News Briefs – October 2013

BROCCOLI COMPOUND MAY PREVENT OSTEOARTHRITIS

Researchers have found that sulforaphane, a compound found in broccoli, may play a key role in preventing, or slowing the progression of, osteoarthritis. (Often called “wear-and-tear arthritis”, osteoarthritis is the most common type of arthritis and occurs when the protective cartilage on the ends of bones wears down over time. It can damage any joint in your body, but osteoarthritis most commonly affects joints in the hands, neck, lower back, knees and hips. Sulfo-raphane is released when eating cruciferous vegetables such as Brussels sprouts and cabbage, but much higher amounts are released from broccoli.)

Mice fed a diet rich in sulforaphane had significantly less cartilage damage and osteoarthritis than those that were not. Lab results showed that sulforaphane slows down the cartilage destruction in joints. The researchers discovered that sulforaphane blocks the enzymes that cause joint destruction by stopping a key molecule known to cause inflammation. Previous research has suggested that sulforaphane has anti-cancer and anti-inflammatory properties, but this is the first major study into its effects on joint health.

This study was released online August 28, 2013 by Arthritis and Rheumatism. The full report can be accessed online for a fee at https://tinyurl.com/ojzdg68

BLOOD PRESSURE DRUGS LINKED TO INCREASED BREAST CANCER RISK

New research shows that postmenopausal women who take a specific class of medicine for high blood pressure, known as calcium-channel blockers, may be at a greater risk for developing breast cancer. Results showed that women who took calcium-channel blockers for 10 years or more had a risk for both ductal and lobular cancer that was 2.5 times higher than those who never used calcium-channel blockers or those who used other forms of antihypertensive drug.

Long-term use of other forms of antihypertensive drugs, such as diuretics, beta blockers and angiotensin-receptor blockers, were not linked to an increased breast cancer risk in the study, just calcium-channel blockers.

(This study is the first of its kind to analyze long-term use of calcium-channel blockers and to associate their use to a risk of breast cancer. It has been previously theorized that this type of drug could increase the risk of cancer because it suppresses cell death, a normal part of the life of a cell. Antihypertensives are the most-prescribed drugs in North America. About 70% of all breast cancers are invasive ductal carcinomas, while about 20% are invasive lobular carcinomas.)

The study authors called for more research to fully understand the underlying biological mechanisms potentially responsible for the added risk. This study was released August 5, 2013 by the Journal of the American Medical Association. It can be read in full at https://tinyurl.com/kmvxawl by subscribers or those who pay an access fee.

FISH OIL KILLS SKIN AND MOUTH CANCER CELLS IN LAB TESTS

New research has found that omega-3 fatty acids, contained in oily fish such as salmon and trout, killed human skin and mouth squamous-cell carcinoma cells that had been cultured in the lab, without harming  healthy human skin cells. (Omega-3 polyunsaturated fatty acids cannot be made by humans in large quantities and must be acquired from diet or supplements. Squamous cells are the main part of the skin, and also occur in the mouth, digestive tract, lungs, and other areas of the body. Oral squamous cell carcinoma is the sixth most common cancer worldwide and one of the difficult and expensive to treat. While previous and unconfirmed studies have linked omega-3s with the prevention of some cancers, there has been very little work done on oral cancer cells.)

In the experiments, the scientists grew cell cultures in the lab and then treated them with fatty acids. The cell lines included both cancerous oral and skin cells, along with pre-malignant cells and normal skin and oral cells. This effect of killing cancer cells and sparing healthy cells was partly due to an over-stimulation of a key growth factor, known as epidermal growth factor, which triggered cell death. For fatty acids, this is seen as a novel type of anti-cancer mechanism. The study team suggested that, if confirmed, fish oil may be used to efficiently block tumour growth and destroy cancerous tissues of the mouth and skin without harming healthy tissue. Also, because skin and oral cancers are often easily accessible, there is the potential to deliver targeted doses locally via aerosols or gels. However further research is needed to confirm this and to then define the appropriate therapeutic doses. This research was just released online by the journal Carcinogenesis. The full study is now accessible at https://tinyurl.com/lw76umz for an access fee.

