May
05
2018

The Benefits Of Drinking Green Tea

Chances are you heard about the benefits of drinking green tea to reduce heart disease. But the polyphenols of green tea also prevent cancer, depression and cognitive decline.

Green tea lowers cardiovascular mortality

A study in the Chianti region of Tuscany, Italy consisted of 807 men and women aged 65 years and older. They had urine tests for metabolites of green tea in the beginning of the study. The study went on for 12 years. 274 participants died, which was 34% of the total study group. Tests measured the total urinary polyphenol (TUP) concentration in both groups, the survivors and the participants who died. Those participants whose TUP was in the highest tertile of the TUP values had the lowest all-cause mortality. And those participants whose TUP was in the lowest tertile had the highest all-cause mortality. 

High blood pressure and stroke

A Taiwanese study from 2004 examined the blood pressure of 1507 subjects. There were 711 men and 796 women with a recent diagnosis of  high blood pressure. The investigators looked at tea consumption (green tea and oolong tea) and blood pressure reduction. They found that those who drank 120 to 599 mL/day of green tea or oolong tea decreased their blood pressure by 46%. Those who drank more than 600 mL/day of green tea or oolong tea lowered their blood pressure by 65%.

Another meta-study involving 194,965 people and 4378 strokes found that there was a reduction of strokes with increasing tea consumption. Those who drank 3 or 4 cups of green tea or black tea per day were the experimental group. Researchers compared them  to the control group that drank less than one cup of tea per day. The experimental group had a 21% lower risk of getting a stroke than the control group.

Cancer prevention more with black tea than with green tea

A meta-analysis of 18 studies from China showed that green tea and black tea consumption was beneficial for prevention of cardiovascular disease and for cancer prevention. The highest consumption of green tea reduced cardiovascular mortality by 33%. The highest black tea consumption lowered mortality by 12%. Cancer mortality turned out to be different. Green tea did not produce a reduction in mortality, but black tea lowered it by 21%.

Another study, this one from Shanghai, China, points out that there are 15 polyphenols in green tea that likely work on different target areas of the body. They target 200 different genes in humans affecting diabetes, cancer, cardiovascular disease, neurodegenerative disease, muscular disease and inflammation.

Other cancers like prostate and breast cancer benefit from green tea

This study shows evidence that habitual green tea drinkers do prevent prostate cancer and breast cancer to a certain extent.

Another study investigates the effect of tea on health. One of the studies from the same authors have shown that the oxidative damage to cells from cigarette smoking can come out in a urine test. Those smokers who drank 4 cups of tea per day had a 31% decrease in their urinary biomarkers to indicate DNA damage. As DNA damage is often the first step in cancer development, these findings are important to note.

Cognitive effects of green tea consumption in dementia patients

A 2017 review of dietary supplements to improve cognitive impairment pointed out several supplements that will improve cognition. Green tea is one of them, but omega-3 fatty acids (EPA), and docosahexaenoic acid (DHA) are also useful supplements to restore neuronal functioning.

A 2017 study from Basel, Switzerland found that green tea improved memory, reduced anxiety and activated the working memory, which could be made visible on functional MRI scans. These researchers also pointed out that green tea has this effect as a whole, you cannot attribute it to a single constituent. Separate tests of  caffeine or L-Theanine  showed that the beneficial effect was smaller than when green tea as a whole was tested.

2016 study on severe Alzheimer’s patients

This 2016 Iranian study looked at 30 patients with severe Alzheimer’s disease. A baseline assessment was first, and 2 months after taking 4 green tea pills daily another assessment followed. A blood test measured the oxidative stress before and after, so was the antioxidant level from the green tea. The oxidative stress test showed an improvement during the study. The antioxidant level in the blood was higher than before the start of the study. The cognitive function test improved only slightly.

A 2018 study from Singapore looked at the effect of drinking tea (black tea or green tea) regarding symptoms of anxiety or depression. In a group of 614 subjects who were elderly individuals, aged 60 years and above; 59% consumed tea for longer than 15 years. These tea-drinking people were significantly less depressed and significantly less anxious when they underwent psychological tests, compared to non-tea drinkers.

