How to Become Smarter (24 page)

Heating of the body affects the regulation of blood pressure and people with hypotension should be careful because there is a risk of fainting. As a rule of thumb, abort a hot shower or hot bath if you experience dizziness, changes of vision, malaise, nausea, or other unusual symptoms. Hot showers can trigger seizures in some patients with epilepsy and headache in some patients with migraine or other headache disorders. Both local and whole-body heating can worsen inflammatory conditions. Heat can cause severe fatigue in patients with multiple sclerosis. The list of contraindications above is by no means complete. Unless you are a healthy person who is not taking any medication, you need to consult your doctor before using hot hydrotherapy or a hot environment in your home.

• Adapted cold showers at 20 degrees Celsius (68°F) are safe for the vast majority of people, with rare exceptions such as Raynaud’s syndrome. To be on the safe side, consult your doctor or a qualified health care professional about adapted cold showers if you have a chronic medical condition or are taking medication.
  
• Water colder than 14°C (56°F) can cause pain in the skin. Swimming in such water can cause hypothermia (lowering of core body temperature).
  
• Don’t use cold showers at night because they can cause insomnia. Daily cold showers in the morning can also cause insomnia and you need to reduce their frequency if this happens.
  
• Because of the stimulant effect, patients with epilepsy need to be careful with cold hydrotherapy.
  
• Adapted cold showers elevate mood and increase impulsivity. Bipolar patients should not use this procedure during manic or hypomanic episodes.
  
• Healthy people should not take adapted cold showers on a daily basis because this procedure can induce symptoms of hypomania: inflated self-esteem, impulsiveness, and risky behavior likely to have painful consequences. On the other hand, adapted cold showers are OK during an illness (fever, weakness, nausea, depression).
  
• People taking some medications or substances (see below) and people with low blood pressure, headache disorders, or inflammatory conditions should avoid heating the body. These people should consult with their physician before trying this approach. The medications or substances in question are alcohol, alpha-andrenergics, amphetamines, anticholinergics, antihistamines, benzodiazepines, beta-blockers, calcium channel blockers, cocaine, diuretics, laxatives, neuroleptics, phenothiazines, thyroid agonists, and tricyclic antidepressants.
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Students and knowledge workers often disrupt their normal sleep pattern when studying or writing keeps them up all night. Boiled grains appear to be mild sedatives, perhaps because they contain small amounts of Maillard reaction products. These are chemicals that form in a chemical reaction of proteins with carbohydrates at high temperatures. Several days of eating a diet of boiled grains only can aid sleep. Moderate heating of the body increases fatigue and shares many biological effects with sedative drugs: similar chemical changes in the brain and slowing of mental processes. Therefore, a warm environment or moderately hot baths or showers should also help to fall asleep. A number of studies on laboratory animals and human subjects support this idea.

In contrast, brief moderate cooling of the body shares many biological effects with psychostimulant drugs, including increased blood pressure (a small and temporary increase), constriction of blood vessels, slightly increased heat production, reduced fatigue, increased activity, increased alertness, and elevation of mood. Adapted cold showers at 20 degrees Celsius (68°F), which include 3- to 5-minute gradual adaptation, promote wakefulness in the morning. Either these showers in the morning or hot hydrotherapy at night can restore a normal sleep pattern if some work-related activities have disrupted it.

Inhalation of cold air may predispose a person to a respiratory infection, whereas cold showers in the atmosphere of room-temperature air will not. The proposed method of cold hydrotherapy is safe for most people. Readers need to exercise caution with
hot
hydrotherapy, especially people taking certain prescription drugs and people with low blood pressure, headache, or inflammatory conditions.
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CHAPTER 3: Attention control, or the ability to concentrate

Attention deficit hyperactivity disorder (ADHD) often comes up in any discussion of attention function in scientific literature. It would be worthwhile to touch on the basics of this complex disorder. Patients with ADHD often have difficulty concentrating on routine day-to-day tasks, the symptom that psychiatrists define as inattention or distractibility [
294
,
295
]. ADHD is a heterogeneous disorder with the core symptoms of inattention, hyperactivity, and impulsivity (depending on the subtype of ADHD). These symptoms can cause discomfort and distress to the patient and have a negative effect on his/her school or work performance [
294
,
295
]. The current classification subdivides ADHD into three subtypes: primarily inattentive, primarily hyperactive/impulsive, and the mixed type.

