Southeast Asia is a region that produces high amounts of key food commodities and includes areas of divergent socio-economic status. The major grain crops produced in the region are rice and maize [1
]. The region experiences public health challenges with undernutrition, as well as over-nutrition [2
]. In particular, the prevalence of obesity [4
] and type II diabetes [5
] have dramatically increased within some countries in this region recently. Therefore, a major future public health focus in Southeast Asia will be reducing the prevalence of non-communicable diseases.
Consistent observational evidence suggests that intake of wholegrain foods is part of an ideal dietary template that is associated with reducing the risk of premature, mortality, cardiovascular disease, metabolic health issues like type II diabetes and colorectal (as well as other site) cancers [6
] and the rate of weight gain over the life-course [9
]. However, dietary intake of whole grains tends to be lower than recommended levels in many parts of the world [11
]. The aforementioned evidence base on whole grain intake and non-communicable disease risk has largely been dominated by studies carried out in Europe and North America, although it appears that studies from other regions of the world are also starting to add to a global body of evidence [15
]. The burden of non-communicable diseases is enormous worldwide. In comparison to worldwide trends, the estimated rate of disability-adjusted life years lost linked to low whole grain intake in Southeast Asia, East Asia and Oceania appears to be increasing rapidly (over 3 million additional years lost between 2005 and 2016) [16
], yet country-specific, objective intake data in Southeast Asia are limited.
The Association of Southeast Asian Nations (ASEAN) consists of ten member states (Brunei Darussalam, Cambodia, Indonesia, Lao People’s Democratic Republic, Malaysia, Myanmar, The Philippines, Singapore, Thailand and Vietnam) and is currently moving towards becoming a free trade region [17
] and has strong economic ties with China [18
]. This will likely affect all intra-ASEAN and external trade in the forthcoming years. Food-related regulations between countries are likely to impact on the future of food provision in the region and, in the case of whole grains, could impact on public health. The regulations and health-related recommendations pertaining to whole grains/wholegrain foods and the current patterns of their consumption across Southeast Asia have not, to the authors’ knowledge, previously been considered in detail. Therefore, the purpose of this paper was to provide an analysis of the current state of play of regulations, dietary recommendations and research related to whole grains in/across ASEAN countries. In order to achieve this, a systematic literature search was carried out and information was collected on health claims and regulations from each member state via survey.
It appears that the previously published research on whole grains in Southeast Asia has provided a considerable body of literature in relation to food science and technology but is perhaps somewhat more limited in consumer- and health-related studies. A lack of evidence from observational studies and randomized, controlled trials in Southeast Asia has the potential to limit the tailoring of “ideal” dietary patterns to region- or country-specific dietary intakes. Filling this evidence gap on whole and refined grain intake and health in Southeast Asia will avoid making potentially inappropriate inferences from data collected elsewhere in the world. Better understanding of the consumer base in the region is also likely to benefit public health messaging around increasing intake of whole grains at a population level and should also help in the development of innovative wholegrain food products.
Consideration of the proportion of articles within each research area at least suggests the available expertise in the region. Over 60% of the studies published to date have come from research institutes in Thailand and Malaysia. Despite ASEAN member states being major exporters of grains, particularly rice [76
], relatively few studies related to production of whole grain crops. It appears that many of the previous publications that related to food production were excluded as they did not contain specific reference of the term “whole grains”. This may have resulted in an under-representation of studies in this important area, even though the original studies described the raw materials (e.g., unprocessed rice grains) from which whole grains and wholegrain foods are produced.
A number of observational studies had collected valuable data on wholegrain intake but whose target population (e.g., patient groups or other sub-groups) may not be entirely representative of the country’s population. Similar to the available national intake data [31
], these findings tend to support that consumption of wholegrain foods is infrequent across population groups in Southeast Asia [23
]. As in other parts of the world, there are limited consumer-centred studies in Southeast Asia aimed at understanding people’s beliefs and attitudes towards whole grains. This remains a necessary focus to consider how best to support individuals in making realistic choices that will help them move towards or meet guidelines for daily whole grain intake. The Fuldkorn public–private partnership included consumer-centred approaches in their campaigns that helped in raising average adult whole grain intake in Denmark from 36 g/d/10 MJ to 63 g/d/10 MJ [77
It was noted that two longer-term randomized-controlled trials have been carried out in Southeast Asia which assessed the impact of switching from refined grains to whole grain alternatives (white rice versus oats and white rice versus pre-germinated brown rice respectively) [50
]. The results have suggested benefits to health in both cases but should be interpreted with some caution in terms of their wider applicability, despite wholegrain alternatives tending to contain higher amounts of essential and non-essential nutrients than refined products. While around half of the existing published randomized, controlled trials based on increasing oat intake have suggested significant improvements in markers of cardiovascular health [78
], challenges still remain when a wholegrain food is a replacement for refined alternatives made with different grain species (e.g., wholegrain oat-based foods are poor substitutes for steamed white rice in meals or dietary plans). Replacement of white rice with brown rice alternatives appears to be a means to increase wholegrain food intake through “like-for-like” substitution. However, pre-germinated rice is differentially processed, and the findings of this study should not necessarily be extrapolated to assume that all brown rice alternatives are better than refined rice, particularly as a previous meta-analyses of prospective data suggested no benefits to morbidity and mortality of increasing brown rice consumption [6
]. The authors believe that a focus on wholegrain foods available in the region and that are easy to substitute for the refined alternatives is the most likely approach to increase wholegrain food intake at a population level.
