Saturday, 20 May 2017

Chili Peppers, the Scoville Heat Scale, and a World Record

Chili peppers or chilis are known for the hot sensation that they produce in the mouth and digestive tract when they're eaten. The heat is produced by a chemical called capsaicin, which has health benefits when used appropriately. The hotness of the pepper is indicated by a number on the Scoville heat scale. Plant breeders have recently created a chili that is said to be so hot and have such a high Scoville number that it may be dangerous, depending on the amount that's eaten. The pepper may have medicinal uses, however.

Photo by Pixel2013, public domain license

Chili Peppers or Chilis

Chili peppers belong to the genus Capsicum, which in turn belongs to the nightshade family, or the Solanaceae. Bell peppers also belong to the genus Capsicum, but unlike their relatives they don't contain capsaicin and aren't hot. Chili and bell peppers contains seeds and are therefore fruits.

Eating chili peppers can irritate the digestive tract, causing a burning sensation—which can sometimes be severe—as well as a flushed face, tears, and sweating. Interestingly, though, researchers have found that although the lining of the digestive tract is temporarily irritated by hot pepper and may feel as though it's on fire, it's not being burned. Nevertheless, the abdominal pain created by the irritation and the nausea and vomiting that may accompany the pain may need medical treatment.

According to the American Chemical Society article referenced below, as someone becomes used to eating hot peppers, they become more tolerant of their effects. A person who is new to eating peppers may experience the most severe effects. It therefore seems like a good idea to start by eating a very small quantity of pepper. It might also be a good idea to have a glass of milk on hand. The casein molecules in milk surround the capsaicin and wash it away.

The Scoville Heat Scale

The Scoville heat scale is named after Wilbur Scoville, a pharmacist who created the scale in 1912. The Scoville rating depends on the capsaicin concentration. Pure capsaicin has a rating of 16 million Scoville Heat Units, or SHU. Bell peppers have a rating of 0 SHU. According to Guinness World Records, the hottest chili pepper at the moment is the Carolina Reaper, which was bred by the PuckerButt Pepper Company in the United States. The full name of the chili is Smokin Ed's Carolina Reaper. The fruit has an average rating of 1,569,300 SHU, but some specimens may have a rating as high as 2 million SHU.

Chili Peppers
Photo by Hans, public domain license

The Dragon's Breath Chili

Information about a new contender for the title of the world's hottest chile pepper has been sent to the Guinness Word Records organization. The Dragon's Breath chili was created as a joint project by a plant breeder in Wales and professors at Nottingham Trent University in the United Kingdom. It reportedly has a rating of 2.48 million SHU. The fruit is orange-red in colour and is about the size of a fingernail.

The new pepper is so hot that eating it might be dangerous as well as painful. The creators have suggested that it could cause anaphylactic shock in some people and block the airways, although this statement is a bit puzzling. Anaphylactic shock is an extreme and very dangerous type of allergic response that affects the whole body, including the airways. Someone would have to be allergic to capsaicin in order to develop this reaction. Still, the pepper has such a high Scoville rating that it might cause harmful effects when eaten. It wasn't created as food, however. The breeders of the chili think that the oil inside it—which contains capsaicin— could be useful as an anesthetic.

Capsaicin in Medicinal Creams

Capsaicin is used in creams to relieve pain from sore muscles and joints. Based on the reports that I've read, it seems to be quite effective for some conditions, including arthritis. It may cause a burning sensation to begin with, but this is often followed by pain relief. The most common explanation for its action is that it reduces the amount of substance P, a neurotransmitter that transmits pain signals. Neurotransmitters control the passage of nerve impulses from one neuron to another. It's interesting that capsaicin has benefits as well as disadvantages. The effects seem to depend on the method of application, the dose, and individual sensitivity to the chemical.


Hot peppers from the American Chemical Society
Capsaicin information from HealthLinkBC (a British Columbia government organization)

Wednesday, 17 May 2017

Mussel Glue Mixture May Significantly Reduce Scarring

A group of researchers in South Korea has just made what could be an important discovery with respect to wound healing. They've used a mixture containing a protein from mussel glue to greatly reduce scarring in rats who experienced a serious skin injury. It's possible that the mixture may be helpful for reducing scarring in humans as well.

