Pleasant Stone Farm Clinical Reports

Italian researchers have found that rooibos tea is able to boost plasma antioxidant defences in humans.

The researchers from the Antioxidant Research Laboratory in Rome found ingestion of fermented and unfermented rooibos tea increased TAC levels, measured as total antioxidant capacity (TAC).

But Professor Mauro Serafini and his team called for more intervention trials to investigate the proposition that rooibos tea can be as good an antioxidant source as green tea.

The study sought to measure how rooibos tea affects TAC levels as well as lipid triacylglycerols, cholesterol and glycemia plasma levels in humans.

In the trial, 15 healthy adults consumed either 500ml of water, unfermented or fermented rooibos teas, with fermented tea increasing antioxidant capacity 6.6 percent and unfermented tea increasing 2.9 percent.

No changes in triacylglycerols, cholesterol or uric acid were observed with any either of the teas or water.

The researchers noted that only a few studies had investigated the effects of rooibos tea in the body and they focused on iron status, antihistaminic effects and dermatological diseases. None of them investigate potential in vivo antioxidant properties.

“Hence, in the present study we evaluated the in vivo antioxidant properties of fermented and unfermented rooibos teas in healthy humans and related these to the in vitro antioxidant capacity of the beverages,” they wrote.

The subjects observed a low antioxidant diet for two days prior to the feeding period of the studies and dietary records were kept. Between feeding periods there was a two-week wash out and all subjects received all three treatments.

“The two rooibos teas exhibited a lower antioxidant potential than did green and black tea infusions but higher than commercially available instant tea,” the researchers said.

Flavonoid questions

But despite the positive antioxidant findings, the researchers enjoined with many other antioxidant researchers in being unable to explain or define potential antioxidant effects.

“On the basis of the data obtained in the bioavailability study, we cannot explain the in vivo antioxidant effect observed after ingestion of the rooibos teas. This is not unusual in intervention studies with antioxidant rich foods where most of the investigations showing an increase in plasma antioxidant defences, measured as TAC, have failed to identify the components responsible, raising questions as to the direct involvement of flavonoid metabolites as antioxidant molecules in vivo.”

Source:

Food Chemistry

123 (2010) 679–683

‘Unfermented and fermented rooibos teas (Aspalathus linearis) increase plasma total antioxidant capacity in healthy humans’

Authors: D. Villaño et al

Higher intake of both soluble and insoluble dietary fibers may reduce the risk of death from cardiovascular disease amongst Japanese men and women, according to a new study.

The study, which appears in the August issue of The Journal of Nutrition, followed 23,119 Japanese men and 35,611 women aged 40-79 years without a medical history of strokes or heart disease between 1988 and 1990.

All participants completed an initial 40-item food frequency questionnaire and had their soluble, insoluble and total dietary fiber and nutrient intake levels estimated. They were then grouped into five equal quartiles or groups depending on their estimated daily consumption of dietary fiber. The lowest-consuming first quartile ate a median of 6.8 g/d of total dietary fiber (TDF), while the highest fifth quarter consumed a median of 14 g/d.

Significant results

During a 14-year follow-up period the relation between dietary fiber intake and CVD was documented, with 2,080 of total participants dying from CVD – 983 from strokes, 422 from coronary heart disease (CHD) and 675 from other CVDs.

The study found that men and women consuming the most fiber were 18 percent less likely to die from cardiovascular disease than those consuming the least during the course of the study. The results were more striking when in specific relation to CHD, with men and women who consumed the most fruit fiber 58 percent and 45 percent less likely to die. Similar trends were noted for cereal-derived but not vegetable fibers over the same period.

“Our results constitute supporting evidence that higher intake of both insoluble and soluble fiber, especially fruit and cereal fibers, may contribute to the prevention of coronary heart disease in Japanese men and women,” the authors wrote.

They pointed out that epidemiologic studies in the west suggest that dietary fiber intake offers protection against cardiovascular disease. Mean Japanese dietary fiber intake (around 14 g/d) is similar to that of some western countries, but until now like studies have been rare in Asia, making their study interesting in a comparative context.

Research limitations

Statistical adjustments were made to account for other variables, given that men and women in the fifth quartile with the highest TDF intake were more likely than the first quartile to have better general diets, be around six to nine years older, be better educated, take more exercise and less likely to drink alcohol and smoke.

Nonetheless, the authors did not rule out the possibility that these other factors may have influenced disease incidence: The apparent protective effect of fiber on risk of CHD may be due to other health-related habits, such as regular exercise, no smoking and a high fish intake by persons who consume greater amounts of dietary fiber.”

