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Older adults experiencing cognitive difficulties might be able to lower the risk of developing dementia that proceeds to Alzheimer’s disease by eating a low-glycemic diet that is also low in saturated fats, U.S. scientists have found. Researchers have known for some time that diet is linked to cognitive ability, but the impact of a specific type of diet on “pathological brain aging” has not been explored. For this study, involving older adults who were either healthy or memory-impaired, 24 participants followed a high-saturated fat/high-simple carbohydrate diet and 25 followed a low-saturated fat/low-simple carbohydrate diet. Findings indicated that “diet may be a powerful environmental factor that modulates Alzheimer disease risk through its effects on central nervous system concentrations of Aβ42, lipoproteins, oxidative stress, and insulin.”
"Diet Intervention and Cerebrospinal Fluid Biomarkers in Amnestic Mild Cognitive Impairment", Archives of Neurology, June 13, 2011
A study by Harvard Medical School researchers has found an association between daytime sleepiness and the ability of the brain to regulate eating. Twelve healthy men and women, ages 19 to 45, underwent magnetic resonance imaging (MRI) as they looked at pictures of high-calorie foods, low-calorie foods and control images of plants and rocks. All were also measured on a sleepiness scale. Results showed that greater daytime sleepiness was linked to decreased activation in the prefrontal cortex – a brain region important to inhibitory processing – when participants viewed the pictures of enticing, high-calorie food images. "Given the chronic level of sleep restriction in our society, such relationships could have epidemiologic implications regarding the current increase in obesity in westernized countries," one researcher said.
"Sleepiness May Impair the Brains Inhibitory Control When Viewing High Calorie Foods", Press release and presenation at the Associated Professional Sleep Societies LLC meeting, June 13, 2011
Overweight and obese people who consume a high-fat diet are at risk for damage to the cells in the brain that control body weight, researchers at the University of Washington have found in an animal study. The researchers fed groups of six to 10 rats and mice a high-fat diet for one day to eight months in an effort to determine the short- and long-term effects. Detailed analyses on the animals' brains found that the animals fed the high-fat diet gained weight, developed inflammation in the hypothalamus, the part of the brain containing neurons that control body weight, and other brain abnormalities. The authors suggested that neuronal damage resulting from overconsumption of the typical Western diet makes it difficult to achieve sustained weight loss.
"Eating a high-fat diet may rapidly injure brain cells that control body weight", Presentation and press release, The Endocrine Society meeting, June 09, 2011
U.S. researchers looking for a way to ward off muscle wasting that results from illness and aging have discovered that a compound found naturally in apple peels protects against atrophy and causes normal muscles to grow. When the compound, ursolic acid, was added to the diet of fasting mice, their muscles resisted the wasting effect of the minimal diet. When ursolic acid was given to normal mice, their muscles grew. In addition, mice given ursolic acid became leaner and had lower blood levels of glucose, cholesterol and triglycerides. The researchers traced the effect to enhanced insulin signaling in muscle and to corrections in the gene signatures linked to atrophy.
"mRNA Expression Signatures of Human Skeletal Muscle Atrophy Identify a Natural Compound that Increases Muscle Mass", Cell Metabloism, June 08, 2011
Expectant mothers who eat a high-fat diet face an increased risk of their children being stillborn, a U.S. study has found. The study in macaque monkeys showed that a diet rich in fat decreases blood flow to the placenta, which provides nourishment to the fetus. The researchers observed 24 pregnant Japanese macaques whose diet consisted either of 32 percent calories from fat or 14 percent calories from fat over four years. The monkeys that ate a high-fat diet experienced a 38 percent to 56 percent decrease in blood flow from the uterus to the placenta, whether the monkeys were obese or slender. The risk of stillbirth was increased when the monkeys were obese with hyper-insulinemia, or pre-diabetes.
"Maternal High-Fat Diet Disturbs Uteroplacental Hemodynamics and Increases the Frequency of Stillbirth in a Nonhuman Primate Model of Excess Nutrition", Endocrinology, June 03, 2011
Scientists in the U.K. have discovered a link between dietary phosphate levels in the blood and both heart disease and insulin resistance. Cholesterol deposits in artery walls increase with a high phosphate diet, which includes foods like biscuits, cakes, sweets, dairy products and meats such as offal (organ meats, etc.) and veal. The researchers suggest that decreasing phosphate intake could reduce the risk of cardiovascular disease. However, very low levels of phosphate in the blood increase insulin resistance (metabolic syndrome), which can also lead to heart problems and type 2 diabetes. “These data indicate for the first time that controlling dietary phosphate intake may influence development of both atherosclerosis and metabolic syndrome,” the researchers concluded.