HIGH-QUALITY DIET ASSOCIATED WITH LOWER RISK OF PANCREATIC CANCER

A large study has found that people whose dietary intake was most consistent with the 2005 Dietary Guidelines for Americans had lower risk of pancreatic cancer. (Previous studies investigating the relationship between food and nutrient intake and pancreatic cancer have yielded inconsistent results. The U.S. Government issues these evidence-based dietary guidelines to promote overall health for Americans.)

The study team evaluated how closely the diets of the 537,218 participants matched the guidelines, as measured by the Healthy Eating Index (HEI-2005), and then compared their risk of pancreatic cancer. Pancreatic cancer risk was then compared between those with high and low HEI-2005 scores, allowing for the influence of other known pancreatic cancer risk factors. Overall, the investigators observed a 15% lower risk of pancreatic cancer among participants with the highest score compared to those with the lowest. While the authors adjusted for known risk factors such as smoking and diabetes status, they caution that other health factors not collected in the questionnaires may be associated with a more healthful diet and might explain some of the observed reduced risk. This study was released August 15, 2013 by the Journal of the National Cancer Institute. It can now be accessed online at https://tinyurl.com/pzy2ss2 with a subscription or fee.

Editor’s note: Key recommendations in the 2005 Dietary Guidelines for Americans included:

1) Choose a variety of fruits and vegetables each day. In particular, select from all five vegetable subgroups (dark green, orange, legumes, starchy vegetables, and other vegetables) several times a week.
2) Consume less than 10% of calories from saturated fatty acids and less than 300 mg/day of cholesterol, and keep transfatty acid consumption as low as possible.
3) Keep total fat intake between 20 to 35% of calories, with most fats coming from sources of polyunsaturated and monounsaturated fatty acids, such as fish, nuts, and vegetable oils.
4) Engage in regular physical activity to promote health, psychological well-being, and a healthy body weight.

SKIPPING BREAKFAST RAISES HEART ATTACK RISK

Scientists have reported the finding that men who don’t eat breakfast have a 27% greater risk of suffering a heart attack or developing heart disease than those who start the day with something in their stomachs. (This confirms earlier research linking eating habits to elevated risk factors for heart disease. Men who skip breakfast are 15% more likely to gain weight and 21% more likely to develop Type 2 diabetes, earlier studies have reported. This link is not necessarily a cause-and-effect relationship; it could reflect the fact that skipping meals commonly occurs in conjunction with other habits that do affect heart risk.)

In the 16-year study of nearly 27,000 male health professionals, researchers found a 55% increased risk of heart disease in men who regularly indulge in late-night snacking, although very few men reported doing this.

Scientists suggested several possible explanations why skipping breakfast can have such a drastic effect on heart health. Breakfast-skippers were more likely to smoke, engage in less exercise, and drink alcohol. Also, men who skip breakfast do not pick up a replacement meal later in the day, suggesting they tend to feast on higher-calorie meals when they do eat; studies have found that feasting can result in high cholesterol and elevated blood pressure, compared with nibbling smaller meals. There is extra strain on the body from eating more calories during the few times in a day that breakfast-skippers do eat. Also, missing breakfast means skipping a meal that usually features oatmeal, fiber, fruit or yogurt, which are healthier choices. Younger men tend to skip breakfast more frequently, which suggests these are men who are rushing out to stressful jobs; stress is bad for heart health and is associated with negative lifestyle choices such as drinking or smoking. The study did not include women, but the lead researcher believes the same pattern likely occurs in women who skip breakfast. This report was published in the July 22, 2013 issue of the journal Circulation, available at https://tinyurl.com/m5966ma

ANEMIA LINKED TO INCREASED RISK OF DEMENTIA

A study has found that anemia may increase the risk of dementia. (Anemia is the loss of red blood cells or less than the normal number of iron-containing elements in red blood cells. The most common form is iron-deficiency anemia, which can result from a loss of blood. Anemia is common in the elderly and occurs in up to 23% of adults aged 65 and older. Anemia has been linked in studies to an increased risk of early death.) Older adults were tested for anemia and for memory and thinking over 11 years. People who had anemia at the start of the study had a nearly 41% higher risk of developing dementia than those who were not anemic. The link remained after considering other factors, such as age, race, sex and education. The researchers suggested several explanations for the connection between anemia and dementia. First, anemia may cause low oxygen levels throughout the body, which have been shown to reduce memory and thinking abilities and may contribute to damage to neurons. Second, anemia may be a marker for poor health in general, in turn potentially raising dementia risk. Although this study will not be print-published until a future issue of the journal Neurology, it was released online July 31, 2013. The full study can be accessed now at https://tinyurl.com/ndxdnhf for a fee.

