More Successful Weight Loss With Online Obesity Programs

Computer and web-based weight management programmes may provide a cost effective way of addressing the growing problem of obesity, according to a team of seven researchers who undertook a Cochrane systematic review. The researchers, from Maryland, Massachusetts, New York, Pennsylvania and Rhode Island, USA, found that delivering weight loss or weight maintenance programmes online or by computer helped overweight and obese patients lose and/or maintain weight.

Being overweight or obese can increase a person's risk of diabetes, heart disease, high blood pressure, stroke and other chronic medical conditions. The World Health Organization predicts that the number of obese and overweight people in the world will reach 1.5 billion by 2015. Computer or internet-based weight management programmes may be a cost-effective approach to treating overweight or obese people, with the potential to have a major impact on public health.

The review focuses on 14 studies of weight loss involving a total of 2,537 people and four weight maintenance studies involving a further 1,603 people. Those who took part were selected based on having a body mass index (BMI) over a certain limit. In weight loss studies, participants lost more weight after six months than those receiving no intervention or minimal interventions, but less than those who received treatment face-to-face. Similarly, participants who took part in weight maintenance studies were more successful at keeping off weight than those receiving no or minimal interventions, but less so than those receiving face-to-face treatment. Minimal interventions included handing out pamphlets or providing usual care.

L. Susan Wieland, PhD, based at the University of Maryland School of Medicine in Baltimore, US, was the lead author of the study. "Computer or web-based weight management programmes may be less beneficial than face-to-face interventions, but health care providers have limited opportunities to provide this care, so lower impact treatment approaches need to be considered," said Wieland.

"These large-scale systematic reviews are helpful to determine - using available peer-reviewed studies - what works and what doesn't work, so health care providers can make evidence-based recommendations," said Karina W. Davidson, PhD, director, Center for Behavioral Cardiovascular Health, Columbia University Medical Center, and an author of the study. "Since more patients are participating in online weight loss or management programs, these results reveal that computer-based delivery can be effective."

According to the researchers, although their review did not cover smartphones, these could now take the place of desktop computers or laptops in delivering online weight management programmes. "Since we started the review, smartphones have become capable of functioning like fully mobile computers with interactive potential similar to that of laptops and desktops," said Wieland. "We hope to include trials of smartphones when we update this review."

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Hypertension May Be Improved By Cocoa Compounds

Compounds in cocoa may help to reduce blood pressure, according to a new systematic review in The Cochrane Library. The researchers reviewed evidence from short-term trials in which participants were given dark chocolate or cocoa powder daily and found that their blood pressure dropped slightly compared to a control group.

Cocoa contains compounds called flavanols, thought to be responsible for the formation of nitric oxide in the body. Nitric oxide causes blood vessel walls to relax and open wider, thereby reducing blood pressure. The link between cocoa and blood pressure stems from the discovery that the indigenous people of San Blas Island in Central American, who drink flavanol-rich cocoa drinks every day, have normal blood pressure regardless of age. However, flavanol concentrations in cocoa and chocolate products vary according to cocoa processing procedures and types of chocolate, so it is difficult to establish the optimal dosage for an effect.

To investigate the effect of flavanols on blood pressure, the researchers reviewed data from trials in which people consumed dark chocolate or cocoa powder containing between 30-1080 mg of flavanols in 3-100 g of chocolate each day. Altogether, 856 people were involved in 20 trials lasting 2-8 weeks, or in one case, 18 weeks. Flavanol-rich chocolate or cocoa powder reduced blood pressure on average by 2-3 mm Hg.

"Although we don't yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease," said lead researcher Karin Ried of the National Institute of Integrative Medicine in Melbourne, Australia, who worked with colleagues at the University of Adelaide.

In a subset of trials, when chocolate or cocoa powder was compared to flavanol-free-products as controls, the beneficial effects were more pronounced (3-4 mm Hg), whereas the researchers found no significant effect on blood pressure in the second subset with low-flavanol products as control. It is possible that low-flavanol products also have a small effect on blood pressure, so that it was harder to observe differences between high and low-flavanol products in these trials. However, results of these subsets of trials may have been influenced by trial length and blinding of participants, as trials using flavanol-free control products tended to be of shorter duration with participants knowing their allocated group.

"We'll also need to see long term trials, including effects on the risk of stroke and cardiovascular disease, before we can come to conclusions regarding clinical outcomes and potential side effects of long-term consumption," said Ried. "These trials should use flavanol-free products in the control groups to eliminate any potential effects of low-dose flavanol on blood pressure."

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Physical And Psychological Well-Being Improved By Exercise During And After Cancer

Exercise may improve quality of life for people with cancer, according to Cochrane researchers. In two separate Cochrane systematic reviews, the authors gathered together evidence showing that activities such as walking and cycling can benefit those who are undergoing or have completed treatment for cancer.