Depression and green tea consumption

There is a 2018 study from South Korea that looked at the link of beverages from 15 studies with depression. 347,691 participants were part  of  these 15 studies, and 20,572 cases of depression developed. Comparing a high consumption of tea or coffee to low consumption, the following statistics were the result: coffee consumption reduced depression by 27%, green tea consumption by 29%.

The Benefits Of Drinking Green Tea

The Benefits Of Drinking Green Tea

Conclusion

Bioflavonoids are powerful antioxidants. But there are many more substances in green tea and coffee that are all beneficial for our health. One of the studies mentioned identified 15 polyphenols in green tea. But another study said that trying to identify one of the components as more active than the others would be a waste of time. They measured some of the factors by themselves and found that the overall effect was much smaller than green tea as a whole.

Other research has shown that the components of green tea activate several genes. This includes anti-inflammatory effects, prevention of heart attacks and strokes, lowering of blood pressure, anti-cancer effects, improvements of cognitive function, as well as improvement of depression and anxiety. As you can see the effect of green tea is diversified. Don’t hesitate to consume another cup of tea!

Apr
23
2016

Healing Powers Of Green Tea

Powerful catechins that are a special form of bioflavonoids provide the healing powers of green tea. Researchers have proven that these catechins are only in green tea, not so much in black tea. The most effective of several catechins contained in green tea is EGCG, which stands for EpiGalloCatechin-3-Gallate. It crosses the blood/brain barrier and is very important for the protection of the brain from Alzheimer’s disease. But green tea or green tea extract has a diversified pharmacological action. Researchers said that green tea protects you from cardiovascular disease, from obesity, from diabetes, from autoimmune disorders, from cancer, from Alzheimer’s and dementia.

In the following I like to comment on how green tea or its extract can protect from all of these diseases.

Alzheimer’s disease

Although there are 5 or 6 approved anti-Alzheimer’s drugs, none of them work for very long. They may at best postpone the deteriorating memory for 6 months, but then the effect of the drug wears off. The reason is that the drugs do not stop the production of the deadly beta-amyloid. It is the beta-amyloid that damages nerve cells that you want to preserve so you can think and memorize. In contrast a simple phytochemical, the catechin EGCG has been shown in animal experiments and in human trials to stop beta-amyloid production and increase solubility of beta-amyloid fragments in the brain. The end result is better memory and no further deterioration.

Two studies showing less strokes and better working memory processing with green tea

In a study of 13,988 elderly Japanese observed over 3 years the group that consumed 3 to 4 cups of green tea daily had 33% less strokes, cognitive impairment and osteoporosis.

Researchers at the University of Basel, Switzerland enrolled 12 healthy volunteers aged 21 to 28 and fed them extracts of green tea or placebo fluid via feeding tubes. They did this to rule out taste as a factor. The patients underwent functional MRI scans and they also received memory-stimulating tasks. Only the green tea extract was boosting activity in the frontal brain of the subjects. This was located in a specific area, called dorsolateral prefrontal cortex. This area has a connection with language comprehension, reasoning and learning. It also switches short-term memory into long-term memory, called working memory processing.

Healing powers of green tea through new nerve cell development

Researchers showed with animal experiments that green tea extract protects nerve cells from the toxic effect of beta-amyloid. At the same time green tea extract triggers the production of new brain nerve cells (neurons). This is really good news for Alzheimer’s disease patients and their families: green tea extract delays further memory deterioration and stimulates the development of new nerve cells in the brain!

Cardiovascular disease

In a 2006 Japanese study 40,530 Japanese adults aged 40 to 79 years without history of stroke, coronary heart disease, or cancer at baseline were observed for 7 years. Diaries were kept about how many cups of green tea each person was drinking per day. The prevention of heart attacks and strokes was the the biggest effect of green tea extracts.

Men had a mortality reduction of 12% for heart attacks when they drank 5 cups or more of green tea; in women the corresponding mortality reduction for heart attack was 31%, a bigger effect. Overall mortality from strokes was lower than from heart attacks. This made the effect of green tea consumption even more beneficial with respect to stroke prevention. This study did not show any cancer prevention effect for green tea.

