Abstracts
Alcohol & CHD
Contents:
Alcohol Consumption (4)
Alcohol Consumption (1)
This study evaluated 2 groups of individuals for alcohol consumption in relationship to coronary artery disease (CAD).
People in all categories of drinking (up to 56 drinks per week) had at least a 40% reduction in risk compared to nondrinkers. Former drinkers had a lower risk of nonfatal myocardial infarction than those who never drank. They did have a similar risk of death from coronary artery disease. The reduction was greater in women than in men in all drinking categories. Evidence supports the hypothesis that light and moderate alcohol consumption reduce the risk of coronary artery disease. A possible effect is the direct relationship between alcohol consumption and HDL cholesterol.
"Alcohol Consumption and The Risk of Coronary Heart Disease", Jackson, Rodney, et al, British Medical Journal, July 27, 1991;303:211-215.
Alcohol Consumption (2)
There was an inverse relationship between increasing alcohol intake and coronary artery disease supporting the hypothesis of the inverse relationship between alcohol consumption and coronary artery disease being causal.
"Prospective Study of Alcohol Consumption and Risk of Coronary Disease in Men", Rimm, Eric B., et al, The Lancet, August 24, 1991;338:464-468.
Alcohol Consumption (3)
Reviewed the effect of specific types of alcoholic drink on coronary risk.
Most ecological studies suggested that wine was more effective in reducing risk of mortality from heart disease than beer or spirits. One type of drink does not seem to be more cardioprotective than the others. Of the 10 prospective cohort studies, 4 found a significant inverse association between risk of heart disease and moderate wine drinking, 4 found an association for beer, and 4 for spirits.
Thus, a substantial portion of the benefit is from alcohol rather than other components of each type of drink.
Rimm EB et al., Review of moderate alcohol consumption and reduced risk of coronary heart disease: is the effect due to beer, wine, or spirits. BMJ, 1996 Mar 23, 312:7033, 731-6.
Alcohol Consumption (4)
Alcohol consumption is associated with a reduced risk of coronary heart disease (CHD) but an increased risk of other causes of morbidity and mortality. It remains unclear whether there is an upper limit to a protective effect of alcohol intake on CHD risk. Whether there is a U- or an L-shaped relation between alcohol consumption and CHD incidence (hospitalization and mortality due to ischemic heart disease:
For females, an increased risk was found above 28 drinks per week relative to abstainers (relative risk = 2.6), which was significant, but was based on small numbers. For males, no upturn in risk was found at higher intake. Mortality data supported these results. Sex differences should be explored further, since they are relevant to understanding causal mechanisms and public policy and prevention.
Rehm JT et al., Alcohol consumption and coronary heart disease morbidity and mortality. Am J Epidemiol, 1997 Sep 15, 146:6, 495-501.
Antioxidants & CHD
Contents:
Antioxidants, Beta-Carotene, Vitamins A and E
Antioxidants & Polyunsaturated Fatty Acids
Antioxidants & Pro-Oxidants
Antioxidants (4)
Antioxidants (1) Beta-Carotene, Vitamins A and E
In over 87,000 US female nurses between 34 and 59 years of age, followed up for 8 years, it was found that there were 437 nonfatal myocardial infarctions and 115 coronary deaths. There was a trend for decreasing risk of coronary heart disease (CHD) with higher vitamin consumption of each of the antioxidant vitamins. In women with the highest quintile of vitamin use, compared to those who were lowest, the multivariate risk of CHD was .66 for vitamin E, .78 for beta-carotene, and .70 for total vitamin A, adjusting for other variables.
Increased dietary intake of antioxidant vitamins may be associated with a reduced risk of coronary heart disease, and supports the need for randomized trials.
"A Prospective Study of Antioxidant Vitamins and Incidence of Coronary Heart Disease in Women", Manson, J.E., et al, J of The American College of Nutrition, October 1992;11(5):633/Abstract 119.
Antioxidants (2) Polyunsaturated Fatty Acids
Patients (#91) with varying degrees of coronary artery disease were compared to controls for the degree of atherosclerosis and its relationship to selenium, alpha tocopherol (vitamin E) and serum polyunsaturated fatty acid levels. Plasma selenium was significantly lower in patients than in controls. The ratio of selenium to linoleic acid, selenium to total polyunsaturated fatty acids and selenium to total omega-6 fatty acids was significantly lower in coronary artery disease patients. These relationships were more significant in individuals with low vitamin E levels. High polyunsaturated fatty acids with insufficient antioxidant protection may increase the risk to cardiovascular disease.
"Do Antioxidants and Polyunsaturated Fatty Acids Have a Combined Association With Coronary Atherosclerosis?", Kok, Frans, J., et al, Arteriosclerosis, 1991;31:85-90.
Antioxidants (3) Pro-Oxidants
It has been of concern that iron may increase lipid peroxidation and thereby aggravate coronary artery disease. Iron, iron binding capacity and ferritin did not contribute to the risk of angina in Scottish men evaluated.
"Anti-Oxidants and Pro-Oxidants in Coronary Heart Disease", Riemersma, R.A., et al, The Lancet, March 16, 1991;337:677.
Antioxidants (4)
Vitamin C, carotenoids, and vitamin E, the 3 main dietary sources of antioxidants, each effect lipid peroxidation and may reduce atherogenesis and lower the risk of coronary heart disease (CHD). Crosscultural studies of antioxidants find that regions with relatively low dietary intake tend to have higher rates of CHD, but in these studies it is difficult to account for other important cardiovascular risk factors.
Studies do not support a cardiovascular benefit for vitamin C, although the cardiovascular effect of vitamin C supplementation among populations with marginal vitamin C deficiency is not known.
Results from recent clinical trials of beta-carotene supplementation show no cardiovascular benefit, although several observational studies have found an inverse association between carotenoid intake or plasma levels and risk of CHD.
The benefit reported in the observational studies may be due to consumption of foods rich in beta-carotene rather than the beta-carotene itself.
The evidence for a cardiovascular benefit of antioxidants is strongest for vitamin E. Short durations and doses of less than 100 IU/d (when data were available) have no significant effect. High doses (400 and 800 IU/day) of vitamin E reduce risk of CHD.
Rimm EB & Stampfer MJ: The role of antioxidants in preventive cardiology. Curr Opin Cardiol, 1997 Mar, 12:2, 188-94.
