Skip to content

Author: Sima

Published on

From Science Daily:

High protein diets lead to lower blood pressure, study finds

Adults who consume a high-protein diet may be at a lower risk for developing high blood pressure, concludes a study that found participants consuming the highest amount of protein -- an average of 100 g protein/day -- had a 40 percent lower risk of having high blood pressure compared to the lowest intake level.

One of three U.S. adults has hypertension and 78.6 million are clinically obese, a risk factor for the development of hypertension. Because of the strain that it puts on blood vessel walls, HBP is one of the most common risk factors of stroke and an accelerator of multiple forms of heart disease, especially when paired with excess body weight.

The researchers analyzed protein intakes of healthy participants from the Framingham Offspring Study and followed them for development of high blood pressure over an 11-year period. They found that adults who consumed more protein, whether from animal or plant sources, had statistically significantly lower systolic blood pressure and diastolic blood pressure levels after four years of follow-up. In general, these beneficial effects were evident for both overweight (BMI ≥25 kg/m2) and normal weight (BMI <25 kg/m2) individuals. They also found that consuming more dietary protein also was associated with lower long-term risks for HBP. When the diet also was characterized by higher intakes of fiber, higher protein intakes led to 40-60 percent reductions in risk of HBP.

Published on

Two studies about blood pressure and how it can be easily changed without medications. From Science Daily:

Small weight gain can raise blood pressure in healthy adults

Gaining a few pounds can increase blood pressure in healthy adults, researchers report. Increased fat inside the abdomen led to even larger increases in blood pressure, their study results showed. Many people understand the health dangers of large amounts of extra body weight, but researchers in this study wanted to see the impact of a small weight gain of about five to 11 pounds.

At the beginning of the eight-week study, a 24-hour monitor tested the blood pressure of 16 normal weight people. Their results were compared to 10 normal weight, healthy people who maintained the same weight over the eight weeks. Researchers found: -Those who gained weight had a systolic blood pressure (top number) increase from an average 114 mm Hg to an average 118 mm Hg. -Those who gained more weight inside their abdomen had a greater blood pressure increase. -A five to 11 pound weight gain didn't change cholesterol, insulin or blood sugar levels. The study was conducted in healthy people ages 18-48. 

From Science Daily:

Restricting calories may improve sleep apnea, blood pressure in obese people

Restricting calories may improve sleep apnea and reduce blood pressure in obese adults. Those who restricted their calories had higher levels of oxygen in their blood and a greater reduction in body weight, a study has demonstrated.

 "Losing weight was most likely the key to all the benefits observed in the calorie-restricted group. A greater reduction in systolic blood pressure can be explained, at least partially, by the reduction in body weight that was associated with reduction in obstructive sleep apnea severity and sympathetic nervous system activity." Systolic blood pressure is the top number in a blood pressure reading, which measures the force of the blood in the arteries when the heart is contracted.

Published on

Amazing possibilities, but more studies needed. The key finding: A diversity of the bacterial community in the gut is good, and perhaps can be altered through diet, and so perhaps alter the future risk of developing breast cancer.From Science Daily:

Diverse gut bacteria associated with favorable ratio of estrogen metabolites

Postmenopausal women with diverse gut bacteria exhibit a more favorable ratio of estrogen metabolites, which is associated with reduced risk for breast cancer, compared to women with less microbial variation, according to a new study.

Since the 1970s, it has been known that in addition to supporting digestion, the intestinal bacteria that make up the gut microbiome influence how women's bodies process estrogen, the primary female sex hormone. The colonies of bacteria determine whether estrogen and the fragments left behind after the hormone is processed continue circulating through the body or are expelled through urine and feces. Previous studies have shown that levels of estrogen and estrogen metabolites circulating in the body are associated with risk of developing postmenopausal breast cancer.

"In women who had more diverse communities of gut bacteria, higher levels of estrogen fragments were left after the body metabolized the hormone, compared to women with less diverse intestinal bacteria," said one of the study's authors, James Goedert, MD, of the National Institutes of Health's National Cancer Institute (NCI) in Bethesda, MD. "This pattern suggests that these women may have a lower risk of developing breast cancer."