Obesity

It appears that green tea increases heat production and burns fat in the process. There was a small effect in terms of weight loss and a beneficial effect increasing the protective HDL cholesterol in this 2012 Polish study on obese patients. The authors compared either 379 mg of green tea extract, or a placebo, daily for 3 months. They concluded: “The results of this study confirm the beneficial effects of green tea extract supplementation on body mass index, lipid profile, and total antioxidant status in patients with obesity.”

Diabetes

Although there are claims in some studies that green tea would prevent diabetes, this question was thoroughly investigated in this Chinese 2014 study.

Researchers did not see any effects on fasting blood sugars or on hemoglobin A1C values. Hemoglobin A1C is a very sensitive indicator for the presence or absence of diabetes. All these lab tests showed no change following consumption of green tea or green tea extract. Forget using green tea for diabetes prevention; cut out sugar and starchy foods instead.

Autoimmune disorders

Sjogren’s syndrome and lupus are both autoimmune diseases. Green tea extract has shown in humans that symptom severity can improve; green tea polyphenols (GTPs) possess anti-inflammatory properties that benefit patients with autoimmune diseases.

In an animal model arthritis researchers determined that T helper cells are weakened and bone resorption is inhibited by EGCG from green tea extract.

Researchers at Harvard Medical School, Boston, MA have noted that green tea extract is useful in calming down the immune response in autoimmune diseases. They concluded: “Altogether, these studies identify and support the use of EGCG as a potential therapeutic agent in preventing and ameliorating T cell-mediated autoimmune diseases.”

Cancer

Many researchers found that EGCG from green tea extract has immune modulatory effects. Furthermore, they saw a positive effect when patients received EGCG in combination with chemotherapy. A combination of cisplatin therapy with green tea extract has been found to have more effects on colorectal cancer and ovarian cancer than each one on its own. Similarly chemotherapy of breast cancer had better results in humans when EGCG from green tea extract was added as an immune modulation. More research, particularly in humans is needed to fully understand the mechanism of action of EGCG.

Toxicity of green tea extract

Animal experiments showed that higher doses of green tea extract could cause toxicity in the liver and in the nose of rats and mice. I was not able to find objective evidence for green tea toxicity in the PubMed system with respect to humans.

Healing Powers Of Green Tea

Healing Powers Of Green Tea

Conclusion

Perhaps the most important discovery regarding green tea extract is as follows. It crosses easily through the blood/brain barrier into the brain. This can postpone Alzheimer’s disease and can even lead to new neuron formation. The beneficial cardiovascular effects are also useful and combine well with exercise and good nutrition for prevention. Particularly stroke prevention is a useful property of EGCG from green tea extract. The effect on obesity is marginal whereas there was no effect of green tea on prevention of diabetes. The immune modulatory effect of green tea extract is useful in the treatment of autoimmune diseases and of cancer. Existing treatments for these conditions are becoming more effective by adding green tea extract.

Sep
28
2013

Sleepless Nights

Sleeping problems (insomnia) are very common. About 10% of the population suffers from chronic insomnia; 30% of the population suffers from occasional sleep problems. In a large outpatient population of a clinic consisting of 3500 patients who had at least one major clinical condition, 50% complained of insomnia, 16% had severe symptoms, 34% had mild symptoms (Ref.1). Insomnia is more common among women, and older people as well as in people with medical or psychiatric illnesses. Long-term studies have shown that the same insomnia problems persist throughout many years. It is not possible to offer a simple remedy for insomnia, because insomnia is a complex problem. Here I will discuss some of the causes of insomnia and also discuss some of the treatment options.

