Science 20 December 2013:
Vol. 342 no. 6165 pp. 1440-1441
To Sleep, Perchance to Clean
In work that Science‘s editors named a runner-up for Breakthrough of the Year, researchers studying mice have found experimental evidence that sleep helps to restore and repair the brain.
Why do we sleep?
Questions of biology don’t get much more fundamental than that. This year, neuroscientists took what looks like a major stride toward an answer.
Most researchers agree that sleep serves many purposes, such as bolstering the immune system and consolidating memories, but they have long sought a “core” function common to species that sleep. By tracking colored dye through the brains of sleeping mice, scientists got what they think is a direct view of sleep’s basic purpose: cleaning the brain. When mice slumber, they found, a network of transport channels through the brain expands by 60%, increasing the flow of cerebral spinal fluid. The surge of fluid clears away metabolic waste products such as β amyloid proteins, which can plaster neurons with plaques and are associated with Alzheimer’s disease.
Until this discovery, researchers thought the brain’s only way to dispose of cellular trash was to break it down and recycle it inside cells. If future research finds that many other species undergo this cerebral housekeeping, it would suggest that cleaning is indeed a core function of sleep. The new findings also suggest that sleep deprivation may play a role in the development of neurological diseases. But with a causal role far from certain, it’s too early for anyone to stay awake worrying.
Basics: The anti-oxidant EGCG can cause DNA strand breaks and mutations.
EGCG stands for Epigallocatechin gallate. Epigallocatechin gallate (ECGC) is a polyphenol found in green tea. Some people take it as a supplement. Or it may be part of “green tea extracts.” Anti-oxidants are thought to protect cells and DNA from oxidative damage. Oxidative damage can occur when one atom or molecule “steals” electrons from important molecules in your body. Cell membranes, for example. Or DNA. When DNA undergoes oxidative damage it may become mutated. Mutations in body cells can lead to cancer. So, protecting your body by taking anti-oxidants seemed to make a lot of sense. No oxidants, no oxidation, no mutations, no cancer. Many people believe(d) that taking anti-oxidants would protect against illness and aging and extend life. The benefits of anti-oxidant supplements now appears to be more complicated that we thought.
Anti-oxidants have had a mixed history when used medicinally.
There are many anti-oxidants. Vitamins C, A, E and selenium are commonly used as nutritional supplements for their anti-oxidant properties. And many have assumed that more is better. As with many other things in life, more is not always better. Sometimes “more” makes more trouble than less. Selenium, for example, seems to have protective effects against cancer. Unfortunately when too much selenium is taken, it can increase the risk of cancer. One of the problems with taking supplements is that we rarely know how much is too much. And we almost never know how much is optimal. Studies of Vitamin A, C and E have also shown signs of creating problems when taken above levels one would normally get eating from food.
EGCG as an inducer of mutations and cancer.
A paper newly released by Nature (Lu et al. 2013) shows how anti-oxidants are able to cause DNA damage and increase risk of mutations. The researchers used epigallocatechin gallate as the test anti-oxidant. The researchers present their data very clearly and efficiently with minimal interpretation. They simply report that Epigallocatechin gallate caused DNA damage and increased number of mutations (among other non-good things.) These results may or may not apply to other anti-oxidants, but they are a good indication that we should exercise caution with anti-oxidant supplements. There is sure to be a lot of discussion and debate over the results of the Lu study. And many additional studies are sure to follow.
This is a very interesting paper and sure to upset a lot of boats. ECGC is a powerful anti-oxidant. Other anti-oxidants may not be strong enough to cause damage. It was just a year ago that ECGC was reported to be the most effective anti-cancer chemo protective compound in green tea. ECGC may turn out to be health protective. It may turn out to be one of those “nutrients” that is good for you at low levels but dangerous when high. Its too early to tell. More research is needed.
Until we know more, eat real food. Eat a varied diet so you don’t get too much of something that may be harmful.
