A. natural.
oily. substance. occurring. in. animal. bodies,. especially. when. deposited. as.
a. layer. under. the. skin. or. around. certain. organs.
In. Chemistry.
Term:. any. of. a. group. of. natural. esters. of. glycerol. and. various. fatty.
acids,. which. are. solid. at. room. temperature. and. are. the. main. constituents.
of. animal. and. vegetable. fat.
Fat. is. a.
nutrient.. It. is. crucial. for. normal. body. function. and. without. it. we. could.
not. live.. Not. only. does. fat. supply. us. with. energy,. it. also. makes. it.
possible. for. other. nutrients. to. do. their. jobs.
Fats,. which.
consist. of. a. wide. group. of. compounds,. are. usually. soluble. in. organic.
solvents. and. insoluble. in. water.. Chemically,. fats. are. usually. known. as.
triesters. of. glycerol. and. fatty. acids. (triester. =. one. of. three. ester.
chemical. groups).
At. room. temperature.
fats. may. be. present. in. either. liquid. or. solid. form,. this. depends. on.
their. structure. and. composition.
It’s. time.
to. end. the. low-fat. myth.. For. decades,. a. low-fat. diet. was. touted. as.
a. way. to. lose. weight. and. prevent. or. control. heart. disease. and. other.
chronic. conditions,. and. food. companies. re-engineered. products. to. be. reduced-fat.
or. fat-free,. often. compensating. for. differences. in. flavor. and. texture.
by. increasing. amounts. of. salt,. sugar,. or. refined. grains.. However,. as.
a. nation,. following. a. low-fat. diet. hasn’t. helped. us. control. weight. or.
become. healthier.
. . . . In.
the. 1960s,. fats. and. oils. supplied. Americans. with. about. 45. percent. of.
calories;. about. 13. percent. of. adults. were. obese. and. under. 1. percent.
had. type. 2. diabetes,. a. serious. weight-related. condition.. . . . . Today,.
Americans. take. in. less. fat,. getting. about. 33. percent. of. calories. from.
fats. and. oils;. yet. 34. percent. of. adults. are. obese. and. 11. percent. have.
diabetes,. most. with. type. 2. diabetes..
Why. hasn’t.
cutting. fat. from. the. diet. paid. off. as. expected?. Detailed. research. shows.
that. the. total. amount. of. fat. in. the. diet. isn’t. really. linked. with. weight.
or. disease.. What. really. matters. is. the. type. of. fat. and. the. total. calories.
in. the. diet.
. . . . Bad.
fats,. meaning. Trans. and. saturated. fats,. increase. the. risk. for. certain.
diseases.
. . . . Good.
fats,. meaning. monounsaturated. and. polyunsaturated. fats. do. just. the. opposite..
They. are. good. for. the. heart. and. most. other. parts. of. the. body.
One. problem.
with. a. generic. lower. fat. diet. is. that. it. prompts. most. people. to. stop.
eating. fats. that. are. good. for. the. heart. along. with. those. that. are. bad.
for. it.. Another. problem. is. that. when. people. cut. back. on. fat,. they. often.
switch. to. foods. full. of. easily. digested. carbohydrates—white. bread,. white.
rice,. potatoes,. sugary. drinks,. and. the. like—or. to. fat-free. products. that.
replace. healthful. fats. with. sugar. and. refined. carbohydrates.. The. body.
digests. these. carbohydrates. very. quickly,. causing. blood. sugar. and. insulin.
levels. to. spike.. Over. time,. eating. lots. of. “fast. carbs”. can. raise. the.
risk. of. heart. disease. and. diabetes. as. much. as—or. more. than—eating. too.
much. saturated. fat.. That’s. why. it’s. important. to. replace. foods. high. in.
bad. fats. with. foods. high. in. good. fats—not. with. refined. carbohydrates.
What. about.
cholesterol. in. food?. For. most. people,. the. mix. of. fats. in. the. diet. influences.
cholesterol. in. the. bloodstream. far. more. than. cholesterol. in. food. does.
