Dietary Fibre - a well being star

Important for digestive health & overall wellness

It’s hailed a digestive health star, yet most people are unaware dietary fibre also takes centre stage for its ability to lower ‘bad’ LDL-cholesterol levels, stabilise blood sugar levels, aid weight control and much more. 

What is dietary fibre?

Found only in foods of plant origin (e.g. grains, legumes, vegetables, fruit, nuts and seeds), dietary fibre is the part of a plant that escapes digestion and absorption in the small intestine. The dietary fibre we eat makes its way into the large intestine (colon), where it is partially or completely broken down by an army of beneficial bacteria that reside in the colon1,2. 

There are several types of dietary fibre:

Soluble fibre:
Think ‘gelatinous’ fibre. These fibres, which attract water to form a thick gel, are totally broken down (fermented) by good bacteria in the colon3. During this process, substances are produced which help keep cells in the colon wall healthy. Good sources include cereal grains (especially oats, barley and rye), legumes (red kidney beans, chickpeas, baked beans), psyllium, some fruits, vegetables, nuts and seeds.

Insoluble fibre:
Think ‘bulking’ fibre. Best known for increasing the weight and volume of faeces and producing softer and bulkier stools, these fibres aid regular bowel movements3. This beneficial stool bulker is found in wholegrains, wheat bran, legumes, nuts and the skins of vegetables and fruits.

Resistant starch:
This is a starch that acts like dietary fibre in that it too escapes digestion in the small intestine. It moves along to be fermented by friendly resident bacteria in the colon, producing substances that help keep the colon healthy. Common sources include legumes like lentils and baked beans, some cereal grains like pearl barley and brown rice, ‘Hi-maize’® (found in some retail breads and cereals) and cooled cooked potato, rice and pasta3,4,5. 

Dietary Recommendations

The total amount of dietary fibre we need to eat each day varies according to age, gender, life stage and disease risk6. Maximise the health benefits of fibre by eating a variety of high fibre grain-based foods and legumes each day, together with a selection of fruits, vegetables, nuts and seeds.

Ways to Increase Your Fibre Intake with Grain-Based Foods

Breakfast
• Wholegrain (wholemeal, mixed-grain) toast, crumpets or English Muffins
• High fibre or wholegrain breakfast cereal or natural muesli
• Porridge or bircher muesli made with rolled oats

Lunch
• Sandwiches, rolls or wraps made with high fibre bread and with your favourite filling
• Salads made with grains like brown rice and cracked wheat (bulgur), or legumes like four bean mix, kidney beans and chickpeas

Dinner
•  Casserole or soup with added legumes
• Stir fry or curry with brown rice or soba noodles
• Wholemeal pasta topped with your favourite vegetable-based sauce
• Wholegrain bread used for crumbing fish or chicken

Snacks
• High fibre or wholegrain snack bars
• Muffins, biscuits or pikelets made with wholemeal flour or rolled oats
• Wholegrain crispbreads/crackers

For more information on Dietary Fibre and its benefits, download our dietary fibre brochure (http://www.gograins.com.au/wp-content/uploads/2011/04/GG_Nutrition-brochure_-Fibre_low-res.pdf)

References:

1. Food Standards Australia New Zealand. Food Standards Code, Standard 1.2.8 – Definition of Dietary Fibre.
2. American Association of Cereal Chemists. The Definition of Dietary Fiber (Report of the Dietary Fiber Definition Committee to the Board of Directors), Jan 2001.
3. Anderson JW, Baird P, Davis Jr RH, Ferreri S, Knudtson M, Koraym A, Waters V and Williams CL. Health benefits of dietary fiber. Nutrition Reviews. 2009; 67(4):188–205.
4. Landon S. Resistant Starch Review, 2011 Update for Health Professionals. Hi-Maize and National Starch Food Innovation.
5. Marlett JA, Longacre MJ. Comparisons of in vitro and in vivo measures of resistant starch in selected grain products. Cereal Chem. 1996 ;73:63–68.
6. National Health and Medical Research Council (2006). Nutrient Reference Values for Australia and New Zealand including Recommended Dietary Intakes.

