Coffee is more than caffeine

We equate coffee with caffeine, but that is not accurate. Caffeine is just one of many health-influencing aspects of coffee.

Coffee has unique impacts on health that we do not get from other caffeine foods, such as tea and chocolate.

See another version of Lara's coffee article in her health blog.

The full sensory experience of coffee is the sum total of all of it's many biochemical components, and the properties of those components are not yet fully understood. That is one reason why the research into the health effects of coffee is often conflicting. Another reason for the conflicting results is is that some people metabolise caffeine better than others.

Slow metabolisers of caffeine are more at risk for long-term health damage from caffeine than fast metabolisers. One can be a slow caffeine metaboliser because of genetics, or because of certain medications including the Pill and HRT, or during pregnancy. Pregnant women should NOT consume caffeine. One might also argue that women on the Pill should not consume caffeine. Or rather, that coffee drinkers should not take the Pill. See Problem with the Pill article.

What is the evidence for the long-term health effects of moderate coffee consumption?

Health Benefits

• Reduced risk of depression
• Reduced risk of Alzheimer's ⁽²⁾, dementia, and Parkinson's disease ⁽³⁾
• Reduced risk of liver disease ⁽⁴⁾ gallstones ⁽⁵⁾ and gout ⁽⁶⁾
• Reduced risk of diabetes and improved insulin sensitivity ⁽⁷⁾
• Reduced risk of some cancers including breast cancer. ⁽⁸⁾

Health Risks

• Stomach ulcer and  reflux
• Anxiety and sleep disturbance
• Iron deficiency (prevents absorption)
• Miscarriage and reduced female fertility
• Tinnitus
  
• Cholesterol. It is not the caffeine itself that raises cholesterol, but two other components called cafestol and kahweol, which can be removed by a paper filter.
• Coffee was previously believed to elevate blood pressure, but recent evidence discounts that. A recent Harvard study found 'no convincing link' between 'paper-filtered coffee' and heart disease ⁽¹⁾.

The big picture

The jury is still out on the long-term effects of coffee, but the weight of the evidence so far is that it might offer some surprising health benefits.

In the big picture, coffee is probably not the worst thing in your diet. A much bigger problem may be the milk and sugar in your flat white, and the sweet cake on the side.

A comment about antioxidants

Yes, coffee provides antioxidants and that may be the reason for some of the observed health benefits. Other foods are a much better source of antioxidants, however, and if you eat enough vegetables, your body should not require the antioxidants from coffee.

Teenagers

The effects of caffeine on a young, developing brain are not well understood, and yet sugary high caffeine drinks are marketed to teenagers. It would be best to limit them.

Choose organic 

Coffee crops are heavily sprayed with pesticide. If there ever was a time to choose organic, it is coffee

Coffee's impact on hormones is mostly positive

• Improves Insulin sensitivity. In this regard, coffee may be beneficial for Type 1 PCOS.
• Clears oestrogen from the body. This can be a good or bad thing.  It decreases the body's total exposure to oestrogens, which is why it may be protective against breast cancer.  It may also be one of the reasons why it decreases female fertility.
• Increases cortisol and adrenalin from the adrenal glands. This may impair the body's ability to deal with stress, and disrupt sleep, and in turn, can disrupt the regularity of ovulation, and produce menstrual symptoms.

References:

Lopez-Garcia E et al. Coffee consumption and coronary heart disease in men and women: a prospective cohort study. Circulation 2006;113:2045-53. PMID 16636169.

Lindsay, J., et al., Risk Factors for Alzheimer's Disease: A Prospective Analysis from the Canadian Study of Health and Aging, Am J Epidemiol 2002; 156:445-453

Benedetti M.D. et al., Smoking, alcohol, and coffee consumption preceding Parkinson's disease, Neurology, 2000:55, 1350-1358

Klatsky AL et al. Coffee, cirrhosis, and transaminase enzymes. 2006 Arch. Intern. Med. 166 (11): 1190-5.

Leitzmann MF et al. Coffee intake is associated with lower risk of symptomatic gallstone disease in women, Gastroenterology, 2002 Dec;123(6):1823-30

Choi, HK et al. Coffee consumption and risk of incident gout in men: A prospective study. 2007 Arthritis Rheum 56 (6): 2049-55. doi:10.1002/art.22712

Huxley R et al. Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus. 2009 Arch Intern Med 169 (22): 2053-2063.

Ganmaa D, et al.. Coffee, tea, caffeine and risk of breast cancer: a 22-year follow-up. 2008 Int. J. Cancer 122 (9): 2071-6. doi:10.1002/ijc.23336. PMID 18183588