How. Fat. Moves. from. Food. to. the. Bloodstream
Almost. all.
foods. contain. some. fat.. Even. quintessential. fat-free. foods. like. carrots.
and. lettuce. contain. small. amounts. of. this. nutrient.. That’s. a. testament.
to. how. important. fats. are. for. life.. Fat. provides. a. terrific. source. of.
energy. as. well. as. a. great. depot. for. storing. it.. It. is. an. important.
part. of. cell. membranes,. helping. govern. what. gets. into. cells. and. what.
comes. out.. The. body. uses. cholesterol. as. the. starting. point. to. make. estrogen,.
testosterone,. vitamin. D,. and. other. vital. compounds.. Fats. are. also. biologically.
active. molecules. that. can. influence. how. muscles. respond. to. insulin’s. “open.
up. for. sugar”. signal;. different. types. of. fats. can. also. fire. up. or. cool.
down. inflammation.
Fat. and. cholesterol.
can’t. dissolve. in. water. or. blood.. The. body. gets. around. this. basic. chemistry.
problem. by. packaging. fat. and. cholesterol. into. tiny,. protein-covered. particles.
called. lipoproteins.. Although. lipoproteins. can. carry. quite. a. bit. of. fat,.
they. mix. easily. with. blood. and. flow. with. it.. Some. of. these. particles.
are. big. and. fluffy,. others. small. and. dense.. The. most. important. ones.
are. low-density. lipoproteins,. high-density. lipoproteins,. and. triglycerides.
Low-density.
lipoproteins. (LDL). carry. cholesterol. from. the. liver. to. the. rest. of. the.
body.. Cells. latch. onto. these. particles. and. extract. fat. and. cholesterol.
from. them.. When. there. is. too. much. LDL. cholesterol. in. the. blood,. these.
particles. can. form. deposits. in. the. walls. of. the. coronary. arteries. and.
other. arteries. throughout. the. body.. Such. deposits,. called. plaque,. can.
narrow. arteries. and. limit. blood. flow.. When. plaque. breaks. apart,. it. can.
cause. a. heart. attack. or. stroke.. Because. of. this,. LDL. cholesterol. is.
often. referred. to. as. bad,. or. harmful,. cholesterol.
High-density.
lipoproteins. (HDL). scavenge. cholesterol. from. the. bloodstream,. from. LDL,.
and. from. artery. walls. and. ferry. it. back. to. the. liver. for. disposal..
Think. of. HDL. as. the. garbage. trucks. of. the. bloodstream.. HDL. cholesterol.
is. often. referred. to. as. good,. or. protective,. cholesterol.. Several. strategies.
can. help. you. lower. the. amounts. of. total. and. harmful. LDL. cholesterol.
in. your. bloodstream,. and. thus. your. risk. of. heart. disease.
Triglycerides.
make. up. most. of. the. fat. that. you. eat. and. that. travels. through. the.
bloodstream.. As. the. body’s. main. vehicle. for. transporting. fats. to. cells,.
triglycerides. are. important. for. good. health.. But. as. is. the. case. for.
so. many. things,. an. excess. of. triglycerides. can. be. unhealthy.
In. general,.
the. lower. your. LDL. and. the. higher. your. HDL,. the. better. your. chances.
of. preventing. heart. disease. and. other. chronic. conditions.. Guidelines. from.
the. National. Cholesterol. Education. Program. suggest. specific. targets.
How. Fat. and. Cholesterol. in. Food.
Affect. Blood. Cholesterol. Levels
The. types.
of. fat. in. the. diet. determine. to. a. large. extent. the. amount. of. total,.
HDL,. and. LDL. cholesterol. in. the. bloodstream.. The. types. and. amount. of.
carbohydrate. in. the. diet. also. play. a. role.. Cholesterol. in. food. matters,.
too,. but. not. nearly. as. much.
Unsaturated.
fats. are. called. good. fats. because. they. can. improve. blood. cholesterol.
levels,. ease. inflammation,. stabilize. heart. rhythms,. and. play. a. number.
of. other. beneficial. roles.. Unsaturated. fats. are. predominantly. found. in.
foods. from. plants,. such. as. vegetable. oils,. nuts,. and. seeds.. They. are.
liquids. at. room. temperature.
There. are.
two. types. of. unsaturated. fats:
. . . . Monounsaturated.
fats. are. found. in. high. concentrations. in. olive,. peanut,. and. canola. oils;.
avocados;. nuts. such. as. almonds,. hazelnuts,. and. pecans;. and. seeds. such.
as. pumpkin. and. sesame. seeds.
