coffee heart and blood vessels

heart and blood vessels coffee

Colophon

Publishers

Coffee and Health Information Bureau

Design and printing

Stimio Consultants, Drukwerk & Design bv, Tiel

Copyright

© november 2007, Coffee and Health Information Bureau, Amsterdam

Availability

The brochure ‘Coffee, heart and blood vessels’ can be ordered free of charge

from Coffee and Health Information Bureau. You can also register here for the

digital newsletter. This free Dutch newsletter is aimed at health care profes-

sionals and keeps you informed about the most recent scientific information

concerning coffee and health and appears four to five times a year.


(Voorlichtingsbureau voor Koffie en Gezondheid)

Postbus 161, 2280 AD Rijswijk

Tel: +31 (0)70 - 336 51 63

Fax: +31 (0)70 - 336 51 67

E-mail: [email protected]

Website: www.koffieengezondheid.nl

Introduction

Is it advisable to drink coffee when you have a ‘heart condition’? Does drinking

coffee have any influence on the occurrence and development of cardiovascular

disease? People used to think so. But what is the current advice? Heavy coffee

drinkers are quite often also heavy smokers. For instance, in one of the first

studies in this field the relationship between drinking coffee and cardiovascular

disease could be wholly attributed to the fact that coffee drinkers had been

smoking more (Katan, 1994). More recent studies, have adjusted for ‘other’

factors that could influence the results.

This does not mean there are no further questions about coffee and heart

conditions and the risk factors for cardiovascular disease (blood pressure and

cholesterol). Coffee is consumed by 8 out of 10 Dutch people every day and

total annual consumption of coffee per head of the population amounts to 144

litres (VNKT, 2006). Research on the effects of coffee and heart health continues

to be an important field of scientific investigation.

In the last few decades there has been significant scientific research into the

relationship between coffee and health, including drinking coffee and risk

factors for cardiovascular disease. This brochure is aimed at health care profes-

sionals and provides a summary of the results of innumerable scientific studies.

The questions were formulated in collaboration with the Dutch Working Group

for Cardiology Dieticians. You can read more about the influence of coffee on

heart conditions in chapter 1. Chapter 2 describes the relationship between

coffee and cholesterol and chapter 3 gives more information about coffee and

blood pressure.

The Coffee and Health Information Bureau (Voorlichtingsbureau voor Koffie en

Gezondheid) sought assistance from three scientists who carry out research in

this field. Dr. Marianne Gelijnse (nutritional epidemiologist, Human Nutrition

Department, Wageningen University) and Dr. Cuno Uiterwaal (MD, clinical

epidemiologist, Julius Centre, Utrecht University Medical Centre) assisted in

Coffee, heart and blood vessels | 3

answering the questions about heart (chapter 1) and blood pressure (chapter

3). Dr. Mark Boekschoten (medical biologist, Department of Human Nutrition,

Wageningen University) contributed to the substantive coordination of chapter

2, on coffee and cholesterol.

Some topics do not yet have an unequivocal answer, because the amount of

research in that area is currently insufficient. We continue to follow scientific

developments.

If you have any questions or comments about this brochure, please let us know.


(Voorlichtingsbureau voor Koffie en Gezondheid)

Literature

Katan MB, Koffie, cholesterol en coronaire hartziekten. Hart Bulletin, 1994; 25:119-123.

Vereniging van Nederlandse Koffiebranders en Theepakkers (VNKT), Jaarverslag 2006.

4 |


1 Coffee and cardiovascular disease

1 Is there a relationship between coffee consumption and the risk of cardiovascular disease? Analysis of several extensive cohort studies (see shaded text on page 35) does

not show a relationship between coffee consumption and the risk of cardiovas-

cular disease (Grobbee, 1990; Woodward, 1999; Willett, 1996; Lopez-Garcia,

2006; Frost-Andersen, 2006). Furthermore, there is no evidence of a link

between coffee consumption and disease prognosis after myocardial infarction

(Mukamal, 2004).

A meta-analysis in 2006 did not indicate that coffee consumption results in a

higher risk of developing cardiovascular disease. Despite a significant associa-

tion between high consumption of coffee and coronary heart disease (CHD)

reported in case-control studies, no significant association between daily coffee

consumption and CHD emerged from long-term follow-up prospective cohort

studies (Sofi, 2006).

In some studies, coffee appears to protect against the risk of cardiovascular

disease (Woodward, 1999; Hammar, 2003; Frost-Andersen, 2006). In 2006,

a study among more than 41,000 women showed that coffee drinkers had

a lower risk of death attributable to cardiovascular disease. It was suggested

that consumption of coffee, a major source of dietary antioxidants, may inhibit

inflammation and thereby reduce the risk of cardiovascular and other inflamma-

tory diseases in post menopausal women (Frost-Andersen, 2006).