Moreover, they conceded that some participants may have changed their diets over the years following the questionnaire in such a way that results were affected: “Multiple evaluations of diet over time are important to reduce measurement errors.”

Source: The Journal of Nutrition (140:1445-1453, 2010)
“Dietary Fiber Intake is Associated with Reduced Risk of Mortality from Cardiovascular Disease among Japanese Men and Women.”
Authors: E-S. Ehab, I. Hiroyasu, D.Chigusa, K.Shogo, T.Akiko, W.Yoshiyuki, W.Yasuhiko, W.Kenji, JACC Study Group.

ATHENS, Greece—Eating according to the Mediterranean diet helped improve heart function in those who have acute coronary syndrome, according to a new study from First Cardiology Clinic School of Medicine University of Athens Greece (Am J Clin Nutr. 2010 May 19). In the study, those who adhered to the diet rich in fruit, vegetables, fish, nuts, low-fat dairy, whole grains and olive oil experienced a preservation of left ventricular systolic function and a better long-term prognosis of their disease.

Researchers sought to evaluate the relation between the Mediterranean diet, the development of left ventricular systolic dysfunction (LVSD) at hospitalization, and the 2-year prognosis of patients who have had an acute coronary syndrome (ACS). During 2006 to 2009, 1,000 consecutive patients with ACS were enrolled; of these patients, 459 had LVSD at hospitalization (367 men with a mean age of 64 ± 14 years, and 92 women aged 71 ± 12 y), whereas 541 had preserved left ventricular systolic function (421 men aged 62 ± 12 years, and 120 women aged 67 ± 12 years). Adherence to the Mediterranean diet was assessed by the validated Mediterranean Diet Score (MedDietScore; theoretical range: 0–55).

Researchers found those who stuck more closely to the Mediterranean diets had a 31-percent lower risk of suffering another heart attack or experiencing chest pain during the first month after they were discharged from the hospital, according to a Reuters article. Additionally, the Mediterranean-diet eaters were half as likely to have another heart-related event within a year, and about 40-percent less likely to experience repeat heart problems within two years.

According to Reuters, for every additional point on the 55-point Mediterranean Diet Score, a person’s risk of having another heart-related event over the next two years fell by 12 percent. When researchers looked at the separate aspects of the Mediterranean diet, they found people who ate vegetables and salad or nuts daily or weekly were at 20-percent lower risk of repeat heart problems within two years of their initial hospitalization compared to people who ate these foods monthly or less often.

Older adults suffering vitamin D deficiency need higher remedial doses than younger adults, according to a new research review.

The study, Correcting poor vitamin D status: Do older adults need higher repletion doses of vitamin D3 than younger adults?, concluded that: “The doses and total time for repleting older adults with vitamin D3 appeared to be greater than for younger adults, in part due to the lower starting baseline vitamin D status.”

Oral supplementation

To ensure almost all patients receive sufficient vitamin D, a daily dose of 125 mcg (5000 IU) is required for older people, aged 65 and above, while for younger patients, below the age of 65, a rate above 50 mcg (2000 IU) was sufficient.

The results applied whether Vitamin D was taken daily or as a bolus oral supplementation. Adults classed as deficient were those with levels of 25-hydroxyvitamin D less than 75 nmol/L.

The researchers further concluded that several regimens, such as loading with a high dose (12500 mcg) of vitamin D3 and then giving 1250 mcg monthly, provide enough vitamin D3 for most patients to achieve and maintain 25(OH)D levels at or above 75 nmol/L.

According to the research review, a promising loading regimen is to provide calcidiol (25(OH)D) itself.

Since information on repletion with vitamin D2 has been published recently, the researchers decided to focus on the use of vitamin D3 from dietary supplements, prescriptions for large oral doses, and bolus dosing or injections.

Most published dosing regimens failed to achieve 75 nmol/L in almost all subjects, whether young adults (below 65 years) or older adults (above 65 years).

The authors, Susan Whiting, College of Pharmacy and Nutrition, University of Saskatchewan, Canada, and Mona Calvo, US Food and Drug Administration, noted many differences among studies, including baseline levels, endpoints, study duration, and compliance.

Adverse effects

All the studies reviewed reported that subjects were free of adverse effects, indicating that the vitamin D3 protocols were safe during the observed dosing periods.

Meanwhile, the researchers noted that: “Vitamin D insufficiency and deficiency is at epidemic proportions worldwide. In temperate countries more than half of the population is at risk and worldwide, even in tropical countries, vitamin D deficiency is a very serious concern due to changes in living and working conditions.”

