Dairy products a good dietary source of some types of vitamin K

Vitamin K, with its multiple forms, is among the lesser known nutrients. Now, new research from scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University sheds new light on the vitamin and its significant presence in some dairy products available in the United States.

In the study, published June 1 in Current Developments in Nutrition, researchers quantified the activity of two natural forms of vitamin K in dairy products of various fat contents and found that common U.S. dairy items, including milks, yogurts and cheeses, contain appreciable amounts of multiple forms of vitamin K. Vitamin concentrations varied by fat content.

Vitamin K, which helps the blood to clot, is most commonly thought to come from leafy greens such as spinach, kale and broccoli. In fact, dietary sources of vitamin K are found in two natural forms: phylloquinone (PK, or vitamin K1), which is widely distributed through plant-based foods, and menaquinones (MK, or vitamin K2), which appear to be primarily in animal products and fermented foods. Almost all MK forms are also produced by bacteria in the human gut. Not much is known about MK amounts in U.S. dairy products.

"Dairy foods contain minute amounts of PK, the best known of the vitamin K forms, and so dairy is not commonly considered a rich dietary source for this nutrient. However, when it comes to MK forms, we found that dairy items already found in many peoples' refrigerators are indeed a good dietary source for vitamin K," said Xueyan Fu, Ph.D., first and corresponding author and scientist in the Vitamin K Laboratory at the USDA HNRCA.

Guidelines for adequate vitamin K intake are based only on PK intake without consideration for other forms of vitamin K. MK differ from PK in structure in that they are compounds with different numbers of isoprenoid units in the side chain, designated as MK4 through MK13. Which forms of MK are present reflects which bacteria might be in the dairy products. Lactic acid bacteria, for example, are widely used in dairy and fermented foods.

To understand the presence of MK and PK in dairy products, the researchers used 50 nationally collected dairy samples provided by the USDA Nutrient Data Laboratory and 148 dairy samples purchased in 2016 from Boston area retail outlets. The products were divided into categories based on dairy types and fat content: milks, yogurts, Greek yogurts, kefirs, creams, processed cheeses, fresh cheeses, blue cheeses, soft cheeses, semi-soft cheeses, and hard cheeses. The effect of fat content on total vitamin K in all forms was compared using a two-sample T-test. The vitamin K content of cream products, for which the researchers had a smaller sample size, was analyzed using a general linear model, with heavy cream as the reference group.

Among the findings:

All full-fat dairy products contained appreciable amounts of MK, primarily in the forms of MK9, MK10 and MK11. Combined, these three forms of MK accounted for approximately 90 percent of total vitamin K present in the foods tested.

• In cheeses, the total vitamin K content varied by type, with soft cheese having the highest concentration, followed by blue cheese, semi-soft cheese, and hard cheese. All of the cheeses contained MK9, MK10 and MK11, and modest amounts of PK, MK4, MK7, MK8 and MK12. Little MK5, MK6 or MK13 was measured in the majority of cheeses.
• In milk, the vitamin K concentrations varied by fat content; both total vitamin K and individual MK concentrations in full-fat milk were significantly higher than in 2 percent milk. PK was only detected in full-fat milk. Only MK9-11 were detected in milk.
• In yogurts, full-fat regular and Greek yogurts exhibited similar vitamin K concentrations as in full-fat milk; neither MK nor PK were detected in fat-free yogurt.

"Estimated intakes of PK and MK in dairy-producing countries in Western Europe suggest that between 10 and 25 percent of total vitamin K intake are provided by MK, and primarily from dairy sources. Additionally, observational data from Europe suggest that MK from dairy products have a stronger association with heart health benefits compared with PK intakes. This data from other countries highlights the need to analyze MK in commonly consumed foods in the U.S.," said Sarah L. Booth, Ph.D., last author on the study. Booth is senior scientist and director of the Vitamin K Laboratory at the USDA HNRCA, interim director of the USDA HNRCA, and professor at the Friedman School of Nutrition Science and Policy at Tufts University.

Additional research is needed to determine the role of microbes used in production of dairy products, and their impact on MK content. The researchers also say there is a need to determine the relative bioavailability of all MK forms given their abundance in the U.S. diet.

The researchers acknowledge limitations of the study, including the reliance on food labels for fat content instead of direct measurement of fat content. Additionally, whereas the dairy product samples obtained from the USDA Nutrient Data Laboratory were geographically representative of the U.S. diet, those purchased in the Boston region were not. However, items purchased locally were selected from retail outlets with national representation.

Olive oil nutrient linked to processes that prevent cancer in brain

A compound found in olive oil may help to prevent cancer developing in the brain, a study shows.

Research into oleic acid -- the primary ingredient in olive oil -- has shown how it can help prevent cancer-causing genes from functioning in cells.

