Green Tea And Cancer

Dr. Greger has a new post on green tea:

Can Green Tea Help Prevent Cancer?, Dr. Michael Greger, 15 February 2019

Tea consumption is associated with a reduced risk of heart disease, stroke, and premature death in general, with each additional cup of green tea a day associated with a 4 percent lower mortality risk. So, perhaps “drinking several cups of tea daily can keep the doctor away,” as well as the mortician—but what about cancer?

There is “growing evidence from laboratory, epidemiologic [population], and human intervention studies that tea can exert beneficial disease-preventive effects” and, further, may actually “slow cancer progression.” Let’s review some of that evidence.

Not only do those who drink a lot of tea appear to live longer than those who drink less, drinking lots of tea may also delay the onset of cancer. At 0:56 in my video below, you can see a table titled “Average age at cancer onset and daily green tea consumption.” The green tea intake is measured in Japanese tea cups, which only contain a half a cup, so the highest category in the table is actually greater than or equal to five full cups of tea, not ten as it appears in the table. Women who did get cancer appeared to get it seven years later if they had been drinking lots of tea compared to those who had consumed less. Men, however, had a three-year delay in cancer onset if they had consumed more than five full cups of green tea daily, the difference potentially “due to higher tobacco consumption by males.”

Green tea may be able to interfere with each of the stages of cancer formation: the initiation of the first cancer cell, promotion into a tumor, and then subsequent progression and spread, as you can see at 1:24 in my video. Cancer is often initiated when a free radical oxidizes our DNA, causing a mutation, but, as you can see at 1:44 in my video, we can get a nice “spike of antioxidant power” of our bloodstream within 40 minutes of drinking green tea. “This increase may, in turn, lower oxidative damage to DNA and so decrease risk of cancer.”

Furthermore, in terms of genoprotective effects — that is, protecting our genes — pre-existing oxidation-induced DNA damage was lower after drinking green tea, suggesting consumption can boost DNA repair as well. We didn’t know for certain, however … until now.

There is a DNA-repair enzyme in our body called OGG1. Within one hour of drinking a single cup of green tea, we can boost OGG1’s activity, and after a week of tea drinking, we can boost it even higher. So, “regular intake of green tea has additional benefits in the prevention and/or repair of DNA damage.” In fact, tea is so DNA-protective it can be used for sperm storage for fresh samples until they can be properly refrigerated.

What’s more, tea is so anti-inflammatory it can be used for pain control as a mouthwash after wisdom tooth surgery, as you can see at 2:41 in my video. In terms of controlling cancer growth, at a dose of green tea compounds that would make it into our organs after drinking six cups of tea, it can cause cancer cells to commit suicide—apoptosis (programmed cell death)—while leaving normal cells alone. There are a number of chemotherapy agents that can kill cancer through brute force, but that can make normal cells vulnerable, too. So, “[g]reen tea appears to be potentially an ideal agent for [cancer] prevention”: little or no adverse side-effects, efficacious for multiple cancers at achievable dose levels, and able to be taken orally.

His original article has links to the science.

It’s hard to ignore this. Maybe other foods also provide these benefits. But foods like blueberries and pomegranates are a lot harder to eat several times a day, every day, than tea.

Modern-Day Hunter-Gatherers, Who Lead Physically Hard Lives, Burn Same Number Of Calories As More Sedentary Populations In US And Europe (Repost)

This is a repost from February 2016, because I like to be reminded of it.

Hadza hunter-gatherers spend hundreds of calories a day on activity yet burn the same total number of calories as city dwellers in the U.S. – Kudu Lodge

You think my title is fake, don’t you? It’s not. It’s what science is finding out. It surprises me too!

Herman Pontzer, an anthropologist at Hunter College, says that FitBits and other fitness trackers lie because they don’t take into account:

The Exercise Paradox, Scientific American, February 2017

The best way to track how many calories someone has burned is with the doubly labeled water method. When Pontzer used it on the Hadza, modern-day hunter-gatherers who lead physically hard lives, he found they burned the same calories as sedentary populations:

The Hadza looked like everyone else. Hadza men ate and burned about 2,600 calories a day, Hadza women about 1,900 calories a day — the same as adults in the U.S. or Europe. We looked at the data every way imaginable, accounting for effects of body size, fat percentage, age and sex. No difference.

