Higher intakes of the B vitamins thiamine and riboflavin from the diet may reduce the incidence of premenstrual syndrome (PMS) by about 35 percent, suggest new findings. According to a new paper published in the American Journal of Clinical Nutrition, the link between B vitamins and PMS is biologically plausible since B vitamins such as thiamine and riboflavin are known to play important roles in the synthesis of various neurotransmitters involved in PMS.
While most women experience mild emotional or physical premenstrual symptoms, as many as 8-20 per cent of women experience symptoms severe enough to meet the definition of premenstrual syndrome, which can substantially interfere with daily activities and relationships. The new study, performed by researchers from the University of Massachusetts, Harvard, and the University of Iowa, indicates that increase intakes of certain B vitamins from food sources may help reduce the incidence of PMS.
Using data from 1,057 women with PMS and 1,968 women without PMS participating in the Nurses' Health Study II cohort, the researchers found that women with the highest average intakes of riboflavin two to four years prior to diagnosis were associated with a 35 percent lower incidence of PMS than women with the lowest average intakes. On the other hand, the researchers did not observe any benefits with other B vitamins, including niacin, folate, B6, and B12. In addition, supplemental intakes of these vitamins was not linked to PMS incidence, they added. “We observed a significantly lower risk of PMS in women with high intakes of thiamine and riboflavin from food sources only,” wrote the researchers. “Further research is needed to evaluate the effects of B vitamins in the development of premenstrual syndrome.”
Beyond the B vitamins, there is also some evidence for the potential of a diet rich in calcium and vitamin D to lower the risk of developing PMS, a condition that affects up to a fifth of all women. According to a study published in 2005 in the Archives of Internal Medicine (Vol. 165, pp1246-1252), researchers from the University of Massachusetts and GlaxoSmithKline reported for the first time that calcium and vitamin D may help prevent the initial development of PMS.
Source: The American Journal of Clinical Nutrition. Published online ahead of print, doi: 10.3945/ajcn.110.009530 “Dietary B vitamin intake and incident premenstrual syndrome” Authors: P.O. Chocano-Bedoya, J.E. Manson, S.E. Hankinson, W.C. Willett, S.R. Johnson, L. Chasan-Taber, A.G. Ronnenberg, C. Bigelow, E.R. Bertone-Johnson
Drinking soft drinks is associated with higher blood pressure, according to a study of over 2,500 people reported this week in the journal Hypertension. High blood pressure is a major risk factor for heart disease, which is the leading cause of death worldwide. Someone with a blood pressure level in millimetres of mercury (mmHg) of 135 over 85 is twice as likely to have a heart attack or stroke as someone with a reading of 115 over 75.
The new research shows that for every extra can of soft drink consumed per day, participants on average had a higher systolic blood pressure by 1.6 mmHg and a higher diastolic blood pressure by 0.8 mmHg. This difference was statistically significant even after adjusting for factors such as weight and height. The study did not examine the mechanism that might link soft drinks with blood pressure. However, the researchers suggest that raised uric acid, which has been linked to soft drink consumption, might raise blood pressure by reducing the levels of nitric oxide, a chemical that relaxes the lining of the blood vessels.
The association between soft drinks and higher blood pressure was especially strong in people who consumed a lot of salt as well as sugar. Diet drinks were linked with lower blood pressure levels in some analyses, but the association was not consistent or strong. Professor Paul Elliott, senior author of the study, from the School of Public Health at Imperial College London, said: “It’s widely known that if you have too much salt in your diet, you’re more likely to develop high blood pressure. The results of this study suggest that people should be careful about how much sugar they consume as well.”
The researchers analysed data from 2,696 volunteers aged between 40 and 59, in eight areas of the US and two areas of the UK. On four separate occasions over a period of three weeks on average, the participants reported what they had eaten in the preceding 24 hours, as well as giving urine samples and having their blood pressure measured. The volunteers were taking part in INTERMAP, the International Study of Macronutrients, Micronutrients and Blood Pressure.