Vitamin D has been shown convincingly to have many functions beyond its role in calcium and bone health, they added.

In addition to maintaining normal blood levels of calcium and phosphorus, Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones. Recently, research also suggests vitamin D may provide protection from osteoporosis, hypertension, cancer, and several autoimmune diseases.

Source: Molecular Nutrition and Food Research
Title: Correcting poor vitamin D status: Do older adults need higher repletion doses of vitamin D3 than younger adults?
Authors: S. Whiting, M.Calvo

Combining probiotics with perinatal dietary counselling could help reduce the risk of diabetes in mothers and provide a “safe and cost-effective” tool in addressing obesity in children, according to a new study from Finland.

Published in the British Journal of Nutrition, the study found that probiotic-supplemented dietary counselling could help reduce the risk of diabetes during pregnancy, improve blood glucose control and improve child health.

“Taken together, long-term health benefits for mothers and children may be conferred by balanced maternal nutrition during pregnancy and lactation and by promoting the healthy gut microbiota in the mother and the child. The results of the present study add weight to the argument that the continuing burden of Western lifestyle diseases is modifiable,” write the researchers.

Methods

Initiated in 2002, the study included 256 women, who were randomized during their first trimester of pregnancy into a control and a dietary intervention group.

The women, none of whom had any chronic diseases, all received dietary counselling provided by welfare clinics according to a national program.

The intervention group received additionally intensive dietary counselling at every study visit provided by a nutritionist, the aim being a dietary intake complying with current recommendations, combined with conventional food products with favourable fat and fibre contents for use at home, said the researchers.

The intervention group was further randomised at baseline in a double-blind manner to receive either placebo capsules or probiotics (Lactobacillus rhamnosus GG supplied by Valio, and Bifidobacterium lactis Bb12 supplied by Chr. Hansen) at a dose of 1010 colony-forming units/d each.

The capsules were taken once per day, and the intervention period extended from the first trimester of pregnancy to the end of exclusive breast-feeding.

Results

The researchers evaluated pregnancy outcome and fetal and infant growth during the 24 months’ follow-up.

All pregnancies were of normal duration, and there were no adverse events noted in mothers or in children, which confirms the safety of this approach, said the researchers.

They noted that those women who had taken probiotics had a reduced frequency of gestational diabetes mellitus (GDM): 13 percent for the diet/probiotics group, compared to 36 percent for the diet/placebo group and 34 percent for the control group.

In addition, the dietary counselling during pregnancy reduced the risk of fetal overgrowth, which is thought to predispose to later obesity.

“Probiotic intervention reduced the risk of GDM and dietary intervention diminished the risk of larger birth size in affected cases,” wrote the researchers. “The results of the present study show that probiotic-supplemented perinatal dietary counselling could be a safe and cost-effective tool in addressing the metabolic epidemic. In view of the fact that birth size is a risk marker for later obesity, the present results are of significance for public health in demonstrating that this risk is modifiable.”

Source: Impact of maternal probiotic-supplemented dietary counselling on pregnancy outcome and prenatal and postnatal growth: a double-blind, placebo-controlled study
British Journal of Nutrition (2010)
doi:10.1017/S0007114509993898
Authors: Raakel Luoto, Kirsi Laitinen, Merja Nermes and Erika Isolauri

Supplements of colostrum from cows may counter the drop in immune function following exercise, says a new study from Wales.

Four weeks of supplementation with bovine colostrum reversed the decreases in the function of immune cells that accompanied intense exercise, according to findings published in the British Journal of Nutrition.

“The main findings of the present study are that 4 weeks of bovine COL supplementation improved the speed of recovery of neutrophil function after exercise-induced immunodepression and reduced exercise-induced alterations in salivary lysozyme concentration and secretion rate,” wrote Glen Davison and Bethany Diment from the Department of Sport and Exercise Science, Aberystwyth University.

“This is the first study to demonstrate that COL supplementation enhances these innate immune parameters in the recovery period after prolonged endurance exercise that causes acute immunodepression.”

Colostrum is obtained from the first milk produced by a mammal after giving birth. It is considered to be a special boost to health thanks to its high level of immune globulin (IgG), a substance that helps build up the immune system of a newborn mammal.

The colostrum used in this study was provided by Neovite UK, which sources the ingredient from Fonterra, a major supplier of colostrum.

Study details

Davison and Diment recruited 12 healthy, active men and randomly assigned them to receive either placebo or a daily bovine colostrum supplement for four weeks. After this time, all the participants cycled for two hours at 64 percent of their maximal oxygen uptake.

