by Неизвестный
In addition, research shows that there are a number of variables affecting the depressive side of caffeine. A recent study measuring the stress hormone cortisol (raised by caffeine consumption) is revealing. Researchers found that in collegiate swimmers, there was a powerful correlation between cortisol levels and depression, but only during periods of intense training.41 Thus, there appears to be a cumulative stress phenomenon, which may be present at certain times and absent at other times. Having this information and being sensitive to your moods will enable you to take the appropriate steps should you start to notice periods of depression.
Above all, I want you to avoid the common mistake of reaching for the coffeepot when you’re feeling “blue.” Coffee may help temporarily, but clinical and laboratory evidence suggests strongly that you will pay a steep price later on. Ironically, the group most likely to use caffeine in an attempt to change their
state of mind are those suffering from clinical depression.42
DAVE KICKS CAFFEINE, SLEEPS BETTER, FEELS BRIGHTER
Dave was a typical, hardworking middle-management professional. And like so many, his intake of caffeine had slowly escalated to four cups a day, the last one coming around 3 P.M. to get him through the overtime hours. Always looking for the competitive edge, he read an article in a health magazine that recommended eight hours of sleep for peak mental performance. That was when he realized that he suffered from insomnia. He was having a hard time getting to sleep, and would often read in bed or watch TV until 1 A.M.
His doctor gave him Ambien, a sleep medication, and told Dave to cut back on coffee. So he dropped the 3 P.M. cup. He started falling asleep earlier, but then he noticed that he was getting “the blahs” almost every afternoon. Not realizing that it was related to caffeine withdrawal, Dave blamed his depression on the sleeping pills. When he came to my office, he said he was looking for a “natural sleeping pill that wouldn’t make him depressed,” but it didn’t take me long to see the real problem.
“You don’t have insomnia because of an Ambien deficiency,” I told him.
“Ambien may help, but I believe you will do much better by getting off caffeine altogether. Caffeine is keeping you awake at night and caffeine is making you depressed.” Dave didn’t like this suggestion, even though I assured him that he would have more energy, a better attitude, and a sharper mind with my Off the Bean program (see Chapter 10). Instead he went back to his doctor, who gave him a prescription for a popular antidepressant.
After a month on the two drugs, Dave felt worse than ever. He was falling asleep all right, but he awoke feeling tired. He felt that his motivation, the sharpness he needed in his competitive field, was gone. He wasn’t depressed, but he also wasn’t feeling great. By the time he got back to me, he’d stopped exercising, and he knew that was not a good sign.
“Look,” I told him, repeating a rationale I had used a thousand times before.
“If you try my program and don’t feel a great deal better, you can always go back to your caffeine, sleeping pills, and antidepressants.” So Dave agreed to give it a try, and over a period of three weeks, he got off coffee entirely. Shortly after that, he was able to discontinue both medications, and that’s when his life really improved.
“At the end of a month,” said Dave, “it was as if the sun broke through. I felt optimistic and powerful. And I was keenly aware that the energy and enthusiasm
optimistic and powerful. And I was keenly aware that the energy and enthusiasm I was experiencing was coming from me, not a coffee mug. I got back into exercising, performed better at my job, and now look back on my caffeine addiction like a junkie who’s finally kicked the habit.”
Depression and Sleep
Dave’s case illustrates another facet of the caffeine-depression connection. Sleep is disturbed in 90 percent of patients with depression. The conventional belief is that when people are depressed, they naturally have difficulty sleeping. New research, however, shows that this is not the case. A study published in the Journal of Clinical Psychiatry found that curing the depression does not necessarily eliminate the sleep problem.43 The most likely explanation?
Depressed individuals frequently use caffeine to give themselves a “lift.” This habit perpetuates their sleep disorders and greatly increases the likelihood of recurrent depression.
What’s more, sleep disturbance is a common side effect of antidepressant medications. New studies presented in Europe indicate that selective serotonin reuptake inhibitors (SSRIs)—which include the popular antidepressant Prozac—can seriously interrupt sleep patterns, making people feel drowsy during the day.44
The vicious cycle could not be more clear. Caffeine contributes to depression, but, not knowing this, people take antidepressant drugs. Both the drugs and the caffeine dis turb their sleep, causing them to feel tired during the day, which causes them to drink more coffee. The only way to break this cycle is to get offthe caffeine. Then you will be able to discern whether or not you truly need an antidepressant.
Depression or Fatigue: Which Comes First?
Fatigue is one of the most frequent reasons why Americans seek medical help.45
It is also one of the most obvious causes of depression, and a source of some confusion among medical professionals. Mrs. Jones turns to her doctor for help with her fatigue and, after ruling out anemia and other disease factors, the doctor will often announce that she is “simply” depressed.
I find this response to be insensitive and unscientific. After all, it is entirely possible that the doctor was simply unable to find the cause of fatigue, and saying that she is depressed, while technically accurate, misses the point. In reality, anyone who becomes fatigued will ultimately become depressed.