. . . . Polyunsaturated.
fats. are. found. in. high. concentrations. in. sunflower,. corn,. soybean,. and.
flaxseed. oils,. and. also. in. foods. such. as. walnuts,. flax. seeds,. and. fish;.
canola. oil,. though. higher. in. monounsaturated. fat,. is. also. a. good. source.
of. polyunsaturated. fat.. Omega-3. fats,. which. are. fast. becoming. the. darling.
of. the. supplement. industry,. are. an. important. type. of. polyunsaturated. fat..
The. body. can’t. make. these,. so. they. must. come. from. food.. An. excellent.
way. to. get. omega-3. fats. is. by. eating. fish. two. or. three. times. a. week..
Good. plant. sources. of. omega-3. fats. include. chia. seeds. (sold. as. Salvia),.
flax. seeds,. walnuts,. and. oils. such. as. flaxseed,. canola,. and. soybean.
Dutch. researchers.
conducted. an. analysis. of. 60. trials. that. examined. the. effects. of. carbohydrates.
and. various. fats. on. blood. lipid. levels.. In. trials. in. which. polyunsaturated.
and. monounsaturated. fats. were. eaten. in. place. of. carbohydrates,. these. good.
fats. decreased. levels. of. harmful. LDL. and. increased. protective. HDL.. . More.
recently,. a. randomized. trial. known. as. the. Optimal. Macronutrient. Intake.
Trial. for. Heart. Health. (OmniHeart). showed. that. replacing. a. carbohydrate-rich.
diet. with. one. rich. in. unsaturated. fat,. predominantly. monounsaturated. fats,.
lowers. blood. pressure,. improves. lipid. levels,. and. reduces. the. estimated.
cardiovascular. risk..
Most. people.
don’t. get. enough. of. these. healthful. unsaturated. fats. each. day.. No. strict.
guidelines. have. been. published. regarding. their. intake.. The. traditional.
Greek. diet,. for. example,. gets. up. to. 30. percent. of. its. calories. from.
monounsaturated. fats,. mostly. from. olive. oil.. For. polyunsaturated. fats,.
the. American. Heart. Association. has. set. 8. to. 10. percent. of. calories. as.
a. prudent. target;. there. is. evidence,. though,. that. eating. more. polyunsaturated.
fat—on. the. order. of. 15. percent. of. daily. calories—in. place. of. saturated.
fat. can. lower. heart. disease. risk.. . Since. no. one. eats. by. percentage.
of. daily. calories,. a. good. rule. of. thumb. is. to. choose. foods. rich. in.
unsaturated. fats. over. foods. rich. in. saturated. fats. whenever. possible..
(To. learn. more,. check. out. this. chart,. Finding. Foods. with. Healthy. Fats.)
Bad. Fats.
There’s. been.
controversy. brewing. over. the. past. decade. about. just. how. bad. saturated.
fat. is. for. health.. Fueling. the. debate,. in. part,. has. been. the. resurgence.
of. the. Atkins. Diet,. which. eschews. carbs. but. allows. liberal. use. of. high-fat.
foods,. including. foods. high. in. saturated. fat—butter,. bacon,. steak,. cheese,.
and. the. like.. . More. recently,. several. studies. seemed. to. suggest. that.
eating. diets. high. in. saturated. fat. did. not. raise. the. risk. of. heart.
disease—a. finding. that. ran. counter. to. decades. of. dietary. advice.. . One.
highly-publicized. report. analyzed. the. findings. of. 21. studies. that. followed.
350,000. people. for. up. to. 23. years.. Investigators. looked. at. the. relationship.
between. saturated. fat. intake. and. coronary. heart. disease. (CHD),. stroke,.
and. cardiovascular. disease. (CVD).. Their. controversial. conclusion:. “There.
is. insufficient. evidence. from. prospective. epidemiologic. studies. to. conclude.
that. dietary. saturated. fat. is. associated. with. an. increased. risk. of. CHD,.
stroke,. or. CVD.”
With. headlines.
like. “Saturated. Fat. is. Not. Your. Heart’s. Enemy,”. and. “NOT. GUILTY:. The.
