Scientists Identify New Markers in Bood and Urine to Know What We Eat and Drink

Researchers at McMaster have identified several chemical signatures, detectable in blood and urine, that can accurately measure dietary intake, potentially offering a new tool for physicians, dietitians and researchers to assess eating habits, measure the value of fad diets and develop health policies.

The research, published in the journal Nutrients, addresses a major challenge in assessing diets: studies in nutrition largely rely on participants to record their own food intake, which is subject to human error, forgetfulness or omission.

“This has been a major issue in nutritional research and may be one of the main reasons for the lack of real progress in nutritional sciences and chronic disease prevention,” says Philip Britz-McKibbin, a professor in the Department of Chemistry and Chemical Biology at McMaster University and lead author of the study, which was a collaboration with Dr. Sonia Anand and colleagues from the Departments of Medicine, and Health Research, Evidence, and Impact.

Scientists set out to determine if they could identify chemical signatures, or metabolites, that reflect changes in dietary intake, measure those markers and then compare the data with the foods study participants were provided and then reported they had eaten. The specimens analyzed were from healthy individuals who participated in the Diet and Gene Intervention Study (DIGEST).

Over a two-week period, researchers studied two contrasting diets: the Prudent diet, rich in fruits, vegetables, lean meats, and whole grains, and a contemporary Western diet, rich in trans fats, processed foods, red meat and sweetened beverages.

Researchers were able to validate a panel of metabolites in urine and plasma that correlated with the participants’ consumption of fruits, vegetables, protein and/or fiber.

“We were able to detect short-term changes in dietary patterns which could be measured objectively,” says Britz-McKibbin. “And it didn’t take long for these significant changes to become apparent.”

Britz-McKibbin cautions that food chemistry is highly complex. Our diets are composed of thousands of different kinds of chemicals, he says, and researchers don’t know what role they all may play in overall health.

In future, he hopes to broaden this work by examining a larger cohort of participants over a longer period of time. His team is also exploring several ways to assess maternal nutrition during crucial stages of fetal development and its impact on obesity and metabolic syndrome risk in children.

Source: McMaster University

Artificial Intelligence Beats Some Radiologists at Spotting Bleeds in the Brain

Dennis Thompson wrote . . . . . . . . .

Computer-driven artificial intelligence (AI) can help protect human brains from the damage wrought by stroke, a new report suggests.

A computer program trained to look for bleeding in the brain outperformed two of four certified radiologists, finding abnormalities in brain scans quickly and efficiently, the researchers reported.

“This AI can evaluate the whole head in one second,” said senior researcher Dr. Esther Yuh, an associate professor of radiology at the University of California, San Francisco. “We trained it to be very, very good at looking for the kind of tiny abnormalities that radiologists look for.”

Stroke doctors often say that “time is brain,” meaning that every second’s delay in treating a stroke results in more brain cells dying and the patient becoming further incapacitated.

Yuh and her colleagues hope that AI programmed to find trouble spots in a brain will be able to significantly cut down treatment time for stroke patients.

“Instead of having a delay of 20 to 30 minutes for a radiologist to turn around a CT scan for interpretation, the computer can read it in a second,” Yuh said.

Stroke is the fifth-leading cause of death in the United States, and is a leading cause of disability, according to the American Stroke Association.

There are two types of strokes: ones caused by burst blood vessels in the brain (hemorrhagic), and others that occur when a blood vessel becomes blocked (ischemic).

Yuh’s AI still needs to be tested in clinical trials and approved by the U.S. Food and Drug Administration, but other programs are already helping doctors speed up stroke treatment, said Dr. Christopher Kellner. He is director of the Intracerebral Hemorrhage Program at Mount Sinai, in New York City.

“We are already using AI-driven software to automatically inform us when certain CAT scan findings occur,” he said. “It’s already become, in just the last year, an essential part of our stroke work-up.”

An AI created by a company called Viz.ai is being used at Mount Sinai to detect blood clots that have caused a stroke by blocking the flow of blood to the brain, Kellner said.

Yuh and her team used a library of nearly 4,440 CT scans to train their AI to look for brain bleeding.

These scans are not easy to read, she said. They are low-contrast black-and-white images full of visual “noise.”

“It takes a lot of training to be able to read these — doctors train for years to be able to read these correctly,” Yuh said.

Her team trained its algorithm to the point that it could trace detailed outlines of abnormalities it found, demonstrating their location in a 3-D model of the brain being scanned.

They then tested the algorithm against four board-certified radiologists, using a series of 200 randomly selected head CT scans.

The AI slightly outperformed two radiologists, and slightly underperformed against the other two, Yuh said.

The AI found some small abnormalities that the experts missed. It also provided detailed information that doctors would need to determine the best treatment.

The computer program also provided this information with an acceptable level of false positives, Yuh said. That would minimize how much time doctors would need to spend reviewing its results.

