Consumption of Vitamin B during pregnancy does not increase the risk of allergy in the infants, says a new study from Japan that challenges previous findings. Maternal consumption of folate and vitamins B2, B6, and B12 during pregnancy was not associated with the risk of the infant developing asthma or eczema, according to findings from 763 infants published in Pediatric Allergy and Immunology.
The link between folate and folic acid, the synthetic form of the vitamin, and respiratory health is not clear cut, with contradictory results reported in the literature. A study from Johns Hopkins Children’s Center found that higher levels of folate were associated with a 16 per cent reduction of asthma in (Journal of Allergy & Clinical Immunology, June 2009, Vol. 123, pp. 1253-1259.e2). However, a Norwegian study reported that folic acid supplements during the first trimester were associated with a 6 per cent increase in wheezing, a 9 per cent increase in infections of the lower respiratory tract, and a 24 per cent increase in hospitalisations for such infections, (Archives of Diseases in Childhood, doi:10.1136/adc.2008.142448). In addition, researchers from the University of Adelaide in Australia reported that folic acid supplements in late pregnancy may increase the risk of asthma by about 25 per cent in children aged between 3 and 5 years (American Journal of Epidemiology, 2010, doi:10.1093/aje/kwp315).
Illumination from the Land of the Rising Sun?
The new study, performed by researchers from Fukuoka University, the University of Tokyo, and Osaka City University, goes beyond folate and folic acid, and reports no link between Vitamin B intake and the risk of asthma or eczema in children. “To the best of our knowledge, there has been no birth cohort study on the relationship between maternal consumption of Vitamin B during pregnancy and the risk of allergic disorders in the offspring,” wrote the researchers. The findings were based on data from 763 pairs of Japanese mother and child. A diet history questionnaire was used to assess maternal intakes of the various B vitamins during pregnancy, and the infants were followed until the age of 16 to 24 months. Japan has no mandatory fortification of flour with folic acid.
Results showed that, according to criteria from the International Study of Asthma and Allergies in Childhood, 22 and 19 percent of the children had symptoms of wheeze and eczema, respectively, but there was no association between these children and the dietary intakes of the various B vitamins by their mothers. “Our results suggest that maternal intake of folate, vitamin B12, vitamin B6, and vitamin B2 during pregnancy was not measurably associated with the risk of wheeze or eczema in the offspring,” said the researchers. “Further investigation is warranted to draw conclusions as to the question of whether maternal Vitamin B intake during pregnancy is related to the risk of childhood allergic,” they concluded.
According to the European Federation of Allergy and Airway Diseases Patients Association (EFA), over 30m Europeans suffer from asthma, costing Europe €17.7bn every year. The cost due to lost productivity is estimated to be around €9.8bn. The condition is on the rise in the Western world and the most common long-term condition in the UK today. According to the American Lung Association, almost 20m Americans suffer from asthma. The condition is reported to be responsible for over 14m lost school days in children, while the annual economic cost of asthma is said to be over $16.1bn.
Source: Pediatric Allergy and Immunology. Volume 22, Issue 1-Part-I, February 2011, Pages: 69–74 DOI: 10.1111/j.1399-3038.2010.01081.x
“Maternal B vitamin intake during pregnancy and wheeze and eczema in Japanese infants aged 16–24 months: The Osaka Maternal and Child Health Study”. Authors: Y. Miyake, S. Sasaki, K. Tanaka, Y. Hirota
Whole-fat dairy products containing high levels of a natural fatty acid might help lower the risk of type 2 diabetes, according to a recent research by U.S. scientists. A diet rich in milk, cheese, yogurt and butter contains trans-palmitoleic acid which is known to shield against insulin resistance and diabetes. “Our results demonstrate an inverse relationship between levels of trans-palmitoleate and metabolic risk factors and diabetes incidence,” Dariush Mozaffarian, MD, DrPH, of the Harvard School of Public Health, and coauthors wrote in conclusion. “The small differences in trans-palmitoleate levels raise questions about whether this is the active compound or a marker for some other, unknown protective constituent of dairy or other ruminant foods.”
The study looked at 3,736 American seniors from Medicare eligibility lists aged 65 years or older. Physical tests, diagnostic testing, questionnaires on health status, and laboratory evaluation was conducted to evaluate the levels of 45 different fatty acids in the participants. They were further followed for 10 years with the help of annual clinic visits and interim telephone calls.
