I’m off for a two week holiday and will not be updating this blog. Nor moderating comments!
I’m off for a two week holiday and will not be updating this blog. Nor moderating comments!
Mice are helping scientists to understand insulin resistance, a precursor to type 2 diabetes. To recap, insulin resistance is a failure of the body to deal with blood glucose normally:
The problem starts during gluconeogenesis–a process by which blood sugar is produced in the liver, explains Marc Montminy, Ph.D., a professor in the Clayton Foundation Laboratories for Peptide Biology, who led the study. During fasting, gluconeogenesis maintains blood sugar levels by increasing glucose production. After a meal, the hormone insulin normally turns down gluconeogenesis ensuring that blood sugar levels don’t rise too high. “But in people with insulin resistance, blood sugar levels are elevated because gluconeogenesis continues when it shouldn’t, increasing the risk of developing type II diabetes,” Montminy says.
In order the understand the inner workings of the liver in the process. Scientists spliced the glowing fire-fly genes into mice in such a way that it could only be turned on in the liver by the [gluconeogenesis] switch. Well that’s cool.
Besides just being incredibly awesome, these glowing mice will be useful in research on the effectiveness of future diabetes drugs. The goal being to find a drug that can turn off the light. More.
Indian Killer Belly is a strange and scary phenomenon. Asian Indians have a much higher incidence of diabetes and heart disease that other races even when other risk factors have been factored in.
Indian men, no matter where they live, have one of the highest rates of heart disease in the world, even if they have low levels of traditional risk factors such as cholesterol. In fact, even non-smoking vegetarians under 40 who exercise regularly may be at high risk.
While 60 percent of heart attacks amongst Americans occur after age 55, nearly half of all heart attacks among Indian men strike under the age of 55 and 25 percent under the age of 40. Indian women share these high rates of heart disease. Thousands of Indian American men in their 40s and 50s succumb to a first, fatal heart attack every year.
A new study may shed some light on this problem. It seems that Indians’ fat is fatter. Or more precisely, their fat cells are considerably larger than those of caucasians and this is inversely correlated with ability to cope with blood glucose (ie insulin resistance):
Compared to Caucasians, in spite of similar BMI, South Asians had higher total body fat (22±6 and 15±4% of body weight; p-value<0.0001), higher subcutaneous abdominal (SA) fat (3.5±1.9 and 2.2±1.3 kg, respectively; p-value = 0.004), but no differences in intraperitoneal (IP) fat (1.0±0.5 and 1.0±0.7 kg, respectively; p-value = 0.4). SA adipocyte cell size was significantly higher in South Asians (3491±1393 and 1648±864 µm2; p-value = 0.0001) and was inversely correlated with both glucose disposal rate (r-value = −0.57; p-value = 0.0008) and plasma adiponectin concentrations (r-value = −0.71; p-value<0.0001). Adipocyte size differences persisted even when SA was matched between South Asians and Caucasians.
The bottom line is that big fat cells and high levels of subcutaneous fat (but not visceral fat) were found to be risk factors for insulin resistance and heart disease. More.
Health warning: the innocence of visceral fat is not supported by other studies. Also, this study only included a total of 29 south Asians and 19 Caucasians. More research is needed.
An interesting article on food labels, radiation and how it’s a lot cheaper to meet your daily fruit and veg needs than you may think… Marion Nestle from What to Eat
Meanwhile in the southern hemisphere, the Kiwis are recommending a system of red, yellow and green labels to indicate the levels of fat, salt and sugar in products in a broadbrush approach to labeling help tackle obesity. Let’s see how “sugar free” Oreos fare.
Cause or effect?
Young adults who lose their teeth to cavities or gum disease may have an increased risk of dying from heart disease later in life, a new study suggests. (…) Tooth loss is an indicator of poor oral health. Scientists speculate that the bacteria in the mouth that cause cavities and gum disease may enter the bloodstream and either damage the blood vessel lining directly or trigger inflammation in the body that then contributes to heart disease. – Reuters
Actually this isn’t exactly news. We’ve been hearing about this correlation for years. And as for the cause and effect relationship between oral hygiene and heart health, this is matter of speculation.
The chief culprit in the mouth is Streptococcus mutans, with Lactobacillus species also playing a role. These germs thrive on sugar, and every time we eat a meal or a snack, sugar levels in the mouth increase and nourish the resident bacteria. Within 20 minutes, sticky, destructive plaque begins to form on our teeth, and decay is underway.
The pathogenic S. mutans bacteria can travel through the bloodstream and infect the interior linings of the heart, causing infectious endocarditis, a very serious disease. In the worst-case scenario, this can lead to damaged heart valves and congestive heart failure. Concern over the possibility of endocarditis is one reason why dentists usually administer antibiotics before performing invasive procedures on susceptible individuals, such as those with periodontal disease. – More
Perhaps S. mutans is the culprit or perhaps a diet high in sugar leads both to heart disease and tooth decay. The fact is that a third actor may be causing the two. At one time, Helicobacter pylori was suspected of being a player in this correlation.
