New Study Sheds Light On Link Between Dairy Intake and Bone Health: Not All Dairy Products Are Equal

Feb. 1, 2013 — A study by researchers at the Institute for Aging Research (IFAR) at Hebrew SeniorLife, an affiliate of Harvard Medical School (HMS), has found that dairy intake — specifically milk and yogurt — is associated with higher bone mineral density (BMD) in the hip, but not the spine. Cream, on the other hand, may be associated with lower BMD overall. Published February 1 in the journal Archives of Osteoporosis, these findings suggest that not all dairy products are equally beneficial in promoting bone strength.


“Dairy foods provide several important nutrients that are beneficial for bone health,” says lead author Shivani Sahni, Ph.D., Musculoskeletal Research Team, IFAR. “However, cream and its products such as ice cream have lower levels of these nutrients and have higher levels of fat and sugar. In this study, 2.5 — 3 servings of milk and yogurt intake per day were associated with better bone density. More research is needed to examine the role of cheese intake (some of which can be high in fat and sodium), and whether individual dairy foods have a significant impact in reducing fractures.”

IFAR researchers based their findings on data collected from a food frequency questionnaire completed by 3,212 participants from the Framingham Offspring study. They then compared participants’ dairy intake with BMD measurement, which revealed the benefits of milk and yogurt versus cream in largely middle-aged men and women. According to the study, nutrient composition varies among dairy foods. Choosing low-fat milk or yogurt over cream can increase intake of protein, calcium and vitamin D while limiting intake of saturated fats.

This study is an example of a growing area of research focused on the relationship between nutrition and bone health. Past studies suggest that dairy products contain more than one beneficial nutrient, and for this reason certain dairy products may contribute towards maintaining healthier bones.

Research like this supports the idea that proper nutrition can help combat osteoporosis and fractures. Osteoporosis is considered a major public health threat for an estimated 44 million Americans, or half of those aged 50 and older.

• An estimated 10 million in the U.S. already have the disease. Women are at higher risk than men.

• Another 34 million Americans have low bone density, putting them at increased risk for osteoporosis and fractures, especially of the hip, spine and wrist. About one-quarter of those who suffer a hip fracture die within a year of the injury.

• Osteoporosis-related fractures were responsible for an estimated $19 billion in health care costs in 2005, with that figure expected to increase to $25 billion by 2025.

Co-authors on the study include, Katherine L. Tucker, Ph.D.; Douglas P. Kiel, M.D., M.P.H.; Lien Quach, M.P.H, M.S.; Virginia A. Casey, Ph.D.; Marian T. Hannan, D.Sc., M.P.H.

This work was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (AR # 053205 and also AR/AG41398) and by the National Heart Lung and Blood Institute’s Framingham Heart Study (N01-HC-25195), the Melvin First Young Investigator Award and General Mills Bell Institute of Health and Nutrition.

 

Story Source:

The above story is reprinted from materials provided byHebrew SeniorLife Institute for Aging Research.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Shivani Sahni, Katherine L. Tucker, Douglas P. Kiel, Lien Quach, Virginia A. Casey, Marian T. Hannan. Milk and yogurt consumption are linked with higher bone mineral density but not with hip fracture: the Framingham Offspring StudyArchives of Osteoporosis, 2013; 8 (1-2) DOI: 10.1007/s11657-013-0119-2
Hebrew SeniorLife Institute for Aging Research (2013, February 1). New study sheds light on link between dairy intake and bone health: Not all dairy products are equal. ScienceDaily. Retrieved February 3, 2013, from http://www.sciencedaily.com/releases/2013/02/130201132336.htm

 

Some Plants Are Altruistic, Too, New Study Suggests

Feb. 1, 2013 — We’ve all heard examples of animal altruism: Dogs caring for orphaned kittens, chimps sharing food or dolphins nudging injured mates to the surface. Now, a study led by the University of Colorado Boulder suggests some plants are altruistic too.


 

The researchers looked at corn, in which each fertilized seed contained two “siblings” — an embryo and a corresponding bit of tissue known as endosperm that feeds the embryo as the seed grows, said CU-Boulder Professor Pamela Diggle. They compared the growth and behavior of the embryos and endosperm in seeds sharing the same mother and father with the growth and behavior of embryos and endosperm that had genetically different parents.

“The results indicated embryos with the same mother and father as the endosperm in their seed weighed significantly more than embryos with the same mother but a different father,” said Diggle, a faculty member in CU-Boulder’s ecology and evolutionary biology department. “We found that endosperm that does not share the same father as the embryo does not hand over as much food — it appears to be acting less cooperatively.”

A paper on the subject was published during the week of Jan. 21 in the Proceedings of the National Academy of Sciences. Co-authors on the study included Chi-Chih Wu, a CU-Boulder doctoral student in the ecology and evolutionary biology department and Professor William “Ned” Friedman, a professor at Harvard University who helped conduct research on the project while a faculty member at CU-Boulder.

