Research Updates [archived]
- Prozac On A Plate
- Cortisol and Cell Death in the Brain
- More Problems with Non-Steroial Anti-Inflammatory Drugs (NSAIDs)
- Appetite and Hormones
Prozac On A Plate
(March 2004)
There is a lot of debate and finger-pointing about who or what is to blame for our nation’s crisis with obesity, diabetes, and the fact that 60% of us are over weight. We read that it is due to our sedentary lifestyles, and that we watch too much TV or sit in front of computers. Or that the problem is that adults not only get too little exercise, but that some of our schools can’t afford physical education classes for our children, so they become overweight and obese. Then there is the progressive increase in high-calorie fast food consumption, with kids between the ages of 4 and 19 consuming five times as much fast food as they did in 1970. No doubt these factors play into the problem. But we need to recognize the insidious cascade of factors at work here, and how these combine to create a hormonal ‘perfect storm’.
Recent research shows that elevated levels of cortisol cause leptin resistance, which turns out to be a significant factor in weight gain and obesity. Leptin is a newly discovered hormone produced by fat cells which helps regulate fat storage and appetite. Elevated cortisol levels make the cells in our brain less responsive to leptin and can cause us to crave fats and over-eat; to add to the problem, consumption of fats causes the brain to release opiates–hence the term ‘comfort food’. Worse still, leptin induces the production of inflammatory chemicals (cytokines) which further increase cortisol production.
As explained on the diet page of this website, fast foods and processed foods are both high in Omega-6 oils. Omega-6 oils cause the production of inflammatory chemicals in the body, to which the adrenal glands respond by secreting cortisol, which is both the anti-inflammatory hormone and the serious fight-or-flight stress hormone.
Cortisol levels, therefore, can become elevated from an inflammatory diet (a good diet would have a 4:1 ratio of inflammation-inducing Omega-6 oils to anti-inflammatory omega-3 oils, whereas the ratio of a typical American diet is 32-1); from intestinal tract inflammation due to overuse of anti-inflammatory drugs; and/or from poor diet, stress, or any combination of these factors.
If you think in terms of a vicious cycle, the whole issue of weight gain and obesity will become crystal clear:
- Cortisol makes our cells resistant to insulin, and insulin is how we transport sugar (glucose) into our cells. The inability to transport sugar into our cells causes cravings for sugar and simple carbohydrates.
- Cortisol results in leptin resistance and makes us crave fats and eat too much, and eating fats causes the brain to release opiates.
- While the adrenal glands are preoccupied with producing cortisol, they become negligent in producing another adrenal hormone called aldosterone, which regulates our mineral content, and results in a loss of sodium: his will result in a craving for salt.
- Many fast foods and processed foods use flavor enhancers such as glutamate (often disguised as hydrolyzed protein: watch those labels) which is an excitotoxin to the brain. A study from Stanford University published in Neuron, February 2003, found that the most addictive drugs (alcohol cocaine, nicotine, morphine, etc.) have a similar action on the brain: they appear to make a specific area of the brain more sensitive to glutamate, which raises the production of dopamine. A diet high in glutamate triggers the brain to secrete addictive chemicals and stimulates addictive neural pathways (the ventral tegmental area).
When you combine cravings for sugar, fat, and salt, the three staples of the fast food and processed food industries, and add flavor enhancers that target the addictive pathways of the brain, how hard is it to figure out why we are struggling with our dietary habits? It is devastating to start feeding children food at an early age that sets them up for cravings and addictions. Children depend on adults to feed them nutritious food, and we should no more feed our kids fast food merely for our own convenience than we should expose them to other addictive substances.
I’ll rest my case with this last fact: a survey of American schoolchildren found that 96% could identify Ronald McDonald; the only fictional character with a higher degree of recognition was Santa Claus.
Cortisol and Cell Death in the Brain
(January 2004)
A series of recent research articles not only confirm the fact that human brain cells can and do regenerate, but also shed some light on the factors that either help or inhibit this process.
A disturbing study on the neurobiology of child abuse reveals that children who are seriously abused have permanent damage to the actual structure of their brain. It appears that the brain is physically sculpted by experience, and the area most severely affected is the limbic system. The limbic system controls the fight or flight response to stress and the production of cortisol (the stress and anti-inflammatory hormone produced by the adrenal glands), as well as regulating memory and emotion. The cells of the limbic system are very sensitive to cortisol, and chronic overexcitement from childhood abuse produces a decrease in the size of the neural components that make up the limbic system, especially the hippocampus.
The ramifications of this are enormous because one of the functions of the limbic system is to filter and interpret incoming sensory information in the context of the individual’s survival and emotional needs and then help to initiate the appropriate responses. The damage inflicted by childhood abuse can permanently render the victim unable to recover from the abuse because the wiring of their brain is forever disabled. This goes a long way in explaining why some people never seem to be able to recover even with years of therapy and why they just can’t "Get over it." Chronic stress and elevated levels of cortisol cause damage to the structures of the limbic system and can cause depression, anxiety, and personality disorders.
Brain imaging studies also show a link between the overall size of the hippocampus and recurrent bouts of major depression. Researchers at Washington University found that patients who spent the most days depressed had the smallest hippocampi.
On the other end of the spectrum, a series of research studies show that antidepressant medications work not only because they raise serotonin levels in the brain, but because the elevation of serotonin promotes the growth of new neurons in the limbic system. Most antidepressants usually take two weeks to have an effect on depression, which is understandable when taken in the context that it is not only the elevation of serotonin that relieves depression, but the creation of new brain cells in the limbic system. As a way of testing this, researchers at Columbia University treated mice with antidepressants but killed off any newly created neurons in the limbic system, specifically the hippocampus which is related to learning and memory. The mice whose new neurons were killed did not improve in memory skills with the antidepressants. The study further states that if new cell growth is the key to fighting depression, then drugs that directly promote neuron growth might be faster and less disruptive than existing antidepressant drugs.