A comparison of the 1995 NNS and 2007 NCNPAS

Are Australian children eating healthier?


Australian National dietary survey’s are few and far between. These large and expensive Australian representative surveys are invaluable for understanding Australian’s food intake and nutrition status and the results provide the evidence base for public health, marketing and policy decisions. With 1 in 4 of Australian children overweight or obese, regular monitoring of the dietary intakes of children is essential.

Australia's most recent National Nutrition Survey was conducted in 1995 (NNS 95), and the 2011-13 Australian Health Survey is currently in field now. In 2007, a National Children’s Nutrition and Physical Activity Survey (NCNPAS07) was completed to understand what Australian Children were eating and their physical activity habits. A group of respected Australian researchers has just published their findings of the nutritional comparison of both surveys, to determine whether there was a change in core food intakes among Australian children between 1995 and 2007, and to review trends over this 12 year period.

The authors analysed the 24 hour recall data from the NNS95 with almost 2500 participants, and the NCNPAS07, with almost 5000 participants aged between 2-16 years. The researchers compared the differences between how many children were consuming each food group, the amounts consumed and the contribution of these foods to energy intake. Based on the Australian Guide to Healthy Eating, core foods were identified as: breads and cereals, meat and alternatives, milk and alternatives, fruit, and vegetables.

The consumption of core foods increased significantly between the 1995 and 2007 surveys by per-capita consumption and percent energy contribution. Core foods contributed 59% of energy intake in 1995 and 65% in 2007. The types of core foods also moved to more healthy choices. In the breads and cereals group there was a significant increase in the percent of children consuming wholemeal and fibre-increased bread, high-fibre breakfast cereal, pasta, noodles and rice. Total breads and cereals consumption remained largely unchanged, but still provided the largest energy contribution of all the core food groups. There were significant increases in per capita consumption of wholemeal bread, pasta, noodles, and high fibre breakfast cereals, along with decreases in white bread. Children in the older age groups were more likely to consume bread as white bread (69%), while younger children consumed a greater proportion as wholemeal (51%). Sales of wholegrain, wholemeal and artisan types of breads have also increased over recent years. The Go Grains Health & Nutrition '4+ serves a day' message, which actively promotes the health and nutrition benefits of grain-based foods, preferably wholegrain, along with increased marketing of wholegrains on pack may have prompted the growing interest in wholegrains.

Overall the authors concluded there appears to have been some notable improvements in the diets of Australian children since 1995. There was an increase in the consumption of healthier food choices, accompanied by decreases in the consumption of unhealthier food choices in 2007.

Breads and cereals remain the most important contributors to the core food intakes of Australian children and since 1995 there has been a trend to healthier wholemeal and high-fibre choices.

New Australian Food Consumption Data

Grain food and legume intakes from 2009 – 2011

A new national consumption tracking study commissioned by Go Grains Health & Nutrition has just been completed by research group Colmar Brunton, comparing grain food and legume consumption from 2009 to 2011. A 2-day food diary was kept by over 1200 participants in 2011 and over 1700 participants in 2009, followed by a series of online questions to understand consumption, awareness and attitudes towards grain foods and legumes.

The study concluded Australians are not eating enough legumes or core (staple) grain foods such as bread, breakfast cereal, rice, pasta and noodles for health and wellbeing as recommended by Australian Dietary Guidelines. Australians are not meeting the recommended minimum ‘4 serves a day’ of core grain foods, with the average intake only 3.2 serves in the 2011 survey compared with 4.1 serves in 2009. For females and children the picture is even worse with neither subgroups reaching above 3 serves of core grain foods a day on average, significantly lower than 2009.

There was a decrease in bread (15.3 to 11.9 serves/wk), equal to almost 1 slice a day, breakfast cereals (3.8 to 2.99 serves/wk), pasta/noodles (0.27 to 0.21 serves/wk) and rice (0.21 to 0.17 serves/wk) consumption over the 2 years. One serve is equivalent to approximately 2 slices of bread, 1 cup of breakfast cereal/ pasta/ rice/ noodles as described in the Australian Guide to Healthy Eating.