Diggle said it is fairly clear from previous research that plants can preferentially withhold nutrients from inferior offspring when resources are limited. “Our study is the first to specifically test the idea of cooperation among siblings in plants.”

“One of the most fundamental laws of nature is that if you are going to be an altruist, give it up to your closest relatives,” said Friedman. “Altruism only evolves if the benefactor is a close relative of the beneficiary. When the endosperm gives all of its food to the embryo and then dies, it doesn’t get more altruistic than that.”

In corn reproduction, male flowers at the top of the plants distribute pollen grains two at a time through individual tubes to tiny cobs on the stalks covered by strands known as silks in a process known as double fertilization. When the two pollen grains come in contact with an individual silk, they produce a seed containing an embryo and endosperm. Each embryo results in just a single kernel of corn, said Diggle.

The team took advantage of an extremely rare phenomenon in plants called “hetero-fertilization,” in which two different fathers sire individual corn kernels, said Diggle, currently a visiting professor at Harvard. The manipulation of corn plant genes that has been going on for millennia — resulting in the production of multicolored “Indian corn” cobs of various colors like red, purple, blue and yellow — helped the researchers in assessing the parentage of the kernels, she said.

Wu, who cultivated the corn and harvested more than 100 ears over a three-year period, removed, mapped and weighed every individual kernel out of each cob from the harvests. While the majority of kernels had an endosperm and embryo of the same color — an indication they shared the same mother and father — some had different colors for each, such as a purple outer kernel with yellow embryo.

Wu was searching for such rare kernels — far less than one in 100 — that had two different fathers as a way to assess cooperation between the embryo and endosperm. “It was very challenging and time-consuming research,” said Friedman. “It was like looking for a needle in a haystack, or in this case, a kernel in a silo.”

Endosperm — in the form of corn, rice, wheat and other crops — is critical to humans, providing about 70 percent of calories we consume annually worldwide. “The tissue in the seeds of flowering plants is what feeds the world,” said Friedman, who also directs the Arnold Arboretum at Harvard. “If flowering plants weren’t here, humans wouldn’t be here.”

 

Story Source:

The above story is reprinted from materials provided byUniversity of Colorado at Boulder.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. K. Baruch, N. Ron-Harel, H. Gal, A. Deczkowska, E. Shifrut, W. Ndifon, N. Mirlas-Neisberg, M. Cardon, I. Vaknin, L. Cahalon, T. Berkutzki, M. P. Mattson, F. Gomez-Pinilla, N. Friedman, M. Schwartz. CNS-specific immunity at the choroid plexus shifts toward destructive Th2 inflammation in brain agingProceedings of the National Academy of Sciences, 2013; DOI:10.1073/pnas.1211270110
University of Colorado at Boulder (2013, February 1). Some plants are altruistic, too, new study suggests. ScienceDaily. Retrieved February 3, 2013, from http://www.sciencedaily.com/releases/2013/02/130201132334.htm

Cooperators Can Coexist With Cheaters, as Long as There Is Room to Grow

Feb. 1, 2013 — Microbes exhibit bewildering diversity even in relatively tight living quarters. But when a population is a mix of cooperators, microbes that share resources, and cheaters, those that selfishly take yet give nothing back, the natural outcome is perpetual war. A new model by a team of researchers from Princeton University in New Jersey and Ben-Gurion University in Israel reveals that even with never-ending battles, the exploiter and the exploited can survive, but only if they have room to expand and grow.


 

The researchers present their findings at the 57th Annual Meeting of the Biophysical Society (BPS), held Feb. 2-6, 2013, in Philadelphia, Pa.

“In a fixed population, cells that share can’t live together with cells that only take,” said David Bruce Borenstein, a researcher at Princeton. “But if the population repeatedly expands and contracts then such ‘cooperators’ and ‘cheaters’ can coexist.”

Our world and our bodies play host to a vast array of microbes. On our teeth alone, there are approximately a thousand different kinds of bacteria, all living in very close quarters. This is amazing, the researchers observe, because many of those species share resources with nearby neighbors, who might not be so cooperative or even related [1].

At the scale of cells, individuals cooperate mainly by exporting resources into the environment and letting them float away. “This is a deceptively complex process in which cells interact at long ranges, but compete only with nearby individuals,” explained Borenstein. “Our models predict that, even when this exploitation prevents any possibility of peaceful coexistence, the exploiter and the exploited can survive across generations in what is basically a perpetual war.” The researchers speculate that similar competition might occur between cancer cells and normal tissue.

Borenstein and his colleagues made their conclusions based on a computer model that considered two types of cells, cooperators and cheaters, and laid them out on a grid. Cooperators were given the ability, not uncommon in nature, to make a resource that speeds up growth in both kinds of cells. Producing this resource slowed down the growth of cooperators, because they have to divert some energy to resource production. This resource then spread out from the cooperator by diffusion, so that the cells closest to a producer have the greatest resource access. The model revealed that the producers tended to cluster, meaning that being a producer gave you greater access to resources. It also meant that even though cheaters are avoiding the cost of production, they pay for it with reduced resource access.