Yuh suspects radiologists always will be needed to double-check the AI, but Kellner isn’t so sure.

“There will definitely be a point where there’s no human involved in the evaluation of the scans, and I think that’s not too far off, honestly,” he said. “I think, ultimately, a computer will be able to scan that faster and send out an alert faster than a human can.”

The new study was published in the Proceedings of the National Academy of Sciences.

Source: HealthDay


Today’s Comic

Study: Sunscreen Chemicals Enter Bloodstream at Potentially Unsafe Levels

Dennis Thompson wrote . . . . . . . . .

For years, you’ve been urged to slather on sunscreen before venturing outdoors. But new U.S. Food and Drug Administration data reveals chemicals in sunscreens are absorbed into the human body at levels high enough to raise concerns about potentially toxic effects.

Bloodstream levels of four sunscreen chemicals increased dramatically after test subjects applied spray, lotion and cream for four days as directed on the label, according to the report.

The levels far exceed the FDA-set threshold which require topical medications to undergo safety studies, said Dr. Kanade Shinkai, a dermatologist with the University of California, San Francisco School of Medicine.

“It’s not like they went a little bit over,” she said. “It’s really quite high, orders of magnitude higher than that.”

However, experts are quick to say you shouldn’t stop using sunscreen because of this study. At this point, the known risk of harm from the sun’s rays exceeds the potential risk posed by these chemicals.

“I am concerned that people are going to stop wearing sunscreen,” Shinkai said. “We know ultraviolet light from the sun has very deleterious effects on the skin. It causes photoaging. It causes sunburn. And, as such, it causes melanoma and [other] skin cancer.”

Dr. Michele Green, a dermatologist with Lenox Hill Hospital in New York City, agreed.

“I think it’s confusing,” Green said. “While it’s more than the FDA recommends for their toxicology, we really don’t know what that means in terms of human health. I would not want people to stop using sunscreen based on this one study.”

Possible effects on hormones

The sunscreen study was led by the FDA’s Dr. David Strauss, and appears May 6 in the prestigious Journal of the American Medical Association, one of the nation’s leading medical journals.

Most sunscreens on the shelf use chemicals such as oxybenzone, avobenzone and octocrylene to block harmful rays. These organic chemicals absorb ultraviolet radiation and convert it into a small amount of heat.

However, animal studies have raised concerns that the chemicals, oxybenzone in particular, might disrupt normal hormone patterns in people, the FDA researchers noted in their study.

“These molecules are chemical rings, essentially, and they absorb light,” said Shinkai, who co-wrote an editorial accompanying the study. “Chemical rings are also the fundamental basis for a lot of hormones, and chemical rings tend to enter cells.”

Oxybenzone has been found in human breast milk, amniotic fluid, urine and blood, the FDA researchers said.

For its study, the FDA randomly had 24 adults apply either a sunscreen spray, lotion or cream four times a day for four days. The participants applied the sunscreen to three-quarters of their body surface.

The study took place in a lab, and the agency drew 30 blood samples from each participant over a week to see whether the chemicals in the sunscreen got absorbed through the skin.

Levels of oxybenzone, avobenzone, octocrylene and ecamsule increased in the bloodstream after sunscreen use, researchers found.

“There is definitely reason for concern, because if you think about it, any medication you buy over the counter, you would expect that everything in there has been tested, it’s safe, it’s effective,” Shinkai said. ‘This has never been proven for sunscreen.”

More real-life data needed

But it was a very small-scale laboratory study that simply shows the need for more research, said Dr. Raman Madan, a dermatologist with Northwell Health’s Huntington Hospital in Huntington, N.Y.

“While this is a starting point, the relevance of this result is unknown,” Madan said. “There needs to be further studies done to show what this really means. While it could have real-world consequences, it could very well mean nothing.”

The study also differs from real life in that people applied the sunscreen while hanging about a lab, Shinkai said.

“They weren’t doing the things people typically do when they use sunscreen,” such as swimming or working in the yard, Shinkai said. Because of this, their exposure might differ from that of everyday people.

The Consumer Healthcare Products Association (CHPA), a group representing sunscreen makers, also said it’s far too soon for consumers to have doubts about these products.

“Sunscreen manufacturers, FDA, and dermatologists are aligned on the goal of protecting the public from the harmful effects of the sun,” the group said in a statement. “Sunscreens save lives.”

CHPA said the FDA is committed to learning more about the safety of chemicals within sunscreens, however, and the new data “is consistent with these efforts.”

Options are out there

The FDA has been tussling with sunscreen manufacturers over studies to test the safety of their products, said Shinkai.

The agency has set a November 2019 deadline for manufacturers to provide safety data on their sunscreens, including evaluations of systemic absorption, the risk of cancer from the chemicals, and their effect on reproductive health, Shinkai said in her editorial.