6 |

Preventive effect of coffee on type 2 diabetes

Type 2 diabetes is a strong risk factor for cardiovascular disease. The inverse

relationship between coffee consumption and type 2 diabetes was first de-

scribed in 2002 (Van Dam, 2002). This Dutch epidemiological study among

more than 17,000 men and women showed that people who drank seven

or more cups of coffee a day were 50% less likely to develop type 2 diabetes

than people who drank two cups of coffee or less. A 2005 meta-analysis also

indicated a link between coffee consumption and a substantially lower risk of

developing type 2 diabetes (Van Dam, 2005). More recent studies confirm this

inverse relationship. Moreover these studies show that this effect occurs with

decaffeinated coffee as well. Furthermore, a recent Finnish study investigating

almost 4,000 people with type 2 diabetes indicated a reduced risk of cardiovas-

cular mortality in the case of those who drank three or more cups of coffee a

day (Bidel, 2006).

2 Is there a relationship between coffee consumption and the risk of heart failure? Little is known about coffee consumption in relation to the risk of heart failure.

A Swedish study examined risk factors for heart failure in a long-term follow-

up among almost 7,500 men. Risk factors for the occurrence of heart failure

included increasing age, family history of myocardial infarction, diabetes, chest

pain, smoking, high coffee consumption, excessive alcohol, high BMI and

hypertension (Wilhelmsen, 2001). Epidemiological data from the Framingham

study indicate that hypertension has the highest impact on heart failure and

is responsible for about 39% of heart failure in men and 59% in women. After

adjustment for age and other factors, hypertension increases the risk of heart


failure by a factor of 2 in men and a factor 3 in women. Diabetes increases

the risk of heart failure by a factor of 2 to 8, more so in women than in men

(Kannel, 2000). This study did not investigate the relationship between coffee

and heart failure. However, coffee is associated with a decreased risk of diabetes

and a lower risk of cardiovascular mortality in the case of people with diabetes

(see shaded text on page 6).

As we have insufficient scientific data at present, no clear pronouncement can

be made on coffee consumption in relation to the risk of heart failure.

3 Can you still drink coffee if you suffer from heart failure? A 2006 study investigated the effect of caffeine on the stamina of patients with

heart failure (Notarius, 2006). Ten patients were infused intravenously with 4

mg of caffeine per kg bodyweight or a placebo. With caffeine, patients were

able to exercise longer at peak effort. However, this study is much too limited to

be able to derive any recommendation from it.

4 Does coffee affect the incidence of cardiac arrhythmia? A large Danish prospective cohort study among nearly 48,000 people investi-

gated the relationship between daily caffeine consumption from various foods

and the incidence of arrhythmia. The study could not find any relationship bet-

ween arrhythmia and caffeine, not even in the case of high concentrations (997

mg/day, equivalent to approximately 10 cups of coffee a day (Frost, 2005)).

8 |

5 Can you drink coffee if you suffer from cardiac arrhythmia? An eight year long prospective cohort study among nearly 129,000 Americans

over a period of 8 years did not show any relationship between coffee con-

sumption and cardiac arrhythmia mortality (Klatsky, 1993). Intervention studies

with caffeine in amounts of up to 450 mg/day (comparable to 5 small cups of

coffee a day) showed no relationship with the nature or frequency of cardiac

arrhythmia, either in healthy people or in heart patients (Myers, 1991; Nawrot,

2003). Conversely, caffeine restriction was found not to have any effect on pa-

tients with ventricular tachyarrhythmia (fast and abnormal heart rate) (Newby,

1996).

Caffeine content of beverages

Beverage (serving size) Average caffeine content in mg

Filtered coffee (150 ml) 85

Instant coffee (150 ml) 65

Espresso (50 ml) 65

Cappuccino (150 ml) 65

Coffee from coffee pods (150 ml) 85

Decaffeinated coffee (150 ml) 3

Tea (125 ml) 30

Cola (180 ml) 18

Energy drink (250 ml) 75

Iced tea (180 ml) 16

Chocolate milk (250 ml) 5

(Source: www.koffieengezondheid.nl)


6 Can coffee influence homocysteine levels of blood? Intervention studies show that high coffee consumption (6 - 10 cups of coffee

a day) increases total plasma homocysteine (tHCys) (Grubben, 2000; Urgert,

2000) and that tHCys decreases if regular coffee consumers stop drinking coffee

(Christensen, 2001). However, a study based on 5 cups of espresso a day did

not show a significant effect on tHCys (Esposito, 2003), possibly because of the

smaller volume. Caffeine is suggested as being partly responsible for the effect

of coffee on tHCys (Verhoef, 2002), but the presence of chlorogenic acid in

coffee can also contribute to the effect on homocysteine (Olthof, 2001). Several

factors influence plasma homocysteine levels, such as intake of folic acid and

vitamin B12, age, gender, heredity, smoking, hypertension and physical activity

(Refsum, 2006). However, it is still unclear whether reducing high homocysteine

levels will lead to a lower risk of cardiovascular disease. No causal relationship

has been established between high tHCys and cardiovascular disease (Higdon,

2006). A high homocysteine level can also be an indication of a low vitamin

status and/or an unhealthy lifestyle (Verhoef, 2004).