ADHD has a strong genetic link, in particular, such genes as DAT1 and DRD4 play a role in ADHD according to genetic studies [
294
,
296
,
297
]. The common treatments are amphetamine-like stimulants methylphenidate (brand names
Ritalin
® and
Concerta
®) and d-amphetamine (brand names such as
Adderall
® and
Dexedrine
®). These drugs have a rapid beneficial effect on such ADHD symptoms as inattention and impulsivity (within 30-60 minutes) [
294
,
298
]. These psychostimulant drugs show beneficial effects in up to 75% of ADHD patients and can reduce symptoms and help patients become more organized and focused [
294
,
296
,
298
].

There is some controversy that surrounds ADHD. Some people in the mass media and among the general public have stated that ADHD is more of a cultural phenomenon than a true medical problem. They believe that ADHD is an artificial, made-up disease. These people think that ADHD does not pose any discomfort or danger to the patients, who are often just overly active young children. The percentage of children with the diagnosis of ADHD is higher in wealthy nations than in developing countries. Nonetheless, several recent studies have shown that ADHD is not a cultural phenomenon of wealthy nations and represents a valid medical problem [
299
].

We already discussed in Chapter One how American physician Benjamin Feingold proposed a hypothesis that certain food additives in the diet of children can contribute to the symptoms of hyperactivity and inattention. This theory became known as the Feingold hypothesis. The subject of the influence of food additives (artificial ingredients in human diet such as refined sugar, food coloring agents, monosodium glutamate, aspartame, and others) on mental health is a controversial one. There are a number of studies that support opposing points of view. The effects of any one food additive are often modest and difficult to detect against the background of numerous other food additives in the diet. On the other hand, elimination of several or all food additives from the diet should have more significant effects on mental performance or mental health. Several recent reviews analyzed existing studies of the role of food additives in the development of symptoms of ADHD. These reviews concluded that food additives have a small but significant effect on mental health of children [
64
]. In particular, food additives can make children somewhat more active and less attentive. Yet the size of this undesirable effect is too small to explain the significant difference between healthy children and children diagnosed with ADHD [
63
,
64
,
929
].

An
elimination diet
excludes all food additives and includes only the most basic foods. A recent randomized controlled trial of an elimination diet showed that this diet has a beneficial effect on children with ADHD [
67
]. The diet caused a statistically significant reduction of symptoms as judged by questionnaires filled out by teachers and parents. The elimination diet in this study consisted of rice, turkey, lamb, vegetables, fruits, margarine, vegetable oil, tea, pear juice, and water. One possible shortcoming of this study is that it did not include a control diet, due to the difficulty of designing a “placebo diet.” Another drawback is that the study was not blinded because parents and teachers had to supervise the diet of the children. The study included a randomly chosen control group of ADHD children who did not follow the elimination diet. As we will see later, the beneficial effects observed in this study may have been due to an increased amount of protein in the elimination diet. Therefore, further research is needed to confirm these results. After this book came out, the authors of the above-mentioned clinical trial have conducted a new, more rigorous study, with extensive controls. This later study shows that food additives are responsible for ADHD symptoms in a subset but not all of the patients [
944
].

Another study [
63
] investigated the effects of a mixture of benzoate and several common food colorings on young children (3-year-olds and 8- to 9-year-olds). The scientists put children on a diet free of all food additives and then added the aforementioned cocktail of food additives to the diet of some children. Controls received a placebo cocktail. This was a double-blind randomized controlled trial. The authors concluded that one of the mixtures of food additives promotes hyperactivity and inattention.

Several studies that investigated the effects of addition or withdrawal of a single food additive failed to detect any significant changes in behavior or mental performance. For example, a study on the influence of refined sugar on preschool children did not detect any effects on mental abilities [
93
]. The authors of that study reached similar conclusions about aspartame. Similarly, two other studies showed that aspartame has no effect on behavior of children [
300
,
301
].

As to the possible physiological mechanisms via which food additives can affect the workings of the brain, this remains unknown
^G
(Chapter One). One possible explanation is that most of the artificial ingredients have entered the human diet recently, during the last several centuries. This is when chemical manufacturing developed into an industry that represents a significant portion of the world economy. From the standpoint of human evolution, several centuries are a miniscule amount of time. Humans could not fully adapt to this change in the diet through natural selection. Therefore, food additives are unusual and “unnatural” components of the diet and thus may cause subtle negative changes in the functioning of the brain.
^G