The publication of this study might be intended to put pressure on the sunscreen industry to meet the deadline, she said.

“The FDA is a regulatory agency. It’s not a testing agency. For them to perform a research study is highly unusual,” Shinkai said. “I think that’s an important thing that suggests how concerned they were about this issue, and maybe perhaps the frustration on their part.”

People who are concerned about the safety of chemical sunscreens can opt to use mineral sunscreens, Shinkai said.

Those sunscreens rely on zinc oxide and titanium dioxide to reflect sunlight from the skin, rather than absorbing it like chemical sunscreens.

“These we know are safe,” Shinkai said of mineral sunscreens. “This is something that is evidence-based.”

Source: HealthDays


Today’s Comic

MCH Levels in Blood Tests: What Do They Mean?

Jon Johnson wrote . . . . . .

To determine MCH levels in the blood, a doctor may order a CBC test.

MCH stands for mean corpuscular hemoglobin.

MCH levels refer to the average amount of hemoglobin found in the red blood cells in the body. Hemoglobin is a protein in the blood that allows red blood cells to deliver oxygen to the cells and tissues in the body.

Though they are very similar, MCH levels should not be confused with MCHC levels.

MCH levels are the average amount of hemoglobin that is in each red blood cell. MCHC levels are the average weight of that hemoglobin based on the volume of red blood cells. Both are a reflection of the health of the hemoglobin in the blood.

What is a CBC test?

A complete blood count test, or simply CBC test, is designed to give doctors a general overview of a person’s health. The test can help screen people for a variety of issues at once and may help diagnose conditions, such as bleeding disorders, infections, and anemia.

Regular health screenings will often include a CBC test. If the results come back normal, the person may not need another test until their next health screening. Doctors may order CBC tests if a person shows signs of any disorder that can affect the blood.

A CBC test can also be used to help monitor individuals who have blood disorders. Doctors will use them to track the progress of a treatment and determine how effective it is.

CBC tests examine all three types of cells in the blood. The test will give a total white, red, and platelet cell count.

CBC tests examine all three types of cells in the blood and will show the total number of white cells, red cells, and platelets in the blood.

MCH levels

Doctors will often order a CBC test to find out a person’s MCH levels. Normal MCH levels are around 27 to 33 picograms (pg) per cell in adults. These numbers may vary based on the machine used to carry out the test.

The numbers are different in young children. A person with a low MCH has concentrations at or below 26 pg per cell. A person with high MCH levels will have concentrations at 34 pg per cell or more.

Causes of low MCH levels

Different types of anemia can cause low MCH levels. For example, microcytic anemia occurs when the blood cells are too small and cannot take in as much hemoglobin as they should. This can be due to malnutrition or nutritional deficiencies.

Some medical conditions can also cause anemia, even if the person eats a balanced and healthful diet.

Low amounts of iron in the blood can also cause low MCH levels. The body uses iron to make hemoglobin. If the body runs out of iron, iron deficiency anemia can cause low MCH levels. This type of anemia may be more common in vegetarians or people with poor nutritional intake.

People with other conditions may also experience low MCH levels. Celiac disease can prevent the body from properly absorbing iron, which makes it very difficult to keep the iron levels where they need to be.

Likewise, people who have had types of gastric surgery may also not be able to absorb iron as well as they need to. Women with excessive menstruation may also become anemic, as they lose more iron in the menstrual blood than they can recover.

Low MCH levels can also appear in a body that is lacking key vitamins. People who do not get enough B vitamins such as folate and B12 may show low MCH concentrations on their tests. Because a lack of vitamins can also show high MCH levels, doctors may request further lab testing and interpretation to make a definitive diagnosis.

Symptoms of low MCH levels

At first, many people with low MCH levels do not experience symptoms at all. When low MCH numbers persist or fall too low, symptoms start to appear. Symptoms of low MCH include:

  • shortness of breath
  • loss of regular stamina
  • consistent tiredness
  • dizziness
  • weakness in the body

Low MCH numbers can also affect the skin. The skin may become pale or bruise very easily in someone with low MCH levels.

Anyone experiencing these symptoms should contact their doctor immediately.

Causes of high MCH levels

High MCH scores are commonly a sign of macrocytic anemia. This condition occurs when the blood cells are too big, which can be a result of not having enough vitamin B12 or folic acid in the body.

High MCH scores may also be the result of the following:

  • liver diseases
  • an overactive thyroid gland
  • drinking alcohol regularly
  • complications from certain cancers
  • complications from an infection
  • taking too many medications containing estrogen

Symptoms of high MCH levels

People experiencing a high MCH caused by macrocytic anemia may experience symptoms that follow a particular pattern. People may not notice symptoms at first, but they can gradually get worse over time. Symptoms of high MCH include:

  • tiredness
  • very pale skin
  • fast heartbeat
  • nails that are brittle and easily broken
  • brain fog or poor concentration
  • confusion and memory loss

People with macrocytic anemia may also experience digestive issues. They may not have an appetite, lose weight, and have regular diarrhea. A person experiencing any of these symptoms should talk to their doctor as soon as possible.

