Category Archive for: ‘Disease outcomes’
Different results for saturated fat, serum cholesterol and CHD in the Zutphen and the Seven Countries Study.
In 1960 the average saturated fat intake of the middle-aged men in Zutphen was high and amounted to 18% of energy with a relatively small standard deviation of 3% of energy. Dietary saturated fat was not associated with serum cholesterol and 10-year CHD mortality in the Zutphen Study. But in contrast, among populations of the Seven Countries Study showed that the average saturated fat intake, average serum cholesterol level and 10-year CHD mortality rates in the 16 cohorts were strongly correlated.
Why this difference?
The strong correlations of population levels of dietary saturated fat and serum cholesterol with CHD mortality in the Seven Countries Study overall was due to large variations in average saturated fat intake, average serum cholesterol level and CHD mortality rates among the 16 cohorts. In the Zutphen Study saturated fat intake of individuals was not related to either serum cholesterol or CHD mortality. The zero correlations were the consequence of a small range in dietary saturated fat among the Zutphen men along with the large day-to-day variation within these men (see the graphs and Jacobs et al 1979).
- Kromhout. Am J Clin Nutr 1983;38:591-8
- Kromhout and De Lezenne Coulander. Am J Epidemiol 1984;119:733-41
- Keys et al. Harvard University Press. ISBN: 0-674-80273-3,1980:248-62
- Jacobs et al. Am J Epidemiol 1979;110:77-87
- Kromhout et al. Br J Nutr 2011;106;627-32
A high intake of animal foods is related to higher long-term CHD mortality
The Seven Countries Study showed that animal food groups, with the exception of fish, were strongly positively related to 25-year CHD mortality and that plant foods, with the exception of potatoes, were inversely related. Of the individual foods, butter, hard margarines and meat were most strongly related to CHD mortality rates. The summary factor score was positive for animal foods and negative for plant foods. The population factor scores were strongly positively correlated with CHD mortality rates. The plant food-based Mediterranean Adequacy Index was inversely related to 25-year CHD mortality rates.
Western, Mediterranean and Japanese dietary patterns
In the 1960s dietary patterns high in animal foods and rich in saturated fat (Western diets) were characterized by a high meat intake in the US, a high dairy (whole fat milk and butter) intake in Finland, a high margarine (hardened fish oils) intake in the Netherlands and a high intake of lard in Slavonia (Croatia). Mediterranean patterns, with olive oil as the main source of fat, were characterized by a high intake of plant foods. The Japanese patterns were high in fish and soy products and had a very low saturated fat intake.
- Menotti et al. Eur J Epidemiol 1999;15:507-15
- Fidanza et al. Nutr Metab Cardiovasc Dis 2004;14:254-8
- Kromhout et al. Am J Clin Nutr 1989;49:889-94
Tea inversely related to coronary heart disease risk
In 1985 the average consumption of black tea in the Zutphen men was approximately 3 cups per day. Elderly men who drank more than 4 cups of tea per day had a 60% lower risk of fatal CHD after 5 years of follow-up, when compared to those who drank less than 2 cups of per day.
Higher tea consumption associated with lower stroke incidence
The average tea consumption in the period 1960-1970 was related to non-fatal and fatal stroke incidence over the next 15-years. Middle-aged men who drank on average at least 5 cups of tea per day had a 3 times lower stroke incidence than those who drank less than 2.5 cups per day.
Potentially, the effects of tea on CHD and stroke might be due to its high content of flavonoids – compounds with potential beneficial properties.
Wine associated with lower cardiovascular risk
Wine drinkers in Zutphen who at entry of the study consumed less than 20 g alcohol from wine per day – the equivalent of 2 glasses – had a 39% lower risk of coronary death and a 32% lower risk of overall cardiovascular mortality. Consumption of beer and spirits was related neither to long-term coronary or cardiovascular mortality. These results are compatible with the idea, but do not establish, that a low intake of wine may protect against CVD.