Trans-palmitoleate was responsible for an average of 0.18 percent of total fatty acid levels, with whole-fat dairy consumption accounting for the highest trans-palmitoleatele proportions. Participants who had consumed high levels of whole-fat dairy products revealed higher levels of trans-palmitoleate acid in their blood three years later, Dariush and his co-authors reported in the December issue of the journal ‘Annals of Internal Medicine.’ Further, participants with the highest levels of the acid circulating in their blood faced two-third the risk of suffering from type 2 diabetes as compared to the ones with the lowest levels. Such people also had lesser fat on their bodies, higher proportions of good cholesterol and lower levels of C-reactive protein.
“This is an extremely strong protective effect, stronger than other things we know can be beneficial against diabetes,” said Gökhan Hotamisligil, the study’s senior author and chair of the department of genetics and complex diseases at Harvard School of Public Health. “The next step is to move forward with an intervention trial to see if there is therapeutic value in people,” he added in a statement.
The research has been funded by the U.S. National Heart, Lung and Blood Institute, the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute of Health Office of Dietary Supplements and National Institute of Neurological Disorders and Stroke.
According to a 2007 University of Toronto study published in the journal Diabetes Care, a quarter-cup of chia seeds supplies as much omega-3 fatty acid as a salmon fillet, 25 percent more dietary fiber than flaxseed, 30 percent more antioxidants than blueberries and as much calcium as three cups of milk.
The study, so far the only peer- reviewed one concerning the health claims of chia seeds, showed that diabetes patients reduced cardiovascular risks by ingesting chia seeds along with standard diabetes therapy.
Dr. Sheri Zidenberg-Cherr of the UC Davis nutrition department says chia seeds have a “nice nutritional profile” but hastens to add they are not the dietary cure-all some are trumpeting. “The redeeming qualities of it is omega-3s, specifically the lenlinic (acid) that's in there,” Zidenberg-Cherr says. “Because of that tie-in with heart disease and diabetes, I see potential for it as something that could be added to someone's diet if they're already following a healthy eating plan with the proper recommendations.”
At the very least, she adds, chia seeds can't hurt.
A new study finds that drinking orange juice, soda and other beverages high in the sugar fructose could increase the small risk that middle-age and elderly women have of developing gout. Gout is a painful form of arthritis caused by too much uric acid in the blood. For women in the study who drank two or more servings of these beverages per day, the risk of gout was more than double that for women who drank sugary sodas and juices less than once per month. Because gout is relatively rare among women, the drinks probably contribute only moderately to a woman's chances of developing it. Still, this is the first study linking sodas and sweetened fruit juices to women's gout risk. Previous research found such a link for men.
The study will be published in the Nov. 24 issue of the Journal of the American Medical Association, and is being presented today (Nov. 10) at the American College of Rheumatology annual scientific meeting.
Gout occurs when levels of uric acid in the blood become too high, and uric acid crystallizes around the joints, leading to inflammation, swelling and pain. Foods than can increase the levels of uric acid in the blood include organ meats (such as kidneys and livers), asparagus and mushrooms, according to the Mayo Clinic. Fructose is also known to increase blood uric acid levels, the researchers said. While gout is not common in the United States, the rate of incidences has more than doubled over a 20-year period, from 16 cases per 100,000 Americans in 1977 to 42 per 100,000 in 1996. Over this period, the researchers noted, the population also consumed increasing amounts of soda and other drinks sweetened with fructose.
The new study followed 78,906 women for 22 years, from 1984 to 2006, as part of the Nurses' Health Study. At the beginning of the study, none of the women had gout. By the end, 778 had developed it. Women who drank one serving of soda per day were 1.74 times more likely to develop gout than those who drank less than one serving per month. Those who drank two or more servings per day were 2.4 times more likely to develop gout. Drinking two or more servings of soda per day caused an additional 68 cases of gout per 100,000 women per year, compared with drinking less than one serving of soda per month, the researchers said. Drinking orange juice also increased the risk. Women who drank one serving of orange juice per day were 1.41 times more likely to develop gout, and those who drank two or more servings were 2.4 times more likely to report gout.
Lifestyle and diet
The rise in gout cases is most likely due to changes in lifestyle and diet and an increase in conditions associated with gout, such as metabolic syndrome, said study researcher Dr. Hyon K. Choi of the Boston University School of Medicine. The results held even after the researchers took into account factors that could have influenced the findings, such as age, body mass index and whether the women had gone through menopause, Choi said.
The findings suggest diets to prevent gout should reduce fructose intake, the researchers said.