Arrhythmias & CHD
Small intravenous doses of magnesium sulfate were given to evaluate the cardiotonic actions of epinephrine in coronary bypass patients. Magnesium significantly blunted epinephrine's hypertensive action and prevented a significant increase in the mean arterial pressure during magnesium-epinephrine administration.
Small infusions of magnesium sulfate after coronary surgery to treat arrhythmias and vasospasm inhibit the vasoconstrictive action of epinephrine but have no effect on its cardiotonic activity. The combination of epinephrine and magnesium augment cardiac output while decreasing systemic vascular resistance. This interaction between magnesium and epinephrine may enhance overall myocardial performance while minimizing any decrease in myocardial oxygen demand, thereby enhancing epinephrine's performance as an inotropic agent.
"Magnesium Inhibits the Hypertensive But Not the Cardiotonic Action of Low-Dosed Epinephrine",Prielpp, RC et al, Anesthesiology, 1991;74:973-979.
Vitamin C & CHD
Contents:
Ascorbate (Vitamin C)
Vitamin C - Britain
Ascorbate (Vitamin C)
Patients undergoing either coronary bypass surgery or heart valve replacement were given 1.0 gm of ascorbate intravenously about 1.5 hours prior to cardiopulmonary bypass, and an ascorbate containing cardioplegic solution at a concentration of 1.0 mL or placebo. Those who received ascorbate had a dramatic reduction in CPK and LDH release. Ascorbate use extends the period in which ischemia can be tolerated prior to reperfusion. This also suggests ascorbate might be minimizing myocardial stress during surgery. These findings are in line with the concept of oxygen derived free radical release during reperfusion which causes myocardial damage.
"A Protective Role For Ascorbate in Induced Ischemic Arrest Associated with Cardiopulmonary Bypass", Eddy, L et al, J of App. Cardiology, 1990;5:409-414.
Vitamin C - Britain
Determined whether vitamin C status, as measured by dietary intake and plasma ascorbic acid concentration, is related to mortality from stroke and coronary heart disease in people aged 65 and over.
Mortality from stroke was highest in those with the lowest vitamin C status. Those in the highest third of the distribution of vitamin C intake had a relative risk of 0.5 compared with those in the lowest third.
A similar gradient in risk was present for plasma ascorbic acid concentrations. No association was found between vitamin C status and risk of death from coronary heart disease.
In elderly people, vitamin C concentration is strongly related to subsequent risk of death from stroke but not from coronary heart disease.
Gale CR et al., Vitamin C and risk of death from stroke and coronary heart disease in cohort of elderly people [see comments]. BMJ, 1995 Jun 17, 310:6994, 1563-6.
Behavior & CHD
Contents:
Behavior
Type A's
Behavior
Assessed the important roles of modifiable dietary and behavioral characteristics in the causation and prevention of coronary heart disease (CHD). [National Health and Nutrition Examination Survey, NHANES I, followup study.]
The following factors were independently, significantly, and inversely associated with coronary heart and vascular disease deaths and hospitalizations: alcohol intake, dietary riboflavin, dietary iron, serum magnesium, leisure time exercise, habitual physical activity, and female gender.
Positive significant independent determinants of CHD events included cigarette smoking, sedimentation rate, Quetelet index, maximum body weight, and age.
These associations emphasize the important role of modifiable dietary and behavioral characteristics in the causation and prevention of CHD.
Gartside PS & Glueck CJ: The important role of modifiable dietary and behavioral characteristics in the causation and prevention of coronary heart disease hospitalization and mortality: the prospective NHANES I follow-up study. J Am Coll Nutr, 1995 Feb, 14:1, 71-9.
Type A's
Type A behavior has been associated with coronary heart disease, but little is known about how Type A behavior relates to diet.
The relation between Type A behavior and diet was examined.
In men Type A score showed a weak but significant association with fat and protein intake, and intake of beef, cheese, yogurt and French fries.
In women, Type A score showed a weak positive association with sugar and alcohol intake. In both men and women, Type A score was positively associated with the "convenience" dietary pattern.
Barker ME et al., Do type As eat differently? A comparison of men and women. Appetite, 1996 Jun, 26:3, 277-85.
Cholesterol & CHD
Contents:
Cholesterol (3)
Dyslipidaemia
Cholesterol (1)
Evaluated adults (3,000 +) of both sexes who had serum cholesterol levels above 200 mg/dl and some had HDL levels of 40 mg/dl. These patients were then assigned to a diet and exercise program. Prevalence of low HDL cholesterol was significantly greater in men.
The National Cholesterol Education Program recommends lipoprotein analysis between cholesterols of 200 and 240 only if 2 or more risk factors are present. In this study 74.3% of the men and 41.3% of the women with total cholesterol levels greater than 200 mg/dl were found to have HDL less than 40 mg/dl.
The prevalence of risk factors was high: 40.5% had hypertension, 9.6% had diabetes and 20.3% smoked. Routine screening for HDL cholesterol in the family practice setting could be a valuable risk factor assessment tool.
"Low-Density Lipoprotein Cholesterol and the Other Coronary Heart Disease Risk Factors in Patients With Total Cholesterol Levels Greater Than 5.17 mmol/l (200 mg/dl) in "Family Practice", Stelmach, W. Jack, MD, J of the American Board of Family Practice, September/October, 1991;285-294.
Cholesterol (3)
Reductions of serum low-density lipoprotein (LDL) levels substantially decrease the risk for coronary heart disease.
Aggressive lowering of LDL levels in high-risk patients promises to significantly reduce morbidity and mortality from coronary heart disease in the first third of the 21st century. However, several additional measures will be required to marginalize coronary heart disease. Other lipoprotein abnormalities and other risk factors, e.g., cigarette smoking, hypertension, and diabetes mellitus, must be controlled to obtain the full benefit of LDL-lowering therapy.
Moreover, the health care delivery system must be reorganized to put more emphasis on prevention.
Grundy SM: Cholesterol and coronary heart disease. The 21st century. Arch Intern Med, 1997 Jun 9, 157:11, 1177-84.
Cholestereol (2) - Finland from 1972 to 1992
Coronary heart disease mortality has declined in Finland by 55% among men and 68% among women between 1972 and 1992. About three-quarters of this decline has been explained by changes in the main coronary risk factors, the decrease in serum cholesterol being the most important one.
