Could Eating More Carbs Help Moderate Seasonal Alcohol Intake?

By this time of year, many of us are now complaining about the effect of late sunrises and early sunsets on our mood, appetite and energy. A friend almost groans in his phone conversation when he describes how dark it is at 3:45 pm. Darkness, as well as frequent bitter, cold days, present a good excuse to stay inside and perhaps...drink?

For some, this light-limited season of the year provokes a return to or increase in their alcohol consumption. Although the holidays, especially if holiday parties finally return this year, may be associated with an increase in alcohol intake, the excessive drinking may continue for weeks beyond the New Year. The significantly reduced hours of sunlight last until mid-spring in some parts of the world; at its worst, the sun may be visible for only a few hours a day. Of course, during polar winters, there are weeks of complete darkness.

Darkness can have a significant effect on our mental and physical well-being, and its potential for causing excessive alcohol intake has been studied. Many of us are familiar with the winter phenomenon known as Seasonal Affective Disorder ("SAD"). This depressive state is characterized by moodiness, depression, irritability, and agitation, a craving for carbohydrates, especially sweets, and, often, an increase in alcohol intake.

Researchers wanted to know whether excess alcohol intake is linked to increased hours of darkness, or to both darkness and cold temperatures. Could a physically unpleasant combination of cold and dark cause people to stay inside and drink, and leave its mark in the form of an increased incidence of excessive alcohol intake and alcoholic cirrhosis? An extensive collection of data on average annual sunshine hours and average annual temperature impacting alcohol intake seems to point to a definite relationship. The authors analyzed data made available to them from the World Health Organization, the World Meteorological Organization and Institute on Health Metrics and Evaluation in 193 countries, including the United States. They found a significant correlation between heavy drinking, and the number of drinkers, and temperature and hours of sunshine. As the latter went down, alcohol intake went up.

Separating the effects of temperature and hours of daylight on alcohol intake may have to wait further studies. At this point, it is hard to see how fluctuations in outside temperature may alter neurotransmitter activity in the brain such that mood and alcohol are affected. Conversely, it is possible that the prevalence of Seasonal Affective Disorder in geographical areas characterized by limited hours of daylight during the winter may affect alcohol intake. Studies carried out in communities that experience only 4-5 hours of light during the depths of the winter have found a significant number of inhabitants suffering from symptoms of SAD. For example, up to 90 percent of Swedes report suffering from SAD to some degree, and their alcohol and sweet-carbohydrate consumption may increase as a result, along with symptoms of depression. Indeed, this seasonal depression may be considerably more intense than simply feeling grumpy because the sun sets too early: People with a severe form of SAD may experience behavioral symptoms similar to those of patients with major depression not linked to winter daylight.

The prevalence of SAD in Sweden led an energy company to voluntarily install phototherapeutic lights in bus shelters in Umeå, a northern Swedish town. (Note: I was in Umeå many years ago in late August for a meeting. The days were growing noticeably shorter by then and people were talking about the coming months of darkness and SAD. One resident who suffered from seasonal depression told me that eating potato sandwiches, i.e. mashed potatoes in a roll, helped his mood considerably.) Such cravings for carbohydrate-rich foods, a common symptom of Seasonal Affective Disorder, and similar cravings for carbohydrate among a subset of alcoholics, point to decreased brain serotonin as a possible link between lack of daylight, depression, and alcohol intake. Lower serotonin activity is now believed to be involved in the symptomatology of SAD, although how a decrease in daylight hours may alter brain serotonin activity is not yet fully understood.

Low levels of serotonin are also associated with chronic alcoholism. In a comprehensive review of how the body metabolizes tryptophan, the amino acid out of which serotonin is made, Badawy presents evidence that, in alcoholics, changes in liver enzymes decrease the amount of tryptophan available to the brain. And of course carbohydrate craving has been found among alcohol-dependent individuals, especially during the acute withdrawal period, as shown in a study of inpatients in an alcohol recovery facility.

The consumption of high-carbohydrate, low-protein foods increases the level of tryptophan in the brain and, subsequently, serotonin levels. Thus, the consumption of potato sandwiches during the months of limited daylight, or consumption of jelly doughnuts during the months of alcohol recovery, may point to the same biological motivation: Increased serotonin = improved mood. One alcohol recovery program promotes a diet that contains substantial amounts of healthy carbohydrates to diminish the negative moods associated with alcohol withdrawal.

Seasonal Affective Disorder generally fades away as the number of hours of daylight increases. Often, all the negative symptoms of SAD, including excessive alcohol intake, are replaced by an increase in mental and physical energy, the loss of carbohydrate cravings, and improved mood. It is really a “light at the end of the tunnel" scenario. Thus, just as alcohol intake increases in locations with a significant increase in winter darkness, so too it should recede to more moderate levels with the increase in springtime light. And, presumably, the need to self-medicate with carbohydrates will diminish, at least for several months.