Treatment for MCH level imbalance

How doctors treat unbalanced MCH levels can vary with every case. Treatment largely depends on treating the cause of the imbalance.

Adding more vitamin B12 and folic acid to the diet can be a good way to address high MCH levels. It is best to get these from a varied and balanced diet, but supplements may also help keep these levels where they need to be.

Low MCH levels usually occur as a result of iron deficiency that has led to anemia. Doctors may recommend that individuals add more iron and vitamin B6 to their diet. Eating vitamin C and fiber, along with foods that contain iron, may also help increase the MCH levels.

People with an imbalance in their MCH levels should always discuss a treatment plan with their doctors before taking any supplement or making drastic changes to their diet.

Source: Medical News Today

High Blood Sugar May Boost Alzheimer’s Risk

Insulin resistance can inhibit signaling between brain cells and affect memory, study suggests.

High blood sugar associated with prediabetes may increase the risk for Alzheimer’s disease, a new study suggests.

Researchers found that insulin resistance — higher-than-normal levels of blood sugar that often precede type 2 diabetes — was related to poorer performance on memory tests taken by late-middle-age adults.

“The findings are interesting because people with diabetes are at increased risk for developing Alzheimer’s disease, but we are only now learning why they may be at increased risk,” said lead researcher Barbara Bendlin, an assistant professor of medicine at the University of Wisconsin-Madison.

The study results suggest that insulin resistance could increase the risk for Alzheimer’s disease by altering the way the brain uses sugar (glucose), which is its primary fuel, she said.

However, “by altering insulin resistance in midlife, it may be possible to reduce future risk of Alzheimer’s disease,” Bendlin said. Medications and a healthy lifestyle are possible ways to do that, she said.

According to the American Diabetes Association, 29.1 million Americans have diabetes, and more than half of adults older than 64 have prediabetes. Poor diet, obesity and sedentary lifestyles are associated with insulin resistance, Bendlin noted.

“Healthier lifestyles may contribute to healthier brain aging by reducing insulin resistance,” Bendlin said.

One expert cautioned that having prediabetes, or insulin resistance, doesn’t mean you’re doomed to develop Alzheimer’s, the most common form of dementia.

This study shows that insulin resistance may make mental functioning worse and may be linked to reduced use of insulin in areas of the brain associated with Alzheimer’s disease, but this does not mean that insulin resistance leads to Alzheimer’s, said Dr. Luca Giliberto, an investigator at the Litwin-Zucker Research Center for the Study of Alzheimer’s Disease at the Feinstein Institute for Medical Research in Manhasset, N.Y.

“We do not know what causes Alzheimer’s disease,” said Giliberto, who was not involved in the study. “We don’t know if lowering blood sugar will prevent Alzheimer’s.”

For the study, Bendlin’s team gave memory tests to 150 adults with no mental impairments, at average age of 61. The researchers also measured insulin resistance and had the participants undergo a PET brain scan.

More than two-thirds of the participants had a parent who suffered from Alzheimer’s, about 40 percent had a gene mutation associated with increased Alzheimer’s risk and roughly 5 percent had type 2 diabetes, according to the study.

The researchers found insulin resistance was associated with poorer processing of sugar throughout the brain. Worse performance in immediate memory was linked to lower sugar metabolism in the left medial temporal lobe, the authors said.

The report was published online in JAMA Neurology.

Dr. Sam Gandy, director of the Center for Cognitive Health at Mount Sinai Hospital in New York City, said it appears there may be a difference “between the dementia related to full-blown diabetes, which seems to be primarily dementia caused by hardening of the arteries in the brain, and the mental impact of insulin resistance, which some investigators believe is associated with Alzheimer’s.”

In the brain, insulin helps transmit messages between cells, he noted.

“We have long thought of Alzheimer’s as a disease of defective brain signaling,” said Gandy, who had no role in the study. “Conceivably, there is also a disease of defective insulin signaling, which this paper would support.”

If that’s true, Gandy added, “then efforts at sensitizing the brain to insulin, using drugs such as pioglitazone [Actos, a diabetes drug], would make sense and might well lead to slowing of degeneration.”

Giliberto recommended healthy living as the best way to keep blood sugar under control and perhaps protect mental health.

“Increasing our health by reducing fats, reducing sugar, improving insulin resistance may reduce the risk of other factors, such as diabetes, on the susceptibility to Alzheimer’s disease and mental decline,” Giliberto said

Source: U.S. Department of Health and Human Services