Analyzed to what extent dietary changes could explain the change in serum cholesterol.
The total fat content of the Finnish diet changed from 38% of energy to 34%, saturated fat from 21 to 16%, and polyunsaturated fat from 3 to 5% and the intake of cholesterol decreased by 16%. Based on Keys equation these changes could have decreased serum cholesterol level by 0.6 mmol/liter (23 mg/dl) in both genders.
A shift from boiled to filtered coffee could have further decreased serum cholesterol by 0.3 mmol/liter (11 mg/dl).
Thus, these changes together could explain the total change in serum cholesterol, which has been on average 1.0 mmol/liter (38 mg/dl). Several other changes in the diet have also been favorable.
Fruit and vegetable consumption has increased two- to three-fold during this time period. Supplementation of fertilizers with selenium since 1985 has tripled the intake of selenium.
Also a decline in smoking among males as well as better blood pressure control.
Pietinen P et al., Changes in diet in Finland from 1972 to 1992: impact on coronary heart disease risk. Prev Med, 1996 May-Jun, 25:3, 243-50.
Dyslipidaemia
Although the strength of total cholesterol levels as a relative risk factor for coronary heart disease (CHD) declines with age, the prevalence of CHD increases dramatically with age. Data from cholesterol treatment trials, although sparse in older adults, suggest that dyslipidaemia treatment has the potential to prevent CHD. In particular, dyslipidaemia treatment appears to be most beneficial in older adults with a history of CHD or who have several other CHD risk factors.
Treatment decisions should be guided by the patient's dyslipidaemic class, which is determined by the cholesterol subfractions and serum triglycerides (TG). Nutritional therapy remains the first step in dyslipidaemia management in high risk, nondebilitated older adults.
An array of cholesterol modifying medications are available which vary widely in treatment effects, adverse effects and cost. Extra care needs to be taken in prescribing these agents in older adults because of greater potential for adverse effects and interactions with other medications.
Management of older adults with hypercholesterolaemia. Pacala-JT et al., Drugs-Aging. 1994 May; 4(5): 366-78.
Copper & CHD
The Western diet, responsible for the epidemic of ischemic heart disease, is low in copper relative to requirements. More than 60 similarities between animals deficient in copper and people with ischemic heart disease have been identified. Some current therapy and dietary practices have copper enhancing effects.
"Ischemic Heart Disease: Nutrition or pharmacotherapy?" Klevay, L.M. J. Trace Element. Electrolytes Health Dis. 1993, 7: 63-69. (Review)
Lipoprotein & CHD
Lipoprotein (1)
Low HDL levels are inversely related to risk for coronary heart disease. Several different mechanisms may account for this relationship.
First, low HDL levels may be directly atherogenic;
second, a low HDL often denotes high levels of other atherogenic lipoproteins (for example, remnants); and
third, a low HDL frequently accompanies other coronary risk factors (for example, insulin resistance, diabetes, and raised blood pressure).
This multiplicity of relationships probably explains the power of low HDL levels to predict acute coronary events.
Vega GL & Grundy SM: Hypoalphalipoproteinemia (low high density lipoprotein) as a risk factor for coronary heart disease. Curr Opin Lipidol, 1996 Aug, 7:4, 209-16.
Lipoprotein (2) - butter or margarine?
Intake of trans fatty acids unfavorably affects blood lipoproteins. As margarines are a major source of trans, claims for the advantages of margarines over butter need to be scrutinized.
Reviewed the effects of butter and margarine on blood lipids.
Calculated the changes in average blood lipid levels between study diets (49 comparisons) as a function of the percentage of calories as margarine substituted for butter. Replacing 10% of calories from butter by hard high-trans stick margarines lowered total serum cholesterol by 0.19, LDL by 0.11, and HDL by 0.02 mmol/l, and did not affect the total/HDL cholesterol ratio.
Soft low-trans tub margarines decreased total cholesterol by 0.25 and LDL by 0.20 mmol/l, did not affect HDL, and decreased the total/HDL cholesterol ratio by 0.20.
Based on the total/HDL cholesterol ratio, replacement of 30 g of butter per day by soft tub margarines would theoretically predict a reduction in coronary heart disease risk of 10%, while replacement of butter by hard, high-trans margarines would have no effect.
Replacing butter by low-trans soft margarines favorably affects the blood lipoprotein profile and may reduce the predicted risk of coronary heart disease, but high-trans hard margarines probably confer no benefit over butter.
Zock PL & Katan MB: Butter, margarine and serum lipoproteins. Atherosclerosis, 1997 May, 131:1, 7-16.
Fetal origins & CHD
Contents:
Fetal nutrition
Fetal origins
Mothers' pelvic size
Fetal nutrition
Recent finding suggest that many fetuses have to adapt to a limited supply of nutrients and in doing so they permanently change their physiology and metabolism. These 'programmed' changes may be the origins of a number of diseases in life, including coronary heart disease and the related disorders stroke, diabetes and hypertension.
Barker DJ: Fetal nutrition and cardiovascular disease in later life. Br Med Bull, 1997 Jan, 53:1, 96-108.
Fetal origins
Adult-onset cardiovascular disease has its origin in childhood. A number of articles have dealt with the effects of fetal nutrition on the development of cardiovascular disease in adult
Two of the most important observations over the past year are: that fetal and early childhood nutrition impact many of the cardiovascular diseases seen in adult individuals and passive smoking increases the risk of developing coronary heart disease.
Fetal and pediatric origins of adult cardiovascular disease. Rocchini-AP. Curr-Opin-Pediatr. 1994 Oct; 6(5): 591-5.
Mothers' pelvic size
People who have a low birthweight show increased death rates from coronary heart disease and a higher prevalence for its risk factors. These findings have led to the hypothesis that the disease is programmed in fetal life.
Explored whether risk of stroke in adult life was linked to impaired fetal growth.
Death rates from both stroke and coronary heart disease tended to be highest in men whose birthweight had been low.
Mortality from stroke was most strongly associated with low birthweight in relation to head size, and low placental weight in relation to head size. These patterns of growth occurred in offspring of mothers with flat bony pelvises.
Stroke may originate in poor nutrition during the mother's childhood, which deforms the bony pelvis and subsequently impairs her ability to sustain the growth of the placenta and fetus in late pregnancy. Coronary heart disease, on the other hand, seems to originate in adaptations made by the fetus to inadequate delivery of nutrients when it occurs for reasons other than failure of placental growth.
