How to Become Smarter (71 page)

The use of prolonged exposure to cold to improve appetite in anorexic patients would be impractical and inconvenient (there are effective appetite-stimulating pharmacological agents). On the other hand, brief repeated exposure to cold is more feasible but may or may not produce a sufficient improvement of appetite. This is because the neurohormonal effects are transient (they usually return to baseline within 1 hour [
785
]) and consequently the effect on appetite is also expected to be transient and brief. My weight and appetite (a healthy subject) did not change when I used adapted cold showers twice a day for many months. On the other hand, this treatment may improve
low
appetite in some groups of patients due to the above physiological changes.

Fever-reducing and anti-inflammatory effects of cold hydrotherapy
(L
AY
L
ANGUAGE
S
UMMARY
): Moderate cooling reduces all signs of inflammation (redness, heat, pain, and swelling). Experiments on laboratory animals show that whole-body cooling produces biochemical changes in the body that prevent fever (in addition to reducing it physically).

There is evidence that exposure to cold can abolish febrile responses to endogenous pyrogens [
786
], suggesting that the antipyretic effect of cold exposure is mediated not only by physical cooling but also by neuroendocrine changes. Exposure to cold inhibits all cardinal signs of inflammation [
412
,
787
,
788
]. In addition to reducing heat and pain, exposure to moderate cold reduces redness (erythema) [
789
-
791
] and swelling (edema) [
792
,
793
]. Although most of the available evidence relates to the effects of cooling on
local
inflammation, moderate exposure to cold inhibits physiological manifestations of
systemic
inflammation as well by reducing fever and causing systemic analgesia as described in
endnote U
and in [
357
].

The relationship between cooling and inflammation is not a simple one, as exposure to extreme cold induces inflammation [
794
]. Cooling of the skin to near-freezing temperatures causes pain [
417
,
418
] and redness [
795
], and cryotherapy of warts with liquid nitrogen induces local inflammation [
796
]. Although repeated systemic exposure to moderate cold reduces physiological manifestations of inflammation [
655
,
786
], it also causes a modest pro-inflammatory shift in serological factors. Namely, it slightly increases the plasma levels of interleukin-6 [
396
,
797
,
798
], tumor necrosis factor alpha [
396
], haptoglobin [
396
], hemopexin [
396
], and slightly decreases the plasma level of alpha
₁
-antitrypsin [
396
] and testosterone [
798
]. As explained in [
393
,
396
,
799
], repeated exposure to moderate cold is not immunosuppressive, in contrast to some other anti-inflammatory treatments such as corticosteroids [
800
,
801
].

Theoretical evidence of antianxiety effects of high-fat diets and safe raw high-protein diets.
The evolutionary predecessors of humans (more than 300,000 years ago) most likely lived on a raw diet that was free of artificial ingredients [
43
,
46
], what is called the “ancestral diet” in this book (
Chapter One
). Since hominids evolved on this type of diet for over 15 million years, it is possible that the human brain will function at its best on the ancestral diet. This optimal functioning includes both cognitive performance and psychological well-being. Conversely, it is reasonable to hypothesize that the modern Western diet (the diet recommended by food pyramids) may cause the brain to function poorly, at least in some percentage of the population, since the modern Western diet is so different in its composition from the ancestral diet. In other words, the abandonment of the ancestral diet may have led to mental disorders such as depression and anxiety [
802
,
934
,
984
] in some percentage of the population (those who are genetically susceptible).

This is, of course, an oversimplification, but the argument presented above is the gist of the theory that one can sum up as the “cooked diet theory of disease.” Guy-Claude Burger was one of the first people who proposed this theory, in the 1960s [
803
] (his theory did not have that title; the title was “instinctive eating”). Burger’s theory did not single out depression and anxiety, but it encompassed almost all human diseases, including cancer. The logical implication of this theory was that a return to the ancestral diet, that is, the diet that consists of raw foods such as fish, meat, fruits, vegetables, and nuts and excludes everything else, should produce a clinical improvement or a cure in almost any disease.

It would be fair to say that the same limitations listed for the natural intelligence theory (
Chapter One
) are applicable to the cooked diet theory of disease. Particularly, the ancestral diet carries a significant risk of infectious disease and can cause more problems than it will solve. Another major limitation is that even if the modern diet did cause some diseases, the ancestral diet will not produce a clinical improvement if the pathological physical changes are severe and irreversible, as in cancer or Alzheimer’s disease. (Incidentally, Burger died of cancer [
803
].) Another limitation of the above theory, which we did not discuss in Chapter One, is that a variety of factors
unrelated to nutrition
—microbes, trauma, genetic mutations, stressful life events, and environmental pollutants—can cause human diseases. Nevertheless, in my view, the cooked diet theory of disease is applicable to some mental disorders, and therefore, safe diets that are similar in composition to the ancestral diet will produce a clinical improvement. We saw in
endnote C
that psychiatrists cannot diagnose mental disorders such as anxiety and depression by a laboratory test [
340
], suggesting that these disorders involve only a minor pathological change in the biochemistry or structure of the brain. These disorders can have biological manifestations, such as slightly increased blood levels of stress hormones, but these changes are within the normal range and therefore are not helpful as diagnostic tools. Therefore, this “minor physical change” may be reversible by relatively non-invasive treatments such as dietary interventions.