The researchers also found that people who drink more soft drinks tended to have more unhealthy diets in general. As well as consuming more sugar, those consuming more than one soft drink a day consumed more calories by 397 kilocalories per day on average, and less fibre and minerals. Those who did not consume soft drinks had a lower body mass index (BMI) on average than those who consumed more than one drink per day. “Individuals who drink a lot of sugar-sweetened beverages appear to have less healthy diets,” said Dr Ian Brown, the study’s first author, also from the School of Public Health at Imperial College London. “They are consuming empty calories without the nutritional benefits of real food. They consume less potassium, magnesium and calcium.” “This is a population study,” Dr Brown added. “It can’t say definitively that sugary drinks raise your blood pressure, but it’s one piece of the evidence in a jigsaw puzzle that needs to be completed. In the meantime, we would advise people who want to drink sugar-sweetened beverages should do so only in moderation.”
Eating a diet rich in fibre has long been known to help keep your digestive tract working properly. It’s also thought to lower the risk of heart disease, some cancers and diabetes. Now, a new study suggests it could reduce the risk of death from cardiovascular, infectious and respiratory diseases. People who ate a high-fibre diet decreased their risk of dying over a nine year period compared to those who ate less fibre, according to a new study in the Archives of Internal Medicine.
The findings are based on a diet study from the National Institutes of Health and AARP, which included 219,123 men and 168,999 women ages 50 to 71 when the study began. Researchers from the National Cancer Institute examined food surveys completed by the participants in 1995 or 1996. After nine years about 11,000 people died and researchers used national records to determine the cause.
People who ate at least 26 grams per day were 22 percent less likely to die than those who consumed the least amount of fibre — about 13 grams per day or less. Men and women who consumed diets higher in fibre also had a reduced risk of cardiovascular, infectious and respiratory diseases, the study found. Getting fibre from grains seemed to have the biggest impact, the authors write.
The study has some limitations — mainly, people who ate high-fibre diets might also have been more likely to eat healthier diets overall, attributing to their longevity. Still, the study offers more evidence that fibre is certainly good for you. Federal dietary guidelines recommend people consume at least 14 grams of fibre per 1,000 calories, so about 28 grams for an average 2,000 calorie-per-day diet. But many experts say many people don’t get enough.
Addiction researchers at Washington University School of Medicine in St. Louis have found that a risk for alcoholism also may put individuals at risk for obesity. The researchers noted that the association between a family history of alcoholism and obesity risk has become more pronounced in recent years. Both men and women with such a family history were more likely to be obese in 2002 than members of that same high-risk group had been in 1992. “In addiction research, we often look at what we call cross-heritability, which addresses the question of whether the predisposition to one condition also might contribute to other conditions,” says first author Richard A. Grucza, PhD. “For example, alcoholism and drug abuse are cross-heritable. This new study demonstrates a cross-heritability between alcoholism and obesity, but it also says — and this is very important — that some of the risks must be a function of the environment. The environment is what changed between the 1990s and the 2000s. It wasn’t people’s genes.”
Obesity in the United States has doubled in recent decades from 15 percent of the population in the late 1970s to 33 percent in 2004. Obese people – those with a body mass index (BMI) of 30 or more – have an elevated risk for high blood pressure, diabetes, heart disease, stroke and certain cancers.
Reporting in the Archives of General Psychiatry, Grucza and his team say individuals with a family history of alcoholism, particularly women, have an elevated obesity risk. In addition, that risk seems to be growing. He speculates that may result from changes in the food we eat and the availability of more foods that interact with the same brain areas as addictive drugs. “Much of what we eat nowadays contains more calories than the food we ate in the 1970s and 1980s, but it also contains the sorts of calories — particularly a combination of sugar, salt and fat — that appeal to what are commonly called the reward centers in the brain,” says Grucza, an assistant professor of psychiatry. “Alcohol and drugs affect those same parts of the brain, and our thinking was that because the same brain structures are being stimulated, overconsumption of those foods might be greater in people with a predisposition to addiction.”
Grucza hypothesized that as Americans consumed more high-calorie, hyper-palatable foods, those with a genetic risk for addiction would face an elevated risk from because of the effects of those foods on the reward centers in the brain. His team analyzed data from two large alcoholism surveys from the last two decades. The National Longitudinal Alcohol Epidemiologic Survey was conducted in 1991 and 1992. The National Epidemiologic Survey on Alcohol and Related Conditions was conducted in 2001 and 2002. Almost 80,000 people took part in the two surveys.
“We looked particularly at family history of alcoholism as a marker of risk,” Grucza explains. “And we found that in 2001 and 2002, women with that history were 49 percent more likely to be obese than those without a family history of alcoholism. We also noticed a relationship in men, but it was not as striking in men as in women.” Grucza says a possible explanation for obesity in those with a family history of alcoholism is that some individuals may substitute one addiction for another. After seeing a close relative deal with alcohol problems, a person may shy away from drinking, but high-calorie, hyper-palatable foods also can stimulate the reward centers in their brains and give them effects similar to what they might experience from alcohol.
