin C (ascorbic acid) is antioxidant, co-factor for formation of collagen
Fat soluble vitamins
Vitamin A: vision, growth, spermatogenesis, maintenance of fetus, differentiation of epithelial cells
Vitamin D: Ca2+ and phosphate homeostasis, bone formation, maybe immune response to specific organisms
Vitamin E: antioxidant
Vitamin K: clotting
Water soluble vitamin deficiencies
B1 (thiamine) in alcoholics esp with gastric bypass
B6 (pyridoxine, pyridoxamine, pyridoxal) in homeless people taking isoniazid (for TB)
B12 in elderly with autoimmune destruction of parietal cells so no intrinsic factor, or vegans or gastric bypass
Folic acid (not anymore because grain enriched)
Fat soluble vitamin deficiencies
Vitamin D in elderly women
Vitamin K in newborns (no intestinal bacteria), people with liver disease, malnourished
Should "food secure" people take vitamins?
Hasn't shown to be effective (except folic acid to prevent birth defects and maybe vitamin D)
Does taking B vitamins to lower homocysteine lower risk for CVD?
Lowers homocysteine, but does NOT reduce risk for CVD
Example of how mechanism should cause certain outcome but does not