The oily substance -- one of a group of nutrients known as fatty acids -- stimulates the production of a cell molecule whose function is to prevent cancer-causing proteins from forming.

The study team says it is too soon to say whether dietary consumption of olive oil may help prevent brain cancer. Their findings, however, point towards possible therapies based on the oil to prevent brain cancer from occurring.

Scientists from the University of Edinburgh analysed the effect of oleic acid on a cell molecule, known as miR-7, which is active in the brain and is known to suppress the formation of tumours.

They found that oleic acid prevents a cell protein, known as MSI2, from stopping production of miR-7. In this way, the olive oil component supports the production of miR-7, which helps prevent tumours from forming.

Researchers made their discoveries in tests on human cell extracts and in living cells in the lab.

The study, published in the Journal of Molecular Biology, was funded by the Medical Research Council and the Wellcome Trust.

Dr Gracjan Michlewski of the University of Edinburgh's School of Biological Sciences, who led the study, said: "While we cannot yet say that olive oil in the diet helps prevent brain cancer, our findings do suggest that oleic acid can support the production of tumour-suppressing molecules in cells grown in the lab. Further studies could help determine the role that olive oil might have in brain health."

Meals later at night can cause weight gain and impair fat metabolism

New findings suggest eating late at night could be more dangerous than you think. Compared to eating earlier in the day, prolonged delayed eating can increase weight, insulin and cholesterol levels, and negatively affect fat metabolism, and hormonal markers implicated in heart disease, diabetes and other health problems, according to results from researchers at the Perelman School of Medicine at the University of Pennsylvania.

The findings (abstract #0064) offer the first experimental evidence on the metabolic consequences of consistent delayed eating compared to daytime eating, and will be presented at SLEEP 2017, the 31st Annual Meeting of the Associated Professional Sleep Societies LLC (APSS), on Sunday, June 4, as an oral presentation at 1:30-1:45 p.m. in room 210 and as a poster presentation from 5 p.m. to 7 p.m.

"We know from our sleep loss studies that when you're sleep deprived, it negatively affects weight and metabolism in part due to late-night eating, but now these early findings, which control for sleep, give a more comprehensive picture of the benefits of eating earlier in the day," said Namni Goel, PhD, a research associate professor of psychology in Psychiatry in the division of Sleep and Chronobiology, and lead author of the ongoing study. "Eating later can promote a negative profile of weight, energy, and hormone markers--such as higher glucose and insulin, which are implicated in diabetes, and cholesterol and triglycerides, which are linked with cardiovascular problems and other health conditions."

In the study, nine healthy weight adults underwent two conditions, one of daytime eating (i.e., three meals and two snacks between 8 a.m. and 7 p.m.) for eight weeks and another of delayed eating (i.e., three meals and two snacks eating from noon to 11 p.m.) for eight weeks. There was a two-week washout period between conditions to make sure there was no carry over effect. The sleep period was held constant, between 11 p.m. to 9 a.m.

Participants visited Penn's Center for Human Phenomic Science to get metabolic measures and blood drawn at the beginning, after the first eating condition, after the two-week washout, and after the second eating condition. This allowed the team to measure changes in weight, metabolism and energy used, and made sure the two week washout allowed all measures to return to baseline before the next condition.

The team found that when participants ate later, compared to the daytime condition, weight increased. Respiratory quotient, i.e. the ratio of carbon dioxide produced by the body to oxygen consumed by the body that indicates which macronutrients are being metabolized, also rose during the delayed eating condition, indicating later eating led to metabolizing fewer lipids and more carbs. The researchers also found that a series of other measures reflecting negative metabolic profiles increased in the delayed condition, including insulin, fasting glucose, cholesterol, and triglyceride levels.

Conducting a 24-hour hormonal profile, they also found that in during daytime eating condition, the hormone ghrelin, which stimulates appetite, peaked earlier in the daytime, while leptin, which keeps you satiated, peaked later, suggesting that the participants received cues to eat earlier, and eating earlier likely helped them to stay satiated longer. This suggests that eating earlier may help prevent overeating in the evening and at night. As sleep-wake cycles were constant, melatonin levels remained constant in both groups.

"While lifestyle change is never easy, these findings suggest that eating earlier in the day may be worth the effort to help prevent these detrimental chronic health effects," said Kelly Allison, PhD, an associate professor of psychology in Psychiatry and director of the Center for Weight and Eating Disorders, and senior author on the study. "We have an extensive knowledge of how overeating affects health and body weight, but now we have a better understanding of how our body processes foods at different times of day over a long period of time."

Similar yet much shorter previous studies have suggested similar results, but this is the first long-term study looking at the timing of eating patterns that also controlled for sleep-wake cycles, exercise, macronutrient intake, etc. to pinpoint the effects of prolonged eating at different times of day.