As part of the cross-sectional study, researchers analyzed fecal and urine samples from 60 postmenopausal women enrolled in Kaiser Permanente Colorado. .

"Our findings suggest a relationship between the diversity of the bacterial community in the gut, which theoretically can be altered with changes in diet or some medications, and future risk of developing breast cancer," Goedert said. 

Published on

Good news! From Science Daily:

Taking short walking breaks found to reverse negative effects of prolonged sitting

Three easy -- one could even say slow -- 5-minute walks can reverse harm caused to leg arteries during three hours of prolonged sitting, researchers report. Sitting for long periods of time is associated with risk factors such as higher cholesterol levels and greater waist circumference that can lead to cardiovascular and metabolic disease. When people sit, slack muscles do not contract to effectively pump blood to the heart. Blood can pool in the legs and affect the endothelial function of arteries, or the ability of blood vessels to expand from increased blood flow.

The researchers were able to demonstrate that during a three-hour period, the flow-mediated dilation, or the expansion of the arteries as a result of increased blood flow, of the main artery in the legs was impaired by as much as 50 percent after just one hour. The study participants who walked for 5 minutes each hour of sitting saw their arterial function stay the same -- it did not drop throughout the three-hour period. Thosar says it is likely that the increase in muscle activity and blood flow accounts for this.

Published on

An opinion piece from Dr. David Johnson, Prof. of Medicine and Chief of Gastroenterology at Eastern Medical School in Norfolk, Virginia but an interesting one that points out the limitations of current probiotic knowledge and that we shouldn't blindly take probiotics (with only a few bacteria strains) after antibiotic use thinking that they're all good, all the time. I'm including this article to show what many medical professionals think about probiotic use and why.

He discusses 2 large studies, but unfortunately both studies only looked at hospitalized patients - and the large PLACIDE study looked at over-65 year old patients. And in the second large study he discusses the benefits of the antibiotic metronidazole.

I agree with his need for caution and the need for more large studies, but I wish he had discussed children, people NOT hospitalized, people who just had a round of antibiotics without life threatening complications, and not dismissed small studies. Hospitalized vs non-hospitalized people are very, very different groups. Small studies are finding benefits of various bacteria, but yes, the research is in its infancy, especially what are "normal microbial communities" in the gut and in other parts of the body. He does not discuss fecal transplants of entire microbial communities for C. difficile and their over 90% success rate. Dr. S. Lynch has theorized that some bacteria act as "keystone species" that could help repopulate a biome after an insult (such as antibiotics). From Medscape:

Probiotics: Help or Harm in Antibiotic-Associated Diarrhea?

Today I want to discuss the issue of probiotics, and whether probiotics are doing an element of benefit or an element of harm. With access to over-the-counter products, use of probiotics has dramatically increased. Physicians recommend probiotics routinely to patients when they are taking antibiotics to prevent antibiotic-associated diarrhea. I would like to take a time-out and reevaluate what we are doing for these patients.

Not infrequently, antibiotics are associated with Clostridium difficile infections, which occur in up to one third of patients with antibiotic-associated diarrhea.

In 2012, highly publicized meta-analyses were published in JAMA [1] and Annals of Internal Medicine. [2]These studies, and a Cochrane review,[3] suggest that not only can probiotics prevent or diminish antibiotic-associated diarrhea, but probiotics may also be helpful in avoiding C difficile infection.

Enter the most recent study, which is called the PLACIDE study, from the United Kingdom[4] It involved 5 hospitals, 68 different medical and surgical units, and more than 17,000 patients aged 65 years or older. All patients were hospitalized and taking an antibiotic.

These patients were randomly assigned, if they met eligibility criteria, to receive either a microbial preparation (which is the term they used for "probiotic") or an identical placebo. The microbial preparation had 2 strains of Lactobacillus and 2 strains of bifidobacteria, which patients received for 21 days.... Even with evaluation for intention to treat, there was no difference in the outcomes for C difficile infection or antibiotic-associated diarrhea between the microbial preparation (probiotic) and placebo group. Of interest, there was an increase in flatus in the microbial preparation group, and patients with C difficile diarrhea who received the microbial preparation reported a 3-fold increase in bloating. 

