This is an odd and interesting bit of research. It relates to reaborption of nitrogen . . . and presents the possibility that more protein is conserved than previously thought. First dietary nitrogen 101: Nitrogen is a major component of amino acids. Amino acids are needed to form proteins. We can synthesize some amino acids ourselves, but others need to be obtained through diet. Dietary protein provides nitrogen and amino acids from plant or animal sources which are resynthesized into human proteins. Unused nitrogen is converted into Ammonia and Urea and excreted.
Can nitrogen be reabsorbed from the intestines?
The answer is a shocking “maybe.” A new nutritional study (published ahead of print in the Journal of Nutrition) has found that nitrogen appears to be reabsorbed. This makes little sense at first glance. Until we consider the vast populations of microorganisms that reside in the gut. Until recently, they were all thought of as “germs” that needed to be quashed. That has changed. We are learning more and more about how important they are for our health and even our survival.
The study is titled:
Nonprotein Nitrogen Is Absorbed from the Large Intestine and Increases Nitrogen Balance in Growing Pigs Fed a Valine-Limiting Diet.
Valine is an essential Amino Acid, so these animals were fed a protein-deficient diet. Then researchers administered urea or casein into the cecumof pigs. Let’s consider this research a step toward greater understanding of how nitrogen may be recycled in living animals. Not a new way to increase protein for strength. (Although who knows. It might work.) The urea was synthesized using Nitrogen-15. Dietary nitrogen is Nitrogen 14. Using nitrogen-15 lets the team know where the cecum-delivered nitrogen ended up.
Researchers found that more than 80% of the cecum delivered nitrogen was absorbed. Some of it was excreted in urine, but some was retained. This is a shocker. I know. Humans cannot synthesize protein using nitrogen. So WTF? The researchers propose that urea traveled through the bloodstream and into to the small intestine. Bacteria (some of which can make amino acids using urea or plain nitrogen) in the small intestine then used the extra urea to make amino acids. Amino acids produced by bacteria could then be absorbed the host (animals).
More research would need to be done to confirm that this happens. But it is very interesting. Humans vary in the types of bacteria they host. Bacterial populations vary according to diet, environment, chance (?) and who knows what else. Do people get extra protein from bacteria? Does this happen under normal circumstances (i.e. not piped in through the back end.)? One thing is sure: there is a lot to learn.
Columbus DA, Lapierre H, Htoo JK, & de Lange CF (2014). Nonprotein Nitrogen Is Absorbed from the Large Intestine and Increases Nitrogen Balance in Growing Pigs Fed a Valine-Limiting Diet. The Journal of nutrition PMID: 24647394
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.
CrossFit News. CrossFit and Yoga seem like polar opposites. CrossFit is hard driving. Speed and raw strength matter. Yoga can also be very challenging, but yoga evokes control, grace and peace. While not ideal, CrossFit participants can often be seen sacrificing grace for reps. What can yoga teach us as CrossFit athletes? Control, grace and inner peace may also be important for CrossFit performance and practice.
Why research on Yoga and the immune system is CrossFit News
First a little background: Humans produce their own anti-bacterial coatings. A peptide called Beta-Defensin-2 was first discovered in infected skin. Since then it has been found to be produced in other cell types too. Examples include cells lining the nose, mouth and airways. Beta Defensin 2 protects against infection by certain types of germs. The germ types are called “gram negative.” Beta Defensin doesn’t seem to protect against Staph infections though. Fortunately there are other forms Defensins that protect against a range of viruses, fungi and bacteria. You should still wash your hands after working out at your CrossFit box or anywhere else where you are sharing workout equipment. Be a friend and wash your hands before you workout too.
Researchers wanted to know if Yoga would increase Beta-Defensin in people who were not physically active. The hope was that gentle stretching and movement would boost immune function in people who could not do vigorous exercise. The study participants were all older adults (ages ~60 to 80). The research team is also hoping to find out if stretching and mobility training (as Yoga) would reduce lung infections.
What was done?
Researchers had participants do yoga for 90 minutes. Subjects didn’t do any of the yoga breathing stuff. Spit samples were collected before and after. The samples were tested for Beta Defensin-2. Results: a single 90 minute yoga session resulted in increased saliva levels of Beta Defensin 2.
CrossFit News take away.
Yoga might be a good thing to add to your fitness life. While the study didn’t look at CrossFit Mobility training its reasonable to expect similar benefits. Some have a hard time doing stretching and mobility. Maybe its time to give stretching, mobility and yoga its due.
Eda N, Shimizu K, Suzuki S, Tanabe Y, Lee E, & Akama T (2013). Effects of yoga exercise on salivary beta-defensin 2. European journal of applied physiology, 113 (10), 2621-7 PMID: 23925803
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
CrossFit and mental toughness. Its a cultural thing. If you do CrossFit you are supposed to be stronger than the pain you are feeling. Sometimes this gets a little nutty. You should stop or slow down if you are going to hurt yourself. You should go lighter on weights sometimes. For some of us, that some times may be all the time. It is dangerous to sacrifice form for heroics. That can be hard to keep in mind when pushing yourself is fun. And rewarding. And you are addicted.
Fitness and getting the right attitude..
New research indicates that a positive mental attitude towards pain can make you feel awesome. Or at least awesomer than you would feel with a negative attitude. The paper, “Pain as a reward: Changing the meaning of pain from negative to positive co-activates opioid and cannabinoid systems” was published this month. You can see the reference at the bottom of this post. Two groups of people were either told “this is going to hurt.” Or: this will make your muscles stronger. The people who thought the pain would make them stronger were able to endure more pain. That may surprise few readers. Here is what is surprising and very interesting:The ability to tolerate pain could be blocked by blocking the chemicals that produce the runner’s high.
Its more than attitude: implications for CrossFit Athletes.
The research mentioned above is especially interesting because the researchers were able to turn off the increased ability to withstand pain by blocking the opiods and cannabinoids. Part of the “runner’s high” is caused by natural opiods and cannabinoids that are produced in the brain. These can be addictive. And lead to people getting addicted to their workouts. Maybe it is attitude that makes some people love working out. And makes other people feel that working out just sucks. Being able to train harder will make you better at CrossFit WOD s. And knowing that you will get better at your workouts will make you better able to handle them. Just don’t try it with an opiod blocker.
Benedetti F, Thoen W, Blanchard C, Vighetti S, & Arduino C (2013). Pain as a reward: Changing the meaning of pain from negative to positive co-activates opioid and cannabinoid systems. Pain, 154 (3), 361-7 PMID: 23265686
Nutrition, Fitness, Health, News, Style and Research for Adventurous Women