Photo by stux, CC0 public domain license

Animal Testing

The experiment that was performed involved creating surface wounds in rats and then observing whether the test mixture reduced scar formation. As with many experiments with lab animals, the treatment of the animals could definitely be criticized. Using stem cells to create different types of human tissue and sections of organs may well reduce the use of animals in medical research in the future. It probably won't persuade researchers to abandon animal research altogether, though, because they sometimes want to look at whole-body effects.

Three classes of medical research are in vivo experiments (done in living things), in vitro experiments (done in lab equipment, and in silico experiments (done with computers or via computer simulations). I'm hoping that the last two types of experiments rapidly become more and more useful.

Collagen in Skin

Collagen is a fibrous protein that could be thought of as the scaffolding for our skin. It forms a network or mesh that helps to support the skin's structure and provide firmness. When we receive a significant wound, the skin that fills in the wound contains parallel strands of collagen in bundles instead of a fibrous network. This is a major contributor to the abnormal appearance of a scar.


Decorin is a protein involved in the normal organization of collagen in the skin. It has been shown to reduce scarring when applied to wounds, but it isn't used therapeutically. It's a complex molecule that is too hard to make and too expensive to use. The Korean researchers used part of the decorin molecule in their experimental mixture, however. They also added a sticky substance from mussels and a collagen-binding molecule to the mixture. The mixture was then applied to the skin of rats with a major wound.

The Rat Experiment

The researchers say that the wounds in some of the animals were treated with the test mixture and then covered with plastic to keep the wound moist. In the other rats in the experiment (which formed the control group), the wound was covered with plastic but nothing else. The wounds on all of the rats had the same width and depth.

The New Scientist article referenced below shows pictures of the rats' wounds over time. Based on these photos, and assuming that there was no further change in skin appearance after day 28, it seems inaccurate to say that the experimental mixture prevented scarring as some headlines do (including the one in the referenced article). The mixture did reduce the size of the scar very significantly, however.

  • By Day 11, 99% of the wounds were closed in the test rats and 78% in the control group.
  • By Day 28, "treated rats had fully recovered" and there was very little scarring. The rats in the control group had thick purple scars.
The scientists found that the collagen in the healed wounds looked normal and that the skin contained oil glands, hair follicles, and blood vessels, structures that are absent from scars. 

Possible Application to Humans

Rats and humans are both mammals, so what applies to one often applies to the other. This isn't always the case, though. The researchers say that one factor which may be significant with respect to the scar experiment is that rats have looser skin than humans and tend to scar less. The scientists plan to experiment on pig skin next, which is more similar to human skin.

Research Reference

Mussel Gloop Can Be Used to Make Wounds Knit from New Scientist

Sunday, 14 May 2017

Sushi and Raw Fish, Parasitic Nematodes, and Anisakiasis

Sushi and sashimi can be delicious, but diners should know that eating a meal of raw fish is potentially dangerous. Unless the fish has been adequately frozen before use, it may harbour a parasitic nematode named Anisakis simplex. The nematode attaches itself to the lining of the gastrointestinal tract (or the digestive tract) and often stays alive for some time. It may cause severe pain as well as other unpleasant and sometimes serious problems.


Nematodes are also known as roundworms. Anisakis is a roundworm with a complex life cycle that involves marine mammals, crustaceans, and fish or squid. The basic steps in the cycle are as follows.
  • The parasite reproduces inside marine mammals such as seals and whales. 
  • The eggs of the parasite are released into the ocean in the animals' feces. 
  • The eggs become larvae, which are eaten by crustaceans.
  • The crustaceans are eaten by fish and squid. The larvae migrate to the muscles of these animals.
  • The fish and squid are eaten by marine mammals. Here the larvae mature and the cycle begins again.
  • If the fish and squid are eaten by humans instead of a marine mammal, a nematode infection may result. 

The parasite can only penetrate the outer layer of the lining of the human digestive tract and eventually dies. This may sound like a good outcome, but the problem is that the presence of the worm triggers a strong response by the immune system. Inflammation occurs and a mass of cells is formed in the tract.