Lu LY, Ou N, & Lu QB (2013). Antioxidant induces DNA damage, cell death and mutagenicity in human lung and skin normal cells. Scientific reports, 3 PMID: 24201298
Du GJ, Zhang Z, Wen XD, Yu C, Calway T, Yuan CS, & Wang CZ (2012). Epigallocatechin Gallate (EGCG) is the most effective cancer chemopreventive polyphenol in green tea. Nutrients, 4 (11), 1679-91 PMID: 23201840
Thangapazham RL, Passi N, & Maheshwari RK (2007). Green tea polyphenol and epigallocatechin gallate induce apoptosis and inhibit invasion in human breast cancer cells. Cancer biology & therapy, 6 (12), 1938-43 PMID: 18059161
Arsenic in rice has been reported as being of no immediate health risk. But the major concern with arsenic is that it is a long-term health risk. Arsenic may be best known as a tool of poisoners. But arsenic poses greater risk as a slow, quiet inducer of cancer. In that way, arsenic is like most carcinogens. The problem is not that someone would eat a bite of rice and then fall face first into his or her plate. The problem is that arsenic causes skin and bladder cancer. It also does other unpleasant things to people who are exposed to relatively low levels over long periods of time.
Arsenic in Rice and Arsenic in Drinking Water
The current limit for arsenic in drinking water is 10 parts arsenic for every billion parts of water. If you are an average adult drinking two liters of water you could get about 20 micrograms of arsenic. As long as your drinking water meets federal standards. If you drink more than two liters of water your will probably be just fine. If you get more than 20 micrograms of arsenic every day you will probably be fine too. Federal standards have built in safety factors. These protect people who are not average 160 pound adults. Who drink two liters of water a day. If people are exposed to additional arsenic in rice on a regular basis in addition to arsenic in water they may face increased risk of cancer. The man in the photo on the right lives in an area where arsenic in drinking water greatly exceeds World Health Organization standards.
Should I worry about Arsenic in Rice?
Maybe. Arsenic in rice may increase your risk of cancer. Especially if you live in an area where arsenic levels in drinking water are high. Or if you are feeding rice to infants or very young children. Infants and young children tend to rely on only a few types of food. If you are a heavy rice eater you should add some other grains to your diet. The best way to protect yourself from contaminants in food is to eat a varied diet. And not depend too heavily on any one food type. To find out if you live in an area where arsenic in drinking water is a high take a look at the map below. Keep in mind that if you live in a high-arsenic area your community drinking water may be less if it is treated. If you live outside the US you can probably find a map for your country online. Keep in mind too that arsenic levels in rice will vary. The amount of arsenic in rice will depend on how much arsenic was in the ground and water at the growing site.
Exercise and weight are closely related. We all know that exercise burns calories and helps maintain body weight. Exercise has a lot of other health benefits. And maintaining a healthy body weight is important too. But ever wonder how gut microbes, exercise and weight interact? If you are like most people you will be thinking about such things as you wander the grocery store aisles, forgetting why you are there in the first place. Or you may wonder about how physical activity changes gene expression. Or how inactivity changes gene expression. You may wonder, as you pass the yogurt section, “what is with this probiotic stuff?” We’ll talk about probiotics another time.
Exercise weight and bacteria.
Exercise and weight are inter-related. But it looks like there is another player involved. (At least one and probably many.) It looks like exercise has influence over the bacteria that live in your digestive tract. Most of us have been taught that bacteria are bad. But they are not all bad. We need some species to help us digest food, access vitamins, stay healthy and defend us against evil germs. New research shows that the kinds of bacteria in the digestive tract differ depending on level of physical activity. The study was of mice. Mice may have been chosen for the project because it is more agreeable to pick up their poop and analyze it. You can scoop them into a flour sifter to remove the litter. And because you can easily control their diets. And keep them in cages with few complaints.
The researchers wanted to know how exercise, obesity, diabetes and gut microbes interact. The mice were placed in a cage with an exercise wheel. OR placed in a cage with an exercise wheel that didn’t work. After five weeks of exercising or not exercising animals were dosed with a common environmental contaminant. The chemical (PCBs) are known to impair glucose handling. They may also increase risk of diabetes. And a lot of other health problems. After dosing doots were collected. Little rodent poops are often called “doots” by the research community.