It’s not just the Hadza:

  • Doubly labeled water studies among traditional farmers in Guatemala, the Gambia and Bolivia showed their energy expenditures were broadly similar to those of city dwellers.
  • Doubly labeled water studies among rural Nigerian women found no difference in energy expenditure between them and African-American women in Chicago, “despite large difference in activity levels.”
  • Data analyzed from 98 studies around the globe showed that populations coddled by the modern conveniences of the developed world have similar energy expenditures to those in less developed countries, with more physically demanding lives.

How is this possible?

How does the body adjust to higher activity levels to keep daily energy expenditure in check? … [One] possibility is that the body makes room for the cost of additional activity by reducing the calories spent on the many unseen tasks that take up most of our daily energy budget: the housekeeping work that our cells and organs do to keep us alive. … For example, exercise often reduces inflammatory activity that the immune system mounts as well as levels of reproductive hormones such as estrogen. In lab animals, increased daily exercise has no effect on daily energy expenditure but instead results in fewer ovulatory cycles and slower tissue repair.

So, we max out at something less than 3000 calories a day, no matter how hard we exercise. And we pay for hard exercise by diverting energy from things like tissue repair. That’s risky business, no?

Of course, exercise it important … for the heart, the brain, the immune system. It’s just not going to whittle away the pounds, not by itself. You must change diet:

If daily energy expenditure has not changed over the course of human history, the primary culprit in the modern obesity pandemic must be the calories consumed.

According to Pontzer, fitness trackers are only weakly related to metabolism.

On average, couch potatoes tended to spend about 200 fewer calories each day than people who were moderately active: the kind of folks who get some exercise during the week and make a point to take the stairs. But more important, energy expenditure plateaued at higher activity levels: people with the most intensely active daily lives burned the same number of calories each day as those with moderately active lives.

In this diagram, the graph on the left is what we assume, but the graph on the right is what has been measured. It’s probably more accurate. Total energy expenditure (TEE) increases with physical activity (PA) only at low activity levels. At higher activity levels, the body adapts by limiting energy spent on “other” (growth, tissue repair, hormone production), keeping TEE constrained:

In Constrained total energy expenditure models, the body adapts to increased physical activity by reducing energy spent on other physiological activity, maintaining total energy expenditure within a narrow range.

Constrained Total Energy Expenditure and Metabolic Adaptation to Physical Activity in Adult Humans, Cell, February 2016

More On Jon Kabat Zinn And Mindfulness

I mentioned Jon Kabat-Zinn in yesterday’s post and while skimming his talks on YouTube came across this one. In it, he introduces the 7 Attitudes of Mindfulness that he first wrote about in his 1991 book, Full Catastrophe Living which I read about 20 years ago. This interview was posted in 2015 and he says he’s revised his first book and added 2 more attitudes.

Here are the 7, now 9 Attitudes that he discusses in this video:

1. Beginner’s Mind 2:38
2. Non-Judging 5:04
3. Acceptance 8:55
4. Letting Go 11.55
5. Trust 15:16
6. Patience 18:17
7. Non-Striving 20:09
8. Gratitude 22:35
9. Generosity 22:27

From Wikipedia:

Jon Kabat-Zinn (born Jon Kabat, June 5, 1944) is an American professor emeritus of medicine and the creator of the Stress Reduction Clinic and the Center for Mindfulness in Medicine, Health Care, and Society at the University of Massachusetts Medical School. Kabat-Zinn was a student of Zen Buddhist teachers such as Philip Kapleau, Thich Nhat Hanh and Seung Sahn and a founding member of Cambridge Zen Center. His practice of yoga and studies with Buddhist teachers led him to integrate their teachings with scientific findings. He teaches mindfulness, which he says can help people cope with stress, anxiety, pain, and illness. The stress reduction program created by Kabat-Zinn, mindfulness-based stress reduction (MBSR), is offered by medical centers, hospitals, and health maintenance organizations.

Study: Meditation Results In More Wakeful, Relaxed Attention Than Just Resting

The study monitored brain waves through the use of EEG (electroencephalography). Electrodes were placed in standard locations of the scalp using this custom-made hat.

This study found that nondirective meditation causes brain wave activity that’s associated with more wakeful, relaxed attention than just resting.