“Ironically, people with alcoholism tend not to be obese,” Grucza says. “They tend to be malnourished, or at least under-nourished because many replace their food intake with alcohol. One might think that the excess calories associated with alcohol consumption could, in theory, contribute to obesity, but that’s not what we saw in these individuals.” Grucza says other variables, from smoking, to alcohol intake, to demographic factors like age and education levels don’t seem to explain the association between alcoholism risk and obesity. “It really does appear to be a change in the environment,” he says. “I would speculate, although I can’t really prove this, that a change in the food environment brought this association about. There is a whole slew of literature out there suggesting these hyper-palatable foods appeal to people with addictive tendencies, and I would guess that’s what we’re seeing in our study.” The results, he says, suggest there should be more cross-talk between alcohol and addiction researchers and those who study obesity. He says there may be some people for whom treating one of those disorders also might aid the other.
Eating a diet high in antioxidants may protect against ischemic stroke, an Italian cohort study showed.
People who had a diet high in total antioxidant capacity — an index that takes into account several different antioxidants and their interactions — had a 59% reduced relative risk of ischemic stroke (HR 0.41, 95% CI 0.23 to 0.74), according to Nicoletta Pellegrini, PhD, of the University of Parma in Italy, and colleagues. But there was no such relationship with hemorrhagic stroke, they reported in the January issue of the Journal of Nutrition. In fact, the highest intake of the antioxidant vitamin E was associated with a greater risk of hemorrhagic stroke (HR 2.94, 95% CI 1.13 to 7.62).
Considering evidence suggesting that oxidative stress and systemic inflammation are involved in the pathogenesis of ischemic stroke, the researchers noted that “a high-total antioxidant capacity diet could be protective as a consequence of its ability to deliver compounds with antioxidant activity and with a demonstrated anti-inflammatory effect.” But, they acknowledged that the mechanism for such activity was unclear may “go beyond the antioxidant activity of the numerous total antioxidant capacity contributors present in foods and beverages.”
Pellegrini and her colleagues set out to explore the relationship between dietary total antioxidant capacity and the risk of stroke among 41,620 people participating in EPICOR, the Italian segment of the European Prospective Investigation into Cancer and Nutrition (EPIC). None had a history of stroke or MI at baseline. Dietary intake was assessed with a food frequency questionnaire. In the study population, more than half of the total antioxidants consumed came from coffee, wine, and fruit. Through a mean follow-up of 7.9 years, there were 112 ischemic strokes, 48 hemorrhagic strokes, and 34 other types of strokes. After adjustment for energy intake, hypertension, smoking status, education, nonalcoholic energy intake at recruitment, alcohol intake, waist circumference, body mass index, and total physical activity, individuals eating a diet in the highest tertile of total antioxidant capacity had a reduced risk of ischemic — but not hemorrhagic — stroke.
Looking at individual antioxidants, the researchers found that participants consuming the highest amounts of vitamin C had a reduced risk of ischemic stroke (HR 0.58, 95% CI 0.34 to 0.99). Controlling for vitamin C intake did not negate the overall association between antioxidants and ischemic stroke, which ruled out the nutrient as the sole driver of the relationship. High intake of vitamin E, on the other hand, was associated with nearly triple the relative risk of hemorrhagic stroke. However, “it must be stressed that the small number of cases observed in this population strongly limits the validity of statistical observations on hemorrhagic stroke,” noted the researchers, who called for further studies.
Aside from anti-inflammatory effects, it is possible that the association between antioxidants and ischemic stroke risk can be explained by the interaction between polyphenols — the major contributors to total antioxidant capacity — and the generation of nitric oxide from the vascular endothelium. That interaction leads to the vasodilation and expression of genes that may be protective for the vascular system, according to the researchers. In addition, coffee — the main source of antioxidants in the study population — reduces blood pressure, which is a recognized risk factor for ischemic stroke, the researchers wrote.
They noted some limitations of the study, including the low numbers of cases when different types of stroke were analyzed, the measurement of total antioxidant capacity at baseline only, and the inability to rule out confounding effects of other dietary components, like sodium and potassium.