Martyn CN et al., Mothers' pelvic size, fetal growth, and death from stroke and coronary heart disease in men in the UK [see comments]. Lancet, 1996 Nov 9, 348:9037, 1264-8.
Fatty acids & CHD
Contents:
Linoleic Acid
Trans fatty acids (3)
Linoleic Acid
Populations with the highest incidence of coronary artery disease (CAD) have the lowest intake and tissue levels of linoleic acid. Linoleic acid is the main essential fatty acid in the biology of man and it is the precursor to arachidonic acid.
Lower linoleic acid tissue status shows an increased risk to CAD. Natural antioxidants include vitamins A, C and E and beta-carotene.
Low linoleic acid intake may indicate a higher saturated fat consumption resulting in other cardiovascular risk factors. Saturated fats tend to have a more prothrombotic tendency whereas polyunsaturated fats have an antithrombotic tendency. Low antioxidant status may increase the risk to long chain polyunsaturated fatty acid peroxidation and LDL oxidation leading to the formation of foam cells for macrophages.
There is an inverse relationship between low linoleic acid, vitamin C and E levels; which warrants assessment of tissue and plasma linoleic acid concentrations and plasma concentrations of vitamins E and C in epidemiologic surveys. He recommends, as a public measure, increasing omega-6 fatty acid consumption along with vitamins E and C.
"Linoleic Acid, Antioxidants and Coronary Heart Disease", Oliver, M.F., Biochemical Society Transactions, 1990;18:1049-1051.
Trans fatty acids (1)
A high intake of trans fatty acids (TFAs) has been shown to have an undesirable effect on serum lipid profiles and lipoprotein(a) (Lpa)) levels and may thereby increase the risk for coronary heart disease (CHD).
Measured the TFA concentration of the plasma phospholipid fraction in CHD patients.
No significant correlations were found between percentages of TFAs in plasma phospholipids and plasma LDL or HDL cholesterol levels.
Findings do not support an association between TFA intake and risk for coronary heart disease.
van de Vijver LP et al., Trans unsaturated fatty acids in plasma phospholipids and coronary heart disease: a case-control study. Atherosclerosis, 1996 Sep 27, 126:1, 155-61.
Trans fatty acids (2) - (Danish Nutrition Council)
Trans fatty acids constitute 0-30% of the fat in Danish margarines, most in industry and bakery margarines and usually less in table margarine. The trans fatty acids make margarines more solid at room temperature and therefore provide an economical storage advantage.
In British and U.S. reports from 1984-1989, the trans fatty acids were more or less acquitted of unhealthy effects. During the last 5-6 years, however, a series of new studies has been published regarding both the connection between the consumption of trans fatty acids and the occurrence of coronary heart disease and the impact on the lipoprotein level in plasma.
Studies suggest that the consumption of trans fatty acids from margarine is equally, or perhaps more, responsible for the development of arteriosclerosis than saturated fatty acids.
In addition, it is now clear that both the fetus and the breast-fed baby are exposed to trans fatty acids in relation to the mother's consumption. A couple of recent studies suggest a possible restrictive influence of the trans fatty acids on the weight of the fetus.
The average consumption of trans fatty acids from margarine in Denmark in 1991 was approximately 2.5 g/day per person. For about 150,000 adult Danes, the consumption is assumed to be more than 5 g/day per person. On this basis, the Danish Nutrition Council recommend that the consumption of trans fatty acids is reduced as much as possible.
Ideally restrict consumption to below 2 g of vegetable trans fatty acids/day. This corresponds to the low-risk groups in the above-mentioned epidemiological studies. In addition, the Danish Nutrition Council encourage the producers of margarines to make products that can be marketed as 'free of trans fatty acids'.
Stender S et al., The influence of trans fatty acids on health: a report from the Danish Nutrition Council [see comments]. Clin Sci (Colch), 1995 Apr, 88:4, 375-92.
Trans fatty acids (3)
Most dietary fatty acids contain at least one double bond, which is usually in the cis configuration. However, biohydrogenation in the rumen of cows and sheep, or catalytic hydrogenation of vegetable oils in the food industries, will convert some of the cis double bonds to the trans configuration.
Trans fatty acid intake in western Europe and North America probably ranges from 5 to 15 g/day. Major dietary sources are frying fats used in industrial food preparation, margarines, and other spreads. In the past, margarines contained up to 50% trans fatty acids; however, these are now being phased out.
Trans fatty acids raise serum low density lipoprotein (LDL) cholesterol and lower high density lipoprotein (HDL) cholesterol in humans when substituted for cis unsaturated fatty acids in the diet. These effects may be mediated by the cholesteryl ester transfer protein. Trans fatty acids also increase lipoprotein (a) levels relative to other fatty acids.
The effects of trans fatty acids on the risk profile for coronary heart disease are thus unfavorable, and labels of food products should state the trans fatty acid content.
Zock PL & Katan MB: Trans fatty acids, lipoproteins, and coronary risk. Can J Physiol Pharmacol, 1997 Mar, 75:3, 211-6.
Costs of CHD (USA)
Estimated the effects of reducing dietary saturated fat intake on the incidence and economic costs of coronary heart disease (CHD) in the United States.
[Framingham Heart Study and the second and third National Health and Nutrition Examination Surveys.],
Approximately 3 million first-time coronary events are estimated to occur over a 10-year period among persons with total cholesterol levels exceeding 5.17 mmol/L.
Reducing saturated fat intake by one to three percentage points would reduce CHD incidence by 32,000 to 99,700 events and yield combined savings in medical expenditures and lost earnings ranging from $4.1 to $12.7 billion over 10 years (estimates in 1993 US dollars).
Population-based interventions to encourage Americans to reduce dietary intake of saturated fat may prevent tens of thousands of cases of CHD and save billions of dollars in related costs.
Oster G & Thompson D: Estimated effects of reducing dietary saturated fat intake on the incidence and costs of coronary heart disease in the United States. J Am Diet Assoc, 1996 Feb, 96:2, 127-31.