10 |

7 Can someone with angina pectoris carry on drinking coffee? Various large cohort studies show that there is no relationship between cof-

fee consumption and cardiovascular diseases (see question 1). Little research

has been undertaken into the effect of caffeine consumption on patients with

angina pectoris. A Dutch study (Riksen, 2006) tested the effect of caffeine on

so-called preconditioning in an experimental model involving healthy volun-

teers (see shaded text on page 11). In an experimental model, healthy patients

received a single intravenous injection of caffeine (4 mg/kg body weight) in

the forearm. Caffeine was found to have an adverse impact on the protective

effect of preconditioning. However, the researcher states that the results of this

experimental study cannot be extrapolated to daily coffee consumption. It is not

possible to give advice on this until further research among patients has estab-

lished whether a high plasma caffeine concentration at the moment a heart

attack takes place will worsen the course of events (Riksen, 2007).

Normally, people drink their coffee in the course of the day, so that the caffeine

is absorbed via the gastrointestinal tract over a longer period of time and the

physiological effect would not be the same as that seen when a single dose of

caffeine is injected into the blood stream. Furthermore, the effect of coffee is not

always the same as that of caffeine (see question 8).


Angina pectoris and preconditioning

A heart attack will not be as serious when people have just had an angina pec-

toris attack. In the case of angina pectoris so-called preconditioning occurs. For

a moment, the heart muscle receives insufficient oxygen. This makes the heart

muscle more tolerant of a longer period of oxygen shortage, such as occurs in

the case of myocardial infarction. Adenosine, which occurs naturally in the body,

plays an important part in preconditioning. Caffeine is a so-called adenosine-

antagonist and can block the effect of adenosine. The preconditioning

mechanism does not reduce the occurrence of cardiovascular disease, but once

a myocardial infarction has occurred it can limit its seriousness.

8 Do the effects of coffee and caffeine differ? Caffeine is without doubt the most examined substance in coffee. The effects of

pure caffeine are regularly translated directly to coffee, but this does not always

prove justified. Pure caffeine (in tablet form) for example is found to be capable

of increasing the blood pressure, while this hardly occurs if at all in the case of

the same quantity of caffeine via coffee (Noordzij, 2005; see chapter 3.)

Coffee contains much more than just caffeine. For instance it contains potas-

sium and magnesium, which may be capable of counteracting the blood-

pressure-increasing effect of caffeine. Coffee is also a good source of anti-

oxidants (polyphenols such as chlorogenic acids).

12 |

Caffeine

After consumption, caffeine (1,3,7-trimethylxanthine) is absorbed rapidly and

achieves its peak value approximately 1 to 1.5 hours after consumption. Its physi-

cal half-life (time needed by the body to process half of the caffeine intake) varies

from 3 to 7 hours and is affected by many factors such as gender, age, smoking

and pregnancy. The most important effect of caffeine is stimulation of the central

nervous system, which results among other things in increased alertness and

countering sleepiness. An overview of published studies reveals that no relation-

ship can be demonstrated between moderate caffeine consumption (400 mg

daily) and the occurrence of cardiovascular disease) (Nawrot, 2003).


9 Can people with cardiovascular disease consume coffee normally? Most studies show that there are no indications that moderate consumption

of coffee (approximately 4 - 5 cups a day) increases the risk of cardiovascular

disease related to healthy people. A number of studies have examined whether

caffeine consumption or abstinence from caffeine consumption affect the blood

pressure of people with hypertension (see chapter 3) or in the case of patients

with cardiac arrhythmia. To date there are no indications for advising people

with cardiac arrhythmia against drinking coffee (see question 5). Nonetheless,

individuals concerned with the possible effects of coffee in relation to cardiovas-

cular disease, should seek the advice of their medical practitioner.

10 Is decaffeinated coffee a better choice than ordinary coffee in the case of cardiovascular disease? In relation to hypertension or cardiac arrhythmia there are no indications to

suggest that individuals should avoid drinking caffeinated coffee in moderation

(4-5 cups a day). If the individual prefers not to consume caffeine, decaffeinated

coffee is a good alternative.

14 |

Literature

Bidel S e.a., Coffee consumption and risk of total and cardiovascular mortality among patients with diabetes type 2. Diabetologia, 2006; 49(11):2618-2626.

Christensen B e.a., Abstention from fi ltered coffee reduces the concentrations of plasma homocysteine and serum cholesterol-a randomized controlled trial. Am J Clin Nutr, 2001; 74(3):302-307.

Esposito F e.a., Moderate coffee consumption increases plasma glutathione but not homocysteine in healthy subjects. Aliment Pharmacol Ther, 2003; 17:595-601.

Frost L and Vestergaard P, Caffeine and risk of atrial fi brillation or fl utter: the Danish Diet, Cancer, and Health Study. Am J Clin Nutr, 2005; 81(3):578-582.

Frost Andersen L e.a., Consumption of coffee is associated with reduced risk of death attributed to inflammatory and cardiovascular diseases in the Iowa Women’s Health Study. Am J Clin Nutr, 2006; 83:1039-1046.

Grobbee DE, e.a., Coffee, caffeine, and cardiovascular disease in men. New Eng J Med, 1990; 323:1026-1032.

Grubben MJ e.a., Unfi ltered coffee increases plasma homocysteine concentrations in healthy volun-teers: a randomized trial. Am J Clin Nutr, 2000; 71:448-484.