Source: Del Rio D, et al “Total antioxidant capacity of the diet is associated with lower risk of ischemic stroke in a large Italian cohort” J Nutr 2011; 141: 118-123.
Researchers at King’s College London and the University of East Anglia have discovered that women who consume a diet high in allium vegetables, such as garlic, onions and leeks, have lower levels of hip osteoarthritis. The findings, published in the BMC Musculoskeletal Disorders journal, not only highlight the possible effects of diet in protecting against osteoarthritis, but also show the potential for using compounds found in garlic to develop treatments for the condition. A relationship between body weight and osteoarthritis was previously recognised, although it is not yet completely understood. This study is the first of its kind to delve deeper into the dietary patterns and influences that could impact on development and prevention of the condition.
Osteoarthritis is the most common form of arthritis in adults, affecting around 8 million people in the UK, and women are more likely to develop it than men. It causes pain and disability by affecting the hip, knees and spine in the middle-aged and elderly population. Currently there is no effective treatment other than pain relief and, ultimately, joint replacement.
The study, funded by Arthritis Research UK, the Wellcome Trust and Dunhill Medical Trust, looked at over 1,000 healthy female twins, many of whom had no symptoms of arthritis. The team carried out a detailed assessment of the diet patterns of the twins and analysed these alongside x-ray images, which captured the extent of early osteoarthritis in the participants’ hips, knees and spine. They found that in those who consumed a healthy diet with a high intake of fruit and vegetables, particularly alliums such as garlic, there was less evidence of early osteoarthritis in the hip joint.
To investigate the potential protective effect of alliums further, researchers studied the compounds found in garlic. They found that that a compound called diallyl disulphide limits the amount of cartilage-damaging enzymes when introduced to a human cartilage cell-line in the laboratory. Dr Frances Williams, lead author from the Department of Twin Research at King’s College London, says: “While we don’t yet know if eating garlic will lead to high levels of this component in the joint, these findings may point the way towards future treatments and prevention of hip osteoarthritis. “It has been known for a long time that there is a link between body weight and osteoarthritis. Many researchers have tried to find dietary components influencing the condition, but this is the first large scale study of diet in twins. If our results are confirmed by follow-up studies, this will point the way towards dietary intervention or targeted drug therapy for people with osteoarthritis.”
Professor Ian Clark of the University of East Anglia said: “Osteoarthritis is a major health issue and this exciting study shows the potential for diet to influence the course of the disease. With further work to confirm and extend these early findings, this may open up the possibility of using diet or dietary supplements in the future treatment osteoarthritis.”
Eating a diet rich in omega-3 fatty acids appears to protect seniors against the onset of a serious eye disease known as age-related macular degeneration (AMD). Researchers did a fresh analysis of a one-year dietary survey conducted in the early 1990s. The poll involved nearly 2,400 seniors between the ages of 65 and 84 living in Maryland’s Eastern Shore region, where fish and shellfish are eaten routinely.
While participants in all groups, including controls, averaged at least one serving of fish or shellfish per week, those who had advanced AMD had consumed less fish and seafood containing omega-3 fatty acids. After their food intake was assessed, participants underwent eye examinations. About 450 had AMD, including 68 who had an advanced stage of the disease, which can lead to severe vision impairment or blindness. Prior evidence suggested that dietary zinc is similarly protective against AMD, so the researchers looked to see if zinc consumption from a diet of oysters and crabs reduced risk of AMD, but no such association was seen.
The researchers believe that the low dietary zinc levels relative to zinc supplements could account for the absence of such a link. However, they cautioned against people to start taking omega-3 supplements to protect against AMD based on this study because they are not sure that the above results have sufficient power to draw any conclusions. The correlation is important but larger studies with longer term follow-up are needed before being able to properly assess the impact.
Alzheimer’s disease, a major form of dementia, has no cure. Luckily, diet and lifestyle can be modified to reduce the risk. For instance, Mediterranean diet and physical activity may each independently reduce the risk of the condition, according to a study in the Aug 2009 issue of Journal of American Medical Association. Dr. N. Scarmeas and colleagues of Taub Institute for Research in Alzheimer’s Disease and the Aging Brain and Department of Neurology at Columbia University Medical Center found men and women those who adhered most closely to Mediterranean diet were 40 percent less likely to be diagnosed with Alzheimer’s disease during a average of 5.4-year follow-up, compared to those who adhered to the diet least closely.