Within these basic constraints it was found that when the two populations must compete directly for survival, no coexistence is possible. “One type always wins out,” observed Borenstein. However, when the two populations can grow into empty space, the researchers found a strange and paradoxical interaction: cheaters may be outcompeting cooperators locally, even as cooperators grow better overall. These complex interactions may play an important role in the maintenance of diverse microbial communities, like those seen in the mouth.

“To our astonishment, we found that while cheaters can exploit cooperators, cooperators can isolate cheaters, just from cooperation and growth,” concludes Borenstein. “As a result, the community can persist in a sort of perpetual race from which a winner need not emerge.”

[1] J. M. ten Cate. “Biofilms, a new approach to the microbiology of dental plaque.” Odontolgy 2006(94):1-9.

 

Story Source:

The above story is reprinted from materials provided byBiophysical Society, via Newswise.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Biophysical Society (2013, February 1). Cooperators can coexist with cheaters, as long as there is room to grow. ScienceDaily. Retrieved February 3, 2013, from http://www.sciencedaily.com/releases/2013/02/130201095947.htm

Note: If no author is given, the source is cited instead.

 

Getting Fit Fast: Inactive People Can Achieve Major Health and Fitness Gains in a Fraction of the Time

Feb. 1, 2013 — With many of us struggling to get enough exercise, sport and exercise scientists at Liverpool John Moores University (LJMU) and the University of Birmingham, under the lead of Professor Anton Wagenmakers, have been working on a time-saving solution.


 

Instead of long stints in the gym and miles of running in the cold, the same results could be achieved in less than a third of the time, according to new research published February 1 in The Journal of Physiology.

The current recommendation of the World Health Organisation (WHO) and UK Department of Health is that people of all ages should do three to five hours of endurance training per week to increase health and fitness and prevent chronic diseases and premature mortality. However, most people find it difficult to set aside this much time in their busy lives.

This study has taken existing research to a new level to prove that replacing endurance training with two types of interval training, High intensity Interval Training (HIT) and Sprint Interval Training (SIT), can make a massive difference to our health and aerobic fitness. In two articles in the 1 February issue ofThe Journal of Physiology, the researchers describe their recent discoveries that three sessions of SIT, taking just 90 min per week, are as effective as five sessions of traditional endurance exercise, taking five hours per week, in increasing whole body insulin sensitivity via two independent mechanisms.

LJMU researcher Matthew Cocks explains: ‘One mechanism involves improved delivery of insulin and glucose to the skeletal muscle and the other involves improved burning of the fat stored in skeletal muscle fibres. Additionally, we found a reduced stiffness of large arteries which is important in reducing the risk of vascular disease.’

On the basis of these novel and earlier findings from other laboratories, Professor Wagenmakers expects that HIT and SIT will turn out to be unique alternative exercise modes suitable to prevent blood vessel disease, hypertension, diabetes and most of the other ageing and obesity related chronic diseases.

LJMU researcher Sam Shepherd describes: ‘SIT involves four to six repeated 30 second ‘all out’ sprints on special laboratory bikes interspersed with 4.5 minutes of very low intensity cycling. Due to the very high workload of the sprints, this method is more suitable for young and healthy individuals. However, anyone of any age or level of fitness can follow one of the alternative HIT programmes which involve 15-60 second bursts of high intensity cycling interspersed with 2-4 minute intervals of low intensity cycling. HIT can be delivered on simple spinning bikes that are present in commercial gyms and are affordable for use at home or in the workplace.’

Lack of time is the number one reason that the majority of the adult population do not meet the current physical activity recommendations. SIT and HIT could solve this problem.

Sam Shepherd comments: ‘A pilot study currently ongoing in the Sports Centre at the University of Birmingham has also shown that previously sedentary individuals in the age-range of 25-60 also find HIT on spinning bikes much more enjoyable and attractive than endurance training and it has a more positive effect on mood and feelings of well-being. This could imply that HIT is more suitable to achieve sustainable changes in exercise behaviour.’

HIT, therefore, seems to provide the ideal alternative to outdoor running, dangerous cycling trips and long boring endurance cycling sessions in health and fitness gyms. That is why the researchers believe that there will be a great future for HIT for obese and elderly individuals and potentially also for patients with hypertension, diabetes and cardiovascular disease.

 

Story Source:

The above story is reprinted from materials provided byWiley, via AlphaGalileo.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. M. Cocks, C. S. Shaw, S. O. Shepherd, J. P. Fisher, A. M. Ranasinghe, T. A. Barker, K. D. Tipton, A. J. M. Wagenmakers. Sprint interval and endurance training are equally effective in increasing muscle microvascular density and eNOS content in sedentary malesThe Journal of Physiology, 2012; 591 (3): 641 DOI:10.1113/jphysiol.2012.239566
Wiley (2013, February 1). Getting fit fast: Inactive people can achieve major health and fitness gains in a fraction of the time.ScienceDaily. Retrieved February 3, 2013, from http://www.sciencedaily.com/releases/2013/02/130201090405.htm