Symptoms of insomnia

The person who suffers from insomnia will usually state that they have problems falling asleep. Worries of the day suddenly circulate through their thoughts and they toss and turn nervously looking at the clock from time to time and getting more and more anxious that they cannot sleep. Others fall asleep OK, but in the middle of the night they wake up perhaps to visit the restroom, but then they cannot go back to sleep. Others wake up 2 hours before their normal alarm clock time and they feel their stomach rumbling making it impossible to fall back to sleep. Older people with chronic diseases and general poor health suffer more from insomnia. In this setting insomnia may be more related to the underlying disease rather than old age. Psychiatric disorders also are associated with more insomnia. Treat the underlying psychiatric illness, and the insomnia disappears.

Although insomnia is a sleep disturbance during the nighttime, people who are affected with this complain of daytime fatigue, of overstimulation, yet they catch themselves making frequent mistakes, and their inability to pay attention gets them involved in accidents and falls. Longitudinal studies have shown (Ref. 1) that people with chronic insomnia are more likely to develop psychiatric disease, such as major depression,  anxiety disorder and alcohol and substance abuse. Unfortunately these disorders can by themselves again cause insomnia, which reinforces chronic insomnia. Insomnia leads to poorer social and physical functioning, affects emotions, leads to a lack of vitality and physical endurance, contributes to worsening of pain and can affect general and mental health.

Research about insomnia

Much has been learnt from sleep studies using polysomnography monitoring during a full night’s sleep. These studies have been used mainly as a research tool. In such studies eye movements, brain wave activity, muscle activity, chest movements, airflow, heart beats, oxygen saturation and snoring (with a microphone) are all simultaneously recorded. This way restless leg syndrome, sleep apnea, snoring, seizure disorders, deep depression etc. that can all lead to insomnia can be diagnosed and separated from insomnia. The stages of sleep (wakefulness, stage 1 to 3 sleep and the REM sleep stage) can also be readily measured using polysomnography (Ref.2). According to this reference the majority of insomnia cases do not need this complex procedure done.

Sleepless Nights

Sleepless Nights

Causes of insomnia

Traditionally insomnia cases are classified into primary insomnia and secondary insomnia. Secondary insomnia is caused by all of the factors discussed below. When they are dealt with, we are left with cases of primary insomnia.

The following medical conditions can cause insomnia: heart disease, pulmonary diseases like asthma and chronic obstructive pulmonary disease (COPD); gastrointestinal disease like liver cirrhosis, pancreatitis, irritable bowel syndrome, ulcers, colitis, Crohn’s disease; chronic kidney disease; musculoskeletal disease like arthritis, fractures, osteoporosis; neurodegenerative disease like MS, Parkinson’s disease, Alzheimer’s disease; endocrine disease like diabetes, hyper- or hypothyroidism, adrenal gland fatigue and insufficiency; and chronic pain conditions. Also, psychiatric conditions like major depression, schizophrenia and anxiety disorders can cause insomnia.

This list in not complete, but it gives you an idea of how complex the topic of insomnia is.
The physician who is seeing a patient with insomnia needs to rule out any of these other causes of insomnia to be certain that the only condition that is left to treat in the patient is insomnia itself. The other diagnoses have to be dealt with separately or else treatment of insomnia will fail.

Ref. 1 points to a useful model of how to think about causation of insomnia: there are three points to consider, namely predisposing, precipitating, and perpetuating factors. Let’s briefly discuss some of these.

Predisposing factors

We are all different in our personal make-up. If you are well grounded, chances are you are not susceptible to insomnia. Anxious persons or persons who have been through a lot of negative experiences in life will have personality traits that make them more prone to insomnia. Lifestyle choices such as late nights out, drinking with the buddies in a bar (extreme circadian phase tendencies) will have an impact on whether or not you develop insomnia.

Precipitating factors

A situational crisis like a job change or the death of a loved one can initiate insomnia.  However, there could be a medical illness such as a heart attack, a stroke or the new diagnosis of a psychiatric illness that has become a precipitating factor. Sleep apnea and restless leg syndrome belong into this group as well as would the stimulating effect of coffee and caffeine containing drinks. Jet lag and nighttime shift work can also be precipitating factors.