The study was funded by the National Institutes of Health.
Nutrition experts at Oregon State University have essentially “cured” laboratory mice of mild, diet-induced diabetes by stimulating the production of a particular enzyme. The findings could offer a new approach to diabetes therapy, experts say, especially if a drug could be identified that would do the same thing, which in this case was accomplished with genetic manipulation.
Increased levels of this enzyme, called fatty acid elongase-5, restored normal function to diseased livers in mice, restored normal levels of blood glucose and insulin, and effectively corrected the risk factors incurred with diet-induced diabetes. “This effect was fairly remarkable and not anticipated,” said Donald Jump, a professor of nutrition and exercise sciences at Oregon State, where he is an expert on lipid metabolism and principal investigator with OSU’s Linus Pauling Institute. “It doesn’t provide a therapy yet, but could be fairly important if we can find a drug to raise levels of this enzyme,” Jump said. “There are already some drugs on the market that do this to a point, and further research in the field would be merited.”
The studies were done on a family of enzymes called “fatty acid elongases,” which have been known of for decades. Humans get essential fatty acids that they cannot naturally make from certain foods in their diet. These essential fatty acids are converted to longer and more unsaturated fatty acids. The fatty acid end products of these reactions are important for managing metabolism, inflammation, cognitive function, cardiovascular health, reproduction, vision and other metabolic roles.
The enzymes that do this are called fatty acid elongases, and much has been learned in recent years about them. In research on diet-induced obesity and diabetes, OSU studied enzyme conversion pathways, and found that elongase-5 was often impaired in mice with elevated insulin levels and diet-induced obesity.
The scientists used an established system, based on a recombinant adenovirus, to import the gene responsible for production of elongase-5 into the livers of obese, diabetic mice. When this “delivery system” began to function and the mice produced higher levels of the enzyme, their diet-induced liver defects and elevated blood sugar disappeared.
“The use of a genetic delivery system such as this was functional, but it may not be a permanent solution,” Jump said. “For human therapy, it would be better to find a drug that could accomplish the same thing, and that may be possible. There are already drugs on the market, such as some fibrate drugs, that induce higher levels of elongase-5 to some extent.”
There are also drugs used with diabetic patients that can lower blood sugar levels, Jump said, but some have side effects and undesired complications. The potential for raising levels of elongase-5 would be a new, specific and targeted approach to diabetes therapy, he said. While lowering blood sugar, the elevated levels of elongase-5 also reduced triglycerides in the liver, another desirable goal. Elevated triglycerides are associated with “fatty liver,” also known as non-alcoholic fatty liver disease. This can progress to more severe liver diseases such as fibrosis, cirrhosis and cancer.
Further research is needed to define the exact biological mechanisms at work in this process, and determine what the fatty acids do that affects carbohydrate and triglyceride metabolism, he said. It appears that high fat diets suppress elongase-5 activity.
“These studies establish a link between fatty acid elongation and hepatic glucose and triglyceride metabolism,” the researchers wrote in their report, “and suggest a role for regulators of elongase-5 activity in the treatment of diet-induced hyperglycemia and fatty liver.”
The study was published in the Journal of Lipid Research. The research was supported by the National Institutes of Health and the National Institute for Food and Agriculture of the U.S. Department of Agriculture.
Eating more olive oil could help prevent ulcerative colitis, according to a new study co-ordinated by medical researchers at the University of East Anglia (UEA).
Presented today at the Digestive Disease Week conference in New Orleans, the findings show that people with a diet rich in oleic acid – which is present in olive oil –are far less likely to develop ulcerative colitis. Oleic acid is a monounsaturated fatty acid found in olive oil, peanut oil and grapeseed oil, as well as in butter and certain margarines.
The researchers, led by Dr Andrew Hart of UEA's School of Medicine, studied more than 25,000 people aged 40-65 living in Norfolk, UK. The volunteers were recruited to the EPIC study (European Prospective Investigation into Diet and Cancer) between 1993 and 1997. The participants, none of whom had ulcerative colitis at the outset, completed detailed food diaries which were later analysed by specially trained nutritionists working in Cambridge.
By 2004, 22 participants in the study had developed ulcerative colitis and the researchers compared their diets with those who did not develop the disease. They found that those with the highest intake of oleic acid had a 90 per cent lower risk of developing the disease.
“Oleic acid seems to help prevent the development of ulcerative colitis by blocking chemicals in the bowel that aggravate the inflammation found in this illness,” said Dr Hart.