For older adults, antibiotics may not be appropriate treatment for some UTIs

In a new research paper published in the Journal of the American Geriatrics Society, Thomas E. Finucane, MD, of the Johns Hopkins Geriatrics Center at Johns Hopkins in Baltimore, suggests that prescribing antibiotics for urinary tract infections (or "UTIs") may often be avoided among older adults.

Here's why:

• "UTI" is a vague, overused diagnosis that may be applied to older adults who have no symptoms but may have bacteria in the urine and also may be experiencing confusion, falls, or other vague signs (including changes in the odor or color of urine). In most cases, antibiotics do not benefit these older people.
• Researchers are coming to a new understanding about the kinds of bacteria, viruses, and other microorganisms that live in the human body naturally. We now know that everyone's urine contains bacteria and viruses, for example. We also know that these microorganisms are usually helpful to overall well-being.
• In some cases, antibiotic treatment can be harmful, especially for older adults.

Some groups of people do still benefit from antibiotic treatment of UTIs. These individual include:

• People who are sick enough to require urgent antibiotic treatment regardless of findings in the urine.
• People with invasive bacterial diseases, especially kidney infections.
• Pregnant women and people about to have bladder or urinary tract surgery.

In his paper, Dr. Finucane says that microbiome studies--which examine the benefits and harms cause by the billions of organisms that naturally live in the human body--suggest that UTI treatment with antibiotics actually may be more harmful than we previously thought. If you think you have a UTI, or if you're currently using an antibiotic to treat a UTI, it's important to speak with a healthcare professional first before changing your care plan. Your doctor, nurse, or other provider can work with you to find a treatment plan that's best for you.

Bisphosphonates may not prevent fractures in older women

Osteoporosis is a disease that causes thinning of the bones, loss of bone density, and increasingly fragile bones. This puts people at higher risk for bone fractures. Risk for the disease increases as we age. In fact, 50% of women over the age of 50 will experience a bone facture due to osteoporosis.

By 2020, an estimated 61 million American adults will have low bone mineral density. A group of medications known as "bisphosphonates" are sometimes used to treat osteoporosis. These medications increase bone mineral density, which strengthens bones and is thought to make them less likely to fracture. Studies have shown that the risk for bone fractures lessens when women with low bone mineral density take these medications for between 1 and 4 years. However, little is known about whether taking bisphosphonates for longer periods of time has the same effect.

Recently, a team of researchers examined whether older women taking bisphosphonates for 10-13 years had fewer bone fractures than older women with similar fracture risks who took these medicines only briefly. Their study was published in the Journal of the American Geriatrics Society.The research team examined data from the Women's Health Initiative study, a large study that began in 1993 to develop ways to reduce heart disease, cancer, and fractures in women after menopause. The researchers looked at information from 5,120 women within the study. These women were bisphosphonate users with a high risk for bone fractures.

More than 95% of participants in the study were over age 70, with an average age of about 80. The length of time the women had taken bisphosphonates when the study started was as follows:

• 13% for 2 years
• 34% for 3-5 years
• 20% for 6-9 years
• 33% for 10-13 years

The researchers followed the women in the study for nearly 4 years. They discovered that women who took bisphosphonates for 10-13 years had higher fracture rates, compared with women who took the medication for 2 years. Taking bisphosphonates for 3-9 years was not linked to a higher fracture risk.

"Our study and several others have found higher risk of fractures among very long-term bisphosphonate users, compared with short-term users. However, the ideal length of bisphosphonate use has not yet been studied in randomized clinical trials, which are considered the gold standard of research studies. Therefore, long-term bisphosphonate users should see their healthcare providers regularly to decide how long to continue bisphosphonate therapy in their individual cases," stated Rebecca L. Drieling, MPH, an author of the study.

Health benefits from consuming mangos

Studies on mango consumption have found potential health benefits associated with the superfruit including improved blood pressure, blood sugar control, and gut health. The research, conducted by of the Department of Nutrition and Food Science at Texas A&M University and the Department of Nutritional Sciences at Oklahoma State University, was presented during the 2017 Experimental Biology conference in Chicago.

Chuo Fang, Ph.D., from Texas A&M University, investigated the metabolic effects of daily consumption of freshly frozen mango pulp (400g) for six weeks in lean and obese subjects and the relationship between mango metabolites to Body Mass Index (BMI) and circulating biomarkers.

