How to Become Smarter (14 page)

People with kidney diseases should not use the modified high-protein diet (because it is a high-protein diet). In general, the diet may have the following undesirable effects: it may increase physical fatigue (you can reduce this problem using cold hydrotherapy as described in Chapter Two).
Rare
side effects include insomnia or other changes in the sleep pattern (Chapter Three) and symptoms of hypomania.

What about the
Paleolithic diet
, can it improve mental abilities? The Paleo diet consists of:

• fruits
  
• vegetables
  
• nuts
  
• cooked animal products (meat, fish, and eggs)
  
• does not allow grains, legumes, dairy, and artificial ingredients (salt, sugar, and other food additives).
  

According to its inventors, the Paleo diet is the diet of our ancestors prior to the advent of agriculture, that is, more than 11,000 years ago. In my experience, the Paleo diet improves mental clarity. Nonetheless, this diet may lower mood and make me feel bad if I follow this diet for several weeks to several months. My general advice is to use strict diets for short periods of time (less than a week). In keeping with this advice the Paleo diet is an excellent choice if you need to concentrate on reading for 2-3 days a week. The effects of the Paleo diet are similar to those of the modified high-protein diet, except that the Paleo diet tends to worsen mood and reduce information processing speed, based on my personal experience. (My experience suggests that diets containing large amounts of cooked meat reduce information processing speed. A recent study, however, shows that a high-protein meat diet improves reaction time [
933
]. It is possible that reaction time and processing speed are related but different things.)

I find it difficult to perform writing tasks (e.g., writing of scientific papers) on diets that exclude grains. The best diet for writing seems to be the
depressant diet
, which consists of cooked red meat, boiled whole grains, nuts, and fruits and vegetables. Because this diet does not improve problem-solving, it is not a “smart diet.” We will discuss the depressant diet in detail later, in Chapters Four and Five.

The absence of grains is one of the problems that I have with the Paleolithic diet. Another minor point on which I disagree with the Paleo diet is that the authors of this diet recommend lean meat. In my experience, small amounts of lean meat are OK, but consumption of large amounts of lean meat on a daily basis is an unbalanced and unhealthy approach. Ethnic groups who live on all-flesh diets consume fatty meat, i.e. they do not remove fat from meat. The northern fauna, such as whale, seal, and polar bear, are fatty types of meat. Chimps in the wild consume whole meat including muscle, fat, and organs. It is doubtful that carnivorous species of animals exist who consume muscle only and throw away the fat. The famous explorer Vilhjalmur Stefansson reported that large amounts of lean meat can cause nausea, abdominal pain, and diarrhea within 1 or 2 days [
251
]. Addition of animal fat to the diet quickly alleviated these symptoms. Robert Atkins also does not recommend high-protein diets that are low in fat. In my personal experience, large amounts of lean meat (less than 7% fat) trigger a headache within one or two days. The headache goes away as soon as I add animal fat back to the diet.

The reverse approach, consumption of fat alone without meat, is also unhealthy and unbalanced. I feel bad physically on diets that contain large amounts of plant oils and on diets that contain significant amounts of pork fat without pork meat. We will discuss the pros and cons of animal fat in more detail in the next section.

Finally, there is another diet that can improve some mental abilities but worsens others. This is the
fruit-and-vegetable diet
(Chapters Three, Four, and Six). The key feature of this diet is that it contains a tiny amount of protein and fat. The fruit-and-vegetable diet does not allow protein-rich plant foods, such as nuts, grains, and legumes. This diet is similar to natural diets of some vegetarian primate species, who are frugivores [
44
,
45
] (the closest genetic relatives of humans among primates are not vegetarians, but omnivores [
39
-
41
]). You can cook up to 90% of the contents of this diet at moderate temperatures; this makes little or no difference. This diet appears to result in the highest information processing speed among any other diets that I know of. This high speed is useful when entertaining people and for tests that contain short questions and require speed. Because this diet worsens attention control, it is not appropriate for tasks that involve a lot of reading. Just like the other “smart diets,” the fruit-and-vegetable diet can clarify the mind. You will start seeing solutions to many (but not all) of the life’s problems that previously seemed insurmountable. Life will seem simpler and easier. Some studies suggest that increased consumption of fruits and vegetables correlates with better mental abilities [
876
,
892
,
901
]. There are no published studies examining a diet consisting of fruits and vegetables only.

The fruit-and-vegetable diet reduces work capacity and will make you unable to perform most types of difficult work. Despite the large amounts of food that you will be consuming, the satiety level is going to be low. This diet also increases impulsivity (reduces self-control) and can cause hyperactivity. Another undesirable effect is that this diet reduces psychological resilience. In other words, any verbal abuse and high-stress situations that you may encounter will seem painful—this is the opposite of “thick skin.” It is best to avoid pungent vegetables while on the fruit-and-vegetable diet (as we will see at the end of Chapter Four). In addition, high-carbohydrate diets such as this one can be problematic for patients with diabetes. Four or more days of the fruit-and-vegetable diet can result in a loss of interest in most activities. On the positive side, there is theoretical evidence that this diet may be useful as a non-sedating neuroleptic treatment.
^F
In brief, this possible neuroleptic effect may be due to the reduced activity of neurons that use a chemical called dopamine to communicate with other neurons in the brain.