Diet & CHD
Contents:
Diet (1)
Mediterranean diet
Diet (1)
The causal factors of CHD are numerous, with diet playing a significant role in progression. As CHD is a chronic, progressive disease, a preventive rather than a palliative approach is indicated. Although health promotion initiatives pledge support for a preventive approach, resources have not followed government rhetoric. Research suggests nurses' knowledge of the dietary factors involved in CHD is poor.
Page M & Ward SL: The role of diet in coronary heart disease. Prof Nurse, 1995 Aug, 10:11, 691-2, 694, 696.
Mediterranean diet
Dietary habits are implicated in coronary heart disease, and the traditional Mediterranean diet is thought to be cardioprotective. However, the exact mechanisms of this protection are unknown.
Described the various cardiovascular complications that occurred in the Lyon Diet Heart Study (a secondary prevention trial testing the protective effects of a Mediterranean type of diet), analyzed their relations with the associated drug treatments and gained insights into the possible mechanisms underlying the beneficial effects of certain nutriments.
Major primary end points (cardiovascular death and nonfatal acute myocardial infarction), secondary end points (including unstable angina, stroke, heart failure and embolisms) and minor end points (stable angina, need for myocardial revascularization, postangioplasty restenosis and thrombophlebitis) were analyzed separately and in combination.
When major primary and secondary end points were combined, there were 59 events in control subjects and 14 events in the study patients, showing a risk reduction of 76%. When these end points were combined with the minor end points, there were 104 events in control subjects and 68 events in the study patients, giving a risk reduction of 37%.
By observational analysis, only aspirin among the medications appeared to be significantly protective
Data showed a protective effect of the Mediterranean diet. However, the risk reduction varied depending on the type of end point considered. Our hypothesis is that different pathogenetic mechanisms were responsible for the development of the various complications. It is likely that certain nutriments characteristic of the Mediterranean diet (omega-3 fatty acids, oleic acid antioxidant vitamins) have specific cardioprotective effects.
De Lorgeril M et al., Effect of a Mediterranean type of diet on the rate of cardiovascular complications in patients with coronary artery disease. Insights into the cardioprotective effect of certain nutriments [see comments]. J Am Coll Cardiol, 1996 Nov 1, 28:5, 1103-8.
Education & CHD
Contents:
Cholesterol Education
Community education
Physician & nurse educators
Cholesterol Education
U.S. Army soldiers (# 59) were divided into groups that completed and did not complete cholesterol nutrition education classes. Differences in the means of repeated cholesterol measures were compared within each group.
Results showed statistically significant declines in total cholesterol and low-density lipoprotein measures. However, cholesterol differences in the means between the two groups were not statistically significant. Results indicate that decreases in serum cholesterol may occur due to at-risk reactive behavior, but that full compliance with the current nutrition education program does not appear to further reduce cholesterol levels to any appreciable degree.
Powell AJ et al., Health risk appraisal and serum cholesterol nutrition education: an outcome study. Mil Med, 1996 Feb, 161:2, 70-4.
Community education
Measured voluntary participation by people with coronary heart disease in community nutrition education and identified any self-selection bias with respect to eating habits among the participants.
A dietary risk score, which was the proportion of all food choices that were high in fat, was calculated from the data.
Results suggest that voluntary participation by people with heart disease in community nutrition education is low and that there is a self-selection bias, with those at highest dietary risk being least likely to attend. The use of existing community networks to recruit participants is also discussed.
Elliott H Community nutrition education for people with coronary heart disease--who attends? Aust J Public Health, 1995 Apr, 19:2, 205-10.
Physician & nurse educators
1. Compared the impact of a brief physician or nurse education session with the impact of education provided by dietitians on patient knowledge regarding coronary risk factors, dietary recommendations, and compliance, and
2. determined the value of additional formal dietary counseling on knowledge, dietary fat, and serum lipids.
Primary care physicians and their office nurses were compared with inpatient dietitians by evaluating patient performance on a standardized test and 3-day dietary food choices.
By participant recall, the dietitians (group II) spent an average of 31 minutes, compared with 8 minutes by the physicians and nurses (group I).
Group II patients had a higher total knowledge score, but they were no better in risk factors, weight control, or calculated dietary fat or cholesterol.
There was no correlation between time spent and percentage of calories from fat or total test score.
Six weeks after the program instruction the mean cholesterol level for all the participants was reduced, and group II had a lower fat intake than did group I, which was associated with significantly lower serum cholesterol, not present at entry.
Primary care physicians and their office nurses, using less time than do dietitians, can be effective educators in providing patient education for coronary risk reduction and dietary fat intake. A second formal dietary consultation appears beneficial in improving compliance and lipid control.
Peiss B et al., Physicians and nurses can be effective educators in coronary risk reduction. Gen Intern Med, 1995 Feb, 10:2, 77-81.
Exercise & CHD
Some investigators have concluded that health beliefs do not influence the maintenance of coronary heart disease (CHD) exercise adherence.
Explored the possible utility of the Health Belief Model (HBM) for explaining attendance at a supervised CHD exercise program, based in a community center. Two dimensions of the model, general health motivation and perceived severity of CHD, were associated with attendance in the theoretically predicted direction, while a third dimension, perceived benefits of exercise, was associated in a direction opposite that predicted by the model.
Health beliefs are associated with CHD exercise adherence.
Mirotznik J et al., The health belief model and adherence with a community center-based, supervised coronary heart disease exercise program. J Community Health, 1995 Jun, 20:3, 233-47.
Folate & CHD
Assessed the relationship between serum folate level and the risk of fatal coronary heart disease (CHD) among men and women. [Nutrition Canada Survey.]
Found a statistically significant association between serum folate level and risk of fatal CHD, with rate ratios for individuals in the lowest serum folate level category (13.6 nmol/L [6 ng/mL]) of 1.69.
Data indicate that low serum folate levels are associated with an increased risk of fatal CHD.
Morrison HI et al., Serum folate and risk of fatal coronary heart disease [see comments]. JAMA, 1996 Jun 26, 275:24, 1893-6.
Fiber & CHD
Examined the relationship between dietary fiber and risk of coronary heart disease.
A 10-g increase in total dietary fiber corresponded to an RR for total MI of 0.81. Within the three main food contributors to total fiber intake (vegetable, fruit, and cereal), cereal fiber was most strongly associated with a reduced risk of total MI (RR, 0.71; 0.55 to 0.91 for each 10-g increase in cereal fiber per day).