"Dietary Phosphate Modulates Atherogenesis and Insulin Resistance in Apolipoprotein E Knockout Mice", Arteriosclerosis, Thrombosis, and Vascular Biology, June 02, 2011
A U.S. clinical study has found that the phenols found in fruits like strawberries exert an anti-inflammatory effect in the body that could reduce the risk of a variety of medical conditions, including metabolic syndrome. Twenty-four obese subjects drank either a strawberry drink or a placebo while eating a high-carbohydrate, moderate-fat meal. A meal of this type tends to induce an inflammatory response, which has been linked to obesity, insulin resistance, diabetes and increased cardiovascular risk. Analysis of their blood revealed that plasma levels of two beneficial strawberry compounds rose significantly after drinking the strawberry drink with the meal. “Overall, these findings suggest beneficial effects that accrue from consumption of fruits that have a high phenolic content,” the researchers concluded.
"Strawberry anthocyanin and its association with postprandial inflammation and insulin", British Journal of Nutrition, June 02, 2011
British scientists who analyzed the results of seven clinical trials found “a small, significant reduction in body weight” of about 1.5 kg a year associated with calcium supplementation. The researchers also found evidence that taking a one gram dose of calcium as a daily dietary supplement was associated with a two kg reduction in body fat per year. The researchers concluded that the evidence from the clinical trials shows that calcium supplementation “generates small, statistically significant weight loss in overweight and obese individuals.” However, they added, “the clinical relevance of this finding is uncertain.”
"Efficacy of calcium supplementation for management of overweight and obesity: systematic review of randomized clinical trials", Nutrition Reviews, June 01, 2011
A Swedish study found that preliminary improvements in obstructive sleep apnoea (also apnea) after a low-energy diet can be sustained after one year in overweight men with moderate to severe degrees of the condition. Results of the single-center, prospective observational follow-up study showed that study subjects who lost the most weight or have severe sleep apnoea at the start of the study benefit most from the treatment. The study focused on 63 men, 30 to 65 years old, with a body mass index of 30-40 and moderate to severe obstructive sleep apnoea. They were treated with continuous positive airway pressure.
"Longer term effects of very low energy diet on obstructive sleep apnea in cohort derived from randomized controlled trial: Prospective observational follow-up study", British Medical Journal , June 01, 2011
Belgian researchers who conducted a clinical trial involving 110 infants found that daily feeding of a formula enriched with prebiotics resulted in an intestinal bacteria profile very similar to that found in breastfed babies. The infants in the trial were fed either 0.4 or 0.8 grams per deciliter of Beneo Orafti Synergy1 – a one-to-one blend of inulin and oligofructose – 0.8 grams per deciliter of a nine-to-one blend of galactooligosaccharides and oligofructose (GOS:FOS), or conventional formula. These infants were all compared against breastfed infants. The researchers found that infants in the prebiotics-fed groups had significantly higher bifidobacterium counts after two and four weeks and were “comparable with the breast-fed group.” Both the Orafti Synergy1 and GOS:FOS mixtures were well-tolerated by the infants as well.
"Physiological and Bifidogenic Effects of Prebiotic Supplements in Infant Formulae", Journal of Pediatric Gastroenterology & Nutrition, June 01, 2011
Finnish researchers who compared the long-term consumption of juices from lingonberries, cranberries and blackcurrants found that of the three lingonberry juice alone has a positive impact on the endothelium of blood vessels. For the study, hypertensive rats consumed diets that included the juices of the three types of berries for eight weeks. Phenol-rich lingonberry intake “normalized the impaired endothelium-dependent relaxation seen in the cranberry, blackcurrant and control rats,” the researchers found, but did not lower blood pressure. The researchers said the high phenolic content of lingonberries probably accounted for the beneficial effect on the bloods vessels. The juice contains more of the phenolic compounds known as flavonols, flavan-3-ols and procyanidins than other juices.
"Lingonberry juice improves endothelium-dependent vasodilatation of mesenteric arteries in spontaneously hypertensive rats in a long-term intervention", Journal of Functional Foods, May 26, 2011
A study in mice by U.S. researchers has found that caffeine reduces muscle activity in the Fallopian tubes that carry eggs from a woman's ovaries to her womb and therefore lowers the chances of becoming pregnant. It is generally assumed that tiny hair-like projections (cilia) in the walls of the Fallopian tubes move the microscopic eggs along with the help of muscle contractions. The study found that caffeine stops the actions of specialized pacemaker cells in the tube wall that coordinate tube contractions. When that happens, eggs can't move down the tubes. The finding suggests that the effect of caffeine on the Fallopian tubes “may contribute to the documented delayed conception in women consuming caffeinated beverages,” the researchers concluded.