The converse is also true. Depressed individuals will invariably experience fatigue. In fact, not all depressed people feel sad. Many just feel bone-weary. So
fatigue. In fact, not all depressed people feel sad. Many just feel bone-weary. So we have another vicious cycle that requires a search for root causes, not a quick diagnosis and a prescription for antidepressants. The caffeine-depression connection is very clear, but caffeine’s contribution to fatigue is often difficult to see. That’s because we are so used to thinking of caffeine as an energizing substance.
It might be good to review the stress-fatigue cycle described in Chapter 3, remembering that caffeine does not provide energy at all, but only delivers a temporary shock to the nervous system that feels like a boost. Think of an exhausted fighter in his corner and the trainer slapping him in the face to get him ready for the next round.
The truth about caffeine and energy is finally getting out. Physicians are starting to warn their patients about caffeine “rebound,” and an article in U.S.
News & World Report listed caffeine addiction as a major cause of fatigue, including a “crash” that occurs after caffeine “buzz” wears off.46 People who become aware of this powerful influence on energy and mood and take steps to improve their energy naturally (see Chapter 10) can experience remarkable improvements in their quality of life.
Mental and Emotional Effects of Caffeine
• Chronic caffeine ingestion may cause or exacerbate anxiety and may be associated with depression and increased use of anti-anxiety drugs.
• Caffeine may cause anxiety and panic in panic disorder patients.
• Caffeine may aggravate the symptoms of premenstrual syndrome.
• Chronic users who are caffeine-sensitive may have symptoms of caffeinism at relatively low doses.
• Individual who regularly consume moderate to heavy amounts of caffeine may develop caffeinism, or they may show signs of caffeine withdrawal syndrome after abstaining from the drug.
Source: G. L. Clementz and J. W! Dailey, “Psychotropic Effects of Caffeine,” American Family Physician, May 1988;37(5): 167–72.
Is Coffee the “Think Drink”? Think Again!
Students the world over use caffeine not only to stay awake, but also because
they believe the drug will improve their performance on exams. Solid research, however, - illustrates that as little as 100 milligrams of caffeine (a six-ounce serving) can cause a significant decrease in recall and reasoning.
One study compared scores on a memory test called the Auditory-Verbal Learning Test, or AVLT. College students who were given 100 milligrams of caffeine recalled significantly fewer words than those given a placebo beverage.
These results were found in both single and multiple presentation trials.
Interestingly, subjects given caffeine did fine at the beginning of the test, but were particularly weak in the middle to end portions of the study.47 This illustrates that the “enhancement” of alertness provided by caffeine is both temporary and illusory.
Research has also found that caffeine ingestion is associated with lower academic performance and greater incidence of psychosomatic illness.48
Ironically, when students are given a questionnaire to evaluate their expectation of benefits from caffeine, those with the highest expectations turn out to be those who consume the most caffeine and who experience greater levels of anxiety, depression, insomnia, headache, and fatigue.49 I believe that heavy caffeine consumption is a significant factor in the epidemic of anxiety suffered by college students. One recent study found that 34 percent of students surveyed were experiencing anxiety sufficient to cause clinical symptoms of psychosomatic illness.50
Caffeine Boggles the Brain
How does caffeine decrease mental acuity and cause all these problems? There are a number of possible explanations, the first of course being stress. Nature did not design the stress response to enable us to engage in abstract or global reasoning, such as may be required for complex tasks or final exams. The stress response causes a shift of mental function to a very primitive survival-oriented part of the brain known as the limbic system.51 Once again, this is great if you’re engaged in a fightor-flight situation, but not so great if you’re trying to write an essay on the fall of the Roman Empire.
What’s more, adenosine receptor antagonists (such as caffeine) have a depressive effect on other brain biochemicals, such as acetylcholine.52, 53 Since acetylcholine is a neurotransmitter directly involved in memory and learning, this could account for some of the observed negative effects. In support of this theory, researchers generally have found that simple tasks such as assembly-line work are enhanced by caffeine consumption, while complex reasoning skills are diminished. Subjects asked to perform auditory recognition tasks, for example, where they had to process verbal information, did worse after ingesting caffeine.54
Other eye-opening research has found that caffeine causes a remarkable decrease in cerebral blood flow. You don’t have to be a neurochemist to see that such an effect would not be good for memory, mood, and learning. Caffeine produces this effect, known as cerebral vasoconstric-tion, by interfering with the normal relaxation of blood vessels in the brain.
“Caffeine, even in small doses, is a potent cerebral
vasoconstrictor.”
Source: R. J. Matthew and W. H. Wilson, “Substance Abuse and Cerebral Blood Flow,” American Journal of Psychiatry, March 1991;148(3):292-3O5.
Is the effect significant? One study illustrated that a dose of 250 milligrams (approximately fifteen ounces of coffee) produced approximately a 30 percent decrease in whole-brain cerebral blood flow.55 This is not only unfortunate, it’s dangerous, because at the same time, caffeine increases blood pressure in the
brain, leading to an increased risk for stroke.56 Researchers have also found that caffeine reduces the oxygen level of brain tissues.57 With all of the attention on brain health today (concerning depression, Alzheimer’s and Parkinson’s disease, as well as stroke) don’t you think it’s a little odd that this data has not even made it to the evening news?