Dr. Weinstein’s Comments: These research studies reveal a lot of the good news-bad news about the effects of stress and cortisol on the brain. The bad news is that chronic elevated levels of cortisol are a factor in cell death in the brain; the good news is that if it is not too severe, the brain cells can recover and regenerate. Clearly, the most important factor is keeping the cortisol levels within a normal range and not only play around the margins of the problem by forever trying to find more effective drugs. One wonders how controllable drugs that cause brain growth will be and what side-effects may come from these therapies. By the same token, people who suffer depression and benefit from antidepressant medication should certainly use them, but they should also do everything they possibly can to normalize their cortisol levels.
More Problems with Non-Steroial Anti-Inflammatory Drugs (NSAIDs)
(November 2003)
On the Diet, Drugs, Stress, and Inflammation web page I discuss the severe gastrointestinal problems that can arise from prolonged NSAID use, i.e., gastrointestinal bleeding which results in the death of 16,500 people yearly in the US alone, and which is approximately the same amount of people who die from AIDS each year in the U.S. However, this is just the tip of the iceberg regarding other health concerns with NSAID use.
The Journal of Rheumatology reports a study undertaken to better define the role of NSAIDs with cognitive/memory decline in the elderly. Respondents were from the Iowa 65 + Rural Health Study, which is a part of the National Institute on Aging Studies of the Elderly. The decline in memory was assessed by a change in immediate word recall in a three year time span, and the results of the study indicated that the use of NSAIDs were a significant risk factor for longitudinal memory decline.
Another study published in the American Journal of Sports Medicine questioned the effect of NSAIDs on soft tissue, and details an experiment performed on 50 rats whose knee ligaments were surgically cut. Half of the rats were given the NSAID Celebrex for the first six days of recovery while the other half were not. The researchers discovered the injured ligaments were 32% weaker in the rats treated with the NSAIDs as opposed to the untreated rats, and that the normal inflammatory response is actually beneficial by removing cellular debris from sites of injury to promote quicker healing, which the NSAIDs inhibited. Of great importance, the authors of this article note that to their knowledge, there are no previous research studies regarding the effect of NSAIDs on soft tissue injuries. They presume the supposed benefits of NSAIDs were in research studies involving the relief of arthritic joint pain.
This brings us to the next insidious problem with using NSAIDs for joint pain, which is that NSAIDs inhibit the synthesis of chondroitin sulfates and other proteoglycans that are essential for cartilage repair and growth. This means that while NSAIDs might temporarily relieve joint pain, in the long run they will actually damage the cartilage and cause an increase in pain, which can trigger a vicious cycle of taking more NSAIDs in a futile effort to alleviate pain.
Dr. Weinstein’s Comments: Clearly, this is an outstanding example of how masking the symptom of pain instead of effectively treating the cause has serious consequences. If you are suffering from chronic or reoccurring back pain, neck pain, headaches, or some other joint pain, you need to seek a resolution to your problem either through chiropractic care, acupuncture, physical therapy, and if necessary, (such as a shoulder rotator muscle tear or a torn knee ligament) surgery. Using NSAIDs to mask symptoms carries the risk of cortisol imbalances due to intestinal inflammation as well as the problems listed above.
Appetite and Hormones
The New England Journal of Medicine published a study on September 4, 2003 about the administration of a hormone produced by the digestive tract that is part of the body’s natural appetite control system, and the study has shown that this hormone curbed the appetites of obese people. The researcher found that obese people have less of the hormone in their bodies.
Volunteers who were given infusions of the hormone, called PYY, before a meal ate about a third less food than they did without it. However, the researcher cautioned that the study was small and brief, and that additional studies involving more people for longer periods of time will have to be conducted to determine whether the hormone can help people lose weight safely and keep it off.
"It looks promising," said Stephen Bloom, a professor of medicine at Imperial College, London who helped conduct the study. Bloom further states, "If you’re going to try to control appetites in humans, you should do so in a physiologically appropriate way that does no harm. Most of the drugs being developed by the pharmaceutical industry affect many parts of the body and have adverse side effects."
"I don’t think it will be the so-called magic bullet that people are always looking for," said Rudolph Leibel, deputy director of the Obesity Research Center at Columbia University in New York, who wrote an editorial accompanying the study.
Dr. Weinstein’s Comments: While it may be promising to be able to administer a hormone natural to the body to control appetite and weight, the fact that nearly 50% of the American population are over-weight and 30% of those are obese begs the question: why do obese people have low levels of this hormone in the first place? Given the surge in obesity in the past twenty years, it’s surely not genetic.
Could it be that their intestinal tracts are inflamed due to the rise in the consumption of processed foods, fast foods, and anti-inflammatory drugs, and they are no longer able to produce this naturally occurring hormone? Would this not explain, in part, the incredible rise in childhood obesity given the average diet of children these days?
Also, have we so quickly forgotten the lessons learned from the administration of estrogen and progesterone to women, where in the most recent and significant study, so many women were exhibiting symptoms of heart disease that the study had to be stopped early? This, of course, occurring after millions of women were told they had to take these hormones for decades with no real research to support the claim that hormone replacement therapy was safe and effective in preventing heart disease and osteoporosis.
The concept of restoring and maintaining health by returning the body to its normal functioning state seems alien to current day health practices. Yet this is exactly the reason why I wrote my book: in order to help people find their way back to vibrant health.