In 2011, there was a significant increase in takeaway/mixed meals (1.2 to 0.9 serves/wk) compared to 2009. Over a quarter (28%) of grain-based food intake came from non-core (“extra’s”) foods like cakes, biscuits, pastries and takeaway foods (like hamburgers, hot dogs and pizza), which has significantly increased from 2009. This indicates that Australians need to swap non-core grain-based foods for core grains with an emphasis on wholegrain, high fibre and low GI grain types.

The study estimates that Australians are eating just over 1 serve of wholegrains a day, less than 1.4 serves in 2009 and a long way from the Go Grains recommendation of at least 48g of wholegrains a day for good health (equivalent to approximately 2 serves, or ½ grain intake as wholegrain). This is consistent with the recently launched 2010 Dietary Guidelines for Americans which recommend half of grain intake as wholegrain (equivalent to 1.5 serves ‘Australian’ serves).

Declining consumption appears to be as a result of misperceptions and lack of understanding about the importance of grain foods in the diet. The study indicates there is a lack of awareness of the health benefits of grains and poor understanding of the recommended amount that should be consumed per day. When asked how many serves would fall with dietary recommendations, only 15% of participants correctly answered 4 or more, as per the Australian Guide to Healthy Eating. Of concern, 42% of females thought “4+ serves a day” is too many serves of grain foods.

There is also lack of knowledge about the foods that contain wholegrains. 9-17% of people surveyed thought vegetables, brown sugar, white rice were wholegrain, and only half thought oats/porridge was wholegrain. The study found people may also limit grain foods as they are concerned about weight management or dietary intolerance.

The findings are a major concern for public health and require supportive action from policy makers to address the issue of declining core grain food consumption. In the 1995 National Nutrition Survey, breads and cereals were the leading source of fibre, thiamin, magnesium and iron and secondary source of folate, niacin, zinc and protein in the diets of Australians. Go Grains is concerned that many Australians may be missing out on these essential nutrients as a results of declining consumption across 2009-2011. We look forward to the results of the Australian Health Survey expected in 2013, however there is a need for realistic quantitative recommendations for the proportion of wholegrains and refined core grain foods in a healthy diet in the upcoming review of the Dietary Guidelines to ensure communication is clear and consistent amongst health care professionals and manufacturers. Helping consumers identify core grain foods will reduce confusion between the nutritious refined grain foods like white rice, white bread, white pasta and lower fibre breakfast cereals and non-core refined grain foods like cakes, biscuits and pastries and takeaway foods with significant amounts of added fat, sugar and salt.

Go Grains recommends an evidence-based guideline: “Eat “4+ serves a day” of grain foods (including breads, rice, pasta, breakfast cereals and noodles), with at least ½ wholegrain”.

Australians need to eat more core grain foods and include more wholegrain and high fibre foods in the diet. Australians should limit their intake of non-core refined grain-based foods such as cakes, pastries, biscuits and takeaway foods.

Green light for soy

New nutrition advice for breast cancer sufferers

We almost all know of someone who has been diagnosed with breast cancer. It is one of the most common causes of cancer related death in women. The incidence is growing, with data from the Australian Institute of Health and Welfare (2010) indicating 1 in 9 women will be diagnosed with breast cancer before the age of 85, and projections to 2015 suggesting the number of new breast cancer cases among women is likely to be 22% higher than in 2006. Early test tube studies conducted in the laboratory caused some concern that soy could promote breast tumour growth. A new study has added to the growing body of evidence that soy foods, like tofu and soy milk, have no adverse affects on breast cancer prognosis.

Most of the earlier studies investigating soy foods and breast cancer examined isoflavones; an antioxidant component found in legumes such as soy beans, in isolation in a test tube and found that they may enhance the growth of breast cancer cells. Based on this early evidence and along with the potential for isoflavones to interfere with the effectiveness of Tamoxifen – a drug that has been used treat breast cancer for over 30 years, some medical professionals treating women with breast cancer advised them to limit their consumption of soy foods. Two recent epidemiological studies conducted with breast cancer survivors have suggested that soy intake does not affect breast cancer prognosis and may even reduce recurrence. New data from the Women’s Healthy Eating and Living study (WHEL), with a larger number of participants further supports the existing research, suggesting there are no adverse affects of soy foods on breast cancer prognosis.