Mice who exercised had different kinds of bacteria in their doots. Bacteria from the digestive tracts of sedentary mice had a dramatic loss of proteobacteria and a hugely dramatic loss of Erysipelotrichaceae. The guts of exercising mice had many different kinds of bacteria.
What does this mean for us humans?
This research fits a piece into a larger puzzle. How are exercise and weight and bacteria related? People who are overweight have different gut bacteria profiles. The profiles change when a person loses weight. There are still many other puzzle pieces to fit And many that are missing. But it looks more and more that we need to move to keep our bodies running the way they should. And that things may go badly if we don’t.
Choi JJ, Eum SY, Rampersaud E, Daunert S, Abreu MT, & Toborek M (2013). Exercise Attenuates PCB-Induced Changes in the Mouse Gut Microbiome. Environmental health perspectives, 121 (6), 725-30 PMID: 23632211
Coconut oil is an extraordinary food. But what makes coconut oil special? Coconut oil is a natural source of fat. But what gives coconut oil its mythic properties as a perfect food?
Coconut oil as a nutrient
Coconut oil is rich in medium chain saturated fat. There is some evidence that medium chain saturated fatty acids may help with weight loss, possibly by suppressing appetite. Some saturated fat in the diet is probably OK. Maybe we need some saturated fat in our diets to be healthy. Who knows? Unfortunately or not, research continues to show that diets high in saturated fat are unhealthy. Research also continues to show that diets that contain more unsaturated fats relative to saturated fats are associated with better health outcomes.
Coconut oil and athletic performance
A well-cited article has been referenced to support the idea that coconut oil improves athletic performance. The study compared cyclists who drank either a glucose containing beverage or a glucose and medium chain fatty acid containing beverage. The study’s authors concluded that the medium chain fatty acid beverage impaired performance. (They did not say that it helped). The authors also concluded that the medium chain fatty acid beverage caused stomach cramps. The authors suggested that the cramps may have been what caused poor performance. More study would be needed to see if cramps are indeed the culprit. This doesn’t mean that having medium chain saturated fatty acids circulating in your blood will provide you with an advantage. In fact the body seems to prefer unsaturated fatty acids for fuel (Raclot 1997).
Coconut oil and longevity
If you Google “Coconut Oil” and Longevity you will find about a half a million hits saying that coconut oil improves longevity. If you do the same research in Web of Knowledge (a database of scientific publications) you will find seven hits. Five are about insect pest control. One is about plants. One is about coconut oil increasing atherosclerosis in rabbits.
Other wonderful properties of coconut oil
Coconut oil seems to work pretty well as a conditioner for cast iron cookware. Coconut oil is made of mostly medium chain fatty acids. Coconut oil has a high smoke point. This means it can be used for frying with less risk of burning. Coconut oil is solid at room temperature. (As long as the room isn’t too warm.) Coconut oil makes good popcorn that is light and doesn’t have a burnt oil taste to it. Coconut oil is good for frying for the same reasons it makes good popcorn. Some people like to use coconut oil as a moisturizer.
What makes coconut oil so special?
Coconut oil has been called a perfect food because someone called it a perfect food. And they must have called it perfect with convincing authority. Free of doubt. Pretty free of logic. And pretty much free of evidence. Dr. Oz may have been involved. Almost all of us respond to authority. Authorities provide us with answers to our questions. The desire and drive for answers is a powerful inborn trait. This quality may be uniquely human. It has helped us make tremendous advances in understanding and controlling our world. Answers may be treasured once we have them in hand. Because they are so treasured we sometimes hold onto them longer than we should. Sometimes we hold and treasure answers that are wrong. Or that are simply expressions of someone else’s wishful thinking.
I would have written about this earlier, but so many people were telling me coconut oil was healthy that I didn’t question it for quite some time. Go figure.
