Killing Jiminy: Stress, Fear, and Cortisol
For those of you that have been following our bi-monthly E-letter, Northwest Senior News, you may remember our series of reviews and digests from Dr. Stephen Sinatra’s book, The Great Cholesterol Myth. Sinatra listed the four leading causes of heart disease. Here they are.
In Chapter 4, Dr. Lustig also references a connection between stress and sugar. Cortisol also gets thrown into the mix. What we can learn from various experts in their respective fields is that their messages, while slightly different and approaching issues from somewhat different vantage points, end up saying some very similar things. Sinatra focused on the myth of the cholesterol problem. Lustig has focused the problem of sugar addiction.
We recently did a serialized transcription of Gary Taubes’ YouTube video, The Case Against Sugar. Taubes’ focus is that sugar consumption leads to insulin resistance. His central theme is that hypertension, heart disease, diabetes, strokes, obesity, etc. are all a subset of insulin resistance. Again, we see these similar themes of hypertension, stroke, and obesity.
Lustig examines the interrelationship between pleasure and happiness and what happens when there is too much pleasure (addiction) and not enough happiness (depression). He very astutely zeros in on what are the drivers of sugar addiction. That is exactly what he does in Chapter 4, Killing Jiminy: Stress, Fear and Cortisol.
The big pictures of these authors (and certainly many others) is how to stay as healthy as possible. And that, of, course, is one of the reasons why we produce Northwest Senior News.
Background: For those that remember Pinocchio, Jiminy Cricket was Pinocchio’s conscience, reminding him of good and bad. Lustig says that the chemical changes that occur when a person is under chronic stress can contribute to a reduction of a person’s constraining forces not to do bad things (Ed: or even evil things).
Our review and digest of Chapter 4 begins.
Lusting tells us that stress is a normal part of life. If there is an immediate threat to our personal safety such as a lion in our path, our blood sugar and blood pressure will rise to prepare us for action. This stress (or fear) causes the release of a necessary hormone called cortisol from the adrenals, which are located on top of our kidneys.
Acute, short term cortisol release is both necessary for survival and is actually good for you. It increases vigilance, improves memory and immune function, and redirects blood flow to fuel the muscles, heart and brain. Your body is designed for cortisol to be released in any given stressful situation, but in small doses in short bursts.
Lustig suggests that modern conveniences such as electricity, air conditioning, and plenty of food have decreased stress in our lives. However, chronic stresses have “gone through the roof.” He says that these chronic stresses are taking a toll on people’s lives.
Chronic stress leads to constant cortisol releases which will slowly kill a person.
Evidence of the association of job stress, psychological distress, and disease is extremely compelling. Psychological stress in adolescence is directly linked to the risk of heart attack and diabetes in adulthood. Chronic stress also directly impacts the reward pathway as described in Chapter 3, and it has been shown that chronic stress can speed the onset of dementia.
My comments: We have a family acquaintance that worked on the staff of a leading orthopedic clinic in North Central Idaho for nine months. She had to quit her job because working for the doctors was too stressful. How many people have to endure stressful jobs because they can’t afford to quit?
Continuing: Lustig reminds us that people in lower socioeconomic or minority groups often have more stress, and because of that they suffer from higher rates of morbidity (sickness).
Stress breeds more cortisol.
. . . the more stress, the more breakdown of the endocannabinoid CBI receptor agonist and anti-anxiety compound anandamide, and the more anxiety.
Lustig references the connection with marijuana and states that its use can help a person “mellow out.” He also cautions that long term marijuana use can lead to a cognitive decline to the tune of eight IQ points. At that point, Lustig quips that those people may be less stressed about reality anyway.
My Comments: Cognitive decline all by itself is a potential aging issue. Why would anyone want to engage in a behavior that could hasten his/her mental decline? If there is a medical reason for using marijuana, that’s one thing. As far as keeping your mental faculties sharp, using pot recreationally doesn’t seem like a very smart idea.
A Bucket of Nerves
Continuing: Lustig explains that your body’s reaction to stress is the result of a cascade of responses. The amygdala is the part of your brain that regulates this. When you encounter a threat such as a vicious dog or being contacted by nasty creditors, the amygdala activates the sympathetic nervous system. This raises your blood sugar and blood pressure to prepare you for the acute stress. The hypothalamus is the part of the brain that controls hormones. That tells the pituitary gland to tell the adrenal glands to release cortisol.
Occasional releases of cortisol are one thing, but continued exposure over the long term can exact a toll on your arteries and your heart, leading to hypertension and stroke. When everything is working well, you remember what caused a particular stress. For example, if you got freaked out by a snarling pit bull on a street you’re walking on, you’ll remember that and not walk down that street again if you can possibly help it.
Lusting explains that the hippocampus might be the most vulnerable part of the brain to cell death.
Almost any brain insult you can imagine (low blood glucose, energy deprivation or starvation, radiation) can knock off the neurons of the hippocampus. And one of the serial killers that attacks the neurons of the hippocampus is cortisol. The longer your cortisol stays elevated, the smaller and more vulnerable your hippocampus gets, which puts you at the risk for depression.