Continuous increase in wine consumption over time in Zutphen
In the Zutphen Study information on alcoholic drinks consumed was collected by questionnaire seven times between 1960 and 2000. Regular wine consumption increased from 2% of the men to 40%. Of the wine consumed, 70% was red. The percentage of beer drinkers was approximately 40% in the period 1960-1970 and fell to about 25% in the period 1985-2000. The percentage of men drinking spirits increased from 15% in 1960 to 55% in 1985 and did not change thereafter.
Only carotenoid intake associated with CVD risk
A 0.6 mg/d alpha-carotene greater intake at entry was associated with a 19% lower 15-year risk of CVD mortality in elderly men in Zutphen. Men with a 1.5 mg/d beta-carotene greater intake had a 20% lower CVD mortality risk. Carrots are the primary source of alpha- and beta-carotene and a high consumption of carrots was related to a 17% lower risk of CVD mortality. Alpha- and gamma tocopherol, and vitamin C intake were not related to cardiovascular mortality.
Conflicting results on carotenoids
Early reports of others in prospective cohort studies suggested that a high intake of beta-carotene was associated with a lower CVD risk. But in sharp contrast, large-scale trials conducted in high risk persons (e.g. smokers) showed that supplements of a large amount of beta-carotene apparently did not decrease but rather increased CVD risk. The role of carotenoids in CVD prevention, therefore, remains controversial.
The Zutphen Elderly Study results suggest that only the intake alpha- and beta-carotene was inversely related to CVD mortality.
High serum cholesterol and high CHD mortality
High levels of cholesterol in blood serum are associated with a high risk of CHD mortality in the different cohorts of the Seven Countries Study. Serum cholesterol levels in middle-aged men are a strong predictor of CHD risk mortality after 10 and 25 years of follow-up. Both past and recent serum cholesterol levels are related to 35-year CHD mortality, although the strength of the association diminishes with increasing age. Serum cholesterol is also related to 40-year CVD mortality in the US railroad cohort.
Associations are similar within cultures, but absolute risk varies between cultures
The relative risks of CHD mortality in relation to serum cholesterol level were similar in the different cohorts. Large differences in absolute CHD risk were observed among the cohorts, with high absolute risks in northern Europe and the United States and low absolute risks in Mediterranean southern Europe and Japan.
The similar relative risks and different absolute risks of CHD among the cohorts implies that at the same serum cholesterol level in high-risk cultures, elevated serum cholesterol levels need to be treated more intensely than in low-risk cultures to achieve target levels and potential prevention.
- Keys et al. Harvard University Pres. ISBN: 0-674-80273-3, 1980:121-35
- Kromhout et al. Arch Intern Med 1988;148:1051-5
- Pekkanen et al. Am J Epidemiol 1992;274:131-6
- Verschuren et al. JAMA 1995;274:131-6
- Menotti et al. Eur J Epidemiol 2004;19:417-24
- Menotti et al. Eur J Epidemiol 2005;20:597-604
- Boshuizen et al. Am J Epidemiol 2007;165:398-409
- Menotti et al. Eur J Cardiovasc Prev Rehabil 2008;15:719-25
The higher the trans fat intake the greater the CHD risk
In the Zutphen Elderly Study a difference of 2% of energy from trans fat at baseline was associated with a 28% difference in risk of 10-year coronary heart disease (CHD) incidence. The strength of the association was similar for trans fat from manufactured and natural sources. We calculated that the decrease in trans fat of 2.4 % of energy between 1985 and 1995 could have contributed to 23% less coronary deaths (equal to about 4,600 of 20,000 coronary deaths in the Netherlands per year).
Phenomenal decrease in trans fat intake in the diet of the Zutphen men
One of the characteristics of the Dutch diet in 1960 was its high amount of trans fat, due to the high content of hydrogenated hardened fish oils in solid fats. The decrease in trans fat intake between 1960 and 2000 has been the most important change in the Dutch diet. The average intake decreased from 19 gram/day (7% of energy) to 4 g/d (1% of energy) in the Zutphen Study. The spectacular decrease in trans fat between 1960 and 2000 started already before the Dutch margarine producers decided, in 1994, to reduce the trans fat content of margarines.