Fang, C. Kim, H. Barnes, R. Talcott, S. Mertens-Talcott, SU. Daily Mango (Mangifera Indica L.) Consumption for 42 Days Differentially Modulates Metabolism and Inflammation in Lean and Obese Individuals. The FASEB Journal, April 2017, vol. 31 no. 1 Supplement 431.3. http://bit.ly/ModulatesMetabolismandInflammation

Researcher Crystal O'Hara, Ph.D., from Oklahoma State University examined the post-prandial response of young, healthy males (18-25 years) following consumption of a typical American high-fat breakfast with or without a mango shake, which included 50g of mango pulp (equivalent to ~250g of fresh mango).

O'Hara, C. Babjide, O. Simenson, A. Hermann, J. Payton, M. Smith, B. Lucas, E. The Effects of Acute Freeze-Dried Mango Consumption with a High-Fat Meal on Post-Prandial Responses in Healthy Young Adult Males. The FASEB Journal, April 2017, vol. 31 no. 1 Supplement 166.3. http://bit.ly/PostPrandialResponses

In a randomized pilot study, researchers from Texas A&M University, led by Hyemee Kim, Ph.D., investigated the potential role of mango consumption in changes of the gut microbiota, bioavailability of galloyl metabolites, and anti-inflammatory activities in lean and obese subjects.

Kim, H. Barnes, R. Fang, C. Talcott, S. Mertens-Talcott, SU. Intestinal Microbiota and Host Metabolism Respond Differentially in Lean and Obese Individuals Following Six-Week Consumption of Galloyl Derivatives from Mango (Mangifera Indica L.) Pulp. The FASEB Journal, April 2017, vol. 31 no. 1 Supplement 431.3. http://bit.ly/IntestinalMicrobiota

Researchers from Texas A&M University examined the absorption, metabolism, and excretion of gallic acid, galloyl glycosides, and gallotannins in lean and obese individuals that consumed 400g of freshly frozen mango pulp daily for six weeks. The study's lead researcher, Susanne Mertens-Talcott, Ph.D. suggests that extended mango consumption may offer increased anti-inflammatory benefits compared to sporadic mango consumption and this would need to be confirmed within an extended efficacy study.

Mertens-Talcott, SU. Kim, H. Talcott, S. Barnes. R. Adaptation of Galloyl Derivatives Metabolism and Excretion After 42 Days of Mango (Mangifera indica L.) Consumption. The FASEB Journal, April 2017, vol. 31 no. 1 Supplement 646.16 http://bit.ly/GalloylDerivativesMetabolsim

Why playing a musical instrument can protect brain health

A recent study conducted at Baycrest Health Sciences has uncovered a crucial piece into why playing a musical instrument can help older adults retain their listening skills and ward off age-related cognitive declines. This finding could lead to the development of brain rehabilitation interventions through musical training.

The study, published in the Journal of Neuroscience on May 24, found that learning to play a sound on a musical instrument alters the brain waves in a way that improves a person's listening and hearing skills over a short time frame. This change in brain activity demonstrates the brain's ability to rewire itself and compensate for injuries or diseases that may hamper a person's capacity to perform tasks.

"Music has been known to have beneficial effects on the brain, but there has been limited understanding into what about music makes a difference," says Dr. Bernhard Ross, senior scientist at Baycrest's Rotman Research Institute (RRI) and senior author on the study. "This is the first study demonstrating that learning the fine movement needed to reproduce a sound on an instrument changes the brain's perception of sound in a way that is not seen when listening to music."

This finding supports Dr. Ross' research using musical training to help stroke survivors rehabilitate motor movement in their upper bodies. Baycrest scientists have a history of breakthroughs into how a person's musical background impacts the listening abilities and cognitive function as they age and they continue to explore how brain changes during aging impact hearing.

The study involved 32 young, healthy adults who had normal hearing and no history of neurological or psychiatric disorders. The brain waves of participants were first recorded while they listened to bell-like sounds from a Tibetan singing bowl (a small bell struck with a wooden mallet to create sounds). After listening to the recording, half of the participants were provided the Tibetan singing bowl and asked to recreate the same sounds and rhythm by striking it and the other half recreated the sound by pressing a key on a computer keypad.

"It has been hypothesized that the act of playing music requires many brain systems to work together, such as the hearing, motor and perception systems," says Dr. Ross, who is also a medical biophysics professor at the University of Toronto. "This study was the first time we saw direct changes in the brain after one session, demonstrating that the action of creating music leads to a strong change in brain activity."

The study's next steps involve analyzing recovery between stroke patients with musical training compared to physiotherapy and the impact of musical training on the brains of older adults.

With additional funding, the study could explore developing musical training rehabilitation programs for other conditions that impact motor function, such as traumatic brain injury.

Research for this study was conducted with support from the Canadian Institutes of Health Research, which supported research staff and equipment.

Dr. Ross' work is setting the foundation to develop hearing aids of the future and cognitive training programs to maintain hearing health.