Results showed that there were no differences between the groups for levels of circulating immune cells (neutrophils), and the ratio of neutrophils to lymphocytes. However, significant differences were observed between the groups for the function of the neutrophils, and for levels of lysozymes in the saliva. Lysozymes are enzymes that are part of the immune system and a natural form of protection against a range of pathogenic bacteria.

“Bovine colostrum supplementation either speeded the recovery (neutrophil function) or prevented the decrease (salivary lysozyme) in these measures of innate immunity,” stated the researchers.

Commenting on the potential mechanism, the Aberystwyth researchers noted that previous findings only provide speculative evidence and that “further research is required to determine whether this is the mechanism by which oral supplementation with bovine colostrum enhances innate immunity after physical stress in human subjects.

“It is also worthy of note that, in the present study, we only assessed one aspect of neutrophil function. In order to determine the mechanisms of action, future studies should also examine other aspects of neutrophil function, such as chemotactic, phagocytic and oxidative burst responses for example,” they added.

Source: British Journal of Nutrition
Volume 103, Pages 1425–1432 doi:10.1017/S0007114509993503
“Bovine colostrum supplementation attenuates the decrease of salivary lysozyme and enhances the recovery of neutrophil function after prolonged exercise”
Authors: G. Davison, B.C. Diment

Higher blood levels of vitamin B6 may reduce the risk of lung cancer by about 50 per cent, says a new analysis of almost 400,000 people, including current and former smokers.

Researchers also report that the amino acid methionine, which is found in most protein, may also reduce the risk of lung cancer.

“Given their involvement in maintaining DNA integrity and gene ex­pression, these nutrients have a potentially important role in inhibiting cancer devel­opment, and offer the possibility of modi­fying cancer risk through dietary changes,” wrote the authors in the Journal of the American Medical Association.

One in three Europeans are smokers, while the US figure is one in five. Tobacco smoke contains over 4,000 compounds, of which 60 are known carcinogens. The oxidative stress levels of smokers are significantly greater than non-smokers, and as such there is a bigger drain on the levels of antioxidants in the body.

Furthermore, the new study indicated that folate may also be beneficial, and that high folate levels combined with methionine and B6 were associated with a 66 per cent reduction in lung cancer risk.

Study details

Led by Paul Brennan from the International Agency for Research on Cancer in Lyon, France, the researchers used data from 385,747 people who donated blood while participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). Out of this, 899 people with lung cancer were identified and matched with 1,770 cancer-free people.

The researchers noted that increasing blood levels of vitamin B6 were associated with lower risks of lung cancer. A similar risk reduction was observed for methionine, which extended to never, former, and current smokers. This indicated that smoking habits were not confounding the results.

“Our results suggest that above-median serum measures of both B6 and methionine, assessed on average 5 years prior to disease onset, are associated with a reduction of at least 50 percent on the risk of developing lung cancer,” wrote the researchers. “An additional association for se­rum levels of folate was present, that when combined with B6 and methionine, was associated with a two-thirds lower risk of lung cancer,” they added.

More research needed

Correlation does not prove causation, however, and more research is needed to clarify the role of B vitamins and methionine in lung cancer, said the researchers.

“It is essential that for lung cancer prevention, any additional evidence about causality does not detract from the importance of reducing the numbers of individuals who smoke tobacco,” wrote Brennan and his co-workers

“With this in mind, it is important to recognize that a large proportion of lung cancer cases occur among former smokers, making up the majority in countries where tobacco campaigns have been particularly successful, and a non-trivial number of lung cancer cases oc­cur also among never smokers, particu­larly among women in parts of Asia.

“Clarifying the role of B vitamins and re­lated metabolites in lung cancer risk is likely therefore to be particularly relevant for former smokers and never smokers,” they concluded.

Authors: JAMA
2010, Volume 303, Number 23, Pages 2377-2385
“Serum B Vitamin Levels and Risk of Lung Cancer”
Authors: M. Johansson, C. Relton, P.M. Ueland, et al.

The heart health benefits of omega-3 fatty acids EPA and DHA may be related to their ability to reduce oxidative stress, suggests new research.

Oxygen-breathing organisms naturally produce reactive oxygen species (ROS), which play an important role in a range of functions, including cell signalling. However, over production of these ROS from smoking, pollution, sunlight, high intensity exercise, or simply ageing, may overwhelm the body’s antioxidant defences and lead to oxidative stress.

Oxidative stress has been linked to an increased risk of various diseases including cancer, Alzheimer’s, and cardiovascular disease.