Whatever the truth, good oral hygeine is always recommended if not for dental health then at least for personal care and for social reasons! Brushing after every meal is also a good way to reduce snacking (how can I get my teeth dirty again?!).
And as always – cut out the sugar.
A much abused substance may have a negative impact on bone growth:
In Medicine, paracetamol is used to soothe every kind of pain, from simple molar pain to pain produced by bone fractures. This medicine is one of the most used nowadays. However, [researchers] showed that taking paracetamol slows down bone growth, as has been proved by ‘in vitro’ studies.
This research is very theoretic ie it has been carried out in a petri dish and the assumption is that the same process takes place in the body. It may be a stretch. However given the role of bones in the regulation of insulin, this may be a factor to consider for those trying to improve their insulin sensitivity.
In a recent symposium, scientists reported what we already know – that once the diet is over the body works overtime to put the fat back on…
[Researchers] suggested that the physiological processes which drive all of us to seek and ingest food and limit energy expenditure during periods of negative energy balance provide an irresistible drive to regain lost adipose stores in weight-reduced obese individuals. This provides a potential basis for the well-recognized difficulty of maintaining weight loss.
But it gets worse! Granted our bodies are designed to conserve energy and store fat during periods of caloric deprivation. But could stress be triggering those same processes?
[Researchers] reported that conditions of reduced food allowance and chronic stress excite central neural networks that may lead toward abdominal obesity. This provides a potential link between stress and obesity.
Time to add some yoga to your weight-loss regime. More.
Via Mark’s Daily Apple:
Proteins from tartary buckwheat and common buckwheat helped reduce cholesterol levels in rats on a high cholesterol diet by at least 25 per cent, report Japanese researchers.
The research, published in the Journal of Food Science, reports that supplementation of a high cholesterol diet with protein from common buckwheat (Fagopyrum esculentum Moench) and tartary buckwheat (Fagopyrum tataricum Gaertn) reduced serum cholesterol levels in rats by 32 and 25 per cent, respectively.
Now if we could just get the rats to cut back on cigarettes we’d be getting somewhere. More
Despite the common name buckwheat is not related at all to wheat – and it’s gluten free. In fact, it’s not even a grain. Buckwheat is actually a fruit, but is usually classified as a grain because it’s prepared and eaten like one. Buckwheat is nutritious as well. It’s a good source of protein and is especially high in the amino acid lysine. Buckwheat is also extremely high in calcium and a good source of B-complex and E vitamins.
Science keeps plodding along to help save us from ourselves…
While the reduction in blood pressure was modest (an average of 5.6/2.2 mm Hg), at 4.3 years the treated group had a relative risk reduction of 14 percent for coronary heart disease events, 18 percent for cardiovascular deaths, 14 percent for deaths of any cause, and 21 percent for developing new or worsening kidney disease.
MacMahon calculated that one death could be avoided among every 78 patients treated for five years. Because type-2 diabetes is so common worldwide, he added that treatment such as this could prevent as many as 1.5 million deaths, even if given to only half of the world’s diabetics.
I love that they have bothered to report the Numbers Needed to Treat here ie 78 people treated saves 1 life. It’s worth pointing out though that they haven’t prevented 1.5m deaths so much as postponed them! More
Glands are organs or parts of organs that make and secrete substances. Liver is considered the largest glands but perhaps our thinking should change…
Adipose tissue is no longer seen merely as a mostly passive energy storage organ but is now also considered to be an active endocrine tissue that by producing a variety of cytokines, hormones and other proteins impacts on a multitude of physiological and pathophysiological processes in the human body. The adipocyte, whose size and numbers are increased in obesity, is the cellular factory that produces these proteins termed adipokines. We have cultured adipocytes from human adipose tissue and used them as a model to study effects of inflammatory mediators on the production of various adipokines by these cells.
Unfortunately, the substances that fat is secreting are not always beneficial and lead to a variety of problems.
Fat also behaves a lot like a tumour building blood vessels so that it can thrive and grow:
VEGF is a protein, which induces the growth of new blood vessels. It is believed that adipose tissue, when it increases in mass, needs additional blood vessels to secure its supply with nutrients and oxygen. In fact, in mice it has been shown that blockade of VEGF leads to a decrease in adipose tissue mass in these animals. We were able to show in mice, for the first time, that inflammatory mediators injected into these animals led to increased blood vessel growth in adipose tissue. Such increase in blood vessel density in adipose tissue would then in turn result in better supply with oxygen and nutrients and could ultimately lead to growth of adipose tissue.
Of course fat is essential to survival but the bottom line is, it’s not a passive payload. Fat is alive and actively influences your health and body chemistry. More.