"Inhibitory effect of caffeine on pacemaker activity in the oviduct is mediated by cAMP-regulated conductances", British Journal of Pharmacology , May 26, 2011
Researchers in Japan aiming to determine the minimum level of serum folate concentration for cutting the risk of colorectal adonema found that patients with serum folate concentrations higher than 8.0ng/ml are the least at risk. No noteworthy difference was found in the prevalence of adenoma among patients who had folate levels higher than 8.0ng/ml.
"Determination of the minimal essential serum folate concentration for reduced risk of colorectal adenoma", Clinical Nutrition, May 25, 2011
Many children who are allergic to cow’s milk can tolerate heated or baked milk in foods like muffins or cheese pizza. U.S. researchers have now found that introducing baked milk into the diets of allergic children increases their tolerance of cow’s milk. Over 37 months, 88 milk-allergic children were introduced to baked milk in various forms. Of 65 children who were tolerant to baked milk, 60 percent became tolerant of unheated milk. The researcher concluded that “the addition of baked milk to the diet of children tolerating such foods appears to accelerate the development of unheated milk tolerance compared with strict avoidance.”
"Dietary baked milk accelerates the resolution of cow’s milk allergy in children", The Journal of Allergy and Clinical Immunology, May 23, 2011
Researchers in Iran have found that consuming five to ten grams of broccoli sprout powder increased the total plasma antioxidant levels and reduced levels of a reactive carbonyl compound that is a marker of oxidative stress. The findings from a randomized clinical trial suggest the possibility that broccoli could reduce oxidative stress in diabetics. The eighty-one diabetics who participated in the study were divided into two groups that received either five or 10grams of broccoli sprout powder or a placebo each day for four weeks. Both broccoli groups showed lower levels of two oxidative stress markers: malondialdehyde (MDA) and oxidized LDL cholesterol. The researchers, who acknowledged that the ideal dose of broccoli sprout powder is still unknown, recommended further studies.
"Broccoli sprouts reduce oxidative stress in type 2 diabetes: a randomized double-blind clinical trial", European Journal of Clinical Nutrition, May 11, 2011
A clinical study in Spain has found that drinking milk fortified with cocoa was associated with a five percent boost in HDL cholesterol levels and a 14 percent drop in oxidized LDL (“bad”) cholesterol. Drinking only milk had no such effect. Study participants, whose mean age was 70, drank 500 ml of skimmed milk fortified with 40 g of cocoa powder every day for four weeks. Scientists said regular consumption of cocoa would be a “useful tool against risk factors” for cardiovascular disease because cocoa is rich in polyphenols that may prevent LDL molecules from being oxidized.
"Regular consumption of cocoa powder with milk increases HDL cholesterol and reduces oxidized LDL levels in subjects at high-risk of cardiovascular disease", Nutrition, Metabolism and Cardiovascular Diseases, May 06, 2011
College undergraduates suffering from colds, flu, and stomach distress because their immune response was lowered by academic stress benefited from prebiotic supplementation in a randomized double-blind clinical study conducted at the University of Florida. The eight-week study, which coincided with fall final exams, involved 427 students variously diagnosed with gastrointestinal problems (i.e., diarrhea, indigestion, reflux syndromes, abdominal pain) and colds or flu. The students were given either 2.5 g or 5.0 g of prebiotic galactooligosaccharides, or a placebo. Using measurements of stress and gastrointestinal symptoms, the researchers found a positive correlation between stress and sickness. They found further that supplementation with the prebiotics lowered gastrointestinal symptom scores and reduced the number of days of cold and flu symptoms by boosting the immune system.
"Galactooligosaccharide supplementation reduces stress-induced gastrointestinal dysfunction and days of cold or flu: a randomized, double-blind, controlled trial in healthy university students", American Journal of Clinical Nutrition , April 27, 2011
Researchers in China, Canada and the U.S. who studied the impact of monosodium glutamate (MSG) on metabolism found a positive association, regardless of calorie intake, between the flavor enhancer widely used in Asian cuisine and weight gain. The study analyzed health data collected on more than 10,000 healthy Chinese adults from 1991 to 2006. They found that a daily intake of .6 g to 3.8 g was positively associated with being overweight, defined as a body mass index (BMI) of 25 or higher. The researchers urged further studies be undertaken to determine how MSG acts in the body, but they guessed that the compound influences energy balance through the disruption of the hypothalamic signaling cascade of leptin action.