Previous reports had suggested that omega-3 fatty acids may actually increase levels of oxidative stress due to their susceptibility to oxidation. New findings in Free Radical Research indicate that EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) may actually reduce oxidative stress by reducing levels of a compound called F2-isoprostanes.

Scientists from the University of Western Australia and the University of Montpellier (France) report that daily supplements of four grams or either EPA or DHA for six weeks were associated with reductions of about 20 per cent.

“The data, therefore, suggest omega-3 fatty acids reduce oxidative stress, which is likely related, at least in part, to their anti-inflammatory actions and the expected reduction in leukocyte activity,” wrote the authors, led by Dr Emilie Mas. “These findings give further support for supplementation of the diet with 3 fatty acids for cardiovascular risk reduction.”

Study details

Dr Mas and her co-workers recruited two sets of people to participate in their study. One group was composed of 59 overweight men with abnormal blood lipid levels, and the other group was composed of type-2 diabetics being treated for high blood pressure. The participants were randomly assigned to receive daily doses of 4 grams of EPA, DHA or olive oil (placebo) for six weeks.

At the end of the study, the researchers noted that EPA reduce urine levels of F2-isoprostanes by 24 per cent in the overweight men and by 19 per cent in the diabetics, while DHA was associated with a 14 and 23 per cent reduction in these groups, respectively, compared with the olive oil groups.

Furthermore, plasma levels of arachidonic acid (AA) were reduced following both EPA and DHA supplementation, said the researchers.

Dr Mas and her co-workers note that a previous study in healthy subjects also found benefits, which, combined with their findings, show that omega-3 supplementation may decrease F2- isoprostanes in both healthy and diseased populations.

“Furthermore, the lack of association with changes in fatty acids is noteworthy, in view of the fact that F2-isoprostanes are derived from free radical oxidation of AA, which is significantly reduced following omega-3 fatty acids,” stated the researchers. “Therefore, the changes in F2-isoprostanes most likely reflect a true reduction in oxidative stress, rather than resulting from a reduction in the supply of substrate.”

“These results show that in humans, EPA and DHA reduce in vivo oxidant stress as measured in human plasma and urine,” concluded the researchers.

The EPA and DHA were supplied by the Fish Oil Test Materials Program and the U.S. National Institutes of Health, and the study was funded by the National Health and Medical Research Council of Australia, the West Australian Health Promotion Foundation, and the Royal Perth Hospital Medical Research Foundation.

Authors: Free Radical Research
Published online ahead of print, doi: 10.3109/10715762.2010.492830
“The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes: Results from two placebo-controlled interventions”
Author: E. Mas, R.J. Woodman, V. Burke, I.B. Puddey, L.J. Beilin, T. Durand, T.A. Mori

Insufficient and deficient levels of vitamin D may increase the risk of metabolic syndrome by about 40 percent, according to new findings.

British researchers have concluded pregnant women should be advised to take vitamin D after determining there is a “strong case” to back the vitamin’s benefits.

The researchers from the University College London Institute of Child Health wrote in the British Journal of Nutrition that supplementation of vitamin D will benefit pregnant women and reduce the risk of diseases such as infantile hypocalcaemia and rickets.

They said the UK was the only country in 31 that did not officially recommend vitamin D use women of reproductive age, even though the Department of Health advises pregnant women to take 10 micrograms per day.

But that advice is contradicted by the National Institute of Health and Clinical Excellence (NICE) which advises against supplements use – even though 10 micrograms is not usually attainable via a regular diet and sunshine.

The paper said the UK was the only one of 31 countries examined which did not recommend that women of reproductive age took a vitamin D supplement.

“The incidence of vitamin D deficiency in pregnant women in Britain is unacceptably high, especially during winter and spring,” said Dr Elina Hypponen, one of the report authors.

“This is compounded by a lack of exposure to sunlight and the limitations of an average diet to meet the optimal need. In the most severe cases, maternal vitamin D deficiency can be life threatening to a newborn.”

“We believe that the routine provision of a daily supplement throughout pregnancy would significantly decrease the number of mothers who are clearly vitamin D deficient, reducing related serious risks to their babies.”

The research also highlighted the problem of women with dark skin who do not absorb as much sunlight and therefore manufacture less vitamin D in vivo.

Source: British Journal of Nutrition

Published online ahead of print doi:10.1017/S0007114510002436

“Avoidance of vitamin D deficiency in pregnancy in the United Kingdom: the case for a unified approach in National policy”

Authors: Elina Hyppönen and Barbara J. Boucher