Perpetuating factors

Daytime napping to make up for lost sleep the night before can undermine sleep initiation the following night, which can lead to a vicious cycle. Similarly, the use of bedtime alcoholic drinks leads to sleep disruption later that night and can become a perpetuating factor, if this habit is maintained. Even the psychological conditioning of being anxious about whether or not you will fall asleep easily or not the next night can become a perpetuating factor.

I will return to this classification and the factor model of causation of insomnia when we address treatment options.

Drugs that can cause insomnia

One major possible cause for insomnia  can be side effects from medications that patients are on (would belong to the ‘perpetuating factors’ among causes). Physicians call this “iatrogenic insomnia”. The antidepressants, called selective serotonin reuptake inhibitors (SSRI’s) like Prozac are particularly troublesome with regard to causing insomnia as a side effect. Other antidepressants like trazodone (Desyrel) are used in small doses to help patients with insomnia to fall asleep. Some asthmatics and people with autoimmune diseases may be on prednisone, a corticosteroid drug. This can cause insomnia, particularly in higher doses; so can decongestants you may use for allergies; beta-blockers used for heart disease and hypertension treatment; theophylline, an asthma medication and diuretics. Central nervous stimulants like caffeine or illicit drugs can also cause insomnia. Hormone disbalance in general and hyperthyroidism specifically as well as Cushing’s disease, where cortisol levels are high will cause insomnia.

Treatment of insomnia

So, how should the physician approach a patient with insomnia? First it has to be established whether there is secondary insomnia present due to one of the predisposing, precipitating or perpetuating factors. In other words, is there secondary insomnia due to other underlying illnesses? If so, these are being addressed first. Lifestyle choices (staying up late every night) would have to be changed; alcohol and drug abuse and overindulging in coffee or caffeine containing drinks needs to be dealt with. Cognitive therapy may be beneficial when mild depression or anxiety is a contributing factor to insomnia.

The remaining insomnia (also medically termed “primary insomnia”) is now being treated.

The following general points are useful to get into the sleeping mode (modified from Ref. 3):

  1. Ensure your bedroom is dark, soundproof, and comfortable with the room temperature being not too warm, and you develop a “sleep hygiene”. This means you get to sleep around the same time each night, have some down time 1 hour or so before going to bed and get up after your average fill of sleep (for most people between 7 to 9 hours). Do not sleep in, but use an alarm clock to help you get into your sleep routine.
  2. Avoid caffeine drinks, alcohol, nicotine and recreational drugs. If you must smoke, don’t smoke later than 7PM.
  3. Get into a regular exercise program, either at home or at a gym.
  4. Avoid a heavy meal late at night. A light snack including some warm milk would be OK.
  5. Do not use your bedroom as an office, reading place or media center. This would condition you to be awake.  Reserve your bedroom use only for intimacy and sleeping.
  6. If you wake up at night and you are wide awake, leave the bedroom and sit in the living room doing something until you feel tired and then return to bed.
  7. A self-hypnosis recording is a useful adjunct to a sleep routine. Listen to it when you go to bed to give you something to focus on (low volume) and you will find it easier to stop thinking.

Drugs and supplements for insomnia

1. In the past benzodiazepines, such as diazepam (Valium), lorazepam (Ativan), fluorazepam (Dalmane), temazepam (Restoril), triazolam (Halcion) and others were and still are used as sleeping pills. However, it was noted that there are significant side effects with this group of drugs. Notably, there is amnesia (memory loss), which can be quite distressing to people such as not remembering that someone phoned while under the influence of the drug, you promised certain things, but you cannot remember the following morning what it was. Another problem is the development of addiction to the drugs with worse insomnia when the drugs are discontinued. Many physicians have stopped prescribing benzodiazepines.

2. There are non-benzodiazepines drugs that are used as sleeping pills (hypnotics), such as Zaleplon (Sonata), Zolpidem (Ambien) and Eszopiclone (Lunesta).  They seem to be better tolerated.

3. Ramelteon, a melatonin agonist, is available by prescription in the US. It probably is the best-tolerated mild sleeping pill and works similar to melatonin, but is more expensive. Chances are that your physician likely would prescribe one of the non-benzodiazepines drugs or Ramelteon for you as they do not seem to be addicting.