Infection, Symptoms and Treatment

Until quite recently, cases of anisakiasis were generally restricted to countries such as Japan, where raw fish is very popular. In the last few years cases have appeared in other parts of the world as the popularity of raw seafood dishes has spread. The disease can develop after eating fish and squid that is raw and improperly prepared. Sushi and sashimi can both be problematic. Sushi consists of raw fish, vinegared rice, and sometimes additional ingredients such as seaweed or other vegetables. Sashimi consists of thin slices of raw fish.

Possible symptoms of the infection include abdominal pain and swelling, nausea, vomiting, diarrhea (which may be bloody or contain mucus) and a slight fever. Some people experience an allergic reaction when they are infected by the parasite. This reaction may involve a rash and itching. Rarely, anaphylaxis may develop. This is a severe and body-wide allergic response that is life threatening and a medical emergency. As with any symptoms and condition, a doctor is needed in order to diagnose the problem.

The treatment for the disorder is often removal of the parasite by endoscopy or surgery. Endoscopy is a process in which a flexible tube with a tiny camera and a light are inserted into the digestive tract so that a doctor can examine the area. Devices can be inserted into the tube to remove items from the tract if necessary. These items include a nematode attached to the lining of the digestive tract.

How to Kill the Parasite

A professional sushi chef will probably know how to prepare sushi and sashimi safely, at least in North America, where I live. Some communities have a law mandating the correct treatment of the fish. People who prepare the fish at home or without training are more likely to cause a problem.

Adequate cooking will kill parasitic worms. According to the CDC (Centers for Disease Control and Prevention), under specific conditions freezing raw fish will also kill the parasites. The CDC says that one of the following procedures for treating the fish should be used. Note that none of them can be obtained in a home freezer.
  • Freeze at -4 degrees Fahrenheit (-20 degrees Celsius) or below for 7 days.
  • Freeze at -31 degrees Fahrenheit (-35 degrees Celsius) until solid and then store at the same temperature or below for 15 hours.
  • Freeze at -31 degrees Fahrenheit (-35 degrees Celsius) until solid and then store at 4 degrees Fahrenheit (-20 degrees Celsius) or below for 24 hours.
It's important that a raw fish lover checks that their preferred source of sushi or sashimi prepares the food properly. If this is done, it should be possible to enjoy the food and stay safe.

References and Further Information

Information about anisakiasis from the CDC

A case report from the British Medical Journal

Tuesday, 2 May 2017

Soy Protein Might Be Helpful for Inflammatory Bowel Disease

Researchers at Pennsylvania State University have made a discovery that might be helpful for people with inflammatory bowel disease, or IBD. They've found that soy protein reduces inflammation and loss of gut barrier function in mice with an induced condition resembling IBD. The discovery may be applicable to humans as well, although this won't be known for certain until clinical trials are performed.

Soybeans: public domain photo by Jing

Inflammatory Bowel Disease

The word "bowel" is another name for the intestine. Inflammatory bowel disease is the general name for a group of illnesses involving intestinal inflammation. The most common types are Crohn's disease and ulcerative colitis. Crohn's disease most often affects the last part of the small intestine (the ileum) and the large intestine. It may affect other parts of the digestive tract instead or as well, however. Ulcerative colitis usually affects the colon (the first and longest part of the large intestine) and the rectum (the chamber at the end of the colon where stool is stored until it's ready to be released). Both diseases can be painful and seriously interfere with life.

Inflammatory bowel diseases affect nearly 4 million people worldwide and have an economic impact of more than $19 billion annually in the United States. Jeff Mulhollen, Penn State News

Crohn's Disease

The cause of Crohn's disease is unknown. It's thought to be due to a mistake by the immune system, however. Certain bacteria or other environmental factors in the intestine may trigger the immune system to behave abnormally, leading to inflammation. There may be a genetic factor that makes some people more susceptible to the disease than others.

Some possible symptoms of Crohn's disease include stomach pain, severe diarrhea, weight loss, fatigue, and a low-grade fever. In addition, there may be blood in the stool. Anyone with any of these symptoms should consult a doctor. The disease often follows a pattern of flare-up, when symptoms are worse, alternating with remission, when symptoms are milder or absent.