A secondary analysis of data from the WHEL study was used for this paper. The WHEL was a randomised controlled trial of a high fibre and high fruit and vegetable intervention in over 3,000 early stage breast cancer survivors in the USA. The participants aged from 18 - 70 years, recently surviving breast cancer, were recruited for the dietary intervention with an average follow up of 7.3 years from the time of enrolment. Soy intake measured by milligrams of isoflavones, (not total soy protein) was measured post diagnosis by the Arizona semi quantitative Food Frequency Questionnaire which included specific soy items and an option to include other soy foods not on the list.

The women in the highest quintile of isoflavone intake (16.3mg/day) had a 54% reduced risk of death compared with the lowest quintle of intake, (effectively non-soy consumers, 0-0.7mg/day) however this was not statistically significant. The highest quintile of isoflavone intake consumed on average the equivalent to around 1 cup of soy milk or approximately 3 ounces (85g) of tofu each day - which is not particularly high and probably reflects a similar amount to common levels of intakes in western consumers who eat soy. Younger women, Asians and those with a college degree or higher were most likely to be in the highest quartile.

Isoflavone intake was unrelated to the risk of a second breast cancer event, and for overall mortality, risk of death tended to be lower as isoflavone intake increased. Although the interaction between Tamoxifen use and mortality was not statistically significant, the observed effect toward lower mortality with increased soy seemed stronger in women who used Tamoxifen.

This study is now the third epidemiological study that shows lack of harm from soy consumption, and provides sufficient evidence that women with breast cancer no longer need to be advised to avoid soy products .

References:

• Soy Food Consumption and Breast Cancer Prognosis. Caan BJ, Natarajan L, Parker B, Gold EB, Thomson C, Newman V, Rock CL, Pu M, Al-Delaimy W, Pierce P. Cancer Epidemiology, Biomarkers & Prevention 2011;20(5):854-8.

• National breast and ovarian cancer centre - www.nbocc.org.au

Fibre helps protect against colorectal cancer

New World Cancer Research Fund Report supports dietary fibre for protection against colorectal cancer

 

The number of new cancer cases in Australia is rising each year. Data from 2007 (AIHW) indicates that bowel cancer (also known as colorectal cancer) is the second most common cancer in Australia and the second largest cause of cancer deaths in Australia, killing almost 80 people a week (Bowel Cancer Australia).

 

Rates of colorectal cancer increase with industrialisation and urbanisation and are generally more prevalent in high income countries, but now becoming increasingly more common in middle and low income countries. Somewhat more common in men than in women, colorectal cancer is fatal in just under half of all cases, however if detected early, it is actually one of the most curable cancers, with food and nutrition having an important role in its prevention and cause.

 

A new update to the Food, Nutrition, Physical Activity, and the Prevention of Colorectal Cancer Report by the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) as part of the Continuous Update Project (CUP) has just been published, including an additional 263 new articles from cohort studies and randomised controlled trials. The CUP provides a comprehensive and up-to-date systematic review of scientific developments on the relationship between diet, physical activity, obesity and cancer, with the panel consisting of leading scientists in these fields.

 

In this new report, the CUP panel agreed that the evidence for a protective effect from foods that contain dietary fibre had strengthened from probable in the previously completed Secondary Expert Report (SER) and therefore the evidence has been upgraded to ‘convincing’. This is highest level of evidence set by the WCRF and AICR, which identifies a causal relationship between a particular aspect of food, nutrition, physical activity or body composition, and cancer.

 

Twelve new papers were included in the review that investigated total dietary fibre and fibre from cereals, wholegrains, legumes, fruit and vegetables. The new report found that 13 of the 18 studies showed a decreased risk for colorectal cancer with increased intake of total dietary fibre.

 

The new meta-analyses showed a 10 per cent decreased risk for colorectal cancer and 11 per cent decreased risk for colon cancer with an increase in dietary fibre of 10g/day, which is a slightly better risk reduction than the 2007 report. The updated meta-analyses for rectal cancer, trended in the direction of decreased risk, but did not reach statistical significance.