Increased Theta and Alpha EEG Activity During Nondirective Meditation, The Journal of Alternative and Complementary Medicine, November 2009

Brain Waves And Meditation, Science Daily, March 2010

There are many styles of meditation. The kind I learned years ago might be considered mindfulness or nondirective meditation, where you become an observer of your thoughts. When you have a thought, because you are going to!, you don’t latch on to it or keep thinking it. You recognize that you’re having it, then you move back to the breath. When you do this, gently, over and over and over again, you come to appreciate that we are not our thoughts.*

This study found that nondirective meditation stimulates certain brain waves that cause us to feel more refreshed.

What this meditation is not:

Meditation research explores how the brain works when we refrain from concentration, rumination and intentional thinking.

Meditation is not the same as resting:

[Participants] were asked to rest, eyes closed, for 20 minutes, and to meditate for another 20 minutes, in random order.

During meditation, theta waves were most abundant in the frontal and middle parts of the brain. “These types of waves likely originate from a relaxed attention that monitors our inner experiences. Here lies a significant difference between meditation and relaxing without any specific technique,” emphasizes [principle investigator] Lagopoulos.

Alpha waves were more abundant in the posterior parts of the brain during meditation than during simple relaxation. They are characteristic of wakeful rest.

Meditation is not the same as sleeping:

Delta waves are characteristic of sleep. There was little delta during the relaxing and meditative tasks, confirming that nondirective meditation is different from sleep.

What nondirective meditation is:

Several studies indicate better relaxation and stress management by meditation techniques where you refrain from trying to control the content of the mind. … “These methods are often described as nondirective, because practitioners do not actively pursue a particular experience or state of mind. They cultivate the ability to tolerate the spontaneous wandering of the mind without getting too much involved. Instead of concentrating on getting away from stressful thought and emotions, you simple let them pass in an effortless way.”

* “… you come to appreciate that we are not our thoughts.”

Here’s Jon Kabat Zinn, whose work we studied back then. Notice what he says about selfing.


Meditation domes at the Beatles Ashram in Rishikesh, India

Back in graduate school, in one of my health classes, we learned about meditation. We learned that it can reduce heart rate and blood pressure, that it calms the mind and relaxes the body which can reduce pain and assist sleep, that it improves digestion. And on. To increase our appreciation, and unbeknownst to many of us, the professor brought in a meditation instructor who had us learn how to meditate. And so we learned. We meditated, kept journals, studied, took tests, got grades, and the semester was over. I was glad because it was a night class and I was working during the day and had a long commute. The 45 minutes per session, at home, was a lot to spend on non-doing. (We learned then and I realized over the years that non-doing is not really non-doing. The instructor used to say that it was the person who was the busiest or most stressed that would benefit most from meditation. I was naive.)

But … I kept it up for a while because I thought it might have been responsible for ending my ever-worsening migraines. Eventually I stopped because I wasn’t willing to give it the time.

Every once in a while I think of returning to it. Now is one of those times. Here’s a simple introduction.
How To Meditate

One thing I learned back then is that if you choose to sit cross-legged on the floor (but you don’t have to, you can sit in a chair or lie on your back or even walk) it’s best to place a pillow or towel under your sit bones so that your pelvis is tilted forward and your legs slope down a bit. Also, some people may wish to support their back so they sit more upright. That would mean leaning against a wall or the back of a chair.

Blueberry Lemon Squares, Vegan, No Added Fat

I’m developing a recipe for blueberry lemon squares, actually blueberry-raspberry lemon squares. I’ve settled on this for the time being. I hope to have more photos as I continue to experiment. (In this one, the fruit is mostly hidden inside.)

Here are a couple squares in the process of defrosting. Very moist!


2 cups whole wheat pastry flour
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1/4 teaspoon cinnamon

1 tablespoon ground flax seed
2 tablespoons warm water

3/4 cup unsweetened low-fat almond milk (or other non-dairy milk)
3/4 cup applesauce
1/4 cup maple syrup
3 teaspoons fresh lemon juice
1 teaspoon fresh lemon zest

1 1/2 cups blueberries (I use frozen)
1/2 cup raspberries


Preheat oven to 360 degrees F. Cut a piece of parchment paper to fit along the bottom and sides of an 8-inch square Pyrex pan. Place the parchment-lined pan into the oven to preheat.

Mix flax seed and water. Set aside.

In a large bowl combine flour, baking powder, baking soda, salt, and cinnamon.