Hammar N e.a., Association of boiled and fi ltered coffee with incidence of fi rst nonfatal myocardial infarction: the SHEEP and the VHEEP study. J Intern Med, 2003; 253(6):653-659.

Higdon JV and Frei B., Coffee and Health: A Review of Recent Human Research. Crit Rev Food Sci Nutr, 2006; 46:101-123.

Kannel WB, Incidence and epidemiology of heart failure. Heart Fail Rev 2000; 5(2):167-173.Klatsky AL, e.a., Coffee, tea, and mortality. Ann Epid, 1993; 3:375-381.

Lopez-Garcia E e.a., Coffee consumption and coronary heart disease in man and women: a prospective cohort study. Circulation, 2006; 113(17):2045-2053.

Mukamal KJ e.a., Caffeinated coffee consumption and mortality after acute myocardial infarction. AmHeart J, 2004; 147:999-1004.

Myers MG, Caffeine and cardiac arrhythmias. Ann Intern Med, 1991; 114(2):147-150.

Nawrot P e.a., Effects of caffeine on human health. Food Addit Contam, 2003; 20(1):1-30.

Newby DE e.a., Caffeine restriction has no role in the management of patients with symptomatic idiopathic ventricular premature beats. Heart, 1996; 76(4):355-357.

Noordzij M e.a., Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials. J Hypert, 2005; 23:921-928.

Notarius CF e.a., Caffeine prolongs exercise duration in heart failure. J Card Fail, 2006; 12(3):220-226.

Olthof MR e.a., Consumption of high doses of chlorogenic acid, present in coffee, or of black tea incre-ases plasma total homocysteine concentrations in humans. Am J Clin Nutr, 2001; 73:532-538.

Refsum H e.a., The Hordaland Homocysteine Study: a community-based study of homocysteine, its determinants, and associations with disease. J Nutr, 2006; 136(6 suppl):1731S-1740S.

Riksen NP e.a., Caffeine Prevents Protection in Two Human Models of Ischemic Preconditioning.J AmColl Cardiol, 2006; 48:700-707.

Riksen NP, Nieuwsbrief Koffi e en Gezondheid april 2007 (www.koffi eengezondheid.nl)Sofi F e.a., Coffee consumption and risk of coronary heart disease: A meta-analysis. Nutr Met Cardiov Dis, 2006; 17(3):209-223.

Urgert R e.a., Heavy coffee consumption and plasma homocysteine: a randomized controlled trial in healthy volunteers. Am J Clin Nutr, 2000; 72:1107-1110.

Van Dam R and Feskens E, Coffee consumption and risk of type 2 diabetes mellitus. The Lancet, 2002; 360(9344):1477-1478.

Van Dam R and Hu F, Coffee consumption and risk of type 2 diabetes: a systematic review. JAMA, 2005; 294:97-104.

Verhoef P e.a., Contribution of caffeine to the homocysteine-raising effect of coffee: a randomized controlled trial in humans. Am J Clin Nutr, 2002; 76:1244-1248.

Verhoef P and Katan MB, A healthy lifestyle lowers homocysteine, but should we care? Editorial AmJ Clin Nutr, 2004; 79:713-714.

Wilhelmsen L e.a., Heart failure in the general population of men-morbidity, risk factors and prognosis. J Intern Med, 2001; 249(3):253-261.

Willett WC e.a., Coffee consumption and coronary heart disease in women. A ten-year follow-up. JAMA, 1996; 275(6):458-462.

Woodward M and Tunstall-Pedoe H, Coffee and tea consumption in the Scottish Heart Health Study follow up: confl icting relations with coronary risk factors, coronary disease, and all cause mortality.J Epid Comm Health, 1999; 53:481-487.



2 Coffee and the serum cholesterol level

1 Does coffee affect the blood serum cholesterol level? That depends on the brewing method used for making coffee. Unfiltered coffee

can increase the serum cholesterol level, while filtered coffee does not have this

effect (Boekschoten, 2003, 2006; Urgert, 1996a; Urgert, 1996b). The increase

in cholesterol is attributable to the diterpenes cafestol and kahweol, two fat-

soluble substances that are naturally present in coffee oil. The effect of cafestol,

in particular, on serum cholesterol levels has been demonstrated (Urgert, 1997).

Only in the case of certain coffee brewing methods the diterpenes do permeate

the brewed coffee. Scandinavian-type boiled coffee, French press (Cafetière

or plunger) coffee, Greek coffee and Turkish coffee for instance contain these

substances in higher concentrations. In the case of filtered coffee and coffee

made with coffee pods, the most common methods of brewing coffee in

the Netherlands, cafestol and kahweol are retained by the filter. These coffees

therefore have no cholesterol-raising effect (Ahola, 1991; Dusseldorp, 1991;

Boekschoten, 2006). Instant coffee and vending-machine coffee based on liquid

coffee concentrate also contain hardly any diterpenes and have a neglible effect

on serum lipids (Urgert, 1997; Sara Lee/DE, 1998).

18 |

2 Do different brewing methods affect the levels of the diterpenes cafestol and kahweol in the coffee? The diterpenes, cafestol and kahweol naturally present in coffee oil increase se-

rum cholesterol levels (see question 1 in this chapter). Whether these diterpenes

permeate the coffee brew and to what extent depends on the brewing method.

