WHAT’S WITH THE CONTROVERSY ABOUT SALT IN FOOD? (from Nutrition Action Newsletter September 2014)
Excess salt is harmful, concluded a recent study, while a second study—which had serious shortcomings—suggested that too little salt can also be dangerous.
An estimated 1.65 million deaths from cardiovascular disease worldwide in 2010 were caused by sodium intakes over 2,000 milligrams a day, according to the first study. It used the results of 103 trials to estimate the effect of sodium on blood pressure, and data on 1.38 million people to estimate the effect of blood pressure on strokes and heart attacks.
The second study reported an increased risk of strokes, heart attacks, and deaths in people who had not just higher sodium intakes (over 6,000 mg a day) but also in those who had lower intakes (below 3,000 mg a day). However, as the authors acknowledged, “reverse causation” couldn’t be ruled out as a cause of the higher risk in people who ate less salt. In other words, it’s possible that eating less salt didn’t cause their illness, but that illness caused them to eat less salt. (People who are sick often eat less food.) As the authors stated, there is no evidence that any of the 102,000 participants—60 percent of whom were from China, India, and other lower-income countries—were intentionally eating less salt to protect their health.
The American Heart Association, which stands by its advice to limit sodium to 1,500 mg a day, has documented potential flaws in studies like the second one. Unfortunately, an editorial published with the studies—written by a former consultant to the Salt Institute (and expert witness for the tobacco industry)—did not cite those flaws.
What to do: Cut back on salt in prepared foods and the salt shaker. Read labels and opt for lower-sodium products. Learn to use spices to liven up recipes, instead of salt.
AEROBIC ACTIVITY HELPS BUILD BIGGER BRAINS (Tufts University Newsletter, June 2014)
Another study has shown that aerobic activity, such as brisk walking, boosts your brain—actually increasing the size of the hippocampus, a key part of the inner brain involved in forming, storing and processing memory. When compared to an earlier study of cognitively healthy older adults, moreover, the findings suggest that aerobic exercise offers greatest benefits to those who need it most: people with mild cognitive impairment (MCI), often a precursor to Alzheimer’s disease.
“While the findings from these studies showed a greater benefit of aerobic exercise in individuals with MCI, a number of previous studies have provided evidence that regular exercise decreases the risk for cognitive decline over time,” says Tammy Scott, PhD, a scientist at Tufts’ HNRCA Neuroscience and Aging Laboratory. “The results from these current studies shouldn’t be taken as an excuse to wait to start an exercise program.”
Brain Building: The new findings, published in the British Journal of Sports Medicine, analyzed data from the earlier Exercise for Cognition and Everyday Living (EXCEL) trial. This secondary analysis, which researchers said was the first of its kind, looked at 86 women, ages 70 to 80, already suffering MCI.
Participants were divided into three groups for a six-month study period: One group engaged in a twice-weekly aerobic walking program, designed to increase in intensity to 70% to 80% of each individual’s age-specific target heart rate. (See box.) A second group was assigned to a resistance-training regimen, while a control group did only balance and stretching activities. MRI scans were used to assess changes in brain volume.
At the study’s conclusion, those in the aerobics group saw a 5.6% increase in the left hippocampus, a 2.5% increase in the right hippocampus, and a 4% increase in total hippocampus volume. Neither the resistance-training group nor the control group experienced significant increases in hippocampal volume.
Aerobics vs. Aging: Researchers Teresa Liu-Ambrose, PhD, of the University of British Columbia, and colleagues commented on their results: “With respect to dementia risk, the hippocampus is a brain structure of intense interest. The hippocampus is sensitive to aging effects and significant hippocampal atrophy is a hallmark of [Alzheimer’s disease]. Thus, understanding the effect of exercise on the hippocampus will increase our appreciation of the role exercise may play in dementia prevention.”
They noted that the increases in hippocampal volume among those with MCI were double that observed in a previous study of cognitively healthy older adults. In that study, participants were assigned to a 12-month, three-times-weekly aerobic exercise regimen.
Liu-Ambrose noted that the comparison seems to suggest that the degree of benefit, in terms of brain structure, might be greater in people with early cognitive impairment than in healthy older people. In an interview, she added, “The relationship between physical activity and brain health is pretty robust and has been demonstrated in healthy older adults, but we haven’t known much about its impact in people with MCI who have the greatest risk for dementia.”
DIRTY LAUNDRY (from ACE Fit Facts)
Whether you’re just starting your fitness journey or have been in the workout game for years, we’ve probably had to deal with one annoying side effect of exercise, namely, dirty laundry.
Different workouts may do different things for your body, but they all do the same thing for your laundry: make it pile up! Your sweaty clothes are proof of a job well done, but they need to be dealt with properly or you’ll have a stinky situation on your hands.
Mildew is nobody’s friend. If you’re not going to wash your clothes immediately after a workout, skip the habitual laundry basket toss and hang them up to dry.
If you are going to hit the washer right away—which is the best way to prevent stains and smells from setting—always set the temperature to the hottest setting your fabric can handle. Try a detergent specially designed for athletic clothes like SportsSuds or Tide Plus Febreze Sport.
If you’re feeling ambitious and want to stop stains in their tracks, pre-soak your sweaty clothing in one part vinegar to four parts water for 30 minutes. Just know that bleach and vinegar do not mix well, so rinse your gear in cold water before washing if your detergent contains bleach.