In another large bowl combine almond milk, applesauce, maple syrup, lemon juice, and lemon zest. Add flax mixture. Stir until blended.

Remove pan from oven and place on hob or trivet. Working quickly, add flour mixture to wet mixture. Stir just until you see no dry flour. Don’t over-blend. Gently fold in the blueberries and raspberries (if you stir too vigorously, the whole batter may turn blue!) Pour batter into pan.

Bake for 45-50 minutes or until golden brown on top. Let cool for 30 minutes then lift cake (cake?) out of Pyrex pan holding the parchment paper edges and place on a cooling rack. After another hour, place onto a cutting board and slice into squares. Leave the parchment paper in place as you do this. Each square will lift easily from the paper if the cake is cool.

I like to freeze the squares and defrost the amount I need on the following days. I find the moisture evens out and the blueberries stay in place when you bite down. Or, you can eat it right away while it’s still warm. 🙂

How Language Shapes Culture

Seven Words That Can Help Us Be A Little Calmer, BBC Culture, 25 January 2019

A new book [by Mari Fujimoto, a linguist] translates 43 Japanese words into English. … Fujimoto believes that by discovering words and phrases unique to other cultures, we can gain a wider understanding of our own lives. “It’s important to give another perspective, see that other life. In the West we tend to seek perfection, and we always feel like we have to be perfect, we have to do as much as we can, and meet other people’s expectations.”

South African artist David Buchler – who has written short essays for the book – has lived in Japan for seven years. “When I speak to people in Japanese, I’m very aware of what I’m saying and my gestures and being polite, thinking about how my words would affect them,” he tells BBC Culture. “It’s a very different approach to talking.”

Some Japanese words the article highlighted:

Shibui: The beauty revealed by the passage of time. This word reminds us to appreciate the things that improve with age.

Mugon-no gyō: A meditation that asks you to take a moment to reflect before doing – act, don’t react.

Fukinsei: Beauty in asymmetry. Symmetry represents perfection, and is alien to human experience. An art form must bring a sense of alternative possibilities, admitting change.

Teinei: A courteous attitude, where each gesture is performed with dedication and precision. Behaving with the utmost care in order to show excellence in your conduct.

Mono-no aware: The ephemeral nature of beauty. Being appreciative of transience. (We visited this word back in August on the Kintsugi post. It was defined as: “a compassionate sensitivity, or perhaps identification with, things outside oneself.”)

Shōganai: Meaning literally “there is no means or method”. Shōganai is a reminder that sometimes we have to accept things as they are, allowing us to let go of negative feelings.

Kodawari: Determined and scrupulous attention to detail. Motivated by a sincere passion and self-discipline, knowing that some of these efforts will go unrecognised.

Yūgen: Prizing what’s mysterious and profound. Yūgen is a kind of beauty that derives from understatement. Deeply tied to kanso, a reminder to perceive beyond what one sees.

I like these. I wouldn’t say the concepts are foreign to me, but wrapping them up in a word or a phrase places emphasis on them, and perhaps can shape the mindset of people who use the words often. Culture shapes language, but language can also shape culture.

In that first paragraph, the author of the book is quoted as saying, “In the West we tend to seek perfection.” Do you think that’s just a Western trait? Look at kodawari or teinei above. There’s some “utmost” going on there. I think humans everywhere seek perfection. Is perfection bad? In one way it is because humans are imperfect, so it’s unrealistic. In another way I think it’s good because it gives us something to shoot for. Maybe a better way of saying “seeks perfection” is “works towards a goal or a dream.” Even if the dream is never attainable, it’s worth having. Hopes and dreams are what propel us!

Now to the second part of that sentence, about how people in the West feel they “have to do as much as we can, and meet other people’s expectations.” Again, I wouldn’t say this is a characteristic of people in the West only or mostly. In fact, the Japanese have a reputation for conforming, for doing what is expected. They have a saying, “The nail that sticks out gets hammered down.”

Like most things, the healthiest place is somewhere in the middle, where we work towards goals that are realistic, and where we promote behavior that helps us get along but not at the expense of uniqueness.

Kintsugi is the Japanese art of repairing broken pottery with lacquer dusted or mixed with powdered gold, silver, or platinum. As a philosophy, it treats breakage and repair as part of the history of an object, rather than something to disguise. Kintsugi is similar to the Japanese philosophy of wabi-sabi, an embracing of the flawed or imperfect.

