Drinking Calories: We've long known that salt consumption drives thirst. Since many people prefer to quench their thirst with something other than water, the following isn't particularly surprising.
"Sugar-sweetened soft drinks are a significant source of calorie
intake in children," said Feng J. He, M.D., lead author of the study. "It has been shown that sugar-sweetened soft drink consumption is related to obesity in young people. However, it is unclear whether
there is a link between salt intake and sugar-sweetened soft drink consumption."
Dr. He and colleagues analyzed data from the National Diet and Nutrition Survey (NDNS) in Great Britain, conducted in 1997 in a nationally representative sample of more than 2,000 people between 4 and 18 years old. Among the participants, more than 1,600 boys and girls had salt and fluid intake recorded using a seven-day dietary record, with all food and drink consumed weighed on digital scales.
"We found that children eating a lower-salt diet drank less fluid," said Dr. He, a cardiovascular research fellow at St. George's. "From our research, we estimated that 1 gram of salt cut from their
daily diet would reduce fluid intake by 100 grams per day."
The researchers also found that children eating a lower-salt diet drank fewer sugar-sweetened soft drinks. From their research, they predicted that reducing salt intake by 1 gram each day would reduce
sugar-sweetened soft drink consumption by 27 grams per day, after considering other factors such as age, gender, body weight and level of physical activity.
In other words, almost 250 calories per week--roughly two sugary soft drinks. That can contribute to weight gain and thus higher blood pressure, both of which can have a number of adverse impacts on one's health. Where does most of the salt in our diets come from?
In most developed countries, about 80 percent of salt intake is from salt already added to food by the food industry. Reducing salt would not necessarily impact food taste, she said.
"Small reductions in the salt content of 10 percent to 20 percent cannot be detected by the human salt taste receptors and do not cause any technological or safety problems," Dr. He said.
Pepsi's ownership of Frito-Lay sure seems like a natural.
Consuming too little salt can also cause health problems, but people in the developed world tend to err to the high side.
Too Simplistic: The following wasn't nearly as definitive as the researchers are trying to claim.
Many animals possess protective markings to avoid predation, including patterns to reduce the risk of detection (camouflage), to
indicate that the animal is toxic or inedible ("warning colours"), or to mimic another animal or object ("mimicry" and "masquerade"). In addition, many creatures such as butterflies, moths, and fish possess two or more pairs of circular markings, often referred to as "eyespots". Many eyespots are effective in startling or intimidating predators, and can help to prevent or stop an attack. For the past 150 years it has been assumed that this is because they mimic the eyes of the predator’s own enemies.
However, recent work by University of Cambridge zoologists, Martin Stevens, Chloe Hardman, and Claire
Stubbins, indicates that this widely-held hypothesis has no experimental support.
No experimental support? How about the studies here and here, just to note a couple? Anyway...
Stevens, Hardman, and Stubbins tested the response of wild avian predators to artificial moths, created from waterproof paper. Specific patterns, such as intimidating eyespots of different shapes, sizes and number, and with different levels of eye mimicry, were printed on to the paper using a high quality printer.
These "moths" were then pinned to trees of various species at a height of one to three metres in the mixed deciduous Madingley Woods in Cambridgeshire, UK. Attached to each of the artificial moths was an
edible mealworm as a temptation for woodland birds such as the blue tits, great tits, blackbirds, and house sparrows.
The zoologists discovered that artificial moths with circular markings survived no better than those with other conspicuous features and that the features of eyespots which most encouraged predators to avoid them
are large size, a high number of spots, and conspicuousness in general.
As Dr Stevens explains, "the birds were equally likely to avoid artificial moths with markings such as bars and squares as they were to avoid those with two eye-like markings. This leads us to conclude that
eyespots work because they are highly conspicuous features, not because they mimic the eyes of the predators' own enemies. This suggests that circular markings on many real animals need not necessarily, as most accounts claim, mimic the eyes of other animals."
There are actually multiple theories regarding the why species have eyespots. The abstract of this study explains it pretty well.