4. However, there is an alternative: Many patients with insomnia tolerate a low dose of trazodone (Desyrel), which is an antidepressant with sleep restoring properties. A low dose of 25 to 50 mg at bedtime is usually enough for insomnia. This allows the patient to fall asleep within about 30 minutes of taking it, and sleep lasts through most of the night without a hangover in the morning. Many specialists who run sleep laboratories recommend trazodone when primary insomnia is diagnosed. However, this is still a drug with potential side effects as mentioned in the trazodone link, but 50 mg is only ¼ of the full dose, so the side effects will also be less or negligible.

5. I prefer the use of melatonin, which is the natural brain hormone designed to put us to sleep. Between 1 mg and 6 mg are sufficient for most people. We know from other literature that up to 20 mg of melatonin has been used in humans as an immune stimulant in patients with metastatic melanoma with no untoward side effects other than nightmares and some tiredness in the morning. A review from the Vanderbilt University, Holland found melatonin to be very safe as a sleeping aid. There are several melatonin receptors in the body of vertebrates (including humans), which are stimulated by melatonin.

6. Other natural methods are the use of L-Tryptophan at a dose of 500 mg at bedtime, which can be combined with melatonin. It is the amino acid contained in turkey meat, which makes you tired after a Thanksgiving meal. GABA is another supplement, which is the relaxing hormone of your brain, but with this supplement tolerance develops after about 4 to 5 days, so it is only suitable for very short term use. Herbal sleep aids are hops, valerian extract and passionflower extract. They are available in health food stores.

Conclusion

A lack of sleep (insomnia) is almost a given in our fast paced lives.

When it comes to treatment, all of the other causes of secondary insomnia need to be treated or else treatment attempts would fail. What is left is primary insomnia. This is treated as follows:

We need to review our sleeping habits, lifestyles and substance abuse. Remove what is detrimental to your sleep. Start with the least invasive treatment modalities such as self-hypnosis tapes, melatonin, L-Tryptophan or herbal extracts. Should this not quite do the trick, asks your doctor for advice. The non-benzodiazepines drugs or Ramelteon would be the next level up. It may be that an alternative such as low dose trazodone would be of help. Only, if all this fails would I recommend to go to the more potent sleeping pills (keep in mind the potential for addiction to them).

References

1. David N. Neubauer, MD (John Hopkins University, Baltimore, MD): Insomnia. Primary Care: Clinics in Office Practice – Volume 32, Issue 2 (June 2005)  © 2005, W. B. Saunders Company

2: Behrouz Jafari, MD and Vahid Mohsenin, MD (Yale Center for Sleep Medicine, Yale University School of Medicine, New Haven, CT, USA): Polysomnography. Clinics in Chest Medicine – Volume 31, Issue 2 (June 2010), © 2010 W. B. Saunders Company

3. Jean Gray, editor: “Therapeutic choices”, 5th edition, Chapter 8 by Jonathan A.E. Fleming, MB, FRCPC: Insomnia, © 2008, Canadian Pharmacists Association.

Last edited Sept. 28, 2014

Jun
01
2004

Green Tea Knocks Out Leukemia Cells

Cancer is less common in eastern Asia, where green tea is the most common beverage.
In April 2004 a study was published in the journal “Blood”, which shows that green tea has killing powers in the unpredictable and slow form of B cell leukemia. A component in green tea called epigallocatechin (EGCG) disturbs the chemical information flow in leukemia cells in lab cultures.

It means that the communication between the cells is disturbed, and cancer cells cannot multiply.

Dr. Neil Kay of the Mayo Clinic in Rochester, Minn. is confident that the compound EGCG will be of benefit especially in the treatment of early-stage patients.
In the meantime, a flavorful soothing cup of green tea has its benefits.

More info on leukemia: http://nethealthbook.com/cancer-overview/leukemia/

Based on National Review of Medicine (Canada), April 30,2004

Green Tea Knocks Out Leukemia Cells

Green Tea Knocks Out Leukemia Cells

Last edited October 26, 2014