Boiled coffee, coffee that is prepared by boiling ground coffee in water and pou-

ring the brew without filtering it, contains the diterpenes, cafestol and kahweol

in higher concentrations. The amounts of diterpenes in boiled coffee vary from

3.0 to 10.9 mg of cafestol and 3.9 to 10.7 mg of kahweol per cup (Urgert,

1995; Boekschoten, 2006). Consuming large amounts of boiled coffee will in-

crease the serum cholesterol level. French press coffee, Greek coffee and Turkish

coffee also contain comparable amounts of cafestol and kahweol (Urgert, 1995).

In the case of filtered coffee and coffee made with coffee pods, the diterpenes

are retained in the paper filter. Both these coffees contain an average of 0.1 mg

cafestol and 0.1 mg kahweol per cup (Urgert, 1995; Boekschoten 2006). The ef-

fect of this on the serum cholesterol content is therefore negligible. Instant cof-

fee and vending-machine coffee based on liquid coffee concentrate also contain

negligible amounts of cafestol and kahweol. These substances are virtually fully

removed during the production process (Sara Lee/DE, 1998).

In the case of espresso coffee and coffee from vending machines in which the

coffee is freshly brewed, these types of coffee may contain cafestol and kahweol.

The ultimate quantity and the effect on serum cholesterol content depends on

a combination of factors, such as the type of machine, the type and quantity of

coffee, the type of filter used and the number of cups consumed daily.

3 How substantial is the effect of cafestol on the cholesterol content? Based on intervention studies (see shaded text on page 35) an estimate has

been made that, daily intake of 10 mg of cafestol for a period of 4 weeks, will

result in an increase of 0.13 mmol/l in the total cholesterol level of the blood

(Weusten van der Wouw, 1994). However, in the case of long-term consump-

tion the increase in serum cholesterol level becomes less, which may point to

partial adaptation by the body to the effects of diterpenes (Urgert, 1996b).

Consumption of a litre per day of very strong coffee brewed in a Cafetière

(plunger or French press) (38 mg of cafestol and 33 mg of kahweol) for a period

of six months resulted after 12 weeks in a maximum increase in serum choles-

terol of 0.52 mmol/l. Thereafter the cholesterol level declined again and after

six months the total increase was still 0.30 mmol/l compared with the starting

values. Shorter-term studies can result in overestimation of the effect (Urgert,

1997).

How much kahweol contributes to raising serum cholesterol is not fully un-

derstood, since no studies have been carried out with pure kahweol. What

is known, however, is that a mixture of cafestol and kahweol has a slightly

stronger effect than cafestol on its own (Urgert, 1997). Moreover the effect

of the diterpenes is reversible. After cessation of consumption of cafestol and

kahweol serum cholesterol levels return to their starting values (Urgert, 1996a).

The table on page 20 shows the various brewing methods, the cafestol and kah-

weol levels of the associated brews and the estimated serum cholesterol increase

in the case of consumption of 5 cups of coffee a day (after Urgert, 1996a).


20 |

Filtered coffee 0.1 0.1 <0.01

Instant (soluble) coffee 0.2 0.2 0.01

Espresso 1.5 1.8 0.10

Boiled coffee 3.0 3.9 0.19

French press coffee 3.5 4.4 0.23

Turkish/Greek coffee 3.9 3.9 0.25

¹Theoretical increase based on the estimation that 10 mg of cafestol causes the serum cholesterol level

to increase by 0.13 mmol/l.

Theoretical¹ increase in

serum cholesterol in the

case of daily consumption

of 5 cups (mmol/l)

Kahweol

in mg/cup

Cafestol

in mg/cup

Coffee type / brewing

method


4 Do regular and decaffeinated coffee have different effects on the blood cholesterol level? This is highly improbable. There is no difference in the concentration of diter-

penes between comparable caffeinated coffee and decaffeinated coffee (Urgert,

1996a). Studies with decaffeinated filtered coffee show no effect on serum

cholesterol content (Dusseldorp, 1990; Urgert, 1997). In the case of abstinence

from caffeine for a period of 9 weeks, randomised research among 69 healthy

young Dutch people also shows no effect on serum lipid contents (Bak, 1989).

5 Does limitation of coffee have a cholesterol-lowering effect? This depends once again entirely on the coffee brewing method (see questions

1 and 2). Filtered coffee does not have a cholesterol-raising effect (see question

1). However, if a lot of unfiltered coffee is drunk, switching from unfiltered to

filtered coffee results in a clear fall in serum cholesterol levels. This is the case in

Scandinavian countries, where traditionally a large amount of boiled coffee was

previously consumed (Pietinen, 1996).

Intervention studies have also revealed that the effect of diterpenes is reversible.

If consumption is ceased, the serum cholesterol values return to their starting

levels (Urgert, 1996a).

22 |

6 What other factors affect the cholesterol content and to what extent is this comparable with cafestol? The amount of cholesterol in the blood is strongly related to the consumption

of saturated fatty acids and trans fatty acids. Smoking and excess body weight

also increase the risk of raising serum cholesterol. Moderate drinking of alcohol

and regular physical activity in fact can reduce risk of raised serum cholesterol

because these factors increase the content of the protective HDL cholesterol.