Eyespots are found in a variety of animals, in particular lepidopterans (butterflies and moths). The role of eyespots as antipredator mechanisms has been
discussed since the 19th Century, with two main hypotheses invoked to explain their occurrence. The first is that large, centrally located eyespots intimidate predators by resembling the eyes of the predators' own enemies; the second, though not necessarily conflicting, hypothesis is that small, peripherally located eyespots function as markers to deflect the attacks of predators to non-vital regions of the body. A third possibility is also proposed; that eyespots intimidate predators merely because they are novel or rarely encountered salient features. These hypotheses are reviewed, with special reference given to avian
predators, since these are likely to be the principal visually hunting predators of the lepidopterans considered. Also highlighted is the necessity to consider the potential influence of sexual selection on lepidopteran wing patterns, and the genetics and development of eyespot formation.
Heck, there are species that only develop eyespots during certain times of the year. Genetic variation also impacts the coloration surrounding the eyespots. Motion can impact their display and predators' reactions to them. Plus, we know that some predator responses are inherited while others are learned. Et cetera.
In other words, various predators respond to various eyespots on various prey in various ways, some of which can vary over time.
Thinking Clearly Longer: Living longer can seem scary if, for instance, we lose those years to the fog of Alzheimer's. Fortunately, the odds of doing so seem to be dropping.
A new nationally representative study shows a downward trend in the rate of "cognitive impairment" — the umbrella term for everything from significant memory loss to dementia and Alzheimer’s disease — among
people aged 70 and older.
The prevalence of cognitive impairment in this age group went down by 3.5 percentage points between
1993 and 2002 — from 12.2 percent to 8.7 percent, representing a difference of hundreds of thousands of people.
And while the reasons for this decline aren't yet fully known, the authors say today's older people are much likelier to have had more formal education, higher economic status, and better care for risk factors
such as high blood pressure, high cholesterol and smoking that can jeopardize their brains.
In fact, among the 11,000 people in the study, those with more formal education and personal wealth were less likely to have cognitive problems.
Interestingly, the more-educated seniors who had cognitive impairment
were more likely to
die within two years. But the researchers say this may actually result
from a protective effect of better education on a person's "cognitive
reserve" — their ability to sustain more insults to their brain before
significant thinking problems arise.
Specifically when it comes to education and health...
"We know mental stimulation has an impact on the way a person’s brain
is 'wired,' and that education early in life likely helps build up a
person’s cognitive reserve. We also know cardiovascular health has a
close link with brain health," he continues. "So what we may be seeing
here is the accumulated effects of better education and better
cardiovascular prevention among the people who were over age 70 in
2002, compared with those who were over age 70 in 1993."
...
At the same time, the use of cholesterol-lowering drugs, blood pressure medications and other preventive cardiovascular medications and strategies increased dramatically in the 1990s. These factors may have helped protect seniors’ brain function by decreasing the incidence of vascular dementia — cognitive problems brought on by mini-strokes, strokes and decreased blood flow to and within the brain due to
"hardened" or clogged arteries.
Additionally, the researchers included the following speculation in their study.
While the new study shows a decline in cognitive impairment prevalence over time, the researchers note that the gains made in the 1990s and early 2000s might be offset by the damage that could result if the current epidemic of
type 2 diabetes keeps growing among the elderly and if current middle-aged and younger people stick with unhealthy eating and exercise habits that lead to unhealthy weights and blood pressures.
Fatter and more forgetful? There was a study on that a couple of years ago...
Scientists have wondered why obese patients who have diabetes also may have problems with their long-term memory. New Saint Louis University research in this month's Peptides provides a clue.
"Leptin is a hormone secreted by fat cells that tells us to stop eating. In obese people, it doesn't
cross into the brain to help regulate appetite," says Susan A. Farr, Ph.D., principal investigator and associate research professor in the division of geriatric medicine at Saint Louis University School of
Medicine.
We've now found leptin affects the brain in other ways, compromising learning and memory. Low
levels of leptin also could be related to cognitive deficits in disorders like type two diabetes."
Farr and her research team
tested the role of leptin in learning and memory using an animal model.
They found that mice navigated a maze better after they received leptin.
But did the mice improve their exercise, sleeping, and eating habits?
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