OBESITY LINKED TO LACK OF SLEEP

Scientists have found a link between inadequate sleep and decision-making about food choices, suggesting that problems with sleep could play a part in developing obesity or remaining overweight. The researchers took powerful scans using functional magnetic resonance imaging (fMRI) of the brains of 23 healthy adults the morning after a normal night of sleep and again, a week later, after a sleep-deprived night. Both times they were connected to sleep monitoring equipment in order to check the levels of sleep they got.

The brain scan pictures were generated as the participants were asked to rate pictures of 80 different foods presented to them. High-calorie foods became significantly more desirable when participants were sleep-deprived. The researchers found that sleeplessness reduces higher order powers of the brain and creates an excessive response in more primitive parts of the brain, leading to poor food choices. (This combination of altered brain activity and decision-making may help explain why people who sleep less also tend to be overweight or obese. Essentially, our power over food is blunted by a lack of sleep.) This study was released August 6, 2013 by the journal, Nature Communications, and is now available for online access at https://tinyurl.com/m8yreq6 for a fee.

COPPER IDENTIFIED AS CULPRIT IN ALZHEIMER’S DISEASE

A shocking study reveals that copper may be the main environmental factor that triggers the onset and enhances the progression of Alzheimer’s disease (AD), by preventing the clearance and accelerating the accumulation of toxic proteins in the brain. Researchers found that over time, copper has a cumulative effect that impairs the normal mechanism by which amyloid beta, a protein believed to be instrumental to the development of AD, is safely removed from the brain. This impairment is one of the key factors that cause the protein to accumulate in the brain and form the plaques that are the hallmark of this memory-robbing and inevitably fatal disease. (Copper is found everywhere in the food supply, in drinking water carried by copper pipes, in nutritional supplements, and in certain foods such as red meats, shellfish, nuts, and many fruits and vegetables. This mineral is important to health and plays an important and beneficial role in nerve conduction, bone growth, the formation of connective tissue, and hormone secretion.)

Despite its importance, the study shows that copper can also accumulate in the brain and cause the blood brain barrier, which is the system that controls what enters and exits the brain, to break down, resulting in toxic accumulation of the protein amyloid beta, a by-product of cellular activity. The research team dosed normal mice with copper over a three month period with an exposure that consisted of trace amounts of the metal in drinking water, amounts equal to one-tenth of the water quality standards for copper established by the U.S. Environmental Protection Agency. (These are extremely low levels of copper, equivalent to what people would consume in a normal diet.) The copper made its way into the blood system and accumulated in the vessels that feed blood to the brain, specifically in the cellular walls of the capillaries. These cells are a critical part of the brain defense system and normally help prevent copper from entering the brain. However, over time the metal can accumulate in these cells with toxic effect. The copper caused cells in the blood brain barrier to become leaky and inhibited the removal of amyloid beta from the brain when tested in both mouse and human brain cells.

It is likely that both aging effects and the cumulative effect of copper stimulated the activity of neurons that boost production of amyloid beta. However, because this metal is essential to so many other vital functions in the body, the researchers said that any new recommendations based on these results should be interpreted with some caution. The key to preventing AD and supporting good health generally, they implied, may be striking the right balance between too little and too much copper. However, the team reported they do not yet know the right level for optimum balance. This report was released on the website of the Proceedings of the National Academy of Sciences on August 19, 2013 in advance of later publication in the journal. Find this study at https://tinyurl.com/manrjob

IRON DEPOSITS, NOT AMYLOID PLAQUE, MAY BE ALZHEIMER’S CAUSE

Following very closely on the heels of a study implicating excess copper intake in the development of the amyloid beta plaque associated with Alzheimer’s disease (AD), a new study suggests that the accumulation of iron in the brain, and not plaque, may be the real cause of this fatal, memory-destroying disease. (Most researchers believe AD is caused by one of two proteins, one called tau, and the other beta-amyloid. Scientists say that these proteins either disrupt signaling between brain cells called neurons or simply kill them. This new evidence suggests iron accumulation as a root, further-upstream, cause.)