People with cancer suffer from many different physical, psychological and social effects related to cancer, as well as treatment-related symptoms. There has been much interest in the effects of exercise on physical and psychological well-being in people with cancer. However, no previous systematic reviews have comprehensively examined the potential benefits of exercise on health-related quality of life, or on treatment-related symptoms. Cancer treatments and survival rates continue to improve, but quality of life remains a priority for people with cancer who are undergoing or have completed treatment.

The first review focused on 56 trials involving a total of 4,826 people undergoing treatment for different types of cancer, including breast and prostate cancer. The second focused on 40 trials involving a total of 3,694 people who had completed treatment for cancer. Exercise programmes in both reviews included walking, cycling, yoga, Qigong, resistance training and strength training. The results show that exercise can improve health-related quality of life for people with cancer. Further, results from both reviews show that exercise improved social functioning and tiredness. Benefits were also seen in the physical well-being of participants undergoing treatment and in self-esteem, emotional well-being, sexuality, sleep, anxiety and pain in people who had completed treatment.

"Together, these reviews suggest that exercise may provide quality of life benefits for people who are undergoing or have undergone treatment for cancer," said lead author Shiraz I. Mishra of the Prevention Research Center at the University of New Mexico in Albuquerque, US.

"However, we need to treat these findings with caution because the trials we included looked at many different kinds of exercise programmes, which varied by type of exercise, length of the programme and how hard the participants had to exercise. We need to understand from future trials how to maintain the positive impacts of exercise in the longer term and whether there are particular types of exercise that are suited to particular types of cancer."

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Success Of Engineered Tissue Depends On Where It's Grown

Cells grown on different types of scaffolds vary in their ability to help repair damaged blood vessels

Tissue implants made of cells grown on a sponge-like scaffold have been shown in clinical trials to help heal arteries scarred by atherosclerosis and other vascular diseases. However, it has been unclear why some implants work better than others.

MIT researchers led by Elazer Edelman, the Thomas D. and Virginia W. Cabot Professor of Health Sciences and Technology, have now shown that implanted cells' therapeutic properties depend on their shape, which is determined by the type of scaffold on which they are grown. The work could allow scientists to develop even more effective implants and also target many other diseases, including cancer.

"The goal is to design a material that can engineer the cells to release whatever we think is most appropriate to fight a specific disease. Then we can implant the cells and use them as an incubator," says Laura Indolfi, a postdoc in Edelman's lab and lead author of a paper on the research recently published online in the journal Biomaterials.

Aaron Baker, a former postdoc in Edelman's lab and now an assistant professor at the University of Texas at Austin, is also an author of the paper.

Shape matters

For the past 20 years, Edelman has been working on using endothelial cells grown on scaffolds made of collagen as implantable devices to treat blood vessel damage. Endothelial cells line the blood vessels and regulate important process such as tissue repair and inflammation by releasing molecules such as chemokines, small proteins that carry messages between cells.

Several of the devices have been tested in clinical trials to treat blood vessel damage; in the new Biomaterials study, Edelman and Indolfi set out to determine what makes one such tissue scaffold more effective than another. In particular, they were interested in comparing endothelial cells grown on flat surfaces and those grown on more porous, three-dimensional scaffolds. The cells grown on 3-D structures tended to be more effective at repairing damage and suppressing inflammation.

The researchers found that cells grown on a flat surface take on a round shape in which the cells' structural components form a ring around the perimeter of the cell. However, when cells are grown on a scaffold with surfaces of contact whose dimensions are similar in size to the cells, they mold to the curved surfaces, assuming a more elongated shape. In those cells, the structural elements - made of bundles of the protein actin - run parallel to each other.

Those shapes determine what types of chemokines the cells secrete once implanted into the body. In this study, the researchers focused on a chemokine known as MCP1, which recruits inflammatory cells called monocytes.

They found that the architecture of the cytoskeleton appears to determine whether or not the cell turns on the inflammatory pathway that produces MCP1. The elongated cells grown on porous surfaces produced eight times less of this inflammatory chemokine than cells grown on a flat surface, and recruited five times fewer monocytes than cells grown on a flat surface. This helps the tissue implants to suppress inflammation in damaged blood vessels.

The researchers also identified biomarkers that correlate the cells' shape, chemokine secretion and behavior. One such parameter is the production of a focal adhesion protein, which helps cells to stick to surfaces. In cells grown on a flat surface, this adhesion protein, known as vinculin, accumulates around the edges of the cell. However, in cells grown on a 3-D surface, the protein is evenly distributed throughout the cell. These distribution patterns serve as molecular cues to inhibit or activate the pathway that recruits monocytes.

Precise control

The findings could help scientists manipulate their scaffolds to tailor cells to specific applications. One goal is using implanted cells to recruit other body cells that will do a particular task, such as inducing stem cells to differentiate into a certain type of cell. "By designing the matrix before we seed the cells, we can engineer which factors they are going to secrete," Indolfi says.

The work should also help researchers improve on existing tissue-engineered devices and test new ones, Edelman says. "Without this kind of understanding, we can't extend successful technologies to the next generation,"

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