The Great Gaurana Hoax
Recently, manufacturers have been tripping over themselves to market products containing guarana, a South American herb. Guarana (botanical name, Paulinia cupand) is in chewing gum, “energy” drinks, a popular soft drink, and nutritional supplements purported to enhance sex drive, mental acuity, and stamina. It’s hyped as an ancient Aztec secret, but the only secret is that guarana contains more caffeine by weight than coffee beans. Manufacturers usually fail to mention that salient fact.
It’s also interesting to note that no manufacturer of guarana products has provided reliable evidence of their effectiveness. In fact, studies have been performed that soundly debunk the product claims. One group of researchers gave memory and learning tests to elderly volunteers. Those given guarana performed no better than those given placebo.58 Another study found that guarana actually had negative effects on a variety of learning tasks.59 The same is true for yerba maté, another herbal source of caffeine.
The DHEA Connection, Part II
In Chapter 3, we learned that DHEA is a hormone that contributes to youthful energy, vitality, and sex drive. Aside from the fact that it is converted by the body to testosterone and estrogen, DHEA also plays an important role in memory, mood, and learning. Recent studies have found that depressed individuals improve when DHEA levels are optimized, and this improvement includes enhanced memory and feelings of wellbeing.60 But before you run to the healthfood store to buy DHEA, you must realize it’s not that simple. Stress and caffeine can abolish nearly all of the neurological benefits you might obtain from DHEA.61
If you want the improvements in brain function that optimal levels of DHEA can provide, you’ll have to cut back on caffeine. That’s because there is a tug-ofwar going on in your body between DHEA and stress hormones. When stress hormones predominate, your immune system, emotional state, energy, vitality, and DHEA levels all suffer—and aging is accelerated as a result.
Can Caffeine Damage Your Brain?
Can Caffeine Damage Your Brain?
Neurological damage from caffeine ingestion is far from proven, but consider the evidence. We know that elderly individuals with symptoms of memory loss and disorientation have degeneration of neurons in an area of the brain known as the hippocampus. In animal studies, raising stress hormone levels produces neuron damage in that precise location.
What’s more, human studies support the concept of stress-induced hippocampal degeneration. Using magnetic resonance imaging (MRI), researchers have found reduced hippocampal activity in people under high stress conditions such as depression and post-traumatic stress disorder.
David Morgan of the University of South Florida’s Institute on Aging explains, “We think that exposure to stress hormones, particularly high levels over a long period of time, may be responsible for the minor learning deficits we have as we get older.”62 He goes on to assert that stress hormones may be responsible for the chronic degenerative diseases that cause most deaths in older people. The message is clear: Keeping levels of stress hormones as low as possible may determine to a great extent the quality of life in your later years.
Caffeine and Mental Illness
If a person were injected with 500 milligrams of caffeine, within about an hour he or she would exhibit symptoms of severe mental illness, among them, hallucinations, paranoia, panic, mania, and depression. But the same amount of caffeine administered over the course of a day only pro duces the milder forms of insanity for which we take tranquilizers and antidepressants.
Mental and emotional health requires a sense of stability, and we have seen that caffeine creates a roller-coaster effect throughout the nervous, endocrine, and cardiovascular systems. Thankfully, mental health professionals are starting to take a close look at the caffeine connection. Regarding the treatment of anxiety, recommendations are now being published to start with avoidance of caffeine,63 and the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) includes an entire section on caffeinism.
However, research concerning caffeine and mental health is mixed, in great part because of the way many studies are designed. In Chapter 1, I presented a s
tudy where hospitalized psychiatric patients were switched to decaf coffee without their knowledge.64 When these individuals did not improve, the conclusion was made that caffeine is not harmful to mental health. Given what we know about the severe emotional and physical symptoms associated with caffeine withdrawal, would anyone wonder why these people did not improve?
To evaluate the matter fairly, we need research that takes into account not only withdrawal, but the fact that it can take three weeks or longer for stress hormones to return to normal after discontinuing caffeine. In addition, it would be useful to know whether psychiatric patients consume higher amounts of caffeine than the general population. One survey of psychiatric hospital admissions found that patients consumed approximately five cups of coffee per day.65 Another put the total even higher and noted that the heavy caffeine users were also most likely to suffer from depression.66
In fact, a recent study revealed that about 40 percent of hospital inpatients consumed sufficient caffeine to produce multiple symptoms of caffeinism—including anxiety, depression, and paranoid delusion. Based upon these startling results, the authors recommend that all psychiatric patients be questioned regarding their caffeine intake, and suggested that caffeinism should be viewed as a primary contributing cause of anxiety-related emotional illness.67
Another facet of this important issue has to do with adverse reactions and long-term damage that may be caused by caffeine s interaction with commonly prescribed psychiatric drugs. Researchers are warning mental health professionals that caffeine can interfere with and even negate the therapeutic benefits of these medications.68