Long-Standing. Vilification. of. Saturated. Fat. Finally. Turning. to. Vindication,”.
. some. of. the. media. and. blog. coverage. of. these. studies. would. have. you.
believe. that. scientists. had. given. a. green. light. to. eating. bacon,. butter,.
and. cheese.. But. that’s. an. oversimplified. and. erroneous. interpretation..
Read. the. study. and. subsequent. studies. more. closely,. and. the. message. is.
more. nuanced:. Cutting. back. on. saturated. fat. can. be. good. for. health. if.
people. replace. saturated. fat. with. good. fats,. especially,. polyunsaturated.
fats.. . . Eating. good. fats. in. place. of. saturated. fat. lowers. the. “bad”.
LDL. cholesterol,. and. it. improves. the. ratio. of. total. cholesterol. to. “good”.
HDL. cholesterol,. lowering. the. risk. of. heart. disease.. Eating. good. fats.
in. place. of. saturated. fat. can. also. help. prevent. insulin. resistance,. a.
precursor. to. diabetes..
Cutting. back.
on. saturated. fat. will. likely. have. no. benefit,. however,. if. people. replace.
saturated. fat. with. refined. carbohydrates—white. bread,. white. rice,. mashed.
potatoes,. sugary. drinks,. and. the. like.. Eating. refined. carbs. in. place.
of. saturated. fat. does. lower. “bad”. LDL. cholesterol—but. it. also. lowers.
the. “good”. HDL. cholesterol. and. increases. triglycerides.. The. net. effect.
is. as. bad. for. the. heart. as. eating. too. much. saturated. fat—and. perhaps.
even. worse. for. people. who. have. insulin. resistance. because. they. are. overweight.
or. inactive..
The. latest.
Dietary. Guidelines. for. Americans. recommends. getting. less. than. 10. percent.
of. calories. each. day. from. saturated. fat.. . The. American. Heart. Association.
goes. even. further,. recommending. limiting. saturated. fat. to. no. more. than.
7. percent. of. calories.. . But. framing. diet. recommendations. in. terms. of.
“percentage. of. daily. calories”. is. not. terribly. useful. for. the. average.
consumer.. That’s. because. people. eat. foods—not. isolated. nutrients.
In. the. U.S.,.
pizza. and. cheese. are. the. biggest. food. sources. of. saturated. fat. in. the.
diet.. . Other. dairy. products. (whole. and. reduced. fat. milk,. butter,. dairy.
desserts). and. meat. products. (sausage,. bacon,. beef,. hamburgers). are. also.
major. contributors,. as. are. foods. made. with. them. (cookies. and. other. grain-based.
desserts,. Mexican. dishes).. Keep. in. mind. that. all. foods. contain. a. mix.
of. fats:. Even. “healthy”. foods. like. chicken. and. nuts. do. contribute. some.
saturated. fat. to. the. diet,. though. they. are. much. lower. in. saturated. fat.
than. beef,. cheese,. and. ice. cream.. A. few. plant. foods. are. also. high. in.
saturated. fats,. such. as. coconut. and. coconut. oil,. palm. oil,. and. palm.
kernel. oil.
As. a. general.
rule,. it’s. a. good. idea. to. keep. your. intake. of. saturated. fats. as. low.
as. possible.. We. can’t. eliminate. saturated. fat. from. our. diets. completely,.
because. foods. that. are. good. sources. of. healthy. fats—olive. oil,. walnuts,.
and. salmon—also. contain. a. little. bit. of. saturated. fat.. And. it. would.
be. a. mistake. to. cut. back. on. nuts,. oils,. and. fish. to. minimize. saturated.
fat.. When. you. add. it. up,. red. meat. and. full-fat. dairy. products. (cheese,.
milk,. ice. cream,. butter). are. among. the. main. sources. of. saturated. fat.
in. our. diets.. So. keeping. these. foods. low. is. the. best. way. to. reduce.
intake. of. saturated. fat.. And. when. you. cut. back. on. red. meat. and. dairy.
products,. replace. them. with. foods. that. contain. healthy. fats—fatty. fish.
like. salmon,. nuts. and. seeds,. plant. oils,. avocadoes—not. with. foods. that.
are. high. in. refined. carbohydrates.