Using sophisticated MRI brain-imaging techniques on AD patients and healthy subjects, the study team found higher iron levels in the hippocampus area of the brain of AD patients, a key memory area. They further found that these high levels were directly associated with tissue damage in that area. However, iron levels were not elevated either in healthy subjects or in the thalamus brain area, an area less affected by AD. The reason that high iron intake was not suggested before as the cause for AD, the lead researcher said, is that the amount of water in the brain is known to increase in AD patients, and this can mask the detection of excess iron. Iron is essential for cell function, but this study implies that lowering red meat and iron supplement intake may reduce iron build-up and prevent AD.

The report was published in one of the several August 2013 print issues of the Journal of Alzheimer’s Disease. The full study is not yet available online, but a summary can be accessed at https://tinyurl.com/km73ajn at no cost.

HIGH INTAKE OF FRUITS MAY REDUCE ANEURYSM RISK

Scientists have found that a diet high in fruit might decrease the risk of developing an abdominal aortic aneurysm, which is often fatal. (This is a bulge in the wall of that part of the aorta, the widest artery in the body, that runs through the abdomen. If an aneurysm ruptures, there is a high risk of death from bleeding.)

This research involved over 80,000 people who were tracked for 13 years. People who ate more than two servings of fruit daily, not counting juice, had a 25% lower risk of developing this type of aneurysm and a 43% lower risk of a rupture among those who did have this type of aneurysm, compared to those who ate less than one serving of fruit a day. It may be that the high levels of antioxidants in fruits deliver this protection by reducing inflammation. Yet eating lots of vegetables, also rich in antioxidants, did not reduce this risk. Vegetables lack some antioxidant types found in fruits.

This study was released August 20, 2013 by the journal Circulation. The full study is available to the public at https://tinyurl.com/kpu4cyc free of charge.

BLOOD SUGAR LEVEL PREDICTS DEMENTIA RISK, EVEN IN ABSENCE OF DIABETES

A new study has found that higher blood-sugar levels are associated with higher dementia risk. Scientists studied more than 2,000 people aged 65 and older. In those without diabetes, the risk for dementia was 18% higher for people with an average glucose level of 115 milligrams per deciliter, compared to those with an average glucose level of 100. And in people with diabetes, whose blood-sugar levels are generally higher, dementia risk was 40% higher for people with an average glucose level of 190 milligrams per deciliter compared to those with an average glucose level of 160. The results showed that every incrementally higher glucose level was associated with a higher risk of dementia.

However, the researchers indicated that eating less sugar or eating lower on the glycemic index will not likely reduce blood sugar or lower dementia risk. The body turns all food into glucose, so blood-sugar levels depend not only on what is eaten but also on individual metabolism. They stressed that taking walks and other physical activity was previously linked to later onset of, and reduced risk of, dementia, including Alzheimer’s disease. Also, this was an observational study, meaning that people with higher glucose levels showed higher risk of dementia; but no data has yet suggested that people who make changes to lower their glucose will improve their dementia risk. Those data would have to come from future studies with different study designs. Published in the August 8, 2013 issue of the Journal of the American Medical Association

, this study has now been made available online at https://tinyurl.com/kvmhgka for a small fee.

STUDY SUGGESTS SUGAR SHORTENS LIFESPAN

A new study reveals that when mice eat a diet of 25% extra sugar – the mouse equivalent of a healthy human diet plus three cans of soda daily – the females died at twice the normal rate, and males were 25% less likely to hold territory and reproduce. In other words, added sugar consumed at concentrations currently considered to be safe by experts exerts dramatic adverse impacts on health. The highly sensitive test used showed an adverse outcome from the added-sugar diet that could not be detected by conventional tests. The 25% added-sugar diet was half dextrose (the industrial name for glucose), and half fructose. (Previous tests fed mice large doses of sugar disproportionate to the amounts most people consume in total from sweetened beverages, baked goods, added sugar, and candy. This study demonstrates the adverse effects of added sugars at human-relevant levels. Both high-fructose corn syrup and table sugar, also called sucrose, are made up of half fructose and half glucose.) Even though the mice did not become obese and showed few metabolic symptoms, the sensitive test showed that they died more often and tended to have fewer babies. The research was published online August 13, 2013 in the journal Nature Communications. It can now be read online at https://tinyurl.com/yce9pb7