Although intended to restore good health, we are seeing a dysbiosis. We have disrupted the microflora in the gut, and are trying to jam it back with strains of bacteria that we think are good bacteria, and it may not be the correct answer. We don't know the right answer. When you alter the microflora, you change some of the metabolism of carbohydrates, bile salts, and complex sugars. We are not clear whether jamming the gut with another strain of bacteria is going to be of benefit.

I want to posit an element of potential harm, and not rush in to recommend probiotics routinely in patients to whom you prescribe antibiotics. I would also caution you not to use probiotics in patients in the intensive care unit, or in any patient with an indwelling prosthesis, particularly an intravascular prosthesis. 

Published on

Reading this is almost guaranteed to make you want to wash your hands. From Science Daily:

How quickly viruses can contaminate buildings -- from just a single doorknob

Using tracer viruses, researchers found that contamination of just a single doorknob or table top results in the spread of viruses throughout office buildings, hotels, and health care facilities. Within 2 to 4 hours, the virus could be detected on 40 to 60 percent of workers and visitors in the facilities and commonly touched objects.

There is a simple solution, though, says Charles Gerba of the University of Arizona, Tucson, who presented the study. "Using disinfecting wipes containing quaternary ammonium compounds (QUATS) registered by EPA as effective against viruses like norovirus and flu, along with hand hygiene, reduced virus spread by 80 to 99 percent," he says.

Norovirus is the most common cause of acute gastroenteritis in the United States, according to the Centers for Disease Control and Prevention (CDC). Each year, it causes an estimated 19-21 million illnesses and contributes to 56,000-71,000 hospitalizations and 570-800 deaths. Touching surfaces or objects contaminated with norovirus then putting your fingers in your mouth is a common source of infection.

In the study, Gerba and his colleagues used bacteriophage MS-2 as a surrogate for the human norovirus, as it is similar in shape, size and resistance to disinfectants. The phage was placed on 1 to 2 commonly touched surfaces (door knob or table top) at the beginning of the day in office buildings, conference room and a health care facility. After various periods of time (2 to 8 hours) they sampled 60 to 100 fomites, surfaces capable of carrying infectious organisms (light switches, bed rails, table tops, countertops, push buttons, coffee pots handles, sink tap handles, door knobs, phones and computer equipment), for the phages.

"Within 2 to 4 hours between 40 to 60% of the fomites sampled were contaminated with virus," says Gerba.

In the intervention phase cleaning personal and employees were provided with QUATS disinfectant containing wipes and instructed on proper use (use of at least once daily). The number of fomites on which virus was detected was reduced by 80% or greater and the concentration of virus reduced by 99% or more.

Published on

A banana a day keeps the doctor away? A recent large study found that older women who eat foods with higher amounts of potassium may be at lower risk of stroke and death, when compared to women who eat fewer potassium rich foods. The association was with ischemic stroke (caused by clot) and not hemorrhagic stroke.

Some good food sources of potassium are: bananas, cantaloupe, grapefruit, oranges, white and sweet potatoes, and white beans. The U.S. Department of Agriculture recommends that women eat at least 4700 mg of potassium daily, but in this study the average intake of the postmenopausal women was 2611 mg per day.

This study followed  90,137 postmenopausal women (aged 50 to 79 years at baseline), and followed them an average of 11 years. Now this same study needs to be done with men and women of all ages. From Science Daily:

Potassium-rich foods cut stroke, death risks among older women

Older women who eat foods with higher amounts of potassium may be at lower risk of stroke and death than women who consume less potassium-rich foods. The health benefits from potassium-rich foods are greater among older women who do not have high blood pressure. Most older American women do not eat the recommended amounts of potassium from foods.

"Our findings give women another reason to eat their fruits and vegetables. Fruits and vegetables are good sources of potassium, and potassium not only lowers postmenopausal women's risk of stroke, but also death."

Researchers studied 90,137 postmenopausal women, ages 50 to 79, for an average 11 years. They looked at how much potassium the women consumed, as well as if they had strokes, including ischemic and hemorrhagic strokes, or died during the study period. Women in the study were stroke-free at the start and their average dietary potassium intake was 2,611 mg/day. Results of this study are based on potassium from food, not supplements.