It’s Harder For Older Adults To Maintain Body Temperature When It’s Cold (And Why Fluid Is So Important)

It’s harder for older people to stay warm when it’s cold:
Body Temperature, Kevin Kregel, PhD, Healthy Aging Project, University of Colorado Boulder, 2017

Some of the mechanisms we rely on to regulate internal temperature become less effective as we age.

I’ll just post the cold conditions. They also discuss hot conditions.

Cold Conditions
In an effort to defend body temperature, our bodies decrease blood flow to the skin to reduce heat loss. We also increase internal heat production through several mechanisms. One example is shivering—or the rapid contraction of muscles—which can quickly produce large quantities of heat within the body. But as we grow older, our bodies become less effective at controlling skin blood flow and generating internal heat. In addition, the layer of fat under our skin that acts as an isolator and helps to conserve body heat thins with age. Because of these changes, it is harder for older adults to maintain internal body temperature in the “normal” range in cold conditions.

Their recommendations are intuitive: raise the temperature of the room, wear more clothes, drink warm beverages. One they didn’t emphasize was to drink more fluid overall. We lose more fluid during cold conditions (see below), and as we age our thirst sensation decreases so we don’t replace lost fluid effectively. And adequate fluid is necessary to regulate our body temperature (thermoregulation).

It looks like the US military commissioned a report on the nutritional needs of personnel in cold temperatures. Chapter 9 dealt with dehydration. Great information:

Nutritional Needs In Cold And In High-Altitude Environments: Applications for Military Personnel in Field Operations, National Academy of Sciences, 1996.
9. Influence of Cold Stress on Human Fluid Balance

Factors Causing Dehydration In Cold Conditions

1. Cold-Induced Diuresis – We urinate more when we’re exposure to cold. It’s thought to be caused by movement of fluid from peripheral tissues to core when peripheral blood vessels constrict to keep the core warm.
2. Respiratory Water Losses – The amount of water vapor exhaled approximately doubles at -4 degrees F (100% humidity) versus 77 degrees F (65% humidity) (Despite high relative humidities cold air contains significantly less water vapor than does warmer air of even lower relative humidity.) The more one exercises in cold weather, the more vapor is lost.
3. Cold-Weather Clothing – Heavy or well-insulated clothing can trap heat and induce sweating to rid the core of that heat. Moderate-to-heavy exercise performed in clothing with high insulation can generate upwards of 2 liters of sweat per hour.
4. Metabolic Cost of Movement – Walking in snow versus a clear sidewalk increases our metabolic rate. Also, cold-weather clothing can be cumbersome and has been measured to increase metabolism by an additional 10 to 20%. Increased metabolic rate = increased water losses through lungs and sweating.
5. Reduced Fluid Intake – Voluntary dehydration (a reduced sensation of thirst) occurs when humans undergo stress. It occurs in hot climates and may be more pronounced in cold climates.

Did you see that number 5? Reduced thirst sensation? Older adults already have a reduced thirst sensation. Add to that reduced thirst due to cold weather and they may never feel like drinking!

Impact Of Dehydration

1. Physical and Cognitive Performance – Studies document significant reductions in muscular strength, muscular endurance, manual dexterity, coordination, and both aerobic and anaerobic work capacity, due to cold-induced dehydration. It has also been shown to reduce cognitive performance.
2. Thermoregulation – You can get too hot (because of reduced sweating) or too cold when dehydrated..
3. Cold-Injury – Dehydration can blunt cold-induced vasodilation, increasing susceptibility to cold injury. (Have you ever banged your hand when it was cold?)
4. A Change in Disposition:

Orth (1949) provides a summary of the potential effects of dehydration on soldiers’ health and performance in cold environments: “The lack of sufficient fluids in the diet to maintain a positive water balance causes at first a change in disposition, sullenness, loss of appetite, chronic thirst, discipline begins to suffer … and finally failing physical efficiency. The final step is dehydration exhaustion, this can take place in 3–4 hours in the desert, but it also can take place in as little as two days in the Arctic where solid water abounds” (p. 205).

Shivering? Irritable? Headache? Constipation? Fatigue? Inability to focus? You may not be drinking enough.

Hot beverages, even if they contain caffeine, can count towards your daily fluid intake. The diuretic effect of caffeine-containing beverages is weak and won’t compromise hydration.