News Briefs – May 2011
SUGAR AND SUGAR-SWEETENED DRINKS LINKED TO HIGH BLOOD PRESSURE
Researchers have found that those who consume more fructose and glucose (sugar) than the median have higher blood pressure, with a more pronounced spike among those who also consume more salt. Also, those who drink just one sugar-sweetened soda per day have modestly higher blood pressure readings. However, those who drink diet soft drinks have lower blood pressure. The systolic and diastolic blood pressure readings for those who consume more fructose and glucose, as well as more salt, were higher by 3.4 and 2.2 millimeters of mercury (mm Hg), respectively. The blood pressure scores for those who consume sugar-sweetened sodas were 1.6 and 0.8 mm Hg higher, for the systolic and diastolic readings, respectively, for every diet soda consumed. (Systolic blood pressure is the upper number in a blood pressure reading and diastolic is the lower. Fructose and glucose are both found in high-fructose corn syrup, the most common sugar found in soft drinks.) This study was released February 28, 2011 by Hypertension, but will not appear in print until a future issue of this journal.
(Ed note: Diet soda is, however, not considered a health drink due to the chemicals used as artificial sweeteners.)
SUGAR-SWEETENED BEVERAGES LINKED TO DIABETES
A study has confirmed prior research showing an increased risk of diabetes type 2 from consumption of sugar-sweetened beverages and has finally clarified the previously unclear relationship between artificially sweetened drinks and diabetes by showing no greater risk when confounding factors are excluded. Compared to people who fall into the lowest quarter of consumption, those in the highest quarter of sugar-sweetened beverage intake showed a 25 percent greater risk of Type II diabetes; when other confounding factors were excluded, the risk remained 24 percent higher. Compared to the lowest intake quartile, those in the highest intake quartile of artificially-sweetened beverages showed a higher diabetes risk before adjustment; but when confounding factors were excluded, the risk dropped to statistically insignificant. (Confounding factors are those that could increase or lower the risk and therefore, skew the results; examples include multivitamin use, family history of the disease, health status, dieting, body mass index and other factors.) Beverages classified as sugar-sweetened included lemonade, fruit punches and fruit drinks.
Released March 23, 2011 by the American Journal of Clinical Nutrition, this study will appear in a future issue but is available now at https://bit.ly/fOJIZs with subscription or fee.
FISH AND FISH OIL MAY PROTECT AGAINST BONE LOSS
A study has concluded that greater consumption of fish or fish oil appears to result in greater bone mineral density (BMD) compared to the BMD of those who consume less or no fish or fish oil, and therefore, may help protect against the loss of bone density with age. Also, results suggested a stronger benefit from these fish oils – the omega-3 polyunsaturated fatty acids known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – with higher consumption of an omega-6 polyunsaturated fatty acid known as arachidonic acid (AA). This added AA effect on BMD may be dependent on the amount of EPA and DHA intake, researchers suggested. (Since little or no AA is found in plant foods, the body must get this essential oil from animal sources – meat, eggs or dairy – or by converting the essential oil linoleic acid, LA, into AA; LA itself is found in a wide variety of oils. All of these oils are termed “essential” because, although they are required by the body, they cannot be synthesized by the body.) A high intake of fish was defined as three or more fish servings a week. The study assessed and followed 75-year-olds for four years. This study was released March 2, 2011 and will not be published in print until a future issue of the American Journal of Clinical Nutrition.
PHYSICIANS INTERESTED IN LEARNING MORE ABOUT SUPPLEMENTS
A study has found that 57 to 75% of physicians use dietary supplements; and 66 to 91% recommend supplements to their patients. Most doctors indicated their medical education had not included any formal training on dietary supplements and expressed an interest in continuing education regarding these products. The study included 300 cardiologists, 300 dermatologists and 300 orthopedists; the percentage of each specialty that took dietary supplements occasionally was 57, 75 and 73%, respectively; the percentage of each specialty that took supplements regularly was 37, 59 and 50%, respectively. The most common supplement taken by physicians was a multivitamin. Over 25% of doctors in each specialty took omega-3 fatty acids and over 20% reported they used botanical supplements. Patients were advised to take specific supplements by 72% of cardiologists, 66% of dermatologists and 91% of orthopedists. The main reasons given for recommending supplements were for heart health; skin, nail and hair health; and bone and joint health. This study was released March 3, 2011 and will be published in a future issue of Nutrition Journal. It is available online now at https://bit.ly/hjL5mx without charge.