“We estimate that around half of the cases of ulcerative colitis could be prevented if larger amounts of oleic acid were consumed. Two-to-three tablespoons of olive oil per day would have a protective effect,” said Dr Hart.
Ulcerative colitis is a distressing disease affecting 120,000 people of all ages in the UK and 1 million in the US. It is characterized by inflammation of the lining of the colon or large bowel, which causes abdominal pain, diarrhoea and weight loss.
Similar work in other countries is now required to determine if these results are reproducible there, before the link can be said to be definite. If it is confirmed that oleic acid is truly protective, dietary modifications should be considered to prevent colitis. Additionally, the use of oleic acid supplements should also be assessed in the future as a possible treatment for colitis sufferers.
In most women folate, a type of B vitamin, reduces the risk of breast cancer. However, in women with a certain genetic make-up it has shown to be the opposite: folate raises the risk of breast cancer.
“Therefore I think it is too soon to introduce a general fortification of foodstuffs with folic acid”, says nutrition researcher Ulrika Ericson of Lund University.
Neither does she think it is a good idea to take multivitamin tablets and other dietary supplements containing folic acid (the synthetic form of folate) without special reason.
“It is better to eat a diet containing a lot of fruit, vegetables, legumes and wholemeal products. Then you get sufficient quantities of the natural form of folate, other vitamins and dietary fibre.”
In her doctoral thesis, Ulrika Ericson has taken as her starting point the major study from the 1990s, Malmö Diet and Cancer, which gathered information and blood samples from over 17 000 women. At the end of 2004, just over 500 of these women had developed breast cancer. Folate levels, genetic make-up and food habits in the breast cancer patients have then been compared with the corresponding data from the healthy women.
Those women whose intake of folate corresponded to the level recommended in Sweden had only half as great a risk of getting breast cancer as those who had the lowest intake of folate. This was the overall finding, which shows that folate generally protects against breast cancer. However, the breast cancer risk increased in line with folate levels for a specific sub-group among the women – those who had inherited a certain variant of an enzyme that affects how folate is used in the body.
The ten per cent of the women who had inherited this variant from both of their parents had the highest risk of breast cancer, particularly if they also took vitamin tablets containing folic acid.
“No-one knows which genetic variant of this enzyme they have. This is why I think people should only take dietary supplements if there is a particular reason to do so, not just because 'it's probably a good idea'”, says Ulrika Ericson.
She considers that there are two groups who could have a particular reason to take a folic acid supplement. These are people with a certain type of anaemia and low folate levels and women who are trying to become pregnant (folate reduces the risk of neural tube defects in babies).
To be on the safe side, others should avoid vitamin tablets containing folic acid while it is still unclear what the link is between folate and different types of cancer. Mandatory folic acid fortification of foodstuffs, which has been discussed in many countries including Sweden, is not appropriate in the current situation, according to Ulrika Ericson.
To examine this thesis, Froy and his colleagues, Ph.D. student Maayan Barnea and Zecharia Madar, the Karl Bach Professor of Agricultural Biochemistry, tested whether the clock controls the adiponectin signaling pathway in the liver and, if so, how fasting and a high-fat diet affect this control. Adiponectin is secreted from differentiated adipocytes (fat tissue) and is involved in glucose and lipid metabolism. It increases fatty acid oxidation and promotes insulin sensitivity, two highly important factors in maintaining proper metabolism.
The researchers fed mice either a low-fat or a high-fat diet, followed by a fasting day, then measured components of the adiponectin metabolic pathway at various levels of activity. In mice on the low-fat diet, the adiponectin signaling pathway components exhibited normal circadian rhythmicity. Fasting resulted in a phase advance. The high-fat diet resulted in a phase delay. Fasting raised and the high-fat diet reduced adenosine monophosphate-activated protein kinase (AMPK) levels. This protein is involved in fatty acid metabolism, which could be disrupted by the lower levels.
In an article soon to be published by the journal Endocrinology, the researchers suggest that this high-fat diet could contribute to obesity, not only through its high caloric content, but also by disrupting the phases and daily rhythm of clock genes. They contend also that high fat-induced changes in the clock and the adiponectin signaling pathway may help explain the disruption of other clock-controlled systems associated with metabolic disorders, such as blood pressure levels and the sleep/wake cycle.
Obvious choices of fruit and vegetables are not necessarily the healthiest, new research has suggested. Scientists have come up with a list of five “powerhouse” foods that may be better alternatives. Experts recommend five portions a day of fruit and veg in a healthy diet – plant foods are known to contain “phytonutrient” chemicals that can protect the heart and arteries and prevent cancers – but the most popular varieties may not be the best, according to US researchers.
