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In a new analysis of 66 research studies, increased consumption of fiber and whole grains is related to a significant decrease in risk of several vascular diseases.

High fiber intakes, including whole grains, are generally recommended for prevention of cardiovascular diseases, but comprehensive and specific research on dosages in humans is relatively unknown.

A new study published in the Journal of Nutrition analyzed longitudinal studies investigating wholegrain and fiber intake in relation to the risk of type-2 diabetes (T2D), cardiovascular disease (CVD), weight gain and metabolic risk factors.

Researchers identified 45 prospective cohort studies and 21 randomized-controlled trials conducted between 1966 and February 2012. After examining whole-grain and fiber intakes, study characteristics and risk estimates from these studies it was determined that compared with those that never or rarely consumed whole grains, those consuming 48-80 grams/day (3-5 servings of whole grains/day) had a 26% lower risk of T2D, 21% lower risk of CVD, and were less likely to gain weight.

In analyzing the randomized-controlled trials, the researchers also found that groups with higher intake of whole-grains had lower total cholesterol, LDL cholesterol and fasting glucose than those that ate less fiber and whole grains.

The results from this meta-analysis offer evidence to support the beneficial effects of whole-grain intake in the prevention of certain vascular diseases and on maintenance of cardiovascular health.  More research is needed to determine the specific mechanisms responsible for the effect of whole grains on metabolic intermediates which correlate to the preventive benefits of fiber and whole grain.

Source:
Eva Qing Ye et al; J. Nutr. 2012. 142(7):1304-1313.

 

 

Colorectal cancer is the third most common type of cancer.  Latest study indicates that increased fibre intake is associated with reduced risk for colorectal cancer.

Epidemiological evidence have demonstrated several health benefits associated with increasing fibre intake and replacing refined grains with whole grains, such as reduced the risk of cardiovascular disease, type 2 diabetes, overweight and obesity.  A recent systematic review investigated the association between dietary fibre and whole grain intake and incidence of colorectal cancer.

Colorectal cancer accounts for about 10% of all cases of cancer.  Evidence suggest that dietary factors are of major importance in the cause of colorectal cancer, particularly intakes of red and processed meat and alcohol are considered to be convincing dietary risk factors for colorectal cancer.  Whole grains are a major source of dietary fibre and contain nutrients that are removed during the refining process.  Whole grains are a major source of several vitamins, minerals, and phytochemicals, which could plausibly influence the risk of colorectal cancer.

Statistical analysis of 25 prospective studies showed that there is a 10% reduction in risk of colorectal cancer for each 10 g/day intake of total dietary fibre and cereal fibre; and a 20% reduction for each three servings (90 g/day) of whole grain daily.

In summary, a high intake of dietary fibre, in particular cereal fibre and whole grains, was associated with a reduced risk of colorectal cancer.  Further studies are warranted to investigate in more details, including those for subtypes of fibre and other risk factors that may have public health implication in relation to risk reduction for colorectal cancer.

Source:
Dagfinn Aune et al; BMJ 2011;343:d6617

 

Some good news. A recent review shows that moderate intake of fructose, when used in place of other carbohydrates, may help improve blood sugar control.

Fructose is a sugar naturally found in fruit, vegetables and honey. There has been much controversy recently regarding the effect of fructose consumption on cardiovascular and metabolic health in humans.

A new study published in Diabetes Care indicates that moderate fructose consumption may not be detrimental as some studies suggested, and that in certain groups it may even provide some benefit.

Canadian Researchers reviewed 18 trials involving participants with Type 1 or Type 2 diabetes. In each trial, subjects were fed diets that included fructose incorporated or sprinkled onto test foods such as breakfast cereals or in coffee. The diets with and without fructose contained the same amount of calories. Data gathered included fasting glucose, insulin and glycated hemoglobin (HbA1c), which is an indication of average blood glucose control over 3 months.

The researchers found that isocaloric exchange of fructose for carbohydrate significantly reduced glycated blood proteins, an indication of improved blood sugar control. The level of improvement was similar to what are typically achieved using oral anti-diabetic medications. In addition, these benefits were seen with no evidence of adverse effects on body weight, blood pressure, uric acid
(gout), or cholesterol. Fructose consumption did not significantly affect fasting glucose or insulin.

The results of this study highlight the need to bring attention back to the concept of moderation. In the popular media, all the emphasis on fructose-related harm draws attention further away from the issue of eating too many calories. Although larger and more comprehensive studies are needed to further assess both possible glycemic benefit and adverse metabolic effects, the current study shows that fructose intake in moderation may have cardiometabolic benefits diabetic adults.

Source:
Adrian I. Cozma, et al. Diabetes Care July 2012 Vol. 35(7): 1611-1620.

 

 

Vitamin D is necessary for optimal health.  However, nearly one-third of Australian adults over the age of 25 have Vitamin D deficiency which raises a serious public health concern.

Vitamin D deficiency is recognized as a global public health problem, but the population-based prevalence of deficiency and its determinants in Australian adults has not previously been properly examined.