INFLAMMATORY BOWEL DISEASE CAUSES IRON DEFICIENCY
Researchers have concluded that those with an active, helicobacter pylori (H. pylori) infection – even those who show no symptoms and may be unaware they have this inflammatory bowel disease infection – have significantly lower levels of iron compared to those who are no longer infected, whether or not they have outright anemia or iron deficiency. The study was limited to children but may apply to all infected individuals. Those whose H. pylori infection was eliminated saw their body iron levels return to normal. (H. pylori are bacteria that infect the stomach and may result in low-level inflammation, gastritis, peptic ulcers and stomach cancers. Half of all people are infected with H. pylori but 80 percent of those infected show no symptoms. Iron levels affect several body functions including brain activity and are linked to higher risk of mortality.) The study raises the questions of whether symptom-free, H. pylori infection may have serious health consequence and whether screening and supplementation may prove beneficial. This study was published in the March 2011 issue of the journal, Journal of Pediatric Gastroenterology & Nutrition. It is available online at https://bit.ly/hUubVo with subscription or fee payment.
LOW-CARBOHYDRATE DIET MAY RAISE COLON CANCER RISK
New research has found that a high-protein, low-carbohydrate diet increases cancer-causing fecal metabolites and decreases cancer-protective metabolites, and that this type of diet results in a greater risk of colon cancer. (Metabolites are small molecules that are the products of normal chemical reactions in the body.) Subjects were placed on different diets: a weight maintenance diet (MD); or a high-protein, moderate carbohydrate (HPMC) weight-loss diet; or a high-protein, low-carbohydrate (HPLC) weight-loss diet. These diets were defined, respectively, by content: 85gm of protein, 116gm of fat and 360gm of carbohydrate per day (MD); 139gm of protein, 82gm of fat and 181gm of carbohydrate per day (HPMC); and 137gm of protein, 143gm of fat and 22gm of carbohydrate per day (HPLC).
Both the HPMC and HPLC dieters experienced increased levels of hazardous, potentially carcinogenic metabolites compared to those on the MD diet. Those on the HPLC diet also experienced decreased levels of cancer-protective metabolites compared to the MD and HPMC diets and therefore, had the greatest increased risk of colon cancer. This study was released March 9, 2011 but will not appear in print until a future issue of the American Journal of Clinical Nutrition. It is available online now at https://bit.ly/dZnmwC with subscription or fee.
HEART ATTACKS TRIGGERED BY AIR POLLUTION AS MUCH AS OTHER FACTORS
Researchers have found that air pollution, and especially traffic pollution, triggers as many heart attacks as other known individual risk factors, such as physical exertion, alcohol and coffee. Data from 32 studies show that air pollution increases heart attack risk by 5%, while coffee and alcohol raise heart attack risk by 150% and 300%, respectively. However, because everyone is exposed to air pollution, that 5% higher risk translates to more heart attacks than attributable to higher-risk factors. Of all heart attacks, traffic exposure triggered 7.4%; physical exertion, 6.2%; alcohol, 5.0%; coffee, 5.0%; air pollution defined by increased heavy particles in the air, 4.8%; negative emotions, 3.9%; anger, 3.1%; heavy meal, 2.7%; positive emotions, 2.4%; sexual activity, 2.2%; cocaine use, 0.9%; marijuana smoking, 0.8%; and respiratory infections, 0.6%. The authors suggested passive smoking triggers as many attacks as outdoor air pollution.
This study was published in the February 26, 2011 issue of The Lancet; but is available online at https://bit.ly/eFLIhu with access fee.
DIET CHANGE REDUCES BISPHENOL A (BPA) LEVELS
It has been unclear whether body levels of the hormone disruptor bisphenol A, or BPA, come from BPA-treated cans and packaging, or from other BPA-containing products such as shower curtains and toys. The same question lingered for bis(2-ethylhexyl) phthalate, or DEHP, another hormone disruptor. (In recent years, controversial reports have questioned whether established safe limits for BPA and DEHP may be too high.) So researchers monitored urine levels of BPA and DEHP in 20 participants first on their regular diet, which included canned and packaged goods, and then on a diet of fresh food not canned or packaged in plastic. On the BPA-free diet, urine levels of BPA and DEHP dropped by an average of over 60%, and 50%, respectively. The team concluded that a substantial proportion, although not all, of the body level of BPA and DEHP comes from food packaging and that food producers could reduce body levels substantially with BPA- and DEHP-free cans and plastic packaging.
