Cholesterol Lecture .doc

5 Pages
Unlock Document

Nutrition Science & Dietetics
NSD 225
Sarah Short

1 Sarah  H. Short,  Ph.D.,Ed.D.,R.D., Prof of Nutrition,  Syr U. NSD225                 CHOLESTEROL  and  more  Lipids   Introduction  and  functions 1. Cholesterol  is a fat  soluble  complex  alcohol  of high  molecular  weight.    It is found  only in ANIMAL tissue. 2.  Cholesterol  is an  essential  nutrient  manufactured  in your  liver.   You need   cholesterol  to make  bile acids  & salts(needed  to emulsify  fat),  some  of   the  sex  hormones,  adrenal  hormones,  vitamin  D, and  as  part  of   cell  membrane Cholesterol  and  heart  disease 1. Cardiovascular  diseases  (CVD) are  the  leading  causes  of death  in the  USA.  CVD is a general  term  for all diseases  of the  heart  and  blood  vessels.    Coronary  heart  disease  (CHD) is atherosclerosis  in the  arteries  feeding  the   heart  muscle.    Atherosclerosis  is an  artery  disease  where  there  are  patchy   nodular  thickenings  of the  inner  walls of the  arteries  ( called  plaques).    2.  Since  the  mid  60s,  there  has  been  a decline  in heart  disease  mortality.    Of the  550,000  heart  attack  deaths  occurring  each  year,  36%  occur  in  people  over  the  age  of 80  which  certainly  cannot  be  called  premature   death. 3.  The  primary  cause  of atherosclerosis  is unknown.   It may  be  injury  to  the  artery  wall, virus  infections,  infiltration  of the  inner  arterial  walls by fatty   compounds  in the  blood.   4. Factors  which  may  lead  to an  increased  risk are:   male  gender,  family  history  of heart  attack  under  age  55,  smoking  more  than  10  cigarettes  a  day,  high  blood  pressure,  HDL­cholesterol  below  35,  diabetes   mellitus,  impaired  circulation  to  brain  or  legs,  being  30%  or  more   overweight,  lack  of  exercise . Lipoproteins 1.  Since  chol is not  water  soluble,  it is transported  through  the   bloodstream  as  lipoproteins,  which  are  lipids  surrounded  by a thin  layer  of  proteins.   The  lipoproteins  are  named  by their  relative  density.   High density   lipoproteins  (HDL) may  reduce  the  risk of CHD while  low density  lipoproteins   (LDL) are  associated  with  increased  risk of CHD. 2. LDL carry  cholesterol  through  the  system,  dropping  it off where  it is  needed  for cell building  and  leaving  any  excess  in arterial  walls and  other   tissue.   HDL pick up  these  cholesterol  deposits  and  bring  them  to the  liver   for reprocessing  or excretion,  so HDL is called  the  "good"  chol and  LDL the   "bad". Research 1. The  association  between  blood  chol and  CHD is statistical  and  not   necessarily  one  of cause  and  effect. 2.  Epidemiology  is the  study  of relationships  between  environmental   factors  and  disease.   It does  not  provide  proof  of causation.   These  studies   are  first  steps  in developing  evidence  relating  to cause  and  effect.   Because   2 of this  and  the  difficulty  of doing  long  term  human  studies,  scientific opinion   is divided  on the  association  of environmental  factors  with  CHD. 3. A study  of 12,000  men  from  7 countries  over  10  years  found  that  men   eating  the  most  SATURATED fats  had  the  highest  CHD rate. 4.  However,  combined  records  of 7000  men  found  no evidence  of more   CHD among  those  eating  high  saturated  fat  diets. 6.  Blood  cholesterol  levels  do not  necessarily  reflect  dietary  practices.    The  Framingham  Heart  Study  (monitoring  5,200  residents  of Framingham,   MA since  1948)  revealed  that  the  intake  of eggs  was  unrelated  to blood  chol   levels  or to CHD incidence.   In only about  20%  of those  with  high  blood  chol  do chol levels  return  to normal  as  a result  of dietary  modification. 7. British  scientists  state  that  there  should  be  no recommendations  on  diet  cholesterol  because  its effects  on serum  cholesterol  are  MINIMAL.   There  are  many  reports  in this  country  indicating  that  CHD is inherited  and   dietary  cholesterol  intake  may  have  little  to with  increased  risk.  The   amount  of saturated  fat  in the  diet  probably  has  much  more  risk attached  to   it. NOTE: Even  if no  cholesterol  is  consumed,  the  body  can   manufacture  from  800 ­1500  mg  per  day.  Only  about  10 ­50%  of   dietary  cholesterol  is  absorbed. Recommendations 1.  Most  guidelines  want  you  to have  no more  than  300  mg  of dietary   cholesterol  per  day  and  no more  than  30%  of kcal from  fat  (and  of this  30%,   no more  than  10%  from  saturated  fat).   2.  The  National  Institute  of Health  (NIH) grouped  blood  levels  into   categories mg  chol/dl blood Desirable borderline high Total  cholesterol <200  (5.2) 200­ 239 >240 LDL­cholesterol <130  (3.4) 130­ 159 >160 Total  chol/HDL <4.5 >4.5 Triglycerides 30­175 250­ 500 Note:  There  is a debate  about  triglycerides  (TG) levels.   Some  people  with   TG more  than  150  and  HDL under  40  are  at  high  risk. Cholesterol  levels  now  are  reported  in SI units  (Systeme  International);   200  mg/dl  equals  5.2  mmol/L (divide  mg  by 38.7). Dietary  Sources  of  Cholesterol 1. The  average  diet  contains  about  500  mg  of cholesterol  per  day.   Cholesterol  is found  only in animal  sources , so there  could  not  possibly  be   any  cholesterol  in vegetable  oil, cereals,  bread,  fruit, vegetables. 2. Food  sources  of cholesterol  are  liver  (370  mg/3  oz), egg  213),shrimp,   3 oz (130  mg),  chicken,  skin  off 3 oz (72  mg);  lean  beef,  3oz  (62  mg);   haddock,  3 oz (63);  1 Tblsp  butter  (31);  1 cup  whole  milk (33);  skim  milk (4). Other  areas  of  dietary  research 1.  Fish oils ­ Large  studies  conducted  in the  Netherlands  found  a direct    3 link between  the  amount  of fish in the  diet  and  the  rate  of death  from   heart  disease.    Cold water  fish such  as  cod,  salmon,  sardines,   mackerel  contain  polyunsaturated  oils that  are  rarely  found  in other   foods  (called  omega­ 3 fatty  acids).   Further  studies  indica
More Less

Related notes for NSD 225

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.