Scientists analysed data from US health surveys of people's dietary habits to examine sources of phytonutrients. They found that for 10 of the 14 phytonutrients studied, a single food type accounted for two-thirds or more of an individual's consumption. It made no difference whether or not a person was a high or low consumer of fruit and veg.
The most common food sources for five key phytonutrients were: carrots (beta-carotene), oranges / orange juice (beta-cryptoxanthin), spinach (lutein/zeaxanthin), strawberries (ellagic acid) and mustard (isothiocyanates).
However, for each of these phytonutrients there was a better food source available.
These were listed as follows: sweet potatoes (nearly double the beta-carotene of carrots), papaya (15 times more beta-cryptoxanthin than oranges), kale (three times more lutein/zeaxanthin than spinach), raspberries (three times more ellagic acid than strawberries), and watercress (one cup contains as much isothiocyanate as four teaspoonfuls of mustard)
Study leader Keith Randolph, technology strategist for the supplement company Nutrilite, said: “These data highlight the importance of not only the quantity but also the significant impact the quality and variety of the fruits and vegetables you eat can have on your health.”
The findings were presented at the 2010 Experimental Biology conference in Anaheim, California.
Trans fats are made through hydrogenation, which involves bubbling hydrogen through hot vegetable oil, changing the arrangement of double bonds in the essential fatty acids in the oil and “saturating” the “unsaturated” carbon chain with hydrogen. Because double bonds are rigid, altering them can straighten or twist fat molecules into new configurations that give the fats their special qualities, such as the lower melting point of margarine that makes it creamy at room temperature.
Kummerow, 94, has spent nearly six decades studying lipid biochemistry, and is a long-time advocate for a ban on trans fats in food.
While the body can use trans fats as a source of energy for maintenance and growth, Kummerow said, trans fats interfere with the body's ability to perform certain tasks critical to good health. Because these effects are less obvious, many researchers have missed the underlying pathologies that result from a diet that includes trans fats, he said.
Trans fats displace – and cannot replace – the essential fatty acids linoleic acid (omega-6) and linolenic acid (omega-3), which the body needs for a variety of functions, including blood flow regulation. Studies have shown that trans fats also increase low-density lipoproteins (LDLs) in the blood, a factor which some believe contributes to heart disease.
Trans fats are associated with increased inflammation in the arteries. And trans fats have been found to change the composition of cell membranes, making them more leaky to calcium. Inflammation, high LDL cholesterol and calcified arteries are the signature ingredients of atherosclerosis.
Trans fats also were shown to interfere with an enzyme that converts the essential fatty acid linoleic acid into arachidonic acid, which is needed for the production of prostacyclin (a blood-flow enhancer) and thromboxane (which regulates the formation of blood clots needed for wound healing). While some in the food oil industry believed this problem could be overcome simply by adding more linoleic acid to partially hydrogenated fats, in 2007 Kummerow's team reported that extra linoleic acid did not overcome the problem.
“Trans fats inhibited the synthesis of arachidonic acid from linoleic acid, even when there was plenty of linoleic acid available,” he said.
The new study reports that in addition to interfering with the production of arachidonic acid from linoleic acid, trans fats also reduce the amount of prostacyclin needed to keep blood flowing. Thus blood clots may more easily develop, and sudden death is possible.
According to the American Heart Association, each year more than 330,000 people in the U.S. die from coronary heart disease before reaching a hospital or while in an emergency room. Most of those deaths are the result of sudden cardiac arrest, the Heart Association reports.
“This is the first time that trans fatty acids have been shown to interfere with yet another part of the blood-flow process,” Kummerow said. This study adds another piece of evidence to a long list that points to trans fats as significant contributors to heart disease, he said.
Kummerow believes the U.S. Food and Drug Administration's new requirement (begun in 2006) that trans fats be included on food labels is inadequate and misleading. Anything less than one-half gram of trans fats per serving can be listed as zero grams, Kummerow said, so people are often getting the mistaken impression that their food is trans fat-free.
“Go to the grocery store and compare the labels on the margarines,” he said. “Some of them say zero trans fat. That's not true. Anything with partially hydrogenated oils in it contains trans fat.”
“Partially hydrogenated fats can be made trans fat-free,” Kummerow said. “The industry would be helped by an FDA ban on trans fat that would save labeling costs, medical costs and lives.”