Very. Bad. Fats:. Trans. Fats
Trans. fatty.
acids,. more. commonly. called. trans. fats,. are. made. by. heating. liquid. vegetable.
oils. in. the. presence. of. hydrogen. gas. and. a. catalyst,. a. process. called.
hydrogenation.. Partially. hydrogenating. vegetable. oils. makes. them. more. stable.
and. less. likely. to. spoil.. It. also. converts. the. oil. into. a. solid,. which.
makes. transportation. easier.. Partially. hydrogenated. oils. can. also. withstand.
repeated. heating. without. breaking. down,. making. them. ideal. for. frying. fast.
foods.. (Fully. hydrogenating. a. vegetable. oil. creates. a. fat. that. acts. like.
a. saturated. fat.). It’s. no. wonder. that. partially. hydrogenated. oils. became.
a. mainstay. in. restaurants. and. the. food. industry,. for. frying,. baked. goods,.
and. processed. snack. foods. and. margarines.
For. years,.
margarine. was. promoted. as. a. heart-healthy. alternative. to. butter.. Since.
margarine. was. made. from. unsaturated. vegetable. oils,. most. people. assumed.
it. would. be. better. for. long-term. health. than. butter,. which. was. known.
to. contain. a. lot. of. cholesterol. and. saturated. fat.. That. assumption. turned.
out. to. be. wrong.. Research. showed. that. some. forms. of. margarine—specifically.
the. hard. stick. margarines—were. worse. for. the. heart. than. butter.. This.
was. because. they. contained. large. amounts. of. trans. fats. from. partially.
hydrogenated. oils.
The. Nurses’.
Health. Study. found. that. women. who. ate. 4. teaspoons. of. stick. margarine.
a. day. had. a. 50. percent. greater. risk. of. heart. disease. than. women. who.
ate. margarine. only. rarely..
So. should.
you. choose. butter. over. margarine?. Whenever. possible,. skip. both. and. use.
a. liquid. vegetable. oil.. At. the. table,. try. dipping. bread. in. olive. oil.
instead. of. slathering. it. with. butter. or. margarine.. When. sautéing,. try. using. olive,.
canola,. or. another. liquid. vegetable. oil,. with. a. little. bit. of. butter.
for. flavor.. If. you. need. something. spreadable,. choose. a. soft. margarine.
that. is. not. only. trans. free. but. low. in. saturated. fat.. A. number. of.
soft. margarines. are. made. from. a. blend. of. healthful. oils,. and. some. have.
the. added. benefit. of. containing. cholesterol-lowering. plant. sterols.. Keep.
in. mind. that. you. need. to. eat. two. servings. of. these. sterol-containing.
margarines. a. day. to. put. a. small. dent. in. your. LDL. level.. Read. more.
about. how. to. spot. trans. fat. on. food. labels.
Partially. hydrogenated.
oil. is. not. the. only. source. of. trans. fats. in. our. diets.. Trans. fats.
are. also. naturally. found. in. beef. fat. and. dairy. fat,. in. small. amounts.
Trans. fats.
are. worse. for. cholesterol. levels. than. saturated. fats. because. they. raise.
bad. LDL. and. lower. good. HDL.. They. also. fire. inflammation,. . an. over. activity.
of. the. immune. system. that. has. been. implicated. in. heart. disease,. stroke,.
diabetes,. and. other. chronic. conditions.. And. they. contribute. to. insulin.
resistance.. (26). Even. small. amounts. of. Trans. fat. in. the. diet. can. have.
harmful. health. effects.. For. every. extra. 2. percent. of. calories. from. Trans.
fat. daily,. the. risk. of. coronary. heart. disease. increases. by. 23. percent..
Eliminating. industrial-produced. Trans. fats. from. the. U.S.. food. supply. could.
prevent. between. 6. and. 19. percent. of. heart. attacks. and. related. deaths,.
or. more. than. 200,000. each. year..
In. the. 1990s,.
the. average. American. was. eating. about. six. grams. of. trans. fats. a. day,.
most. of. that. from. partially. hydrogenated. oils. found. in. commercially. prepared.
baked. goods,. margarines,. snack. foods,. processed. foods,. French. fries,. and.
other. fried. foods. prepared. in. restaurants. and. fast. food. franchises.. .