Ideally preventive interventions should focus simultaneously on several factors

which cause an unfavourable cholesterol level, such as excessive intake of satu-

rated fat, trans fatty acids, smoking, physical inactivity and excess weight (www.

rivm.nl).

A review from 2006 provides an overview of the LDL-cholesterol reducing effect

of various nutritional measures (Devaraj, 2006). The following reductions are

achievable:

• 8-10% in the case of consuming maximum 7 energy % saturated fat

• 6-10% in the case of consuming phytosterols/stanols up to 2 grams daily

• 5-8% in the case of losing 4.5 kilos in weight

• 3-5% in the case of consuming a maximum of 200 mg cholesterol per day

• 3-5% in the case of 5 to 10 grams higher daily consumption of (soluble)

dietary fibre

Based on theoretically estimated increases in serum cholesterol on the basis of

the cafestol contents of various brews (see table on page 20), switching from

5 cups of filtered coffee to 5 cups of espresso can be expected to increase the

cholesterol level by approximately 2% (Urgert, 1996b).

Spread of cholesterol measurements

An individual’s cholesterol level can vary substantially, on average by 0.35

mmol/l (Smith, 1993; Cooper, 1988). For someone with a normal cholesterol

level this amounts to some 7%. In order to be able to determine whether there

is an increase or a fall in cholesterol, it is necessary to measure the cholesterol

level several times. This applies particularly in the case of patients with a slightly

raised cholesterol level.

7 Are positive effects of kahweol and cafestol also known? In epidemiological studies it has been suggested that consumption of coffee

is associated with a lower risk of certain forms of cancer (Giovannucci, 2000;

Tavani, 2000). In various studies diterpenes have been found to have inflamma-

tion-inhibiting and anti-carcinogenic properties and possibly to provide pro-

tection against certain forms of cancer (Cavin, 2002; Huber, 2004; Kim, 2004;

Lee, 2007). In vitro studies and animal studies suggest that a potential anti-

carcinogenic effects can be explained by the induction of detoxification in the

liver and intestine by cafestol and kahweol. However, there is no direct proof of

an anti-carcinogenic effect of cafestol or kahweol in people (Ricketts, 2007).


24 |

8 May someone with a raised cholesterol level continue to drink coffee? People with a raised cholesterol level may choose to continue to drink coffee

with negligible amounts of cafestol, such as filtered coffee and coffee made with

coffee pods; or up to 2-3 cups of espresso coffee consumed over the course of

the day (Urgert, 1996a).

In view of the cholesterol-raising effect of consuming boiled coffee, Turkish or

Greek coffee or Cafetière (French press) coffee, people with a raised serum cho-

lesterol levels are advised to limit coffee from these methods of brewing coffee.

26 |

Literature

Ahola I e.a., The hypercholesterolaemic factor in boiled coffee is retained by a paper fi lter. J Intern Med, 1991; 230:293-297.

Bak AA and Grobbee DE. The effect of serum cholesterol levels of coffee brewed by fi ltering or boiling. N Eng J Med, 1989; 321:1432-1437.

Boekschoten MV e.a., Reproducibility of the serum lipid response to coffee oil in healthy volunteers. Nutr J, 2003; 2(1):8.

Boekschoten MV e a., Verwaarloosbare hoeveelheden cholesterolverhogende diterpenen in koffie gezet met de koffiepadmethode bij vergelijking met ongefi lterde koffi e. Ned Tijdschr Geneeskd, 2006; 52:2873-2875.

Cavin C e.a., Cafestol and kahweol, two coffee specifi c diterpenes with antiocarcionogenic activity. Food Chem Toxicol, 2002; 40(8):1155-1163.

Cooper GR e.a., Standardization of lipid, lipoprotein, and apolipoprotein measurements. Clin Chem,1988; 34(8):B95-B105.

Devaraj S e.a., The role of dietary supplementation with plant sterols and stanols in the prevention of cardiovascular disease. Nutr Rev, 2006; 64:348-352.

Dusseldorp M van e.a., Effect of decaffeinated versus regular coffee on serum lipoproteins. A 12 week double blind trial. Am J Epidem, 1990; 132(1):33-40.

Dusseldorp M van e.a., Cholesterol-raising factor from boiled coffee does not pass a paper fi lter. Arthe-rios Thromb, 1991; 11:586-593.

Giovannucci E, Meta-analysis of Coffee Consumption and Risk of Colorectal Cancer. Am J Epidemiol, 1998; 147(11):1043-1052.

Huber W e.a., Potential chemoprospective effect of the coffee components kahweol and cafestol pal-mirates via modifi cation of hepatic N-acetyltransferase and glutathione-S-transferase activities. Environ Mol Mutagen, 2004; 44(4):265-276.

Kim JY e.a., Suppressive effects of the kahweol and cafestol on cyclooxygenase-2 expression in macro-phages. FEBS Letters, 2004; 569:321-326.