Ulcerative Colitis

Ulcerative colitis is  "ulcerative" because sore or ulcers develop on the intestinal lining. "Colitis" means inflammation of the colon. The condition is believed to be an autoimmune disease. Symptoms of ulcerative colitis often resemble those of Crohn's disease, including the occurrence of flare-ups and remissions. There are a few differences between the two conditions, however.

  • Ulcerative colitis is generally restricted to the colon and affects the inner layer of its lining. Crohn's disease can affect any part of the digestive tract and causes damage that penetrates deeper into the lining.
  • In ulcerative colitis, the entire colon is affected. In Crohn's disease, the damage generally occurs in patches.
Mice are often used in medical experiments.
Public domain photo by auenleben

The Soy Protein Research

The Penn State researchers studied both mice and isolated cells from the human colon. They found that concentrated soy protein produced protective effects in the colon cells. The researchers replaced some of the protein in the diet of the mice with soy protein concentrate. They tried to keep the quantity of soy reasonable instead of using a huge amount. Not only did the intestinal inflammation improve in the mice with induced IBD, but in addition weight loss and spleen swelling were reduced.

Since soy protein is available commercially, both in the form of a protein powder and in meat substitute products, people with IBD may want to try it now to see if it helps them. If this is done, it's probably a good plan to start with a small amount at first to see how the body reacts. If the condition doesn't worsen, the amount of soy that's ingested could be increased. A huge amount of soy may not be good for other aspects of health, however. It might be a good idea for a patient to talk to their doctor before incorporating the protein into the diet. Hopefully the clinical trials will be performed as soon as possible in order to determine the optimal amount of protein, assuming it helps humans as it does mice.


Friday, 28 April 2017

Marmite, GABA, and Improved Brain Function

Marmite on toast ready for me to eat
Photo by Linda Crampton

A Potentially Helpful Sandwich Spread

Marmite is a dark brown spread with a strong taste that some people love and others hate. Research performed by scientists at the University of York in Britain suggests that eating marmite can be beneficial for brain function, possibly by stimulating the production of a chemical known as GABA.

Half of the subjects in the British experiment ate a teaspoon of marmite every day for a month in addition to their normal diet; the other subjects added a daily teaspoon of peanut butter to 
their diet instead of marmite. At the end of the month, the researchers found that the people who ate marmite had an approximately thirty percent reduction in their brain's response to visual stimulation caused by an image of flickering stripes. This was demonstrated by detecting the electrical activity in the brain via electroencephalography, or EEG.

What Is GABA?

The researchers believe that the decreased brain activity in the subjects occurred because the marmite stimulated the production of GABA. "GABA" is an abbreviation that stands for gamma-aminobutyric acid. The chemical is a neurotransmitter. Neurotransmitters control the passage of a nerve impulse from one neuron (nerve cell) to another. Some transmit the impulse and are said to be excitatory. Others stop the transmission and are said to be inhibitory. GABA is an inhibitory neurotransmitter. It night sound bad that a chemical stops the passage of a nerve impulse, but that's exactly what sometimes needs to happen in order to quell overactivity in the nervous system. 

GABA is often low in people with epilepsy, as is taurine. Its role in the disorder isn't fully understood, however. It's very important that someone with epilepsy or a seizure disorder doesn't take GABA or taurine supplements without their doctor's supervision. According to the University of Maryland Medical Center, there is no scientific evidence that supplements containing the chemicals will reduce the number of seizures. 

DO NOT take taurine or GABA supplements without your doctor's supervision. DO NOT take taurine or GABA if you have a history of bipolar disorder, or if you take psychoactive medications. (Quote from the University of Maryland Medical Center)

Some Unanswered Questions

The results of the marmite experiment are interesting and could be important, but there are some unanswered questions relating to the research.