Ideally. that. should. be. under. two. grams. a. day,. and. zero. from. partially.
hydrogenated. oils. is. best.
A. 2006. labeling.
law. that. forced. food. companies. to. list. trans. fats. on. the. label. has.
reduced. trans. fat. levels. in. the. U.S.. food. supply,. since. many. food. makers.
have. switched. to. using. trans-free. oils. and. fats. in. their. products.. And.
recent. study. from. the. Centers. for. Disease. Control. and. Prevention. finds.
that. Americans’. blood-levels. of. trans. fats. dropped. 58. percent. from. 2000.
to. 2009—evidence. that. the. labeling. law. has. had. its. desired. effect.. .
. Some. experts. had. feared. that. food. makers. would. replace. trans. fat. with.
saturated. fat,. diminishing. any. health. benefits. from. the. switch.. But. 2010.
survey. of. 83. major-brand. grocery. store. products. and. restaurant. dishes.
offers. encouraging. news:. When. most. of. these. food. makers. reformulated. their.
products,. they. cut. back. on. trans. fat. without. increasing. saturated. fat..
As. Trans. fat.
intake. dwindles. in. developed. countries,. it. is. on. the. rise. in. some. developing.
nations.. Inexpensive. partially. hydrogenated. soybean. oil. has. become. a. staple.
not. only. for. the. food. industry. but. for. home. use.. This. shift. away. from.
traditional. cooking. oils. and. toward. trans-rich. partially. hydrogenated. oils.
is. contributing. to. the. growing. epidemic. of. cardiovascular. disease. in. developing.
nations. around. the. world.
Cholesterol.
in. Food
eggs-cholesterol..
The. discovery. half. a. century. ago. that. high. blood. cholesterol. levels. were.
strongly. associated. with. an. increased. risk. for. heart. disease. triggered.
numerous. warnings. to. avoid. foods. that. contain. cholesterol,. especially. eggs.
and. liver.. As. it. turns. out,. most. people. make. more. cholesterol. than. they.
absorb. from. their. food.. A. body. of. scientific. studies. shows. only. a. weak.
relationship. between. the. amount. of. cholesterol. a. person. consumes. and. his.
or. her. blood. cholesterol. levels. . (weak. but. still. important. for. heart.
disease).. In. studies. of. more. than. 80,000. female. nurses,. Harvard. researchers.
found. that. consuming. about. an. egg. a. day. was. not. associated. with. higher.
risk. of. heart. disease. (too. few. women. in. the. study. were. eating. more.
than. an. egg. a. day. to. evaluate. the. effects. of. higher. egg. intakes).. One.
reason. for. the. lack. of. association. is. that. eggs. are. a. good. source. of.
many. nutrients. that. may. counterbalance. a. slight. increase. in. risk. of. heart.
disease.. . Also,. eggs. can. take. the. place. of. other. breakfast. foods. that.
have. adverse. effects,. such. as. white. toast. with. butter.. . One. note. of.
caution:. Among. women. in. this. study. with. diabetes. and. in. another. study.
of. men. with. diabetes,. higher. egg. consumption. has. been. associated. with.
increased. risks. of. heart. disease.
Research. suggests.
that. moderate. egg. consumption. can. be. part. of. a. healthy. diet.. But. this.
research. doesn’t. give. the. green. light. to. daily. three-egg. omelets,. especially.
for. people. who. already. have. heart. disease. or. diabetes.. Read. more. about.
eggs. and. heart. health.
For. most. people,.
the. amount. of. cholesterol. eaten. has. only. a. modest. impact. on. the. amount.
of. cholesterol. circulating. in. the. blood.. (37). For. some. people,. though,.
blood. cholesterol. levels. rise. and. fall. very. strongly. in. relation. to. the.
amount. of. cholesterol. eaten.. For. these. “responders,”. avoiding. cholesterol-rich.
foods. can. have. a. substantial. effect. on. blood. cholesterol. levels.. Unfortunately,.
at. this. point. there. is. no. way. other. than. by. trial. and. error. to. identify.
responders. from. non-responders. to. dietary. cholesterol.
