How to Become Smarter (10 page)

Most of the above studies examined effects of individual artificial ingredients or, in some cases, a mixture of a small number of artificial ingredients. A great number of different artificial ingredients are present
simultaneously
in a typical modern diet. Therefore, these ingredients may also produce novel unexpected effects on health due to
interactions
among the effects of individual food additives. In other words, just as prescription drugs can have adverse interactions when taken simultaneously, artificial chemicals in the diet may also produce adverse interactions. Studies of individual artificial ingredients cannot identify these additional effects of interaction. A good tool for studying the collective effects of all artificial ingredients is an elimination diet, or a so-called “few foods diet” [
67
]. Elimination diets consist of several essential types of food and exclude all food additives and dietary supplements. Therefore, an elimination diet can eliminate both individual effects of each food additive and interaction effects; this will produce detectable changes in mental state or mental abilities. Another useful research tool is the use of cocktails consisting of many food additives [
63
].

To sum up, artificial ingredients in the diet, such as food additives and dietary supplements, can have negative effects on health and mental abilities. Yet when scientists test a single food additive, the negative effects are small and often undetectable. Collective negative effects (interaction) of all artificial ingredients in the diet may be more significant. Further studies of elimination diets will shed light on this issue.

• Various studies on humans and laboratory animals show that, at high doses, food additives can impair learning, memory, alertness, or activity level. The list includes allura red AC, carmoisine, erythrosine, iron, leucine, magnesium sulfate, monosodium glutamate, nitrates, nitrites, ponceau 4R, propionic acid, propylene glycol, quinoline yellow, refined sugar (sucrose), sodium benzoate, stannous chloride, sunset yellow, and tartrazine.
  
• The research into the effects of food additives on mental state remains controversial, and government regulators have approved all existing food additives as safe. This is because their effects on mental state are subtle or non-existent and they do not have adverse effects on physical health at approved doses.
  
• Cocktails of many food additives are better tools for investigating the effects of food additives on mental performance than studies of individual additives. Elimination diets, which simultaneously exclude
  all
  artificial ingredients from the diet, are another useful research tool.
  
• Recent studies suggest that elimination diets are beneficial in attention deficit hyperactivity disorder (ADHD) and further research is needed in this area.
  
• Nutritional or dietary supplements, such as vitamins, herbal extracts, and minerals, are another category of artificial ingredients in the human diet.
  
• Nutritional supplements do not have beneficial effects on the health of people consuming a balanced diet.
  
• Vitamin supplements can have adverse effects on health.
  
• Nutritional supplements do not improve mental abilities of people consuming a balanced diet, or this improvement is negligible.
  
• There is a lot of deceptive advertising related to nutritional supplements.
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That cooking degrades vitamins to some extent is a well-known fact, and we will not discuss this topic at length. For many vitamins, degradation with cooking does not exceed 10 to 30% [
108
,
109
]. Although this may have negative effects on health in theory (by causing a slight vitamin deficiency), in real life, people who consume a balanced, mostly cooked diet do not have vitamin deficiencies. As mentioned above, vitamin supplements do not provide long-term health benefits to people who consume a balanced diet [
99
], at least in industrialized countries. Some short-term studies show that micronutrient supplementation (vitamins and minerals) can slightly improve mental abilities in people who consume a balanced diet [
106
,
107
]. Therefore, one can interpret these findings as showing that cooking reduces nutritional value of food and worsens mental abilities to some extent, and we can correct this by vitamin supplementation. Put another way, you could say that vitamin supplementation of a balanced (cooked) diet can restore the amount of vitamins to the level characteristic of an equivalent raw diet. This is supposed to restore mental performance to its “natural level.” Note that the reported beneficial effects of vitamin supplementation are tiny and often non-existent. It is more interesting to explore the other side of the coin: cooking creates novel chemicals that are absent in raw food.

I did some literature research on chemical changes that occur in different types of food during thermal cooking. With respect to the effects on mental state, I was able to find data on some problematic chemicals. These chemicals form in muscle meats (such as beef or fish) and in cereal grains (such as wheat and barley) during cooking. Despite my best efforts, I was unable to find any such problematic chemicals that are formed in pasteurized milk or in fruits and vegetables cooked at moderate temperatures. One can interpret these data in two ways.

1. Pasteurization of dairy products and cooking of fruits and vegetables do not produce chemicals that have negative effects on mental abilities. Judging by the effects on mental abilities and mental state, it makes no difference whether you consume these products raw or pasteurized/cooked. (Pasteurized milk is safer than raw milk.)
   
2. Alternatively, the existing knowledge base (scientific literature) concerning chemical differences between raw and cooked foods is limited at present. Therefore, intelligence-worsening chemicals may be present in pasteurized dairy and in cooked fruits and vegetables. We do not yet know about the existence of these chemicals.
   

My personal experience suggests that the first interpretation is likely to be correct. Namely, pasteurization of dairy and cooking of fruits and vegetables at moderate temperatures have no effect on mental state or mental abilities.

