remember, too, that vitamin D helps regulate the production of dopamine, the other mood-friendly hormone, in the brain. One of the most important studies in the last decade of how bright light can be used to treat PMS was led by Dr. D. J.
Anderson and published in the Journal of Obstetrics and Gynecology. Dr.
Anderson’s six-month study involved a group of twenty women who had unsuccessfully tried in a variety of ways to reduce their serious, ongoing problems with PMS. The women were given fifteen to twenty-nine minutes of bright-light therapy every day for four consecutive menstrual periods. At the end of the study, Dr. Anderson and his colleagues found that the bright-light treatments had reduced by 76 percent the severity of PMS symptoms such as depression, anxiety, irritability, poor concentration, fatigue, food cravings, bloating, and breast pain.
There may be a vitamin D link as well. Because ovarian hormones influence calcium, magnesium, and vitamin D metabolism, scientists have long believed that PMS can be partly blamed on low levels of these micronutrients. Dr. Susan Thys-Jacobs of Columbia University published a study in 2000 making a strong case for calcium, highlighting that the addition of not just calcium but also magnesium and vitamin D can completely reverse PMS. A year before that study, Dr. Thys-Jacobs’s investigations revealed that polycystic ovarian syndrome also could be corrected by supplementation of vitamin D and calcium.
Polycystic ovarian syndrome is a condition in which a woman’s hormones become imbalanced, often causing a disruption in her menstrual cycle and infertility. Dr. Thys-Jacobs examined thirteen premenopausal women with a history of abnormal ovulation and related menstrual problems. Their mean 25-vitamin D levels were 11.2 (yes, that’s deficient). After they were treated with calcium therapy and their vitamin D brought up to sufficient levels, seven of the women had normal menstrual cycles within two months, including two who had resolved previously dysfunctional bleeding. Two of the women became pregnant, and the other four patients maintained normal menstrual cycles.
Another side effect of some women’s monthly cycle—menstrual migraine—
has also been associated with low levels of vitamin D and calcium. Recall that we saw earlier how vitamin D deficiency is common in chronic migraine sufferers; this is aside from the menstrual factor and includes men, too.
You have PMS if five or more of these symptoms are associated with your menstrual period:
• feeling of sadness or hopelessness, possible suicidal thoughts
• feelings of tension or anxiety
• mood swings marked by periods of crying
• persistent irritability or anger that affects other people
• disinterest in daily activities and relationships
• trouble concentrating
• fatigue or low energy
• food cravings or binging
• sleep disturbances
• feelings of being out of control
• Physical symptoms, such as bloating, breast tenderness, headaches, and joint or muscle pain
Shift Worker Syndrome
Tens of millions of Americans work the night shift. Night-shift workers experience a variety of problems, such as a higher risk of psychological ailments and an increased likelihood of fatigue-related accidents. Night workers also have higher rates of heart disease, cancer, diabetes, and gastrointestinal disorders.
Despite the additional expense of paying people to work the night shift and the problems it causes for the workers, in this modern age we need people working unfavorable hours. Certain industries, such as oil refining, shipping, and transportation, need to operate around the clock; others find it economically desirable to keep the assembly line moving; emergency response and law enforcement need personnel operating their stations twenty-four hours a day; and convenience stores need to keep their doors open in case someone needs a gallon of milk at two o’clock in the morning.
Night-shift workers experience problems because their lives operate in opposition to their circadian rhythms. No matter how long a person works the night shift, when he leaves work and walks into the daylight to go home to bed, his body clock tells him it is time to wake up. That makes it hard for that person to get a full night’s sleep during the day.
Studies of night-shift workers have shown that, on average, they sleep one to two hours less than day workers. That sleep loss is cumulative and is primarily responsible for the problems night shift workers tend to have staying alert during their shifts and experiencing a fulfilling life outside work. Shift workers also pay a huge toll in their relationships with others and ability to maintain a stable household.
A large number of studies have shown that bright-light therapy is extremely helpful in helping night-shift workers adapt to their work schedules. Companies that have employees working the night shift should fully utilize bright-light technology to improve worker morale and reduce errors and accidents on the job. The keys to this are having the appropriate bright-light equipment installed and timing its use to synchronize workers’ body clocks to their working and sleeping hours.
Guidelines for Decreasing Circadian Rhythm Disruptions Caused by Shift Work
• Reduce the number of consecutive night shifts you work. Night-shift workers get less sleep than day workers. Over several days, they become progressively more sleep deprived. If you limit the number of night shifts you work to five or fewer, with days off in between, you are more likely to recover from sleep deprivation. If you work a twelve-hour shift instead of the usual eight hours, limit this to four consecutive shifts. After several consecutive night shifts, you should ideally receive a forty-eight-hour break.
• Avoid working prolonged shifts, working excessive overtime, and taking only short breaks.
• Avoid long commutes, because they waste time you could spend sleeping.
• Avoid rotating shifts more than once a week. It is more difficult to cope with such alteration than it is to work the same shift for extended periods.
The sequence of shift rotation can be important as well. Working the first shift, then the second shift, and then the third shift is easier than working the first, the third, and then the second.
• Get enough sleep on your days off. Practice good “sleep hygiene” by planning and arranging a sleep schedule and by avoiding caffeine, alcohol, and nicotine to help you sleep or stay awake.
• Avoid reliance on stimulants, over-the-counter and otherwise. Caffeine and stay-awake pills only temporarily trick the body into thinking it is functioning properly, which will only further disrupt your circadian rhythms.
Sleep Disturbances and Elder Care
Bright light is being used with increasing frequency and success to treat a variety of disorders that affect our older citizens, especially sleep-pattern disturbances and forms of dementia such as Alzheimer’s disease.
As people get older, their circadian rhythms “flatten out” and they become predisposed to sleep disturbances. This usually manifests itself in going to sleep too early and then waking before the sun comes up—often at three or four o’clock in the morning. In the most extreme cases, elderly nursing home patients may sleep at any hour of the day or night, sometimes even sleeping for part of every hour in the day. Bright-light therapy first thing in the morning, following the same guidelines used for seasonal affective disorder, has been effective in resetting elderly people’s biological clocks and restoring their circadian rhythms.
Increasingly, attention is being paid to the kinds of lighting that should be provided for seniors, not just in the form of directed therapy but also as it should be incorporated into the design and architecture of homes and group living facilities.