The researchers found: -Women who ate the most potassium were 12 percent less likely to suffer stroke in general and 16 percent less likely to suffer an ischemic stroke than women who ate the least. -Women who ate the most potassium were 10 percent less likely to die than those who ate the least. They also said there was no evidence of any association between potassium intake and hemorrhagic stroke, which could be related to the low number of hemorrhagic strokes in the study.

The U.S. Department of Agriculture recommends that women eat at least 4,700 mg of potassium daily. "Only 2.8 percent of women in our study met or exceeded this level. "Our findings suggest that women need to eat more potassium-rich foods. You won't find high potassium in junk food. Some foods high in potassium include white and sweet potatoes, bananas and white beans."

Published on

Another interesting study that makes you think about our microbiome. From NPR:

Stinky T-Shirt? Bacteria Love Polyester In A Special Way

Anyone with a drawerful of T-shirts knows that the synthetic ones can get sour after just a brief jog, while old-school cotton T-shirts remain relatively stink-free all day. And now science explains why. The bacteria that flourish on a sweaty polyester T-shirt are different from those that grow on cotton, researchers at the University of Ghent in Belgium found. Polyester makes a happy home for Micrococcus bacteria, while Staphylococcus, a common armpit denizen, was found on both poly and cotton.

Microbes love the cozy warmth of the human armpit; it's like a trip to the tropics without ever having to leave home. And it's crowded in there. Those microbes eat compounds in sweat and generate odors, which support a flourishing deodorant industry. 

The scientists asked 26 volunteers to take a spinning class while wearing shirts made of cotton, poly or blends. The shirts were then incubated for a day, and the microbes extracted and DNA fingerprinted. Volunteers also had their armpits swabbed. 

It turns out the bugs on the shirts are different from the bugs in the pits. While Corynebacterium is thought to be the main cause of armpit body odor, there was no Corynebacterium on the clothes. Instead, Staphylococcus flourished on cotton and poly, and Micrococcus, bacteria also known for making malodor, loved polyester.

He's also trying to help people with excessive body odor by giving them armpit bacteria transplants. "We have done transplants with about 15 people, and most of them have been successful," Callewaert, a Ph.D. student in applied biological sciences at the University of Ghent, tells Shots. "All have had an effect short term, but the bad odor comes back after a few months for some people."

Manufacturers have tried to make polyester fabric less hospitable to bacteria by impregnating it with antimicrobials like silver nanoparticles or triclosan. Both products have been criticized as having potentially negative impacts on the environment, and there are few data on how they might affect the wearer. Callewaert thinks the ultimate solution will be something more organic — supplant bad bugs with good ones. 

Published on

The great effects (especially for hemorrhagic stroke) were found in people eating just 1 1/2 portions of fresh fruit daily. The amazing part is that 6.3% admitted to never consuming fruit. From Science Daily:

Fruit consumption cuts cardiovascular disease risk by up to 40 percent

Daily fruit consumption cuts the risk of cardiovascular disease (CVD) by up to 40 percent, according to research. The findings from the seven-year follow-up study of nearly a half million people in the China Kadoorie Biobank found that the more fruit people ate, the more their risk of CVD declined.

Dr Du said: "CVD, including ischaemic heart disease (IHD) and stroke, is the leading cause of death worldwide. Improving diet and lifestyle is critical for CVD risk reduction in the general population but the large majority of this evidence has come from western countries and hardly any from China."

The current study included 451 681 participants with no history of CVD and not on anti-hypertensive treatment at baseline from the China Kadoorie Biobank(1) conducted in 10 different areas of China, 5 rural and 5 urban. Habitual consumption of fruit was recorded at baseline according to five categories: never, monthly, 1-3 days per week, 4-6 days per week, daily.

Over the seven year follow up period there were 19 300 cases of IHD and 19 689 strokes (14 688 ischaemic and 3562 haemorrhagic). Some 18% of participants consumed fruit daily and 6.3% never consumed fruit. The average amount of fruit eaten by the daily consumers was 1.5 portions (~150g).

The researchers found that compared to people who never ate fruit, those who ate fruit daily cut their CVD risks by 25-40% (around 15% for IHD, around 25% for ischaemic stroke and 40% for haemorrhagic stroke). There was a dose response relationship between the frequency of fruit consumption and the risk of CVD.