Results suggest an inverse association between fiber intake and MI and that fiber, independent of fat intake, is an important dietary component for the prevention of coronary disease.
Rimm EB et al., Vegetable, fruit, and cereal fiber intake and risk of coronary heart disease among men [see comments]. JAMA, 1996 Feb 14, 275:6, 447-51.
Insulin & CHD
Insulin resistance
The insulin resistance syndrome has recently been implicated in the etiology of coronary heart disease, with a possible metabolic defect at the level of the adipocyte.
Compared the effects of a low- versus high-glycemic-index (LGI and HGI, respectively) diet on insulin and glucose response as assessed by oral glucose tolerance test (OGTT) and insulin-stimulated glucose uptake in isolated adipocytes in a group of patients with advanced coronary heart disease (# 32).
The area under the insulin curve following OGTT was significantly reduced after 4 weeks in the LGI group but not in the HGI group. Insulin-stimulated glucose uptake in isolated adipocytes harvested from a presternal fat biopsy was significantly greater following the LGI diet.
Simple, short-term, dietary measures can improve insulin sensitivity in patients with coronary heart disease.
Frost G: The effect of low-glycemic carbohydrate on insulin and glucose response in vivo and in vitro in patients with coronary heart disease. Metabolism, 1996 Jun, 45:6, 669-72.
Nutrition & CHD
Nutrition (1) - serum lipids
The association between nutrition and coronary heart disease is mainly due to the effect of nutrients on serum lipids and lipoproteins. Cholesterol intake does not play a very important role for plasma cholesterol although there is a strong interindividual difference in response.
The intake of saturated fatty acids strongly negatively affects plasma low-density lipoprotein cholesterol concentration while mono- and polyunsaturated fatty acids are generally regarded as beneficial.
Omega-3 fatty acids mainly decrease triglyceride concentration while omega-6 polyunsaturated fatty acids mainly affect low-density lipoprotein cholesterol.
Other nutrients which affect risk for coronary heart disease are dietary fiber, calcium, magnesium, iron, antioxidants as well as vitamins.
Dietary fiber decrease intake of calories and fat, while iron and antioxidants play a role in oxidative modification of low-density lipoproteins. A low intake would lead to an accelerated uptake of low-density lipoprotein into the macrophage. Yet, intervention studies have not shown conclusively the benefit of a high-dose supplementation of the antioxidants vitamin E or beta-carotene on coronary heart disease. Homocysteine plasma concentration is influenced by folate as well as vitamin B6 and B12. Whether a high-dose supplementation with these substances does not only decrease plasma concentrations of homocysteine but also positively influence the course of coronary heart disease remains to be established.
Klor HU et al., Nutrition and cardiovascular disease. Eur J Med Res, 1997 Jun 16, 2:6, 243-57.
Nutrition (2)
Nutrition and food science have each enhanced the development of an abundant, nutritious, safe food supply. A healthy diet should contain all of the required nutrients and sufficient calories to balance energy expenditure and provide for growth and maintenance throughout the life cycle.
Importantly, dietary factors are associated with 5 of the 10 leading causes of death, including: coronary heart disease, certain types of cancer, stroke, noninsulin dependent diabetes mellitus and atherosclerosis.
National health care expenditures for 1990 totaled $666 billion of which 30% are related to inappropriate diet. Identification of external factors that contribute to premature death would aid preventive efforts, improve the quality of life, and reduce health care costs.
Even though genetic predisposition increases susceptible people's risk for many of these chronic diseases, these conditions may be diminished or prevented by improvements in the American diet.
Each stage of the life cycle has specific nutrient needs. Throughout infancy, childhood and adolescence nutrients are required to meet the growth processes as well as cognitive function. During pregnancy nutrients are required for both mother and developing infant needs. Calcium intake at early ages affects development of bone density and manifestation of osteoporosis.
Adult nutrition focuses on tissue maintenance, nutrient and energy needs, and disease prevention. As the population of elderly increase in number and greater age, nutritional needs must be met to minimize certain disease states and assure the quality of life.
Nutrition associated health risks have been identified for coronary heart disease, cancer and diabetes mellitus. Recommendations for each includes: a decrease in dietary fat, awareness of caloric intake and enhancement of nutrient density including an increase in fruit and vegetables. These recommendations also impact obesity and diminish the compounding of other disease states affected by excessive body weight.
Improved quality and availability of nutritious foods will result in a healthier, more productive population. A decrease in the occurrence and duration of chronic disease should diminish the cost of health care and allow these resources to further benefit the nation.
International concerns about undernutrition include 780 million people who are malnourished, lacking sufficient food to meet their basic nutritional needs for protein and energy, and 2 billion people who subsist on diets lacking essential nutrients needed for growth, development and physiological maintenance.
National concerns about undernutrition exist based on incomplete data identified by indices of hunger and characterized by an increased demand for food assistance for women, children and the elderly.
Major health problems in the US impacted by diet and nutrition include coronary heart disease, atherosclerosis, some types of cancer, non-insulin dependent diabetes mellitus and hypertension.
Bidlack WR: Interrelationships of food, nutrition, diet and health: the National Association of State Universities and Land Grant Colleges White Paper. J Am Coll Nutr, 1996 Oct, 15:5, 422-33.
Nuts & CHD
Throughout history, nuts have been a staple food providing energy, protein, essential fatty acids, vitamins, and minerals. Today, nuts are classified as part of the USDA Food Guide Pyramid's Meat/ Meat Alternate Group. Foods in this group contribute protein as well as important vitamins and minerals to the diet. Nuts are also being studied for their potential health benefits.
Research suggests that there may be a connection between frequent nut consumption and a reduced incidence of coronary heart disease.
Dreher ML et al., The traditional and emerging role of nuts in healthful diets. Nutr Rev, 1996 Aug, 54:8, 241-5.
BMI & CHD
Contents:
Anthropometric measurements
Body mass index
Overweight
Anthropometric measurements
Examined the association between anthropometric measurements [body mass index (BMI), waist/hip ratio (WHR), and waist/thigh ratio (WTR)] and cardiovascular risk factors; and assessed whether a combination of BMI and WHR could be used in routine screening of risk for cardiovascular arteriosclerotic disease at worksites.
Serum cholesterol, triglyceride, fibrinogen, and blood pressure were positively related to the anthropometric variables, while high-density lipoprotein (HDL) was inversely related with them.