A recent study evaluated the vitamin D status of Australian adults aged ≥25 years and risk factors associated with vitamin D deficiency in this population group. A national sample of 11247 Australian adults enrolled in the AusDiab was drawn from 42 randomly selected districts throughout Australia from Darwin to Hobart.  Serum concentrations of 25-hydroxyvitamin D were measured by immunoassay. Vitamin D deficiency was defined as a concentration <50 nmol/L.

The overall prevalence of vitamin D deficiency (<50 nmol/L) was 31% with women being more commonly affected (39% in women vs 23% in men).

When evaluated by season and latitude, deficiency was more common during winter and in people residing in southern Australia (latitude >35°S); 42% of women and 27% of men in southern Australia during summer/autumn had deficient levels, which increased to 58% and 35% in women and men, respectively, during winter/spring.

The prevalence of vitamin D deficiency also increased significantly with age, in women, in those of non-European origin, in the obese and those who were physically inactive and with a higher level of education.

Low levels of vitamin D has been found to be associated with a number of medical conditions such as softened bones; diseases that cause progressive muscle weakness leading to an increased risk of falls, osteoporosis, cardiovascular disease, certain types of cancer and type 2 diabetes.

Results from this latest study confirmed that vitamin D deficiency is common in Australia affecting nearly one-third of adults aged 25 years and older.  The study authors further commented that national strategies are urgently needed to develop an awareness campaign for balancing safe sun exposure and adequate vitamin D intake, and to tackle the high prevalence of vitamin D deficiency in Australia before the problem worsens.

Source:
Daly RM et al. Clin Endocrinol (Oxf). 2012 Jul; 77(1):26-35.

 

 

Appropriate nutrition in early childhood is important for normal growth and may influence long-term health and chronic disease status.

There is concern that while the energy intakes of young children are increasing, this may not be matched by the nutrient density of their diets. This has been interpreted by some to indicate a modern phenomenon of malnutrition in the developed world – an increasing prevalence of childhood obesity co-existing with key micronutrient deficiencies.

A recent study published in Medical Journal of Australia conducted a cross-sectional survey of children aged 1–5 years from a representative population sample in Adelaide, South Australia, to determine the nutrient intakes and status of preschool children.

The survey found that overall energy contributions from carbohydrate, protein, fat and saturated fat intakes were 50%, 17%, 33% and 16%, respectively. 95% of children over 2 years of age had a saturated fat intake that exceeded the maximum recommended limit of 10% of total energy.  Only a minority of children achieved the adequate intake for omega-3 long-chain polyunsaturated fatty acids (32%) and dietary fibre (18%).  32% of children had zinc deficiency.

The study author concluded that the dietary intake of children in the study was adequate for macronutrients and the majority of micronutrients. However, low intakes of fibre and n-3 long-chain polyunsaturated fatty acids and high saturated fat intakes have raised concerns that this dietary pattern may be associated with adverse long-term health effects.  There is a need for increased attention on establishing healthy eating patterns in early childhood, as dietary patterns established early in life often carry through to adulthood.

[Note: It is worth pointing out that this survey used the EAR (Estimated Average Requirement) as reference value when evaluating nutrients intake adequacy. EAR is much lower than RDI (Recommended Dietary Intake).  If RDI were used as reference value, the prevalence of deficiency for key micronutirents might be higher than findings from this survey.  Further studies are warranted to better define optimal nutritional requirements.]

Source:
Shao J Zhou et al; MJA 2012; 196: 696–700

Studies revealed that the majority of the pediatric population may fall short of recommended dietary intakes of omega-3 fatty acids.

According to NHMRC Nutrient Reference Values for Australia and New Zealand, the daily Adequate Intake of essential fatty acids and omega-3 fats such as DHA/EPA/DPA is 55mg/day for children aged 4-8 years of age. However estimates of actual dietary intake of these beneficial fatty acids are limited in children.

A study in the Journal of Nutrition has published direct quantification of fatty acid intakes in 41 children aged 4-8 years.  Identical portions of all food and dietary supplements consumed over 3 days were collected. Duplicate samples were analyzed for calories, macronutrients, and fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA).

Based on the dietary analysis, the children averaged 1,404 kcal energy intake per day, and their fatty acid intakes were at the following levels in mg/day: alpha-linolenic acid 1,611; EPA 38.4; DPA 26.3; and DHA 54.1.

Based on the US government recommended Dietary Reference Intakes (DRI), 61% of the children met the adequate intake for ALA, and only 22% met the recommended intake for DHA + EPA. These intakes were compared with recently established Australia/New Zealand recommendations for children, where only about half the children (51%) met suggested intakes for EPA + DPA + DHA.

The result of this study indicates a significant deficit in the actual intakes of polyunsaturated fatty acids, including DHA, among Canadian and Australian children when compared to recommended intakes. This deficit gap can be readily filled with an increased consumption of fish/seafood, foods (dairy products, breads, and others) that have been enriched with various delivery forms of omega-3 EFA, and the use of supplementation where necessary.

Source:
Madden SM et al; J Nutr. 2009 Mar; 139(3):528-32.

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