Why immoral foods are good for your brain

This is not an endorsement for a bad diet

Posted Jun 08, 2011

Within the lifespan of each person, the consequences of diet upon brain health are as slow and imperceptible as the changes that characterize normal brain aging.  The long timescale of our lives tends to obscure the importance of each days dietary choices.  Most of us underestimate the importance of the redundant aspects of our lifestyle and diets, e.g. those three cups of coffee and a sugar-coated donut in the morning, a piece of chocolate after lunch, a glass of wine or beer for dinner, a pack of cigarettes throughout the day and those few puffs of a marijuana cigarette at a party with friends.   Yes, all of these things should be considered part of your diet, whether they are obviously nutritious or not.  They are chemicals that you ingest or inhale into your body and they have subtle, long-term consequences whether you like it or not.  We all know about their potential for negative consequences.  I want to introduce you to a few reasons why they're also good for your brain and emphasize the point that what is good for your brain is not always good for your body. 

Coffee is rich in biologically active substances that provide anti-inflammatory and anti-oxidant benefits to the brain.  Recent studies have confirmed that coffee drinking significantly lowers the risk of developing Parkinson's disease. This effect requires about five to six cups of coffee per day for many years and appears to be mostly beneficial only to males primarily due to their lower levels of estrogen. Women benefit from coffee-drinking in other ways, particularly with regard to a reduced incidence of type-2 diabetes. Overall, people who drink substantial amounts of coffee daily tend to live longer than people who do not. Coffee drinking has also been correlated with a reduced incidence of colon cancer and liver cirrhosis. Recent evidence suggests that moderate coffee-drinking of about two to three cups each day might reduce your chances of developing Alzheimer's disease later in life. 

Be sure to always include a donut in your morning routine.  Your brain needs the choline (as lecithin) and sugar in donuts to function normally. Once inside the brain, the choline and sugar are used to produce two very important neurotransmitter chemicals called glutamate and acetylcholine.  These two chemicals play a critical role in learning and memory; they regulate your attention and mood and control how well you can move.  If possible, make that a double-chocolate donut. 

Chocolate contains an array of psychoactive compounds.  The fats in chocolate induce the release of endogenous opiates in your brain and produce a feeling of euphoria.  Chocolate contains phenethylamine, a molecule that resembles amphetamine although it is not nearly as potent.  Chocolate also contains a small amount of the marijuana-like chemical called anandamide. Anandamide is also used by your brain as a regular neurotransmitter and appears to be critical for you to experience pleasure. Chocolate contains some estrogen-like compounds, a fact that may explain a recent series of reports showing that men who eat chocolate live longer than men who do not eat chocolate (the effect was not seen for women who have an ample supply of their own estrogen until menopause). Chocolate also contains magnesium salts, the absence of which in elderly females may be responsible for the common post-menopausal condition known as chocoholism.  And finally, a standard bar of chocolate contains as many anti-oxidants as a glass of red wine. Clearly, there are many good reasons for men and women to eat chocolate to obtain its indescribably soothing, mellow, and anxiety-reducing effect.

Nicotine in those cigarettes affects cortical function in a complex dose-dependent fashion; low doses tend to activate the left hemisphere and produce mental stimulation and a feeling of arousal, whereas high doses tend to activate the right hemisphere more strongly and are associated with the sedative effects of nicotine.  Therefore, when doing boring tasks, you could take a low dose of nicotine by, say, smoking one cigarette and could increase your subjective feelings of arousal and attention.  In contrast, during anxious or stressful situations, you could take a high dose of nicotine by chain-smoking and may actually reduce your stress by activating the right hemisphere and producing a bit of sedation. These findings nicely demonstrate the competing roles of nicotine receptors in the two hemispheres and tell us something profound about how the two halves of the brain normally function to produce a balance of emotions, attention, and arousal. Moreover, 60% of adults diagnosed with attention deficit disorder smoke cigarettes as compared to less than 30% of the rest of the population, another interesting finding that indicates that acetylcholine nicotinic receptors play an important role in paying attention.  Nicotine may also be neuroprotective, as may the contents of tobacco smoke, which contains very high levels of chemicals that are efficient chelators of heavy metals. Thus, each time a smoker exhales they're expelling heavy metals from their body. There is, in any case, a reduced incidence of Parkinson's disease in people who smoke. 

The regular consumption of alcohol, in any form, has been correlated with a later onset of Alzheimer's disease; this might result from the ability of alcohol to reduce blood levels of cholesterol, which is directly correlated with a greater risk of dementia in later life. 

Recent investigations have also shown that stimulating the brain's marijuana receptors may offer protection from the consequences of stroke, chronic pain, and neuroinflammation.  Surprisingly, it may also protect against some aspects of age-associated memory loss. Ordinarily, we do not view marijuana as being good for our brain and certainly not for making memories. How could a drug that clearly impairs memory while people are under its sway protect their brains from the consequences of aging?  The answer likely has everything to do with the way that young and old brains function and a series of age-related changes in brain chemistry.  When we are young, stimulating the brain's marijuana receptors interfere with making memories.  However, later in life, the brain gradually displays increasing evidence of inflammation and a dramatic decline in the production of new neurons, called neurogenesis, that are important for making new memories.  Research in my laboratory has demonstrated that stimulating the brain's marijuana receptors may offer protection by reducing brain inflammation and by restoring neurogenesis. Thus, later in life, marijuana might actually help your brain, rather than harm it.  It takes very little marijuana to produce benefits in the older brain. 

This is not an advertisement for you to take up smoking cigarettes and pot or drinking beer and coffee because you think doing so will save you from the ravages of brain aging. I mention the beneficial effects of these substances only to emphasize a point: Scientists know about the correlations between the regular use of these popular herbal-based drugs and the reduced incidence of some age-related brain disorders because millions of people have administered billions of doses of these substances during the past thousand years, but only relatively recently has careful record-keeping allowed us to observe the quite subtle, yet very consistent, benefits provided by these drugs. Thus, it is only because these drugs are so widely abused that we've noticed their positive effects on the brain. There may be wonderful new drugs to be discovered in, say, cauliflower or haggis, but too few people have been willing to eat them in sufficient numbers and for a sufficient period of time for epidemiologists to take notice of their hidden benefits on our brain, if they exist.

© Gary L. Wenk, Ph.D. Author of Your Brain on Food (oxford, 2010)