[embedplusvideo height=”387″ width=”480″ standard=”http://www.youtube.com/v/Ir9LhF01KtA?fs=1″ vars=”ytid=Ir9LhF01KtA&width=480&height=387&start=&stop=&rs=w&hd=0&autoplay=0&react=1&chapters=¬es=” id=”ep3720″ /]
Raclot T, Langin D, Lafontan M, & Groscolas R (1997). Selective release of human adipocyte fatty acids according to molecular structure. The Biochemical journal, 324 ( Pt 3), 911-5 PMID: 9210416
Jeukendrup AE, Thielen JJ, Wagenmakers AJ, Brouns F, & Saris WH (1998). Effect of medium-chain triacylglycerol and carbohydrate ingestion during exercise on substrate utilization and subsequent cycling performance. The American journal of clinical nutrition, 67 (3), 397-404 PMID: 9497182
Clegg, M. (2010). Medium-chain triglycerides are advantageous in promoting weight loss although not beneficial to exercise performance International Journal of Food Sciences and Nutrition, 61 (7), 653-679 DOI: 10.3109/09637481003702114
Crossfit aerobic training and running. You have probably heard that exercise improves mood, memory and brain function. And that it may protect against Alzheimer’s disease and cognitive decline. Former runners who have turned to CrossFit may remember their runner’s high. It was that wonderful feeling of peace and well-being. CrossFit is a great fitness program. For many people it has become a way of life. But it does not seem to produce the “high” that many people get from running. Combining CrossFit running is something to think about.
Running. The moderate stuff matters.
The “runner’s high” is thought to be caused by chemicals called endocannabinoids. These chemicals are produced in the brain (and possibly in other areas). They reduce feelings of pain and increase feelings of well-being. Endocannabinoids are also involved in appetite suppression and synaptic plasticity. Synaptic plasticity refers to the ability of neurons to adapt and change. An area where Synaptic plasticity is important is in learning and memory formation. New research (April 2013) on endocannabinoids shows that moderate aerobic exercise increases production. Low intensity exercise (like walking) does not. High intensity exercise does not seem to increase endocannabinoids either. CrossFit is very high intensity exercise. Including moderate intensity running with CrossFit (CrossFit running) is probably a good idea. If you are interested in preserving cognitive function. Or if you are interested in improving cognitive function. Some of us are just trying to keep from losing ground. CrossFit is fun. And great for full-body fitness. But it may be that a relaxing run, bike or swim is just as important. If not more.
Raichlen DA, Foster AD, Seillier A, Giuffrida A, & Gerdeman GL (2013). Exercise-induced endocannabinoid signaling is modulated by intensity. European journal of applied physiology, 113 (4), 869-75 PMID: 22990628
CrossFit Training and recent research on links between adaptation to fitness and increased levels of anti-oxidants. Anti-oxidants lower risk of cancer, diabetes and heart disease.There are many benefits in maintaining fitness. Regular exercise reduces risk of cancer, diabetes and heart disease. While the association of exercise and disease prevention has been strong, understanding why has been unclear. But this is changing.
CrossFit Training, Anti-oxidants, free-radicals and fitness.
Uncontrolled free-radicals are major factors in the development of serious diseases. Diabetes, cancer and cardiovascular disease are all conditions where free-radicals are thought to play major roles. Free radicals are molecules or atoms that have lost an electron. These pose problems because they are very reactive and will grab electrons from other molecules. Free radicals can also interact with other molecules, stress cells and throw wrenches in the works. This includes wrench throwing into your DNA. Damaged DNA that is not repaired can result in cancer. Or birth defects. Free radicals also damage tissues and organs by damaging large numbers of cells. They can damage pancreatic beta cells and increase risk of type 2 diabetes.
CrossFit Training and How fitness protects from cancer, heart disease, diabetes.
Of CrossFit Training and General Health. Anti-oxidants protect us from free-radicals by neutralizing them. Having enough anti-oxidants reduces risk of diabetes, cancer, or heart disease. Exercise causes a number of changes beyond weight loss and fitness. And these changes play into the free-radical games. These changes are adaptions to the increased stress of exercise. When people are first getting in shape there is an increase in free-radical production. And a temporary increase in physical stress. As a result, your body suffers inflammation, along with aches and pains. This is very much like what happens when you get sick with a fever. This may be a good part of why getting in shape sucks so much. When you are getting in shape (or trying to push yourself to a higher level) your body will produce more free-radicals, including more reactive oxygen species, until it adapts to your new level of activity. Part of that adaptation includes increasing production of its own anti-oxidants. Once you have adapted you will be producing enough anti-oxidants to protect against other sources of free-radicals.
