Advice from mice, trade in your weekend benders for moderate daily tippling

Image Credit: Daniel Farrell.

Is consuming alcohol good for you or bad for you? The research often seems contradictory. Drinking is linked to health benefits one day and ghastly diseases the next. Amount of alcohol consumed seems to be one predictor of relative help or harm, but how much is too much? For example, is 14 drinks per week a lot or a little? Before you answer that question, you may want to ask about when (and how often) those drinks are being drunk, as patterns of drinking may play as large a role in determining how alcohol affects health as the actual amount consumed. To better understand the relationship between drinking and cardiovascular disease, University of Rochester scientists recently spent a month sousing up mice and found that different drinking schedules yielded very different health impacts.*

The advantage of working with mice is that, unlike human subjects who tend to choose when and how much to drink, alcohol consumption of experimental rodents is determined solely by their lab-coated bartenders. The mice were thus divided into three groups. A “daily-moderate” group received the mousey equivalent of two drinks per day seven days a week, while a “weekend-binge” group were instead assigned seven rodent-sized cocktails in a sitting, but on only two days each week.† A control group of teetotalling mice received a non-alcoholic cornstarch mixture (in order to match the caloric intake of the boozers). Additionally, all three groups were subjected to an “atherogenic diet” a high calorie, high fat menu designed to induce atherosclerosis – a thickening or “hardening” of the walls of the arteries caused by fatty deposits, which impedes blood flow and potentially leads to heart attacks and strokes. Essentially, they ate like average Americans.

While the daily-moderate mice consumed the same total amount of alcohol per week as the weekend-binge group (and ate the same unhealthy meals), their bodies fared considerably better. Mice in the moderate group actually emerged with healthier blood vessels than those in the non-drinking control group on the same diet, with 40% less build-up of plaque on their arteries. Meanwhile, the binge group had pretty dismal numbers with a 60% increase in arterial plaque build-up compared to the control mice.

The binge-drinking mice not only sustained more damage to their arteries, they also got the fattest. While all three groups were fed the same junk food diets, changes in body weight varied with different alcohol intake schedules. Over the course of 4 weeks, non-alcoholic control mice increased in mass by about 8.5%, while the moderate-daily-drinking mice only increased by about 5%, a modest improvement. The binge drinkers, however, gained double the weight of the control group and more than triple that of the moderate drinking mice, adding a mighty 17.5% to their initial body weight.

How can the same amount of alcohol protect the cardiovascular health (and figures) of the daily drinkers while doing so much damage to the bingers? While exact mechanisms of action are yet undetermined, part of the difference lies in how the two patterns affect cholesterol in the blood. While both groups of boozing mice experienced an increase in HDL (the “good cholesterol” associated with removing build-up from arterial walls) their drinking regimens produced opposite effects in LDL levels (“bad cholesterol” that can cause build-up). Relative to the control group, the daily-moderate group showed a 40% decrease in LDL while the unfortunate binge group experienced a 20% increase in LDL.

Alcohol metabolism itself differs in moderate versus binge drinking episodes. While much to-do has been made over demon alcohol, its metabolite acetaldehyde is the more damaging molecule. When alcohol is consumed, the body breaks it down so that it can be removed. It’s a two-step process, first to acetaldehyde and then to acetate (a nontoxic chemical similar to vinegar). This is all fine and well except that the supplies needed to do the second step (breaking down nasty acetaldehyde into benign acetate) run out after a few drinks worth of metabolizing. So with binge drinking, acetaldehyde hangs around causing problems until the materials required to deal with it can be replenished.‡

Of course cardiovascular disease isn’t the only health concern out there. This study does not aim to address the overall effect of drinking patterns on all systems in the body. But it’s information worth noting for those who believe that abstaining from alcohol during the week is sufficient to balance out weekend bacchanalian excesses. That and it might be a good idea to lay off the cheese fries.

* The study will be published in a forthcoming issue of the journal Atherosclerosis. If you’re too impatient to wait for it, you can download the accepted manuscript in all its unformatted, un-copyedited majesty.

† The blood alcohol levels attained by moderate vs. binge drinking mice were roughly 0.07% and 0.23% respectively. This placed the moderate daily drinkers at a level where they could still legally drive in most U.S. states….if they weren’t mice, that is.

‡  Lingering acetaldehyde is also a major contributor to hangovers.