The antidepressant diet (
Chapter Four
and
Appendix II
) is in many ways similar to the ancestral diet: it contains raw animal protein (the
fifth section
of Chapter Four explained why pasteurized milk is a source of raw protein) and it excludes all artificial ingredients. My self-experimentation suggests that this diet has similar beneficial effects on mood and cognition compared to the ancestral diet. The quality of protein is somewhat worse in the antidepressant diet and, consequently, the attention control is slightly worse. On the positive side, the antidepressant diet does not carry a risk of infectious disease. In this diet, you can cook up to 90% of fruits and vegetables: this does not make any difference in the effects on mental state and mental abilities.

According to the theoretical argumentation in
Chapter Four
, the antidepressant diet, as a raw high-protein diet, may be beneficial in depression. Since many classes of antidepressant drugs have antianxiety properties [
448
,
450
], it is reasonable to assume that the antidepressant diet can be beneficial in some anxiety disorders,
if
somebody proves it to be effective in depression. Another reason why this diet may be beneficial in anxiety is that it closely resembles the ancestral diet and thereby may reverse the pathological state of the brain [
802
], in accordance with the “cooked diet theory of disease.” Finally, the proposed dietary intervention is most likely compatible with other treatments for anxiety.

There is another diet that is likely to have antianxiety properties. It is the ketogenic diet (low-carbohydrate, protein-normal, high-fat diet), which is sometimes prescribed to patients with treatment-refractory epilepsy. There are several lines of evidence pointing to the beneficial effects of the ketogenic diet in anxiety disorders. First, this diet reduces the level of activity in laboratory animals [
629
,
630
], which is similar to the effects of CNS depressants such as benzodiazepines or barbiturates. Second, this diet has anticonvulsant (anti-seizure) properties, and the most effective antianxiety drugs (e.g., benzodiazepines) are also effective anticonvulsants. The anticonvulsant properties of this diet are probably due to its effects on the adenosine signaling in the brain [
937
]. Third, this diet contains a lot of fat and high-fat diets reduce anxiety both in humans and in laboratory animals [
280
,
281
]. In order to be an effective antianxiety treatment, the ketogenic diet should contain little if any cooked meat because high-protein (meat-rich) diets tend to increase emotional tension and may provoke symptoms of anxiety in susceptible people, as we saw in the main text. The antianxiety diet would have to contain significant amounts of melted beef fat or pork fat (added to boiled grains or soups) instead of dairy fat because the latter contributes to constipation.

Going back to the physical changes in the brain of psychiatric patients, some physical illnesses also involve minor or undetectable pathological changes, for instance, some headache disorders such as migraine. Therefore, the ancestral diet or similar safe diets (the antidepressant diet, fruit-and-vegetable diet, and modified high-protein diet) are likely to produce a clinical improvement in this case. Diets are unlikely to provide instantaneous relief of headache, although they can reduce recurrence of chronic headaches; therefore, pain-reducing treatments such as pharmacotherapy and head cooling
^U
(
seventh section
of Chapter Two) will still be beneficial. As to why the modern diet may cause headache in genetically susceptible people, it is possible that some components of the modern diet may have weak vasodilatory properties (dilate blood vessels) or may provoke aseptic meningitis (inflammation of the membranes that surround the brain) similar to the effects of some pharmacological agents [
804
]. Possible candidates include novel chemicals that form during cooking of food (cooking mutagens, Maillard reaction products) and some food additives (such as nitrates [
81
] and others). There are hundreds of chemicals known to be absent in the ancestral diet and present in the modern diet. The possible headache-provoking effects of these compounds are unknown and further research is needed in this area. Some investigators are actively studying possible provoking foods in the diet of patients with headache disorders [
805
] and there are some reports of successful treatment of migraine by elimination diets [
806
,
807
]. The list of things that can cause headache in me is the following: smoked food eaten on a daily basis; roasted nuts consumed on a daily basis; large amounts of lean meat, 5% fat or lower (this effect is highly reliable; reintroduction of animal fat into the diet will quickly reverse the problem); honey in relatively large amounts (6 tablespoons per day) but only in the context of a vegan diet (see section “
A diet that can worsen mental abilities quickly
” in Chapter One); fasting longer than 24 hours; and the depressant diet (sometimes).

Strictly speaking, hypomania can also be characterized by increased irritability instead of elevated mood [
340
]. The experimental model proposed in this book deals with the euphoric version of hypomania. Raw high-protein diets and exposure to cold do not cause depletion of dopamine stores within neurons and it is not known how much they increase the level of dopamine outside neurons. Therefore, the effect of these treatments on mood and behavior may be somewhat different from that of dopamine reuptake inhibitors, such as cocaine and amphetamine. In particular, since there is no depletion of dopamine, the state of euphoria that may result from the “creativity regimen” proposed in
Chapter Four
may be more sustainable compared to the euphoria induced by dopamine reuptake inhibitors. The magnitude, however, of the euphoriant effect may be smaller with the nonpharmacological approach.