On the other hand, my self-experimentation with raw meat and raw grains suggests that cooking these products causes noticeable changes in mental abilities, compared to a 100% raw diet. In other words, if we replace cooked meat and cooked grains with the corresponding raw products, both the subjective mental state and mental abilities should improve. The difference is detectable (subjectively) even after a single meal. You should not experiment with raw meat and fish because they pose serious risks to health (see
Table 1
). It is possible to improve mental abilities without resorting to such dangerous measures (and to achieve similar or even better results). Please don’t interpret the discussion that follows as encouragement to consume raw animal products. This type of food may become safe for the general population in the future if and when somebody develops new food-testing technologies and the government approves them.
^B

With respect to cooked animal products, some studies have shown that, in humans, high-protein diets can lower mood [
110
,
111
] and cause bad breath [
112
], fatigue [
111
,
113
], and emotional tension [
110
,
114
]. Some high-protein diets, when combined with a regimen of physical exercise, can worsen mood [
110
,
111
]. There are studies suggesting that vegetarians tend to have better subjective ratings of mood than people consuming a mixed diet [
115
,
116
]. Even a single high-protein meal consisting of cooked chicken and eggs can lower mood [
117
]. There is a report of a healthy person with a history of anxiety who had a relapse of panic attacks and anxiety symptoms after switching to a high-protein, low-carbohydrate diet [
118
]. Most people tolerate high-protein, low-carbohydrate diets well for extended periods of time [
119
], but these diets may still cause halitosis and fatigue [
111
-
113
]. Consumption of foods that contain protein of highest quality, such as red meat, correlates with an elevated risk of cancer and cardiovascular disease [
120
-
123
] according to epidemiological studies. The process of cooking forms some chemicals that are either absent or present at very low levels in raw animal products. These chemicals include heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, nitropyrenes, cholesterol oxidation products, and creatinine [
124
-
137
]. It is possible that these chemicals are the cause of some of the above-mentioned adverse effects on health. (Readers can skip the detailed discussion of this topic and jump to the key points: press the skip button or
this link
.) On the other hand, a recent study shows that a high-protein meat diet (3 weeks) does not cause deterioration of mental abilities [
933
]. This diet can improve reaction time [
933
].

As mentioned above, high-protein diets (which often include substantial amounts of red meat) can have adverse effects on health. These negative effects of animal products may in part be responsible for the popularity of vegetarian diets [
115
,
116
]. If animal products (such as red meat) can have adverse effects on health, then the question arises whether humans by nature are vegetarians. Is human physiology
incompatible
with consumption of muscle meats? The answer is “no” because studies show that some species of primates in the wild are vegetarians (frugivores) but others are omnivores. The omnivorous primates often kill invertebrate and vertebrate species of animals for food [
39
-
41
,
44
]. The closest genetic relatives of humans, chimpanzees [
138
], consume meat, including red meat [
39
-
41
]. The gastrointestinal tract of humans has a structure intermediate between that of carnivorous and vegetarian mammals. These data suggest that humans have adapted to consuming both plant and animal food [
44
,
45
]. The notable difference between humans and primates living in the wild is that the former consume animal products that are predominantly cooked whereas the latter consume animal products that are raw [
45
].

Cooking with fire reduces the risk of infectious disease because it kills most bacteria and viruses [
139
]. It also introduces significant chemical modifications into food by denaturing proteins [
140
,
141
], causing degradation of vitamins and lipids [
142
-
145
], and creating novel chemical compounds [
124
-
137
,
146
,
147
]. Studies show that cooking fish and meat at both high and moderate temperatures leads to the formation of a number of chemicals with mutagenic and carcinogenic properties [
148
-
150
]. A number of studies have reported the presence of a mutagenic activity in cooked meat and fish [
127
,
129
,
131
-
137
,
146
,
151
]. This mutagenic activity is undetectable in raw meat and fish [
136
,
146
,
152
,
153
]. The mutagenic activity exists in cooked muscle meats only and is undetectable in cooked organ meats and in cooked plant and dairy products [
152
,
154
]. The mutagenic chemicals are absent or below detection level in
raw
animal products but are present in
cooked
meat and fish. These compounds include heterocyclic aromatic amines [
128
,
129
,
133
,
134
,
137
,
146
,
151
,
152
,
155
-
159
], polycyclic aromatic hydrocarbons [
125
,
131
,
160
-
162
], and nitropyrenes [
132
,
135
]. (Small amounts of polycyclic aromatic hydrocarbons may be present in raw products as a result of environmental pollution [
163
,
164
].) Polycyclic aromatic hydrocarbons form in animal products during cooking on an open flame (e.g., barbequing). The amount of mutagenic compounds increases with the temperature and duration of cooking [
136
,
146
,
165
]. Animal products cooked at
moderate
temperatures (for example, by boiling or steaming) do contain mutagenic compounds [
133
,
136
,
148
,
157
,
166
,
167
]. Yet the concentration of mutagens is much lower, sometimes undetectable, compared to
high-temperature
cooking procedures such as grilling or frying [
146
,
152
]. Some of the mutagens detectable in cooked meat and fish have carcinogenic properties in laboratory animals [
128
,
134
,
156
,
160
,
168
]. Among other chemical changes during cooking, the concentration of cholesterol oxidation products can increase 5- to 10-fold [
124
,
126
,
169
]. The amount of creatinine can increase over 30-fold in cooked meat compared to uncooked meat [
130
].