The Star Online: Lifestyle: Health
The Star Online: Lifestyle: Health |
| Sleep helps brain stay fit by clearing waste Posted: Research shows what the brain does when one is sleeping. Like a janitor sweeping the halls after the lights go out, major changes occur in the brain during sleep to flush out waste and ward off disease, researchers said. The research in the journal Science offers new answers to explain why people spend a third of their lives asleep and may help in treating dementia and other neurological disorders. In lab experiments on mice, researchers observed how cellular waste was flushed out via the brain's blood vessels into the body's circulatory system and eventually the liver. These waste products included amyloid beta, a protein that when accumulated is a driver of Alzheimer's disease. In order to help remove the waste, cerebral spinal fluid is pumped through brain tissue. The process is sped along during sleep because the brain's cells shrink by about 60%, allowing the fluid to move faster and more freely through the brain. The whole operation takes place in what researchers call the glymphatic system, which appears to be nearly 10 times more active during sleep than while awake. "The brain only has limited energy at its disposal," said lead author Maiken Nedergaard of the University of Rochester Medical Centre. "You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can't really do both at the same time." Co-authors of the study, which was funded by the US National Institutes of Health, came from Oregon Health and Science University and New York University. — AFP Relaxnews |
| Doing battle with breast cancer Posted: Although we can't change our genetics, mounting research underscores the importance of taking steps to beat back the odds of breast cancer. SILVANA Davis was 16 when breast cancer took her mother. Now a mother herself, the 41-year-old is doing everything she can to make sure that she does not face the same diagnosis. "For someone else, it's like saying 'You're at risk for heart disease, so take an aspirin.' For me it was, 'You're at risk for breast cancer, so lose some weight,'" she said. Although we can't change our genetics, mounting research underscores the importance of taking steps to beat back the odds of breast cancer, a disease that this year will be diagnosed about 232,340 times and will cause about 39,620 deaths, according to the American Cancer Society. The research is clear: Cut back the alcohol. Approach hormone replacement therapy with caution. Shave off calories, too. If the body is the interface between genetics and environment, food is a "buffer", said Dr Sofia Merajver, director of the Breast and Ovarian Cancer Risk Evaluation Program at the University of Michigan's Comprehensive Cancer Center. "It can protect us or hurt us, depending on what we eat," she said. Her advice? Limit alcohol to three to four drinks a week. Eat at least five vegetables a day – both leafy and cruciferous like cauliflower, broccoli and cabbage. Go for lean protein and Vitamin D. Exercise 30 minutes a day, six days a week. Go for core and upper-body strength training as well as aerobic exercise. Reducing risk A growing body of research has strengthened the link between exercise and breast cancer risk, especially in postmenopausal women. One recent study of more than 95,000 women found that increases in physical activity after menopause lowered breast cancer risk by 10%, according to the American Cancer Society's Breast Cancer Facts & Figures report. It's a lot of the same nutrition advice used to control other chronic diseases, making the lifestyle change "a win-win-win", Merajver said. "What we know right now is that essentially the same behaviours that help us control our weight and decrease the risk of diabetes, decrease the risk of strokes, decrease the rate at which we develop cardiovascular disease, and reduce the risk of developing cancer," she said. Davis' mother was 35 when she was diagnosed with breast cancer. When Davis and her three sisters approached the same age, "we all just kind of freaked out", she said. Davis, a physician's assistant at the University of Michigan, decided to undergo genetic testing to see whether she carried a mutation of the BRCA gene, the same one that Angelina Jolie carries and that prompted the actress to undergo a double mastectomy earlier this year. The BRCA1 and BRCA2 genes help suppress tumours and stabilise a cell's genetic material. A mutation of those genes boosts the risk for cancer. About 12% of women in the general population will develop breast cancer sometime during their lives; the risk jumps to 45% or more for those who inherit a BRCA mutation, according to the National Cancer Institute (NCI). While waiting nearly two months for the results of the genetic tests, Davis began to make lifestyle changes. She typically ate the right foods, she said, chuckling: "I'm Italian, it was about portion control." Davis stopped finishing the food on the plates of her two children, eight-year-old Nico and 10-year-old Elena. And while usually involved with their activities, she now threw herself into them even more. As it turned out, Davis doesn't carry a BRCA mutation and her mother may not have either. But the news didn't send cancer out of her mind completely. She shed 15 pounds from her 5-foot-4 frame, a loss that helped her feel like she has an edge on the disease that killed her mother: "I feel like I have a bit of control over this." Get the right advice There's a growing awareness of trying to prevent cancer, not just treating it after diagnosis, Merajver said. But patients are often confused. They've heard advice from friends and others about preventing cancer – taking this pill or avoiding this particular food, for example. Sometimes, it's just "quackery, like snake oil," Merajver said. Other times, it's from very preliminary research that only hints at a possible link, but that will take much more work to confirm. "Just because there's a study, it doesn't mean there's validity to it," said Lisa Chism, a nurse practitioner and director of the Women's Wellness Clinic at Detroit's Barbara Ann Karmanos Cancer Institute. The recent American Cancer Society report attempted to debunk persistent myths linking breast cancer to hair dyes, antiperspirants, abortion, and breast implants. They "are not associated with breast cancer risk". To be clear, there are no guarantees against cancer. Our genetic coding is permanent. Ageing is non-negotiable, too. Almost eight of every 10 new breast cancer cases and almost nine of every 10 breast cancer deaths are in women 50 years old and older. But in July, a study published by NCI researchers clarified those risk factors that we can control. Developed for researchers, NCI published new risk-prediction tools for breast cancer that included factors such as family history and when a woman started menstruating, as well as behaviours we can change – alcohol consumption, use of hormone replacement therapy, and to some extent, body mass index. They correctly predicted the number of breast cancers – 2,930 breast cancer cases among 56,638 women, or just four off the number of cancer cases that actually occurred. The researchers found no link between tobacco use and the development of breast cancer, adding to earlier studies that question a link between smoking and breast cancer. Of the factors we can control to reduce the risk of breast cancer, using oestrogen plus progestin hormone replacement therapy contributed the most to breast cancer risk, followed by alcohol consumption and body mass index. Consider, for example, a 50-year-old postmenopausal woman without a family history of breast cancer. She has never used hormone replacement therapy, has a normal BMI, had her first child before age 25, and has never had any diagnosis with previous breast disease. And she doesn't drink regularly drink alcohol. All are factors that mean she is low-risk: She has a 3.3% risk of developing breast cancer in 20 years. Now add one or more alcoholic drinks per day to her life. That risk jumps to 4.1%. How to learn your risk assessment Even with surprisingly accurate risk assessment, it's unclear how women use the information when faced with their odds of breast cancer. At least one in five women in an August study at the University of Michigan didn't believe the results of a risk assessment, believing instead that their low-risk outcome must have missed something important or that their high-risk outcome was overstated. That doesn't surprise Dr Ruth Pfeiffer, the lead author of a National Cancer Institute study in July geared for researchers: People want guarantees, not probabilities, she said. "If there are 100 women and we can say five will get cancer, the question is, will 'I be one of the five?'" she said. "No statistical model can answer that." For those who would like to know more, a tool for consumers gives women an idea of their chance of developing breast cancer. It's somewhat less refined than the most recent research, but it can offer some insight to a woman's risk factors after answering questions about family history, race and the age at which she had her first child. It is at www.cancer.gov/bcrisktool. – Detroit Free Press/McClatchy-Tribune Information Services |
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