Dr Du said: "Our data clearly shows that eating fresh fruit can reduce the risk of cardiovascular disease, including ischaemic heart disease and stroke (particularly haemorrhagic stroke). And not only that, the more fruit you eat the more your CVD risk goes down. It does suggest that eating more fruit is beneficial compared to less or no fruit."

The researchers also found that people who consumed fruit more often had significantly lower blood pressure (BP). Eating fruit daily was associated with 3.4/4.1 mmHg lower systolic/diastolic BP compared to those who never ate fruit. 

In a separate analysis, the researchers examined the association of fruit consumption with total mortality and CV mortality in more than 61,000 patients from the China Kadoorie Biobank who had CVD or hypertension at baseline. They found that compared to those who never ate fruit, daily consumers of fruit cut their overall risk of death by 32%. They also reduced their risks of dying from IHD by 27% and from stroke by around 40%.

Published on

Unfortunately the first article doesn't list the herbal supplements causing liver problems, but the earlier NY Times article mentions green tea extracts as one of them. From Science Daily:

Liver injury caused by herbals, dietary supplements rises in study population

Liver injury caused by herbals and dietary supplements increased from 7% to 20% in a U.S. study group over a ten-year period, research shows. According to the study, liver injury caused by non-bodybuilding supplements is most severe, occurring more often in middle-aged women and more frequently resulting in death or the need for transplantation than liver injury from bodybuilding supplements or conventional medications.

In response to the need for research in this area, the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK) supported the establishment of the Drug-Induced Liver Injury Network (DILIN) in 2003 to track cases of liver injury caused by medications (excluding acetaminophen (Tylenol®)), herbals, and dietary supplements. Herbals and dietary supplements were identified as the second most common cause of liver injury in the first DILIN report.

The present study examines hepatotoxicity due to supplements compared to medications, enrolling 839 patients with liver injury from 8 U.S. DILIN referral centers between 2004 and 2013 While bodybuilding supplements caused prolonged jaundice (median 91 days) in young men, no fatalities or liver transplantations occurred. Death or liver transplantation occurred more frequently among cases of injury from non-bodybuilding supplements, 13%, than from conventional medications, 3%. Liver injury from non-bodybuilding supplements was more common in middle aged women.

From NY Times (Dec. 2013):

Spike in Harm to Liver Is Tied to Dietary Aids

But the supplement business is largely unregulated. ... But a federal law enacted in 1994, the Dietary Supplement Health and Education Act, prevents the Food and Drug Administration from approving or evaluating most supplements before they are sold. Usually the agency must wait until consumers are harmed before officials can remove products from stores. Because the supplement industry operates on the honor system, studies show, the market has been flooded with products that are adulterated, mislabeled or packaged in dosages that have not been studied for safety.

The new research found that many of the products implicated in liver injuries were bodybuilding supplements spiked with unlisted steroids,and herbal pills and powders promising to increase energy and help consumers lose weight.

 More popular supplements like vitamins, minerals, probiotics and fish oil had not been linked to “patterns of adverse effects,” he said.

Since 2008, the F.D.A. has been taking action against companies whose supplements are found to contain prescription drugs and controlled substances, said Daniel Fabricant, the director of the division of dietary supplement programs in the agency’s Center for Food Safety and Applied Nutrition. For example, the agency recently took steps to remove one “fat burning” product from shelves, OxyElite Pro, that was linked to one death and dozens of cases of hepatitis and liver injury in Hawaii and other states.

A second trend emerged when Dr. Navarro and his colleagues studied 85 patients with liver injuries linked to herbal pills and powders. Two-thirds were middle-aged women, on average 48 years old, who often used the supplements to lose weight or increase energy. Nearly a dozen of those patients required liver transplants, and three died

But one product that patients used frequently was green tea extract, which contains catechins, a group of potent antioxidants that reputedly increase metabolism. The extracts are often marketed as fat burners, and catechins are often added to weight-loss products and energy boosters. Most green tea pills are highly concentrated, containing many times the amount of catechins found in a single cup of green tea, Dr. Bonkovsky said. In high doses, catechins can be toxic to the liver, he said, and a small percentage of people appear to be particularly susceptible.