Lee KJ e.a., Hepatoprotective and antioxidant effects of coffee diterpenes kahweol and cafestol on carbon tetrachloride-induced liver damage in mice. Food. Chem. Toxicol., 2007: doi:10.1016/j. fct.2007.05.010.

Pietinen P e.a., Changes in diet in Finland from 1972 to 1992: impact on coronary heart disease risk. Prev Med, 1996; 25:243-250.


Ricketts, ML e.a., The Cholesterol-Raising Factor from Coffee Beans, Cafestol, as an Agonist Ligand for the Farnesoid and Pragnane X Receptors. Mol Endocrinol, 2007; 21:1603-1616.

Sara Lee/Douwe Egberts, intern rapport, 1998.

Smith SJ e.a., Biological variability in concentrations of serum lipids: sources of variation among results from published studies and composite predicted values. Clin Chem, 1993; 39(6):1012-1022.

Tavani A, Coffee and cancer: a review of epidemiological studies, 1990-1999. Eur J Canc Prev, 2000; 9(4):241-256.

Urgert R e.a., Levels of the Cholesterol-Elevating Diterpenes Cafestol and Kahweol in Various Coffee Brews. J Agric Food Chem, 1995; 43:2167-2172.

Urgert R and Katan MB, The cholesterol-raising factor from coffee beans. J R Soc Med, 1996a; 89(11):618-623.

Urgert R e.a., Comparison of effect of cafetiere and fi ltered coffee on serum concentrations of liver aminotransferases and lipids: six month randomised controlled trial. Br Med J, 1996b; 313:1362-1366.Urgert R and Katan MB, The cholesterol-raising factor from coffee beans. Annu Rev Nutr, 1997; 17:305-324.

Weusten van der Wouw PME e.a., Identity of the cholesterol-raising factor from boiled coffee and its effects on liver function enzymes. J Lip Res, 1994; 35:721-733.


3 Coffee and blood pressure

1 Does coffee affect blood pressure? Regular consumption of coffee has either very little or no effect on blood pres-

sure in the case of people with normal blood pressure (Myers, 1991; Stamler,

1997; Jee, 1999; Geleijnse, 2004; Noordzij, 2005; Winkelmayer, 2005; Uiter-

waal, 2007).

There is, however, a difference between the short-term effect and the effect in

the longer term. Shortly after consumption, drinking coffee slightly increases

blood pressure, the effect being comparable with the effect on blood pressure

of holding a conversation (Nurminen, 1999). This type of acute effect results

from the caffeine, and the blood pressure falls again within a few hours to its

starting level. In addition, tolerance appears to occur in terms of the effect of

caffeine (Casiglia, 1992; Jee, 1997). Studies relating to a longer term effect indi-

cate that coffee has negligible if any impact on blood pressure (Geleijnse, 2004;

Noordzij, 2005; Winkelmayer, 2005; Uiterwaal, 2007).

30 |

2 How substantial is the acute effect of coffee on blood pressure? A meta-analysis in 2005 comprising 16 intervention studies (see shaded text

on page 35) of the effect of coffee or caffeine on blood pressure, gave different

results for coffee and caffeine. Coffee (average 725 ml per day (approximately

5 cups)) resulted in an increase of 1.2 mg Hg in systolic blood pressure and 0.5

mg Hg in diastolic blood pressure (Noordzij, 2005). A comparable amount of

caffeine administered in tablet form resulted in increases of 4.2 and 2.4 mg Hg

in systolic and diastolic blood pressure respectively. Why pure caffeine raises

blood pressure and caffeinated coffee has negligible if any such effect is not

fully understood. It is possible that the effect of caffeine when consumed in cof-

fee is negated by other components in coffee, such as potassium, magnesium

and polyphenols.

3 Is there a relationship between drinking coffee and the risk of hypertension? Various studies show that coffee has no specific effect on the risk of hyperten-

sion (Klag, 2002; Geleijnse 2004; Winkelmayer, 2005, Uiterwaal, 2007). In the

Dutch cohort study carried out by Uiterwaal et al on almost 3,000 men and al-

most 3,400 women without hypertension, the long-term effects of drinking cof-

fee on the risk of hypertension (systolic pressure >140 mmHg) were examined.

Even after correction for other factors, the group that never drank coffee was

found to have a lower risk of hypertension than people who consumed small

amounts of coffee (1 - 3 cups a day) (Uiterwaal, 2007). However, the group of

non-coffee drinkers was small and it is possible that not drinking coffee is linked

with a different and more healthy lifestyle which could not be entirely corrected

for. A striking result was that women who drank a lot of coffee (>6 cups a day)


had a lower risk of hypertension. A comparable result was also found in the case

of the Nurses’ Health Study of more than 155,000 women without hyperten-

sion, who were monitored over a period of 12 years (Winkelmayer, 2005).

Consumption of more than 6 cups of coffee a day was found to have a slightly

protective effect on the risk of hypertension. Cola on the other hand was found

to be related to an increased risk of hypertension.

4 What are the results of limiting coffee in the case of hypertension? Research in people with hypertension shows that withholding coffee has no ef-

fect on the blood pressure of hypertensive patients (MacDonald, 1991; Nurmi-

nen, 1998). Blood pressure was also not further increased as a result of drinking

coffee in the case of people with moderate hypertension.