  • Although the researchers think that the vitamin B12 in the marmite was the helpful component of the spread (because it triggered the production of GABA), this wasn't tested. Another substance may have been responsible for the benefit. It's also possible that a combination of chemicals produced the benefit.
  • The proposal that the marmite exerted its effect by triggering GABA production wasn't tested. 
  • Only twenty-eight people were involved in the research (fourteen in each group). The experiment needs to be repeated with a larger sample size.
Thickly spread marmite
Photo by TheJackal, CC BY-SA 3.0 License

The Nature of Marmite 

Marmite is a yeast extract. For some people, eating a whole teaspoon of the spread all at once would be difficult because of its strong and often overpowering taste. I love marmite myself, but I spread it very thinly on my bread, as shown in my photo at the start of this article. I would find it very hard to eat the thick layer shown in the photo above. I suspect that some marmite haters might like the product if they ate a thin layer instead of a thick one

The marmite that's sold in Britain contains added B vitamins, including vitamin B12. The version that's sold in Canada, where I live, doesn't contain these additions. I can get British marmite only if I go to a food import store instead of my local supermarkets. I sometimes do this, but I usually buy the product locally. It would be nice if it was beneficial for brain health as well as being tasty. It would also be nice to know if the marmite version with added vitamins is necessary in order to get the special health benefit discovered in the research.


Marmite may affect brain function from ScienceDaily

Marmite may be brain food from CTV News

Seizure disorders from the University of Maryland Medical Center

Tuesday, 25 April 2017

How Much Salt Are We Supposed to Eat?

Salt is tasty, but is it good or bad for us?
Public domain photo by hansbenn

Nutritionists and health practitioners have been telling us for many years to limit our salt (sodium chloride) intake. One reason for this recommendation is to reduce the chance of high blood pressure, or hypertension. High blood pressure can in turn increase the chance of a stroke, heart disease, and a heart attack. Now the results of a study of sodium intake and blood pressure are calling into doubt the benefit of the reduced salt recommendation. The results were announced in April 2017 in the Experimental Biology meeting in Chicago.

The Research

The study was performed by the Boston University School of Medicine and was called the Framingham Offspring Study. It involved 2,632 people aged 30 to 64 and lasted for 16 years. The participants all had normal blood pressure at the start of the study. The researchers found that consuming less sodium wasn't linked to a lower blood pressure. In fact, they found that people eating less than 2,500 milligrams of sodium a day had a higher blood pressure than those who ate more sodium. The researchers also stated that other large studies in the past have discovered that both people with low sodium intake and those with a very high intake have an increased risk of heart disease.

The researchers say that the current recommendation for a low sodium intake may be "misguided". Their study suggests that most people with an average sodium intake - 3,400 mg a day according to the American Heart Association - don't need to worry about sodium and actually have the lowest risk of heart disease. One of the researchers does say that there is "likely a subset of people sensitive to salt who would benefit from lowering sodium intake", however.

Heart Association Recommendations

A representative of the heart association disagrees that their recommendations for sodium intake are misguided and has criticized the protocol followed by the new study. This study says that less than 2,500 milligrams of sodium a day is unhealthy; the American Heart Association says that more than 2,300 milligrams a day is unhealthy and that 1,500 mg a day is a better goal for most adults. Clearly we have a problem.

Should a salt shaker be on the table?
Public domain photo by Ben_Kerckx

Other Important Minerals

As is often the case, it's hard for the average person to decide what to do when the experts can't agree. There may be a way out of this conundrum, however. An interesting discovery in the recent study was that people who had higher intakes of potassium, magnesium, and calcium as well as an average intake of sodium had lower blood pressure. The lowest blood pressure of all was found in people who ate 3211 mg of potassium a day and 3717 mg of sodium a day - an amount of sodium that the heart association considers dangerous.

Many nutritionists say that it's important to eat enough potassium and magnesium, so that's a goal that I'm aiming for. The minerals are abundant in green, leafy vegetables. Since nutritionists seem to agree that green vegetables are healthy foods in many ways, I'm going to try to keep my intake high.

As far as the sodium level in foods is concerned, I'm still going to avoid foods with a very large amount of added salt, such as some varieties of prepared soups and some canned vegetables and meats. I don't feel comfortable about deliberately eating salty foods when the topic is controversial amongst health researchers. Other than reducing the foods with the highest salt content, I'm not going to worry too much about sodium, though, as long as I keep eating vegetables. I hope the experts soon reach a consensus about what we should do with respect to our salt intake, as long as this consensus is good for our health.