- Kromhout et al. Prev Med 1995;24:308-15
- De Vries et al. J Food Comp Anal 1997;10:115-41
- Oomen et al. Lancet 2001;357:746-51
Many Mediterranean diets
Ancel Keys and his Italian colleague Flaminio Fidanza and their SCS colleagues were central to the modern recognition, definition, and promotion of the eating pattern they found in Italy and Greece in the 1950s and ’60s, now popularly called “The Mediterranean Diet”. Ancel Keys was the first researcher who associated the traditional Mediterranean diet with a low risk of CHD. However, the Mediterranean diet does not exist. The Mediterranean Sea borders 18 countries that differ markedly in geography, economic status, health, lifestyle and diet.
Traditional Mediterranean diets had olive oil as their principal component of fat, were high in cereal products, legumes, fruit and vegetables, moderate in fish and low in dairy and meat products. Moderate amounts of wine were taken with meals. The traditional Mediterranean diets were nutritionally adequate with a varying amounts of total fat, low in saturated fat and very low in trans fat, rich in fiber and in antioxidant vitamins or flavonoids.
Mediterranean diets in the the Seven Countries Study in the 1960s
The Seven Countries Study included four Mediterranean cohorts: Crete and Corfu in Greece, Dalmatia in Croatia and Montegiorgio in Italy. In the 1960s the Greek diet had the highest content of olive oil and was high in fruit, the Dalmatian diet was highest in fish and the Italian diet was high in vegetables. In line with their diet, these cohorts were characterized by low mortality rates from CHD.
- Keys, Ancel and Margaret. Eat well and stay well. Doubleday, 1959.
- Kromhout et al. Am J Clin Nutr 1989;49:889-94
- Fidanza Proc Nutr Soc 1991;50:519-26
CVD Main topics
Eating fish associated with lower risk of fatal CHD and stroke
The Zutphen Study showed in 1985 that eating fish once or twice a week compared to eating no fish was associated with a 50% lower 20-year fatal CHD risk.
In 1994 we also found that fish consumption was inversely associated with a 50% lower incidence of non-fatal and fatal stroke.
Fatty fish compared to lean fish
The Finnish, Dutch and Italian cohorts showed that men eating fatty fish (e.g. mackerel and herring) had a 34% lower 20-year CHD mortality risk compared to those eating no fish. The consumption of lean fish, such as plaice and cod, had no comparable association with lower CHD risk.
Analysis of the dietary data repeatedly collected between 1960 and 2000 in the Zutphen Study also showed that eating fatty fish but not lean fish was inversely associated with long-term risk of sudden coronary death.
- Kromhout et al. N Engl J Med 1985;312:1205-9
- Keli et al. Stroke 1994;25:328-32
- Oomen et al. Am J Epidemiol 2000;151:999-1006
- Streppel et al. Eur Heart J 2008;29:2024-30
High fiber associated with low CHD mortality
Every additional amount of 10 g/d of recently consumed fiber was associated with a significant 17% lower risk of fatal CHD during 40 years of follow-up. A non-significant 13% lower risk was observed for long-term fiber intake.
A dietary fiber intake of more than 36 g/d at entry in 1960 was also associated with a 4 times lower risk of fatal CHD during 10 years of follow-up, when compared to an intake of less than 20 g/d. However, this association became non-significant in multivariable analysis.
Dietary fiber intake in 1960 and 2000
Between 1960 and 2000 seven dietary surveys were carried out in the Zutphen Study. The average dietary fiber intake was 33 g/d in middle-aged men in 1960 and 21 g/d among survivors in 2000. The average energy intake amounted to 3100 kcal/d in 1960 and 2100 kcal/d in 2000.