Known risk factors that play a major role in the case of hypertension are obesity,

physical inactivity, high salt intake and low potassium intake (Geleijnse, 2004).

5 Is decaffeinated coffee better in the case of hypertension? There are no indications for advising against moderate consumption of caffein-

ated coffee (4 to 5 cups a day) for people with hypertension (see question 4).

If people prefer not to consume caffeine, decaffeinated coffee is an alternative

choice.

32 |

6 What advice regarding coffee consumption can be given to people with hypertension? There are no indications for advising against coffee consumption for individuals

with hypertension. At this moment most research suggests that regular intake of

caffeinated coffee does not increase the risk of hypertension.

Sensitive to caffeine?

Caffeine has a mildly stimulating effect on the central nervous system. This ex-

presses itself in the form of heightened alertness and concentration and a redu-

ced feeling of fatigue. In the case of people who are sensitive to caffeine, it can

also cause restlessness, trembling or increased time taken to fall asleep. Caffeine

sensitive individuals are advised to limit the quantity of caffeine to an amount

at which the individual experiences minimal effects from caffeine. These people

may also choose for example to drink decaffeinated coffee. Women who are

pregnant or breast-feeding are advised to limit their daily intake of caffeine to a

maximum of 300 mg. In some countries e.g. the UK, the upper recommended

limit is 200mg. Tea, cola, energy drinks, drinking chocolate and some painkillers

are also sources of caffeine intake (see table on page 8).

34 |

Literature

Casiglia E e.a., Haemodynamic effects of coffee and purifi ed caffeine in normal volunteers: a placebo-controlled clinical study. J Hum Hypertens, 1992; 6(2):95-99.

Geleijnse JM e.a., Impact of dietary and lifestyle factors on the prevalence of hypertension in Western populations. Eur J Pub Health, 2004;14:235-239.

Jee SH e.a., The effect of coffee on blood pressure, a meta analyses of controlled clinical trials. CanJ Cardiol 1997; 13(Suppl B):36B.

Jee SH e.a., The effect of chronic coffee drinking on blood pressure: a meta-analysis of controlled clini-cal trials. Hypertension, 1999; 33(2):647-52.Klag MJ e.a., Coffee intake and the risk of hypertension: the Johns Hopkins precursors study. Arch Intern Med, 2002; 162(6):657-62.

MacDonald TM e.a., Caffeine restriction: effect on mild hypertension. Br Med J, 1991; 303:1235-1238.Myers MG en Reeves RA, The effect of caffeine on daytime ambulatory blood pressure. Am J Hypert, 1991; 4:427-431.

Noordzij M e.a., Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials. J Hypert, 2005; 23:921-928.

Nurminen ML e.a., Dietary factors in the pathogenesis and treatment of hypertension. Ann Med, 1998; 30(2):143-150.

Nurminen ML e.a., Coffee, caffeine and blood pressure: a critical review: Euro J Clin Nutr, 1999; 53:831-839.

Stamler J e.a., Relation of Relation of body mass and alcohol, nutrient, fi ber, and caffeine intakes to blood pressure in the special intervention and usual care groups in the Multiple Risk Factor Intervention Trial. Am J Clin Nut, 1997; 65(suppl):338-65.

Uiterwaal C e.a., Coffee intake and incidence of hypertension, Am J Clin Nutr, 2007; 85:718-723.Winkelmayer WC e.a., Habitual Caffeine Intake and the Risk of Hypertension in Women. JAMA, 2005; 294:2330-2335.


Study of coffee and health

Every type of research has its own evidential value and limitations. Most of the

studies reported in this brochure can be differentiated into:

1. Meta-analysis: A literature study of various studies (intervention studies,

cohort studies and/or patient control studies) of the relationship between

coffee consumption behaviour and a biomarker or (medical) condition,

with the aim of obtaining a more precise outcome.

2. Intervention study: In the case of this type the effect of the substance to

be investigated on a group of people is measured and compared with a

control group, which is not given the substance. Intervention studies in

the area of coffee research are usually relatively short and the group size is

limited.

3. Cohort study (prospective): In this brochure in the case of this type of study

large groups of people have been monitored (prospectively) over a longer

period. In this context at the start of the study differences in coffee con-

sumption between people who have and have not developed a (medical)

condition during the study are examined. The pattern of coffee consump-

tion of the participants has therefore not been influenced by the condition.

4. Patient-control study: In the case of this type of study the differences in

coffee consumption patterns are investigated in groups of people who have

and have not developed the (medical) condition. In this case therefore

questions are asked after the event about previous coffee consumption

behaviour. A disadvantage of this type of study may be that the coffee

consumption pattern of the people who have that condition has been

modified or is assessed differently than in the case of people who do not

have the condition.

KOFF IE EN GEZONDHE ID

heart and blood vessels coffee

www.koffieengezondheid.nl

coffee heart and blood vessels

Health & Medicine

drinking coffee

effects of coffee

coffee vessels heart

coffee consumption results

high consumption of

linkbetween coffee consumption

coffee andblood pressure

free of chargefrom coffee