CrossFit Training, Endurance or Weight Training?
What is CrossFit looking like in terms of increasing anti-oxidants? Is Endurance Training best? Or Resistance Training? So far animal testing indicates that endurance exercise works best for protection against inflammation and production of anti-oxidants (Oliveira et al. 2012). The animals in the study were subjected to endurance training, resistance training or combination training. Hopefully more work will be done in this area and we will get a better picture of what is optimal for humans. Weight training (resistance exercise) remains important. And CrossFit exercises (and high intensity interval training) show very promising results on other aspects of health and fitness. It seems likely that adaptation to these forms of exercise (i.e. CrossFit) will produce similar results to endurance training.
de Lemos ET, Oliveira J, Pinheiro JP, & Reis F (2012). Regular physical exercise as a strategy to improve antioxidant and anti-inflammatory status: benefits in type 2 diabetes mellitus. Oxidative medicine and cellular longevity, 2012 PMID: 22928086
de Oliveira VN, Bessa A, Jorge ML, Oliveira RJ, de Mello MT, De Agostini GG, Jorge PT, & Espindola FS (2012). The effect of different training programs on antioxidant status, oxidative stress, and metabolic control in type 2 diabetes. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme, 37 (2), 334-44 PMID: 22458821
CrossFit vs Running: evidence from High Intensity Interval Training.
Endurance exercise is recommended for cardiovascular health. High Intensity Interval Training (like CrossFit) shows promising results. Years of research have found that about 30 minutes of cardio will reduce risk of stroke and heart attack. It will also improve insulin sensitivity, reduce risk of diabetes and improve memory and brain function. Until very recently, there has been little research on the benefits of CrossFit type exercise on health. These studies focus on High Intensity Interval Training. High Intensity Interval Training consists of multiple sets of intense exercise that last 1-4 minutes. These are spaced with short rest periods. Or periods of light exercise. Research on this approach to exercise indicates that this approach may be better than running (or other sustained types of cardio) in a number of ways. These include cardio and respiratory fitness. And also insulin sensitivity and arterial stiffness. Arterial stiffness is an indicator for risk of cardiovascular disease. It is also looking like High Intensity Interval Training may be better at controlling or preventing high blood pressure than the traditional 30 minutes of sustained cardio.
Is CrossFit better than running?
The question of is CrossFit better than running is not known yet. And CrossFit is different than the types of High Intensity Interval Training being tested. In a nutshell, CrossFit is a fitness program that involves high intensity exercise. Many different muscle groups are targeted in a CrossFit workout (also known as a CrossFit WOD.) Workouts may last 5-20 minutes and involve springs, weight lifting, pull-ups and other bodyweight exercises. If you are wondering “what is CrossFit” try this link. CrossFit exercises may or may not include periods of rest between sets. However, there is a lot of shifting of focus. Intensity may be sustained, but not sustained on the same muscle groups. This might be better for vascular health.
CrossFit vs Running: More research needed
Short periods of high intensity exercise improve capillary growth. This allows for greater blood flow to tissues. Including muscle. It is possible that intense exercise impacting multiple muscle groups would be better than exercise that impacts only legs (as in running). This is an exciting area of research. It will be interesting to see what comes up next. Hopefully more research will be done soon that will look at whether or not CrossFit or High Intensity Interval Training does as well with brain health and control of diabetes. For a look at recent papers take a look at:
Cocks, M., Shaw, C., Shepherd, S., Fisher, J., Ranasinghe, A., Barker, T., Tipton, K., & Wagenmakers, A. (2012). Sprint interval and endurance training are equally effective in increasing muscle microvascular density and eNOS content in sedentary males The Journal of Physiology, 591 (3), 641-656 DOI: 10.1113/jphysiol.2012.239566
Spence AL, Carter HH, Naylor LH, & Green D (2013). A prospective randomised longitudinal study involving 6-months of endurance or resistance exercise on conduit artery adaptation in humans. The Journal of physiology PMID: 23247114
CrossFit has many devoted followers. Crossfit health, crossfit training, crossfit nutrtion: the CrossFit world seems to teem with experts. Some can get quite dogmatic. There are several ways by which an idea becomes dogma, or an idea becomes “truth.” Sometimes an idea gets picked up and passed around. And gets momentum. And repeated is so often that it becomes true in people’s minds. Because it seems true to so many people it is not questioned. And some people seem to be more vulnerable to dogma than others.
