Coffee: Drink Java for Good Neurologic Health?

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For some people starting their day with coffee is as vital as waking up. Others believe that caffeine is a vice to be avoided.

What is the truth about this popular beverage? Is coffee a magic drink-or a bad habit to kick?

A recent review published in Food & Function reveals coffee’s secrets and how the dark brew may affect health.¹

The remarkable coffee bean is associated with the reduced prevalence of several diseases, including Parkinson disease, Alzheimer disease, cancer, cardiovascular disease, and diabetes. Finding what it is in coffee that confers health benefits is the focus of much recent research.

Amazingly coffee is the second most consumed beverage after water. It is cultivated all over the world, and picked as red berries. Growers remove the pulp to reveal a green berry, which can be roasted to produce the characteristic brown to black beans that most people associate with coffee. Roasting develops flavor and aroma. It also removes some of the components of the coffee bean, while introducing others than are unique in the human diet. There could be something in roasting process that has healthful properties.

There are in fact several bioactive compounds found in roasted coffee specifically, including chlorogenic acids, caffeine, trigonelline, melanoidins, cafestol, and kahweol.

Chlorogenic acids act as anti-oxidants, but researchers also believe they may be cancer-preventing agents specifically. Any anti-oxidant is a potential neuroprotectant, based on theories of oxidative damage occurring in many neurological conditions.

Caffeine has many interesting effects on the nervous system. In an Alzheimer mouse model, moderate caffeine intake was observed to reduce brain and plasma amyloid beta. Interestingly, decaffeinated coffee did not have this effect.²

Caffeine acts primarily through adenosine receptor antagonism on the A1 and A2 receptor subtypes in the hippocampus-an area important for memory consolidation, and several studies suggest that caffeine intake enhances memory. Adenosine receptors are also found in several other brain regions, including the cerebral and cerebellar cortex as well as thalamic nuclei. The A2 subtype in particular is located in areas of the brain that produce dopamine, predominantly the substantia nigra. In Parkinson disease, caffeine’s action in this region could be protective of substantia nigra neurons.

In fact, a meta-analysis consisting of 8 studies conducted in 4 countries between 1968 and 2001 indicated that people who drink coffee have a 31% lower risk of developing Parkinson disease than people who abstain from coffee. Two of the 8 studies found that more cups per day decreased the disease risk even further-up to 49% lower.³ It is tempting to contemplate that a substance found in coffee has a direct effect on preventing Parkinson disease. It is also possible, however, that another lifestyle habit common to coffee drinkers contributed to the risk reduction. Naturally, more research is needed.

Trigonelline may have many healthful properties, including acting as a hypoglycemic, a neuroprotective, and an antibacterial agent. In separate rodent studies, trigonelline was shown to protect neurons from toxins and to prevent axonal and dendritic axons from degeneration caused by neurotoxins.

As far as other components of roasted coffee, the beverage is a major source of melanoidins in the human diet. Melanoidins may act as anti-oxidants, behave as a dietary fiber, and have been proposed to be an anti-microbial. Kahweol and cafestol are also proposed anti-oxidants.

Although coffee could have beneficial physiological effects, it is important to remember that different brews of coffee could have different components and thus likely have different degrees of benefit. Regardless. . .  for those who drink coffee, it is nice to think that a morning cup of coffee is not only a pleasant habit but a neurologically healthful one as well!

References:

1. Ludwing IA, Cliffford MN, Lean MEJ et al. Coffee: biochemistry and potential impact on health. Food Funct. 2014; DOI:10.1039/c4fo00042k.
2. Arendash GW, Cao C. Caffeine and coffee as therapeutics against Alzheimer’s disease. J Alzheimers Dis. 2010;1:S117-S126.
3. Hernan MA, Takkouche B, Caamano-Isorna F, Gestal-Otero JJ. A meta-analysis of coffee drinking, cigarette smoking and the risk of Parkinson’s disease. Ann Neurol. 2002;52:276-284.