BMI, WHR, and WTR were positively related to serum cholesterol, triglycerides, fibrinogen, diastolic blood pressure, and systolic blood pressure, and inversely related to HDL.
Overall, the anthropometric variables BMI and WHR were considered the best predictors for CAD risk when taking several risk factors into consideration.
A joint variable between BMI and WHR, called "body score", constituted the four categories lean, lean android, overweight gynoid, and overweight ovoid. This body score was positively associated with levels of serum lipids, fibrinogen, and blood pressure, and inversely associated with HDL.
Data support the hypothesis that BMI, WHR, and WTR are independent predictors for risk factors for CAD among oil workers, and that combinations of BMI and WHR are strong enough predictors to be useful in routine screening for CAD risk at worksites.
Oshaug A et al., Use of anthropometric measurements in assessing risk for coronary heart disease: a useful tool in worksite health screening? Int Arch Occup Environ Health, 1995, 67:6, 359-66.
Body mass index
Increased body weight has been associated with an increased risk of morbidity and mortality from coronary heart disease (CHD) in several populations.
Studied the distribution of body mass index (BMI, kg/m2) in men (n = 1566; mean age, 49 +/- 10 years) and women (n = 1627; mean age, 49 +/- 10 years) participating in the third examination cycle of the Framingham Offspring Study and the association of BMI with known CHD risk factors.
In men, BMI increased with age until age 50 years, when it reached a plateau. In women, there was a trend toward an increase in BMI with age up to the seventh decade of life. Seventy-two percent of men and 42% of women had a BMI > or = 25.00, the cutoff point for the definition of overweight.
In age-adjusted analyses, BMI was significantly and linearly associated with systolic blood pressure, fasting glucose levels, plasma total cholesterol, VLDL cholesterol, and LDL cholesterol levels and was inversely and linearly associated with HDL cholesterol levels in nonsmoking men and women.
The association between BMI and apolipoprotein B and A-I was similar to that of LDL and HDL cholesterol, respectively. LDL size was also linearly associated with BMI: subjects with higher BMI had smaller LDL particles.
Lipoprotein(a) levels were not associated with BMI in this population.
Of all these risk factors for CHD, reduced HDL cholesterol levels and hypertension were those more strongly associated with higher BMI in both men and women. Elevated triglyceride levels and small LDL particles, and diabetes in women, were also strongly associated with higher BMI values in this population.
Results indicate that a high prevalence of adult Americans are overweight and support the concept that increased BMI is associated with an adverse effect on all major CHD risk factors. Illustrate the importance of excess body fat as a public health issue.
Lamon-Fava S et al., Impact of body mass index on coronary heart disease risk factors in men and women. The Framingham Offspring Study. Arterioscler Thromb Vasc Biol, 1996 Dec, 16:12, 1509-15.
Overweight
Evaluated risk of late life coronary heart disease associated with being overweight in late middle or old age and assessed whether weight change modifies this risk.
Body mass index of 27 or more in late middle age was associated with increased risk of coronary heart disease in late life (relative risk = 1.7 while body mass index of 27 or more in old age was not (1.1).
This difference in risk was due largely to weight loss between middle and old age. Exclusion of those with weight loss of 10% or more increased risk associated with heavier weight in old age (1.4). Thinner older people who lost weight and heavier people who had gained weight, showed increased risk of coronary heart disease compared with thinner people with stable weight.
Heavier weight in late middle age was a risk factor for coronary heart disease in late life. Heavier weight in old age was associated with an increased risk once those with substantial weight loss were excluded. The contribution of weight to risk of coronary heart disease in older people may be underestimated if weight history is neglected.
Harris TB et al., Cohort study of effect of being overweight and change in weight on risk of coronary heart disease in
Vitamin E & CHD
Patients (#24) with stable angina pectoris admitted for elective revascularization were given alpha-tocopherol acetate preoperatively.
There was a decrease in myocardial alpha-tocopherol levels with the onset of reperfusion (cross-clamp removal). The myocardial tocopherol levels were not statistically different from preoperative levels by 20 minutes of reperfusion.
At least 300 mgs of alpha-tocopherol must be taken orally for 14 consecutive days to double the myocardial alpha-tocopherol levels.
Vitamin E is a major lipid soluble chain-breaking antioxidant that is important in the prevention of myocardial damage from oxyradical ischemia-reperfusion injury.
Effect of Orally Administered Alpha-Tocopherol Acetate on Human Myocardial Alpha-Tocopherol Levels. Mickle, D et al., Card. Drugs & Therapy, 1991;5:309-12.
Fish oil & CHD
Patients (#176) undergoing their first coronary bypass surgery were given 15 gm/d of MaxEPA or placebo starting 3 weeks before surgery, versus 100 mg/d of aspirin or its placebo starting 7 hours after surgery. Fish oil was not superior to low dose aspirin in preventing early (7 days) and mid (1 year) term saphenous venous graft obstruction following coronary artery bypass surgery.
"A Double-Blind, Randomized Placebo Controlled Study Comparing the Efficacy of Fish Oil and Low Dose Aspirin to Prevent Coronary Saphenous Vein Graft Obstruction After CABG", Roy, Louis, et al, Circulation, October 1991;84(4):Supplement 2/II-285/Abstract 1136.
Seasonality of CHD
Seasonal variation
Seasonal variation in the plasma lipids and lipoproteins is reported in the literature. Whether this variation is the result of changes in diet, or other factors, has not been adequately addressed.
Investigated the effects of a controlled diet on the seasonal variation in the levels of plasma lipids and apolipoproteins and also on the excretion of urine metabolites of TXA2 and PGI2 in healthy males.
Seasonal fluctuations were observed in all subjects in plasma Apo A-1 (zenith = July) and Apo B (zenith = October). Although there was no significant variation in plasma cholesterol levels, the increase in Apo B is consistent with an increase in LDL particle number during the fall/winter. Additionally, excretion of both eicosanoid metabolites and the ratio of 6-keto-PGF1 alpha/TXB2 was markedly elevated in July.
Three seasonal fluctuations were observed both in participants who consumed a highly-controlled experimental diet and in the non-intervention controls. Thus, these results suggest a diet-independent seasonal variation in parameters thought to be involved in coronary heart disease risk status.
Mustad V et al., Seasonal variation in parameters related to coronary heart disease risk in young men. Atherosclerosis, 1996 Sep 27, 126:1, 117-29.