Sometimes a health or science story comes up in the news that catches people’s interest. Often a journalist will pick up on one aspect of a study and not mention other aspects, or limitations, or may misinterpret the conclusions of the study authors. So take a look at the original yourself if you can. Peer-reviewed articles published in highly-ranked journals put out quality work. Sure, its not perfect, but its better than stuff that’s been pulled straight out of someone’s hopeful ass. Getting through peer-review is a rigorous process as exemplified in this video Scientific Peer Review ca. 1945. [embedplusvideo height=”350″ width=”430″ standard=”http://www.youtube.com/v/-VRBWLpYCPY?fs=1&hd=1″ vars=”ytid=-VRBWLpYCPY&width=430&height=350&start=&stop=&rs=w&hd=1&autoplay=0&react=1&chapters=¬es=” id=”ep8516″ /] Here is some simple advice:
If you are wondering “what is dogma anyway?” it is: A principle or set of principles laid down by an authority as incontrovertibly true. Dogma cannot be changed or put aside without threatening the foundation of the organization or institution that sets it in stone. The problem with dogma is that it cannot change and we are always learning new things. We are also adding to data, improved technology, increasing understanding of how things work. It gets harder and harder to make dogma fit. Ideas should change and grow. The only people who are helped by dogma are those trying to gain and keep control of power, prestige, or wealth. I’m not talking about religion although some can be quite dogmatic. I’m thinking of people who think of something, maybe innocently, and present it as truth. Or of people who state something unknown or unknowable as fact so they can sell you something. They may become very defensive or offensive if you question them. If they are questioned they are faced with the possibility of losing status and wealth. Such people may sincerely believe that what they are saying is true. And that can make them quite convincing. When many people believe something and remain loyal to the idea (because they are loyal to their friends and the “experts” they follow) beliefs turn into dogma. But belief does not make something true.
There are a lot of things that influence health beyond diet and exercise, and many ways in which our health may be influenced by the world we create.
Exposure to light:
Psychological stress (traffic, kids, job etc.)
Quality of friendships and community
Exposure to environmental agents
and etc. It is important to keep in mind that all of these things can impact your physical health, and that they can all influence each other. We’ll do our best to discuss these things and try to make sense of them as new research comes to our attention. Subscribe to hear the latest on human health research. We’ll be looking at peer-reviewed scientific studies and writing about them. Hopefully we’ll learn something and be able to share it.
Articles and commentary on fitness, aches, pains, research, and adventure. The WODMasters started as a small group of masters crossfit athletes. We wanted high quality shirts that fit well and looked good. We wanted crossfit shirts that went beyond telling everyone we had great snatches, could squat, beat up other children’s parents and/or were covered with death skulls. We wanted crossfit shirts that were about us. So we made our own. That was about five years ago, in 2009. We now design and produce unique, high-quality athletic shirts. They are ideal crossfit shirts in that they are crossfit themed and made by people who do crossfit. They are also ideal apparel all those who are stiff, inflexible and off-beat. We are not affiliated with CrossFit the brand. Or with Reebok CrossFit. We are our own thing. We also write and talk about nutrition, health, fitness, aches and pains, and adventure expeditions and how to stay tough and have fun. WODMasters creates and provides original content. If you would like to use it please reference our site and provide a link.
If you are looking for an original, off-beat, high quality athletic shirt check out our designs. Our shirts are perfect crossfit gifts (we started out with CrossFit, but are open to all kinds of interesting pursuits). They are also perfect gifts for the Masters Athlete, and anyone else who is stiff, inflexible and off-beat.
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