 

Likewise, the updated reviews for sources of fibre and colorectal cancer showed a 10 per cent decreased risk for cereal fibre, but estimates for other sources of fibre were in the direction of decreased risk, but again did not reach statistical significance.

 

With 3 servings of wholegrains per day there was a 21 per cent decreased risk for colorectal cancer and 16 per cent decreased risk for colon cancer. There was also convincing evidence that physical activity protects against colon cancer. It is interesting to note the review concluded there is probable evidence that consumption of garlic, milk, and calcium may also protect from colorectal cancer.

 

The way in which fibre helps reduce the risk of colorectal cancer is due to several effects in the gastrointestinal tract, but the precise mechanism is still yet to be fully understood. Fibre dilutes faecal content, decreases transit time and increases stool weight whilst healthy gut bacteria from a wide range of dietary carbohydrates that reach the colon produce fermentation products, particularly short-chain fatty acids such as butyrate which helps to maintain healthy colon cells. Fibre intake is strongly correlated with intake of folate, however, adjusting for this does not often affect the risk reduction attributed to fibre.

 

The latest evidence from the WCRF review report also shows that consumption of red meat and processed meat, ethanol from alcoholic drinks (by men and probably by women), as well as body fatness and abdominal fatness, the factors that lead to greater adult attained height, or its consequences are convincing or probable causes of colorectal cancer.

 

Australian healthy eating guidelines recommend we eat at least 4 serves of core grain-based foods a day such as breads, breakfast cereals, rice, pasta and noodles, preferably wholegrain. One serve is equal to 2 slices of bread, approx 1 cup of breakfast cereal, 1 cup of cooked rice/noodles/pasta/oats. Don’t forget legumes are also a great source of fibre. Aim for at least 2 serves per week, 4 serves or more is even better for improved health outcomes. One serve is equal to half a cup of cooked dried beans, lentils, chickpeas etc.

 

References:

WCRF/AICR World Cancer Research Fund / American Institute for Cancer Research.Continuous Update Project Interim Report Summary.Food, Nutrition, Physical Activity, and the Prevention of Colorectal Cancer. 2011

http://www.aihw.gov.au/

http://www.bowelcanceraustralia.org/

Draft Australian Dietary Guidelines:

Are the 2010 Dietary Guidelines for Americans a preview of our own?

Every 5 years the US government is required by federal law to review and update its dietary guidelines, which then guides all federal food programs in the US. The new 2010 Dietary Guidelines for Americans were released a couple of months ago, and with Australia’s draft guidelines currently under review, and a draft expected for consultation in April/May we can’t help but wonder if America’s Dietary Guidelines are a preview of our own.

The message from the 2010 Dietary Guidelines for Americans with regards to grains is “whenever possible, replace refined grains with whole grains." The 2005 message to "make at least half your grains whole" still holds true, however, this time the guidelines are full of reminders to replace refined grains with wholegrains. For most Americans the recommendation for grain-based foods is 6 serves a day (one American serve is equivalent to 1 slice of bread or ½ cup of cooked rice or pasta), with at least 3 of those wholegrain. This amount is equivalent to the 48g Daily Target Intake for wholegrains, as recommended by Go Grains Health & Nutrition.

A series of swap this for that options are promoted in the new 2010 Dietary Guidelines for Americans such as swapping white rice with brown rice, white pasta with whole wheat, cornflakes with oatmeal and doughnuts with wholegrain bagels. The concept is similar to that of the Australian Governments’ current “Swap it, Don’t stop it” campaign, where by Australians are urged to swap some of the things they are doing now for healthier choices - http://www.swapit.gov.au/

The current Australian Dietary Guidelines do not recommend a quantitative amount for wholegrains, instead stating ‘Australians should eat plenty of cereals (including bread, rice, pasta and noodles) preferably wholegrain’. If the new Australian Dietary Guidelines follow the US, it is likely the food industry will develop and manufacture more food products with wholegrains to promote the additional health benefits of these foods. If the US is a preview of our market, wholegrain foods may become the norm. The growth in popularity of wholegrain foods has been demonstrated recently in the US, as The Wholegrains Council’s wholegrain stamp reports a 25% growth over the past 9 months, now appearing on over 5000 wholegrain products in over 22 countries.