Low sodium diet and blood pressure from Science Daily
A high sodium diet from the San Diego Tribune

Friday, 21 April 2017

Reoviruses and Celiac Disease: A Possible Connection

Reoviruses infect the respiratory tract and intestine of humans. Researchers have recently made a potentially important discovery about the viruses in relation to celiac disease. The scientists have found a link between a reovirus infection and the development of celiac disease in mice that are genetically susceptible to getting the disease. The scientists have also discovered that at least in the people that they tested, people with celiac disease have an elevated level of antibodies against reoviruses compared to people without the disease.

Wheat bread contains gluten, which is harmful for people with celiac disease.
Public domain photo by Couleur

What Is Celiac Disease?

Celiac disease involves an immunological reaction to a protein complex in certain grains known as gluten. As a result of this reaction, the inner lining of the small intestine becomes inflamed and the villi (tiny folds on the lining) flatten. Villi increase the surface area for nutrient absorption. When they're flattened, the quantity of nutrients that can be absorbed is greatly reduced. The intestinal effects can lead to a host of unpleasant and sometimes dangerous symptoms that appear in the digestive system and sometimes far beyond this location. Even a small amount of gluten can trigger inflammation. The immediate effects of this inflammation are not the only problem. Untreated celiac disease produces an increased risk of intestinal cancer.

Gluten is found in wheat and all its varieties, including spelt and kamut, as well as in rye and barley. It's not completely understood why the gluten provokes an immune response and triggers inflammation, although researchers have found some possible or partial explanations.

What Are Reoviruses?

Reoviruses get their name from the term "respiratory enteric orphan viruses". They were originally referred to as orphan viruses because they were thought to have no effect on the human body. The words respiratory and enteric in the name refer to the parts of the body where the viruses are most often found. ("Enteric" refers to the intestine.)

Viruses contain DNA or RNA surrounded by a protein coat called a capsid. Many viruses have a lipid envelope outside their capsid. The DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) contain the genome or genetic instructions of the virus. Reoviruses have double-stranded RNA, a double-shelled capsid, and no lipid envelope.

People with celiac disease must avoid these products, but fortunately
gluten-free breads are available.
Public domain photo by Couleur

Avoiding Gluten 

If scientists knew that reoviruses can cause celiac disease in genetically susceptible people, it would be useful to develop a vaccine or other method to prevent an infection. The current cure for celiac disease is to stop eating gluten so that the villi grow back. This may seem like an easy step to take. There are problems with the treatment, however. 

One problem is that it's hard to avoid gluten. Though there are gluten-free grains, they may be contaminated with gluten in the field, in the storage area, in the processing area where products are made, or in the home when meals containing gluten are made. Flour containing gluten can drift through the air and land on gluten-free food. A person with celiac disease may pick up gluten from crumbs left in a toaster or particles left on countertops and cutting boards. In addition, non-food items such as toothpaste may contain gluten. Eating outside the home, such as in restaurants or at school events, is always a time for vigilance.

Despite the potential difficulties, someone with celiac disease who tries hard to avoid all sources of gluten can generally reduce their exposure to such a low level that the intestinal inflammation disappears and their villi recover. Some people find that even after avoiding gluten for as long as a year, however, their intestine doesn't heal. This condition is rare, but it's very unfortunate for the people who experience it.

Mice are often used in lab experiments that may apply to humans.
Public domain photo by auenleben

The Mouse Experiments

The scientists involved in the recent research found that one type of reovirus triggered celiac disease in genetically susceptible mice if the animals were eating gluten when they developed the viral infection. While it's true that results of mouse experiments don't always apply to humans, they often do. An interesting aspect of the research was the fact that the scientists also found that antibodies against reovirus were two to five times higher in people with celiac disease compared to the situation in people without the disease. This doesn't mean that all patients respond abnormally to the virus, but some may. 

It could be very helpful if reoviruses are proven to cause celiac disease because the discovery could lead to prevention of the disease. Biologically, though, one mystery will have been replaced by another. We don't know all the details involved in gluten's action in the body and we don't know how reoviruses trigger celiac disease in humans (if in fact they do). Many discoveries in science build on previous ones, so we may eventually have answers to the puzzles.


A common virus might trigger celiac disease (from NPR, or National Public Radio)

Celiac disease information (from the Mayo Clinic)