Survival with CHD
Survival - gender
Examined the sex differential in long-term survival after incident coronary heart disease (CHD). [the Epidemiologic Followup Study to the First National Health and Nutrition Examination Survey.]
The relative risk of death among women compared to men was 0.70. Women's survival advantage after myocardial infarction was 0.81. Women who had ever taken post-menopausal estrogens were most likely to survive after CHD or myocardial infarction compared to men (relative risks [RRs] = 0.42 and 0.57, respectively), although women who did not take estrogen were also significantly more likely than men to survive after CHD (RR = 0.79) but not after myocardial infarction (RR = 0.88).
Brett KM & Madans JH: Long-term survival after coronary heart disease. Comparisons between men and women in a national sample [see comments]. Ann Epidemiol, 1995 Jan, 5:1, 25-32.
HRT & CHD
HRT - Hormone replacement therapy
The importance of cardiovascular disease as a cause of morbidity and mortality in women is well appreciated. Cardiovascular disease accounts for approximately 48% of deaths in women in the United States. In particular, coronary heart disease (CHD) accounts for approximately one-half of these deaths.
It is premature to recommend hormone replacement therapy (HRT) as a proven prevention strategy for CHD.
Sotelo MM & Johnson SR: The effects of hormone replacement therapy on coronary heart disease. Endocrinol Metab Clin North Am, 1997 Jun, 26:2, 313-28.
Depression & CHD
Depression
According to this article, depression may contribute to development of and mortality from ischemic heart disease. In the last several years, there have been six community surveys which have followed populations initially free of disease, and five have observed an increased risk of ischemic heart disease among those who are depressed. This association may be due to depression's effect on the autonomic nervous system and immune system. In one particularly well-designed study in patients with depression, in the period immediately after a myocardial infarction they were 3.5 times more likely to die than the nondepressed patients.
Glassman, Alexander H., M.D. and Shapiro, Peter A., M.D.: Depression and the Course of Coronary Artery Disease, American Journal of Psychiatry, 1998;155:4-11.
Chocolate and Tea
Chocolate and Tea
Chocolate contains more antioxidant catechins than black tea. Catechins are flavonoids, an antioxidant that prevents heart disease and boosts the immune system. In a Dutch laboratory study, the catechin concentrations of tea and chocolate were compared. As a result, dark chocolate had 53.5 mg of catechins per 100 g, milk chocolate contained 15.9 mg per 100 g, and black tea contained the least amount of catechins, 13.9 mg/100g. Dr. Arts and colleagues conclude, "In the end…the old Dutch habit of drinking a cup of tea and eating a chocolate cookie might be not only enjoyable but healthy as well."
Arts IC, Hollman PC, Kromhout D. Chocolate as a source of tea flavonoids. Lancet 1999 Aug 7;354(9177):488.
Polyunsaturated Fatty Acids
n-3 polyunsaturated fatty acids
Long-chain polyunsaturated fatty acids, such as eicosapentaenoic and docosahexaenoic acids, have been shown to effectively reduce fasting plasma triacylglyerol levels. High triacylglycerol concentrations have been associated with an increased risk of coronary heart disease, reduced levels of HDL cholesterol, and increased numbers of highly atherogenic LDL particles. Triacylglycerol levels in the blood increase dramatically after a high-fat meal, and this intensity of increase is determined, in part, by fasting triacylglycerol levels.
Roche HM, Gibney MJ: Effect of long-chain n-3 polyunsaturated fatty acids on fasting and postprandial triacylglycerol metabolism, Am J Clin Nutr 2000 Jan;71(1 Suppl):232S-7S
Polyunsaturated fatty acids
According to an Italian clinical study, one gram of n-3 polyunsaturated fatty acids (PUFA) consumed daily reduces the risk of recurrent coronoary events in myocardial infarction survivors. In this study, the effects of n-3 PUFA, vitamin E, a combination of both, or neither were compared for 3.5 years. Supplementation with n-3 polyunsaturated fatty acids lowered the risk of cardiovascular deaths by 15% on a four-way analysis of all treatment groups. No beneficial effects of vitamin E were established. The effects of combined treatment with n-3 PUFA and vitamin E were similar to those of n-3 PUFA alone. Further study of vitamin E is recommended.
Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico. Lancet 1999 Aug 7;354(9177):447-55.
Green Tea
Green Tea
Green tea may lower the risk for coronary heart disease by preventing the oxidation of LDL-cholesterol, according to this study. Lung Chen Tea, a non-fermented Chinese green tea, was studied in vitro for its affect on LDL cholesterol. Amounts of 5-10 microg/ml significantly lowered lipid peroxidation products and improved cellular cholesterol.
Yang TT, Koo MW: Inhibitory effect of Chinese green tea on endothelial cell-induced LDL oxidation, Atherosclerosis 2000 Jan;148(1):67-73
Olive Oil and CHD
Olive oil and CHD
Hydroxytyrosol and oleuropein - two phenolic components of olive oil - are potent scavengers of free oxygen radicals, which cause oxidative damage leading to coronary heart disease and cancer. The Mediterranean people, who eat diets rich in olives and olive oil, exhibit a markedly lower incidence of heart disease and cancer than Western countries. This phenomena is most likely due to the antioxidant functions of olive oil.
Visioli F, Bellomo G, Galli C: Free radical-scavenging properties of olive oil polyphenols, Biochem Biophys Res Commun 1998 Jun 9;247(1):60-4
Blood lipids & CHD
Blood lipids
Blood lipid levels may be an independent risk factor for stroke in people with coronary heart disease (CHD), according to this study. An association between high lipid levels, low HDL cholesterol levels, and stroke was found in this study of 941 patients with CHD, 487 of whom suffered from a first-time ischemic stroke during the 6 to 8-year follow-up period. The correlation between high blood lipids and increased risk of stroke was apparent in patients with no significant variations due to age, sex, patient characteristics, and cholesterol fractions. These results suggest that blood lipids are an important modifiable risk factor for stroke.
Tanne D, Koren-Morag N, Graff E, Goldbourt U: Blood lipids and first-ever ishemic stroke/transient ischemic attack in the bezafibrate infarction prevention (BIP) registry: High triglycerides constitute an independent risk factor, Circulation 2001 Dec 11;104(24):2892-2897
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