How strong is the scientific evidence that adherence to certain diets can improve your mental abilities? There are quite a few studies showing that people who consume a healthier diet tend to have better mental abilities [
49
,
826
,
837
,
838
,
846
,
858
,
863
,
866
,
908
,
943
]. Most of those are epidemiological studies, which demonstrate a statistical correlation but not causation. Several statistical studies also show that a healthier diet of students correlates with better academic performance [
843
,
845
,
868
,
871
,
876
,
913
,
940
] (academic performance correlates with intelligence). Randomized controlled trials such as [
839
,
887
,
888
,
928
,
933
] are needed to prove that a healthier diet can indeed improve intelligence in healthy people. One possible problem with this type of research is that the notion of what constitutes a “healthy diet” differs among different authors. In addition, some studies show that weight-loss dieting can worsen some cognitive abilities [
847
,
872
]. According to those studies, adherence to a strict diet may not always have beneficial effects on mental performance.

Going back to the smart diets, one hundred percent compliance with any of the above diets is going to be problematic if you try to follow a strict diet for a week or longer. It is not necessary to follow strict diets for extended periods of time because even a temporary improvement of mental abilities can have long-term benefits. When I have to make an important decision or if I face some difficult problems, I go on one of the above-mentioned strict diets for several days with 100% compliance. Once I have a clear plan in my head or on paper, I can reduce compliance with the diet to 95-98% or lower. I can follow the conventional dietary guidelines (official food pyramids) and live without any strict diets for extended periods of time or most of the time. Diets are a means to an end; they are not the purpose or a meaning of life. As you will see later, diets are not the only way to improve mental abilities. Nevertheless, I devised a food pyramid, which I try to follow. It has three parts:

• the base (foods that can constitute 70-80% of the diet);
  
• the middle (foods that can constitute 20-30% of the diet);
  
• the top (foods that one should avoid or consume sparingly, no more than 5% of the diet).
  

I named it the “Natural Food Pyramid” (Table 3 below) because most of it is based on the evidence for what is “natural” and what is “unnatural food” for humans. We reviewed this evidence in an earlier section of this chapter. The “good food” constitutes the base of the pyramid, “sedative food” the middle, and “problem food” the top of the natural food pyramid.

Table 3.
The natural food pyramid.

-----------------------------------

Problem food
(avoid or consume it sparingly; it can impair mental abilities or cause other health problems): food containing food additives (white sugar, brown sugar, vinegar, nitrates, nitrites, monosodium glutamate, and others), dietary supplements (artificial vitamins, minerals, and herbal extracts), baked grains (bread), roasted nuts, fried, grilled or broiled meat (contains carcinogens), fried fish or any other fried food, smoked foods (contain carcinogens), honey, processed cheese, all kinds of junk food (candy, cake, ice cream, pastry, hot dogs, hamburgers, cheeseburgers, pizza, cookies, chocolate, pancakes, sandwiches, pasta, ketchup, mustard, mayonnaise, salad dressings, other seasonings; potato chips, soft drinks, chewing gum, and so on); large amounts of lean meat can cause problems; pungent vegetables may contribute to feelings of anger or hostility: this may also be true of some spices; bananas and legumes cause a lot of gas.

Sedative food
(can lower mood or cause slowing, without impairing judgment): minced meat (15% fat or higher) cooked by boiling or steaming, boiled or steamed fish, boiled eggs, whole grains cooked by boiling or steaming (for example, shredded wheat cereal, steamed brown rice); boiled legumes, such as beans; raw nuts.

Good food
(does not cause sedation and does not impair mental abilities): raw fruits and vegetables; boiled or steamed vegetables, including boiled potatoes; pasteurized juices (free of additives); pasteurized low-fat milk, kefir, or buttermilk (free of dietary supplements), unsalted unprocessed cheese; minced meat (15% fat or higher) cooked by boiling or steaming when you consume it (not in the same meal) with an equal or greater amount of the above dairy products; raw water extract of certain grains (optional) such as wheat, buckwheat, and oats; natural fats (used as a seasoning) such as unrefined vegetable oils.*
------------------------------------

*Be careful with plant oils. I do not tolerate them well and avoid them. Dairy fat, such as butter and whole milk, tends to promote constipation according to some studies [
1006
,
1007
] and my personal experience.

Some placements of food products within this pyramid may seem contradictory and this is based on my personal experience, rather than on any convincing theory. I can explain some of these contradictions as follows. For example, honey, a natural food product, is at the top of the pyramid, among foods that you should avoid. In my experience, it is impossible to think clearly while consuming honey and this is why I try to avoid it or consume no more than a teaspoon per day. On the other hand, buttermilk and water extract of wheat can be considered “unnatural” because they are a processed type of food. Yet they are located at the base of the pyramid, with foods that one should consume in abundance. Earlier in this chapter, Limitations
#5
and
#6
of the natural intelligence theory explained this particular choice. At first glance, grinding and juicing may appear to be “unnatural.” But they do not change chemical composition of digestible nutrients. Juicing removes components that are virtually indigestible by humans. Therefore, juicing and grinding will not pose a problem. In my view, chewing of acid-rich (sour) types of fruit can be harmful for the teeth
^B1
(for instance, citrus fruits, apples, cranberries, strawberries, other berries). Using a blender or consumption of fruit juices is less taxing on the teeth. One potential problem with fruit juices is a sugar overload if a person drinks large amounts of juices.