Released March 30, 2011, this study will not be published until a future issue of Environmental Health Perspectives but is available now at https://bit.ly/hBUlDQ without fee.
VEGETARIANS AT LOWER RISK FOR CATARACTS
While previous studies had focused on the link between specific nutrients and cataracts, new research has found that the risk of developing cataracts is 40% lower for vegans compared to those who eat the most meat. (A cataract is a clouding of the crystalline lens of the eye.) The study included 27,670 non-diabetic participants aged 40 and over. The subjects were divided into dietary groups according to their degree of consumption of meat and animal products. The risk of cataracts within each group was calculated by comparing each group with the highest meat-consuming group (100 or more grams of meat a day). Compared to the high meat eaters, the risk of developing cataracts in the moderate meat eaters (50-99 grams of meat a day), low meat eaters (less than 50 g of meat a day), fish eaters who ate no meat, vegetarians, and vegans was lower by 4%, 15%, 21%, 30% and 40%, respectively. This study was released March 23, 2011 and will be published in a future issue of the American Journal of Clinical Nutrition.
VITAMIN B12 PREVENTS NERVE DISORDERS IN OLDER ADULTS
Researchers have concluded that older adults who show no anemia, spinal cord degeneration, or other symptoms of vitamin B12 deficiency, still experience an improvement in nerve responses and function after supplementation with vitamin B12. (Vitamin B12 deficiency is very common in older adults but many people do not experience typical symptoms such as anemia or spinal cord degeneration.) In 200 individuals aged 75 or greater, the scientists measured certain electrophysiological indices that show the level of neurological functioning. Those administered oral supplements of 1mg (1000mcg) for one year showed a distinct improvement in these indices of peripheral and central neurosensory responses, which indicates an improvement in nerve function necessary for mobility and sensory function. This is the first study to prove deficiency-related, nerve impairment regularly occurs in seniors even in the absence of B12-deficiency symptoms; the researchers concluded that supplementation could have considerable significance for public health. This just-released study will appear in a future issue of Nutrition Journal but is available online now at https://bit.ly/gBE5Al without charge.
FISH AND OMEGA-3 FATTY ACIDS LOWER RISK OF AMD BLINDNESS
A study has found that consumption of one or more servings of fish weekly, or greater intake of either docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA), two oils found in some fatty fish, reduce the risk of age-related macular degeneration (AMD) significantly. (AMD is a loss of vision in the center of the visual field due to retina damage and usually affects older adults, although it can have an early onset.) Compared to less than one serving of fish a month, one or more fish servings per week lowered AMD risk by 42%. And those who consumed the most EPA, or the most DHA, or the greatest amount of both EPA and DHA combined, all experienced about the same reduction in AMD risk: 36%. A slightly higher risk of AMD from greater consumption of linoleic acid, an omega-6 fatty acid, was not considered significant; no link was found between AMD risk and the omega-6 oil, arachidonic acid. This study was released March 14, 2011 but will not be published until the June, 2011 issue of the Archives of Ophthalmology. It is available online now at https://bit.ly/fTAQVr without charge.
LOWER AFRICAN AMERICAN POTASSIUM INTAKE MAY EXPLAIN GREATER DIABETES RISK
Researchers have found that a lower consumption of potassium appears to explain 18% of the greater risk of Type II diabetes among African Americans. (This is comparable to the percentage of risk – 22% – among this group that has been attributed to higher average body mass index, BMI.) Different studies have found that African Americans are from 1.4 to 2.2 times more likely to have diabetes than white persons. According to a 2000 study in Diabetes Care, the percentages of people in different groups who have diabetes are: 10.8% of non-Hispanic blacks, 10.6% of Mexican Americans, 9.0% of American Indians, and 6.2% of whites.) Lower potassium levels are linked to higher diabetes risk; and low dietary potassium is more common in African Americans, compared to whites. The team concluded that further study is needed before higher potassium intakes could be recommended. This study was released March 2, 2011 but will not be published until a future issue of the American Journal of Clinical Nutrition.