Lustig tells us that this is the likely reason why chronic stress leads to memory loss. Put more bluntly, he posits that chronic stress literally fries your brain, and it gets worse.
He continues by explaining that chronic stress impairs your ability to reason. The prefrontal cortex (PFC) is your high order or executive function part of your brain. Lustig uses the Jiminy Cricket analogy. Put another way, this is what tells us the difference between right and wrong and keeps us from going off the deep end, or what keeps us from indulging in bad behavior and keeps our baser desires in check.
A bad guy rapes Bill Smith’s daughter, and Bill finds out who the perp is. Bill is so angry at what happened that he feels like going over and taking the guy out. However, his rational side of his brain kicks in and tells himself that 1) he has no right to commit murder and 2) if he gets caught, tried and convicted of pre-meditated murder, he goes to the pen for a long time. His Jiminy Cricket says, “Okay, that’s your thought, but stop right there and get it out of your mind. You don’t want to be as bad as the other guy.”
In an uncontrollable, stressful situation, the amygdala-HPA trio (hypothalamus-pituitary gland-adrenal glands) axis commands the release of neurotransmitters including dopamine (yep, that again). These flood the prefrontal cortex (PFC), silencing Jiminy, which disinhibit you from doing some wild and crazy things. When your PFC is under fire by cortisol, your rational decision-making ability is toast.
My Comments: In the past few years we have heard of some things that people have done that are absolutely crazy. The woman in San Diego loses some YouTube revenue, so she drives up to the Bay Area and shoots some YouTube employees. Joe Blokes gets fired from his Post Office job, so he returns with a gun and shoots his boss. As I read this section of the text, I thought of these and other similar situations. You wonder, did these people just lose it without being aware of the consequences of what they were doing?
Continuing: Lusting explains that the more cortisol the amygdala is exposed to, the less it is dampened down by . . . the law of mass action.
More cortisol means fewer cortisol receptors in the amygdala, and the more likely your amygdala will do the talking from here on. Chronic stress day by day weakens your inner Jiminy.
Increased stress can turn a small desire into a big dopamine drive, which can be quenched by either drugs or food, or both. This is how the pizza and beer scenario typifies the American food experience.
My comments: There is a move afoot to absolve people of responsibility for their actions. Some suggest that we should have sympathy for the murderer or rapist because he had a bad childhood. This is along the lines of “he Devil made him do it.” The flip side here is that everyone has issues in his/her life, and everyone has to deal with various stresses. Maybe we have some events that are adding more stress compared to 20, 30, or 40 years ago. The key questions are, “What are the stresses I face and how can I minimize their effect on me?
Continuing: Lustig continues by saying that stress-induced dopamine has the capacity to remodel the prefrontal cortex so that it doesn’t work as well as before. Poor Jiminy Cricket has been squashed like a bug.
These neurons (the ones that house the dopamine receptors) are fewer and farther between. . . You need even more to get less. By driving the stimulation of the amygdala and decreasing your cognitive control centers, stress and cortisol make it much more likely that you will succumb to temptations.
Lustig poses a rhetorical question. Do you take three deep breaths or eat three doughnuts? Now it gets even scarier.
When cognitive control is lost, the ability to inhibit the drive to seek pleasure is lost. Stress promotes faster addiction to drugs of abuse and is likely the reason why drug addicts find it difficult to quit. Chronic stress kills off neurons in the PFC . . .
He reminds us that the preferred drug of choice when dealing with stress is, yes, yes, it’s SUGAR. Gary Taubes in his YouTube video The Case Against Sugar says essentially the same thing. It’s cheap, socially acceptable, and doesn’t appear to have immediate consequences. This sets up a vicious circle.
With chronic stress, eating is the preferred coping behavior of the individual. The person seeks energy dense food, usually loaded with sugar, which may become addictive. Since cortisol is an appetite stimulant, the infusion of cortisol into a person rapidly increases his/her food intake.
It gets even worse. Cortisol actually kills neurons that help inhibit food intake. Now a person eats even more food, usually sugar. The cycle continues.
If Only I Could Sleep at the Switch
Lustig tells us that another outcome of stress is reduced sleep. Reduced sleep also contributes to obesity. Short sleepers generally have an increased body moss index (BMI). Those deprived of sleep may consume up to 300 additional calories per day. The vicious circle gets worse and worse.
Dopamine makes you more likely to eat. The more you eat, the more likely you are to become obese. Obesity leads to sleep deprivation.
Lustig finishes the chapter by explaining that the impact of stress on children is even worse compared to adults. He says that this stress can lead to unhealthy snacking during adolescence. The result of that is overweight teens.
Lustig closes the chapter with:
The more chocolate cake you eat in response to stress, the less pleasure you will get and the sicker you will start to feel, which will drive even more stress. Those dopamine receptors need more but deliver less. You’ll become more tolerant or worse yet, addicted.