The researchers also found those who most actively engaged in physical activity were up to 33 percent less likely to be diagnosed with Alzheimer’s compared with those who were least active. For the study, Scarneas et al. followed 1880 community-dwelling elderly people who lived without dementia at baseline in New York for their dietary habits and physical activity.
Adherence to a Mediterranean-style diet was assessed on a scale of 0-9, or trichotomized into low, middle, or high and dichotomized into low and high. Physical activity was trichotomized into no physical activity, some, and much and dichotomized into low and high. Neurological and neuropsychological measures were conducted about every 1.5 years from 1992 to 2006. During the 5.4-year follow-up, 282 incident cases of Alzheimer’s were identified.
Those who adhered to the Mediterranean diet with a high score were at 40 percent reduced risk of Alzheimer, compared to those on the diet with a low score. A Mediterranean diet with a middle score did not seem to help compared to a diet with a low score. Those who engaged in some physical activity or much physical activity were at a 25 percent or 33 percent reduced risk of Alzheimer’s disease, respectively, compared with those who did no physical activity. Men and women who had neither followed Mediterranean diet nor much physical activity had an absolute Alzheimer’s risk of 19 percent. This is compared to 12 percent for those who followed both high scored Mediterranean diet and engaged in much physical activity – a difference of 45 percent.
The researchers concluded “both higher Mediterranean-type diet adherence and higher physical activity were independently associated with reduced risk for AD (Alzheimer’s disease).”
For thousands of years, the people of China, Japan, India, and Thailand have consumed green tea and used it medicinally to treat everything from headaches to heart diseases. Over the past few decades, however, research in both Asia and the West have taken place providing scientific evidence of green tea’s numerous health benefits. As a whole, studies indicate that regular consumption of green tea may slow or prevent conditions including high cholesterol, heart disease, arthritis, impaired immune disease and liver disease. In yet another recent study on the beverage’s healthful properties, published in the academic journal Phytomedicine, researchers have found evidence that enzymes in the drink may help in fighting Alzheimer’s and other forms of dementia.
Researchers at the Newcastle University have also found that the Chinese brew may also play a vital role in guarding against cancer. The Newcastle team focused on whether or not once the tea was in the digestive system if the protective properties were still as effective. “What was really exciting was that we found when green tea is digested, the resulting chemicals are actually more effective against key triggers of Alzheimer’s,” said Ed Okello, from the university’s School of Agriculture, Food and Rural Development. “The digested compounds also had anti-cancer properties, significantly slowing down the growth of tumour cells which we were using in our experiments,” Okello said.
Previous studies have shown that polyphenols, present in black and green tea, bind with the toxic compounds and protect brain cells. When ingested, the polyphenols are broken down to produce a mix of compounds and it was these the team tested in their research. According to Okello, there are many factors that together have an influence on diseases such as cancer and dementia – a good diet, plenty of exercise and a healthy lifestyle are all important. “But I think it’s fair to say that at least one cup of green tea a day may be good for you and I would certainly recommend it,” he added.
A popular pastime for many older people is to try and figure out their chances of getting one ailment or another. Mayo Clinic researchers have simplified it – they have figured out the lifetime risk of developing rheumatoid arthritis and six other autoimmune rheumatic diseases for both men and women. “We estimated the lifetime risk for rheumatic disease for both sexes, something that had not been done before — separately or collectively,” says Cynthia Crowson Mayo Clinic biostatistician and first author. “Prevalence and incidence rates existed, but prevalence figures underestimate individual risk and incidence rates express only a yearly estimate.”
The researchers were looking for an accurate basis to offer an easy-to-understand average risk over a person’s lifetime, knowing that risk changes at almost every age. They used data from the Rochester Epidemiology Project, a long-term epidemiology resource based on patients in Olmsted County, Minn. The cohort of 1179, consisted of patients diagnosed between 1955 and 2007, allowed the team to extrapolate the nationwide estimates.
The adult lifetime risk in the United States of having some kind of inflammatory autoimmune disease is 8.4 percent for women and 5.1 percent for men. Based on year 2000 population figures, that means one woman in 12 and one man in 20 will develop one of the conditions in their lifetime. The authors consider that a substantial risk and say their findings should encourage more research on the value of early diagnosis and intervention for people with increased genetic risk of arthritis. They hope the new figures will help in counseling patients and in fundraising efforts to find improved treatments.
The research was supported by the National Institutes of Health.