Now the daffs are finally out, are you feeling frisky? Energetic enough to run a marathon? Have your thoughts turned to love and does the world suddenly seem a better place? If so, you may have spring fever, which scientists have confirmed really does exist.
Each year at this time millions of people across the upper half of the northern hemisphere begin to feel more upbeat and sexually active, if somewhat distracted, according to Professor Norman Rosenthal, a clinical psychiatrist at Georgetown University, Washington DC. The reason, he says in new research, is just that spring has sprung.
“Poets have written for centuries about the effects of spring,” Rosenthal says. “They have known, for example, that sex drives and energy levels surge for many people in the spring. But we are only now beginning to under- stand why.”
For people who suffer from seasonal affective disorder (SAD), spring fever can be particularly pronounced. “They act as giddy as a puppet on a string this time of year,” says Rosenthal. “But they are simply extreme examples of the changes that occur in all of us in spring.”
Scientists know that when seasons change, the retina — the part of the eye connected to the brain by the optic nerve — naturally reacts to variations in the amount of daylight. This triggers hormonal changes.
Particularly important is the adjustment in melatonin, a hormone that affects our mood and how we sleep. As a result of light changes, the body naturally produces less melatonin during spring, causing a lift in mood, a reduced desire to sleep, an increase in sexual appetite and a need to eat less.
New findings published in the European Journal of Clinical Nutrition, by researchers at the University of Massachusetts medical school, have also proved that activity levels rise as the days get longer. After analysing the exercise habits and food intakes of almost 600 men and women over a year, Professor Yunsheng Ma found that most subjects gained up to 2lb (1kg) in winter; they ate lots of carbohydrate and exercised little. Come spring, however, activity levels soared and calorie intake dropped. It seemed that the only reason for this was the change in season.
This is partly a psychological effect but also physical. Evolutionary biologists believe that our bodies are programmed to be more active as the hormone mix changes with more light. Released from the chemical messages that make us withdraw in winter, the body feels energised, ready to hunt for food and to give birth.
Spring is also the time, supposedly, when a young man’s thoughts turn to sex. And it is true that men are more fertile at this time of year than any other. Ironically, though, this is because levels of actual sexual activity seem to drop in spring. The less sex men have, the more they save up their sperm and the greater their sperm count when they do have sex.
Professor Michael Smolensky, a chronobiologist from the University of Texas specialising in the relationship of biology to the rhythms of hours, days and months, says that statistics indicate that sexual activity in human beings is much greater in autumn,. “When we look at couples who have kept sex diaries and single males who have kept their own data, sexual activity is rather low in spring,” Smolensky says.
This fits with studies that have shown conclusively that levels of testosterone, the male sex hormone, are higher in late summer and early autumn than spring, so that’s when men have the greatest sex drive and when conception rates are high.
But sperm counts do peak in March, April and May. Smolensky says: “In sexually active males, sperm count is affected by two factors, environmental temperature and sexual activity. When men are sexually active, sperm count goes down; when they’re not sexually active, they’re not using it, so it goes up.” That could explain Smolensky’s findings that there are more unplanned babies conceived during spring than any other time of year. There are more sperm around, so despite less sex, one’s more likely to hit the mark.
Spring not only improves our mood and energy levels, it can protect our teeth and bones. On the first few sunny days of spring many people feel the urge to take off those winter togs and do a bit of prancing in the sunshine. This is in response to the fact that for several months our bodies have been starved of vitamin D, essential for healthy bones and teeth. And we make it only when our skins are exposed to sunlight. We’re craving a top-up.
As little as 30 minutes a day of exposure to the face and arms between April and October when the sun’s rays are at their strongest is enough to ensure that vitamin D levels remain stable, says Professor Graham Bentham, an environmental scientist at the University of East Anglia. He says that spending time outside once spring arrives is the key and “ideally people should be getting ten-minute stints in the mid-day and afternoon sun during those months when the UVB radiation that creates vitamin D is strongest”.
But there is a downside to spring bursting out all over. First we can pay for our urge to exert ourselves. Smolensky says that a lot of heart attacks occur in spring because the energy surge causes many people to overdo it in the gym or in the garden.
It’s also the time when suicides and hospital admissions for depression peak. Psychologists have speculated that depressed individuals survive the winter clinging to the hope that spring will rejuvenate their lives. When it arrives, however, their expectations are dashed as life continues as before and the depression persists. For some people, as the poet T. S. Eliot said, April is indeed the cruellest month.
Suffering spring
Migraines Scientists who have looked into the relationship between weather and health believe that stormy weather, which often occurs in April, may be linked to an increase in headaches. Some migraine sufferers say that they can predict storms by their symptoms.
Sunburn The first sunny week of spring always brings a rash of sunburn cases; people who strip off their clothes at the first opportunity sometimes forget that it’s not just in summer that ultraviolet rays can cause skin damage.
Hypomania Researchers into weather and health believe that the changeable spring weather may be linked to sudden changes in brain chemistry, leading to hypomania — relentless activity, reduced sleep, elevated thoughts. This can particularly affect people with seasonal affective disorder.
More information on your health through the year can be found in the Times Healthy Living Yearbook
