I was holding off on commenting on this study until I reveal a project I’m working on, but so many wine blogs out there have talked about it, I feel like adding my $0.02.
As you may be aware, I am a medical researcher who spends countless hours each week studying the hippocampus. Each day I take little glass electrodes and place them on brain cells in the rodent hippocampus observing changes in cellular calcium and electrical current in response to glutamate (excitatory neurotransmitter) stimulation that I control with a laser. My research has implications in memory and epilepsy. As a neuroscientist studying the hippocampus and a wine enthusiast, the recent topic of the effects of wine on the hippocampal volume hits pretty close to home.
Here is my overview of the study (I’m trying to not be too technical here – please leave a comment with questions):
The study in question was conducted by Stefan Bleich’s group at the University of Erlangen-Nuremberg (Germany) and appeared in the January 31 issue of the journal Alcohol and Alcoholism. The title of the study is pretty straightforward: Hippocampal Volume Loss in Patients with Alcoholism is Influenced by the Consumed Type of Alcoholic Beverage.
To get us on the same page: Hippocampal, means pertaining to the structure of the brain called the “hippocampus ” (see image from Wikipedia.com). This sea-horse shaped region is present in each of the temporal lobes (we have two hippocampus) of the brain and has been implicated in short-term and long-term memory, and is a major through-way for a lot of information in the brain. The hippocampus is also a major area of interest in epilepsy and it is often studied in rats/mice due to it’s ease of “in-tact” dissection (we can remove it without damaging it with basic surgical tools) and well understood morphology (we have detailed maps of how the cells in this brain region are connected).
“Alcoholism” in this study is defined as “alcohol dependent” – there were 52 patients in total mixed into groups of preferred beverage type: beer, wine or spirits.
Hypothesis: Based on alcohol preference, participants will have different levels of damage to their hippocampus as measured by hippocampal volume using an MRI.
Their findings: Patients preferring wine had the smallest hippocampus, followed by the spirits group. The beer group, on average, had the largest hippocampus (but still smaller compared to a group of non-drinkers). Homocystiene (a chemical homologue similar to the amino acid cysteine) levels were elevated in the spirits group, but no other group.
Their conclusions: Elevated homocysteine may be causing increased cell death resulting in smaller hippocampus. Further, the wine drinkers are most susceptible to hippocampus damage.
MAJOR PROBLEMS from my perspective:
Observe the percentage of women in each group:
- Beer: 21%
- Wine: 67%
- Spirits: 22%
- Control (non drinkers): 47%
Although human studies are inconclusive, there is evidence suggesting that women have smaller hippocampal volumes. In this study, the authors grouped the men and women which may give you large standard error, and in this case, questionable findings. I find this can be too common in MRI research and may be very misleading. In Table 2, they acknowledges that GENDER has the biggest reported effect on hippocampal volume (meaning that they are aware that women had smaller hippocampal volumes overall then men). Again, they say that GENDER was the biggest predictor of hippocampal volume – then they say the wine group (containing 2/3 female) had the smaller hippocampus – doesn’t take a neuroscientist to see this flaw in logic.
Another interesting note, look at the average lifetime consumption of ethanol:
- Beer: 1774 kg
- Wine: 800 kg
- Spirits: 1266 kg
- Control (non drinkers): 0
So in consuming less ethanol over one’s lifetime versus the beer group, the wine group did significantly more damage? I don’t buy it. This conclusion isn’t very well supported by pre-clinical (cultured cells, rats, mice etc) or other clinical (human-study) data.
Let’s keep in mind these people are all alcoholics. They reported their “preferred” beverage is wine, but that doesn’t mean they didn’t drink other things from time to time. Last time I checked, most alcoholics aren’t very particular about what they are drinking, as long as they are drinking something. Finally, the issue I brought up about women participants IS A huge confound and in my opinion shouldn’t have allowed this paper to get past peer review.
The right way to do this study would be longitudinal; meaning, get a group of alcoholics (beer vs. wine vs. spirits, is OK), scan their brains today, then each year for 10 years (making sure that men/women are equally represented in each group). Monitor their consumption as to ensure they remain in a particular group then look for changes from the first scan (baseline) to the last.
The biggest problem with all of this: The uproar caused by this study in the media and wine world. I have seen this study mentioned on all the major wine magazines websites as well as a majority of the more popular wine blogs (including one who calls himself “Dr. Vino” of which I am a daily reader). What has happened is without serious analysis of the study, the conclusions of the authors of the study are being portrayed as fact (or at least as strong evidence) and people are all worked up that wine is more damaging that beer or spirits.
This is just the latest in what the media can do to science. I have read on other blogs (vinography.com for example of which I read daily) attack science and scientists as having alternate agenda’s, poor scientific strategy, and misleading the public for personal gain. I’d like to make it clear I do not think that was the intention of the authors to blatantly mislead the public. Nor is it the intention of the vast majority of scientists.
We scientists spend countless hours in labs working for mediocre wages (those of us in academia, especially grad students!) in pursuit of a better understanding of human physiology and behavior. Before you attack the scientists come visit a lab sometime. The vast majority aren’t out for fame or fortune. By nature we are just curious souls wandering through life trying to figure out the intricacies of how and why things behave in the way they do while in some way contributing to the betterment of human life.
The lesson here is take the media’s reporting of science with a large grain of salt. Scientific articles are all available to the public and although often technical and boring, reading them yourself will allow you to draw your own conclusions from the data. At the very least, if you have questions about science or health, ask someone who is familiar with the field – don’t rely on those that make a living by presenting controversy to create “news”.