"Consumption of monosodium glutamate in relation to incidence of overweight in Chinese adults: China Health and Nutrition Survey (CHNS)", American Journal of Clinical Nutrition, April 06, 2011
Scientists in the U.S. who tested a proprietary herbal blend in a clinical trial with 30 older adults with cardiovascular risk factors found that it improves nitric oxide metabolism and enhances the effectiveness of an enzyme associated with a healthier cardiovascular system. The special blend of beetroot and hawthorn berry, developed at the University of Texas and licensed by Neogenis Laboratories, is called Neo40. It works by improving the bioavailability of nitric oxide, an effective vasodilator that reduces blood pressure and eases strain on the heart. According to the researchers, the herbal blend “shows promise in restoring nitric oxide homeostasis in human subjects at risk for cardiovascular disease for use as a dietary supplement.”
"All-natural nitrite and nitrate containing dietary supplement promotes nitric oxide production and reduces triglycerides in humans", Nutrition Research, April 01, 2011
A study that aimed to better understand the determinants of human salt intake found that low dietary sodium intake made rats more anxious. Researchers at the University of Haifa, Israel, focused on the effects of low dietary sodium on acute unpredictable stress factors, on chronic mild stress (CMS), and in depression and anxiety behavior. Results showed that while reduced sodium intake intensifies anxiety in the "elevated maze and open field," it does not make worse modeled depression in rats that have chronic and acute stress.
"Low dietary sodium is anxiogenic in rats", Physiology & Behavior, March 29, 2011
Patients suffering from advanced hepatitis C and chronic liver disease who drank coffee while receiving peginterferon plus ribavirin treatment experienced better outcomes than non-coffee drinkers, according to a U.S. study. Researchers found that 46 percent of patients who did not drink coffee experienced an early virologic response to treatment, compared to 73 percent of coffee drinkers. Twenty-six percent of non-coffee drinkers had no detectable hepatitis C virus at week 20, compared to 52 percent of coffee drinkers. “High-level consumption of coffee (more than 3 cups per day) is an independent predictor of improved virologic response to peginterferon plus ribavirin in patients with hepatitis C,” the researchers concluded.
"Coffee Consumption is Associated with Response to Peginterferon and Ribavirin Therapy in Patients with Chronic Hepatitis C", Gastroenterology, March 02, 2011
Canadian researchers studying the metabolic impact of pistachios have found that eating pistachios during a high-carbohydrate meal may reduce the risk of diabetes and coronary heart disease. For one study, 10 healthy adults were fed 28 g, 56 g and 84 g of pistachios alone or with white bread. A second study examined the impact of 56 g of pistachios eaten with various foods (i.e., rice, mashed potatoes, bread, etc.) on postprandial glycemia. The researchers found that higher doses of pistachios significantly reduced the relative glycemic responses (RGRs) of the foods. “The beneficial effects of pistachios on postprandial glycemia could be part of the mechanism by which nuts reduce the risk of diabetes and CHD,” the researchers concluded.
"The impact of pistachio intake alone or in combination with high-carbohydrate foods on post-prandial glycemia", European Journal of Clinical Nutrition, March 02, 2011
A Greek study of the impact of low-glycemic index/low-glycemic load (low-GI/GL) desserts on weight loss has found that overweight girls who eat sugar-free, low-fat desserts a few times each week lose more weight and have an easier time staying on a healthy diet. Twenty-nine overweight or obese girls ages 10 to 14 participated in the study. One group ate a balanced diet that included sugar-free desserts, the other ate the same diet but with normal desserts. After three months, both groups improved their body mass index (BMI), but the group that ate the low-GI/GL desserts lost significantly more weight and had better average BMI and systolic blood pressure, the authors reported. The sucralose-sweetened desserts were made by the Giotis Company of Greece.
"Desserts With a Low Glycemic Index May Benefit Weight Loss Efforts for Obese Children", Presentation and press release, The Endocrine Society meeting, January 01, 1996
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Reproductive Toxicology, May 31, 2011
National Resources Defense Council (NRDC), May 25, 2011
Food Quality and Preference, May 14, 2011
Translational Psychiatry, April 26, 2011
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