The Australian Dietary Guidelines provide evidence-based nutrition information and advice for health professionals and consumers. The National Health & Medical Research Council (NHMRC) is leading the review of Australia’s guidelines together with the Department of Health and Ageing.

The Australian Dietary Guideline review process started in April 2008, with a group of nutrition experts – The Dietary Guidelines Working Committee meeting to establish the terms of reference and review the latest scientific research to make recommendations for updates to the guidelines. The first review process for the Australian Dietary Guidelines is expected to be commence in April/May this year, with the final guidelines planned to be released at the end of the year. We are waiting with anticipation that a quantitative recommendation for wholegrains is included in the draft 2011 Australian Dietary Guidelines. A quantitative recommendation encourages consistency in wholegrain public health messages in the media and on product packs, ultimately helping consumers understand the actual amount of wholegrains they need for good health.

www.health.gov/dietaryguidelines
www.nhmrc.gov.au/publications/synopses/dietsyn.htm
http://www.swapit.gov.au/

We 'heart' legumes

Sound science supports legumes and cholesterol lowering for a healthier heart

There is consistent evidence from epidemiological studies showing that eating legumes can play a role in preventing some of our most serious chronic diseases, including cardiovascular disease, diabetes, as well as improving gut health and assisting with weight management. Despite this, Australians are not eating enough legumes. A consumption survey conducted by Go Grains Health & Nutrition in 2009 (which is currently in field again for 2011) found that not even a quarter of the 1700 Australians surveyed consumed legumes over the 2 day period food intake data was collected.

The research in support of legumes and health is not as extensive as that for cereal grains, mainly because there is generally a low intake of legumes in most free-living populations. Much of the legume research has focused on soy beans due to higher intakes of soy products such as tofu, soymilk, tempeh and textured soy protein; however, a meta-analysis just published has focused on non-soy legumes in relation to blood lipids. This is the second meta-analysis of this topic, is more vigorous in its methodology and includes four new studies since the 2002 review.

A total of 140 papers were retrieved from a search through MEDLINE, EMBASE and Cochrane databases through to July 2009. Ten randomised controlled trials were selected for analysis that compared a non-soy legume diet to a control diet. Each of the 10 studies lasted a minimum of 3 weeks duration, and reported blood lipid changes (in cholesterol, hypercholesterolemia or hypertriglyceridemia and/or cardiovascular disease) in intervention and control diets. The research included a total of 286 participants (70% males) from 5 countries with a mix of high, borderline high and normal baseline cholesterol levels.

The legume intake in the 10 studies ranged from 80-440g/day of peas, lentils, baked beans, pinto beans, lima beans or black eyed peas with a study length of 21 to 56 days. All studies reported net decreases in total cholesterol with a mean reduction of 11.76mg/dL (translating to around a 5% reduction). The combined results showed a significant decrease in unhealthy LDL cholesterol and triglycerides, however little effect on HDL cholesterol.

Although the number of participants was relatively small and majority were middle aged hypercholesterolemic men, the meta-analysis appears to be carried out very carefully. There was no publication bias or significant differences in the way the protocols were performed, and sensitivity analysis found no effect of study type, length or type of control on the results. The levels of legume intake in the studies are considerably above average legume consumption in Australia today, limiting the potential applicability in the findings, but also highlighting the potential health benefits if legume consumption can be increased amongst Australians, especially in those at higher risk of raised cholesterol and cardiovascular disease.

Non-soy legumes have a similar effect as soy-based supplementation on cholesterol lowering. The authors concluded this meta-analysis of randomised controlled trials provides the strongest evidence to date that non-soy legume consumption lowers serum total and LDL cholesterol and therefore may lower the risk of cardiovascular disease. This provides added weight to the body of scientific evidence supporting the role of legumes in the diets of Australians.

Bazzano et al 2011 Non-soy legume consumption lowers cholesterol levels: A meta-analysis of randomised controlled trials. Nutrition, Metabolism and Cardiovascular Disease (21) 94-103.
 http://www.ncbi.nlm.nih.gov/pubmed/19939654