ALA AND NUTS REDUCE INFLAMMATION MORTALITY RISK
Researchers have concluded that the risk of dying from an inflammation-caused disorder – other than cancers or cardiovascular disease – is reduced over 50% in both men and women by a higher consumption of nuts, and reduced in women as much as 44% by a higher overall intake of omega-3 polyunsaturated fatty acids. But this inflammation-related mortality risk is not reduced in men or women by a greater consumption of fish, or by a higher intake of either omega-6 oils or the specific omega-3 oils known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). (In addition to cancer and cardiovascular diseases, inflammatory disorders include allergies; autoimmune disorders ranging from ALS and MS to diabetes and COPD; myopathies, or muscle diseases; and many others. An example of an omega-3 fatty acid that is neither EPA nor DHA is alpha-linolenic acid or ALA.) The 2,514 participants in this 15-year study were all 49 years of age and older.
Released March 16, 2011, this study will not be published until a future issue of the American Journal of Clinical Nutrition.
DIETARY FIBRE MAY REDUCE MORTALITY RISK
A nine-year study has found that a diet rich in dietary fiber, especially grains, may reduce the risk of death from cardiovascular, infectious and respiratory diseases by 24 to 56 percent in men and by 34 to 59 percent in women. Also, a diet rich in fiber from grains – but not from other sources – reduced the overall risk of death from all causes for both men and women. In men – but not in women – the greater the amount of fiber ingested regularly from all sources, the lower the risk of death from cancer. (Fiber is found in fruits, vegetables and whole grains and is known to lower the risk of diabetes and some cancers. It binds to agents that could cause cancer and excretes them from the body. Current dietary guidelines recommend 14 gm of fiber for every 1,000 calories.) This study was released February 14, 2011 but will not be published in print until a future issue of the Archives of Internal Medicine. It is available online now at https://bit.ly/eiOwTx with subscription or access fee.
MODERATE SLEEP AND REDUCED STRESS AIDS WEIGHT LOSS
Researchers have found that people who had the lowest stress levels, and who slept more than six hours but not more than eight, were twice as likely to succeed at losing ten pounds over six months, even on the same weight loss program. However, there was no association between weight loss success and the level of depression or the amount of time spent watching TV or using a computer. Previous studies have found a link between these factors and the level of obesity but this study is the first to show these factors can predict weight loss success. The researchers suggested that, to achieve weight loss, some people may have to get more sleep, or less, and others may have to supplement their weight loss regimen with stress-relieving, mind-body techniques such as meditation. The team also observed twice the rate of success at weight loss among people who kept a food diary. This study was released March 29 but will not appear in print until a future issue of the International Journal of Obesity.
GRAPES CAN BE TOXIC TO PETS
Even a single grape can destroy the liver of a dog, cat or other pet and cause death. The list of human foods potentially fatal to pets is extensive, running from chocolate, nuts and onions to tomatoes, potato peels and broccoli; we just don’t have the full list. Cats are carnivore obligates, meaning they can derive no nutrition at all from plant foods. Dogs are carnivores, meaning that they can digest some plant foods but, like cats, they must get a lot of protein and fat to survive.
CHICKEN SKIN RANKED HIGHEST IN CANCER-CAUSING COMPOUNDS
A study of the relative amounts of cancer-causing compounds known as heterocyclic amines (HCAs) in various meat products has found that rotisserie-cooked chicken contained the highest levels – and that chicken skin itself contained eight times that amount. There are many considerations when choosing meat products, including the amounts of saturated fat, trans fat, preservatives and sodium, all of which can be high in pre-cooked, ready-to-eat meats. But when looking only at mutagenic HCAs, rotisserie-cooked chicken showed the highest content, outranking ready-to-eat meats such as pepperoni. Ranked from lowest to highest HCA content, the tested meats were pepperoni, hot dogs and deli meat, fully cooked bacon, rotisserie chicken meat and rotisserie chicken skin, which were found to contain, respectively, 0.05, 0.5, 1.1, 1.9 and 16.3 micrograms per gram. The reason chicken skin contained over eight times the HCA of chicken meat is that skin holds relatively less water and more fat and protein; HCA tends to be most concentrated where there is less water. This study will be published in the June, 2011 issue of the journal, Meat Science but is already available online at https://bit.ly/hiftd5 with subscription or fee.