Glycaemic index is an acute physiological response to carbohydrate-containing foods. Longer-term adherence to low glycaemic index and glycaemic load diets has been associated with improvements to cardiovascular and metabolic health outcomes [79
]. Published glycaemic index data suggest that brown rice types have comparable values to white rice alternatives [80
]. A number of the lowest glycaemic index values for rice have been attributed to white rice varieties [82
], which may be a result of the digestibility of the starch being lower in some cultivars compared to others [83
]. This highlights that the impact of rice on health cannot simply be inferred from whether it is whole grain or not. There is still a clear need for further randomized, controlled trials on the impact of whole grains relevant to the region on the health of Southeast Asians.
The Food and Agriculture Organization of the United Nations’ website includes overviews of food-based dietary guidelines in Thailand and Vietnam, although no recommendation for intake of whole grains is presented within these guidelines [84
]. However, it appears that food-based dietary recommendations do not exist in the other ASEAN/UN member states—Brunei Darussalam, Cambodia, Lao People’s Democratic Republic and Myanmar [86
]. The limited nationally-representative nutrition survey data in the region means that better defining absolute amounts of whole grain intake within populations is challenging [88
] and has the potential to limit the development and applicability of recommendations to increase whole grain intake within member states. Target intake amounts (in grams per day) of whole grains are only currently recommended by public health agencies and non-government organisations in a handful of countries worldwide [89
]. To date, most longitudinal data and randomized, controlled trials that suggest whole grain intake might benefit health outcomes have been collected in Europe and North America [15
]. This situation appears to be improving in Southeast Asia, particularly in relation to cross-sectional and/or longitudinal data [31
]. Such findings should help develop rational food-based recommendations for wholegrain consumption and help in the development of strategies to move population level intake towards this. These findings suggest that current intake of whole grains in across ASEAN is low.
As in other parts of the world, there are very few regulations in the ASEAN region that relate to definitions of whole grains and wholegrain foods. Previous calls have come from consortia of international experts to improve and standardize the definitions of wholegrain foods [90
], which would allow dietary intake data from different countries to be more comparable, improve clarity of labelling to consumers and provide objective criteria for the food industry to follow. Recent recommendations to define a wholegrain food included minimum cut-off values for percentage of wholegrain ingredient content (≤30%) on a dry weight basis [91
]. Clear definitions of what a wholegrain food is that include a minimal content of whole grains seems likely to improve consumer clarity, provide standards for the manufacturers of wholegrain foods and ensure that dietary guidelines aimed at eating more whole grains have a greater potential to lead to measurable public health benefits. The divergence is whole grain regulations noted in this work is perhaps a microcosm of the wider issues with trade harmonization across ASEAN member states [92
]. The authors restate the need for and importance of clear and consistent definitions of wholegrain foods, as this is likely to form a better platform for public health messaging and product marketing around whole grains.
In 2015, China was the largest importer to and exporter from the ASEAN region [93
]. Consideration of the current whole grains landscape in China therefore also seems important to ASEAN wholegrain ingredients suppliers, manufacturers, importers and exporters. There are no public health food-based dietary guidelines, although the Chinese Nutrition Society have provided such recommendations since 1989 [94
]. The most recent update (The Food Guide Pagoda for Chinese Residents 2016) includes the detail “A cereal-based diet is an important characteristic of a balanced diet” with further comment that “whole grains [presumably wholegrain foods] and legumes should make up 50–150 g and tubers 50–100 g (of daily intake)” [95
]. One previous study estimated the intake of “coarse grains” in Chinese adults in relation to the recommendations of the Chinese Nutrition Society, with less than 20% of individuals consuming 50 g of whole grains or more [96
]. Millet and maize were the most frequently consumed grain sources, while other types of whole grain (e.g., adlay and buckwheat) that were absent or considerably less prevalent from the ASEAN studies were also noted to be eaten by Chinese participants [96
To the authors’ knowledge, the current paper is the first to consider whole grain-related regulations, recommendations and research across the ASEAN region. It is hoped that the findings of this project will help to focus future efforts in Southeast Asia in public health, food provision and research related to whole grains. While the approach to evaluating the existing research base on whole grains in Southeast Asia provides limited potential to compare these findings to other parts of the world, it helps to qualitatively assess what expertise exists in the region. Collecting and checking information through in-country experts has the advantage of accessing content that would not be otherwise accessible to non-native speakers. However, there is still the potential that in-country regulations, recommendations and intake data related to whole grains exist but are not particularly visible. The authors sought input from in-country experts with a strong background in whole grains to try and reduce this risk and also tried to check the validity of responses wherever possible. In some cases, regulatory frameworks and public health recommendations develop or change rapidly, so it is possible that those cited in this work may be superceded in a short space of time. It was not possible to screen country-specific, non-English language literature in the same way which may have meant that important research findings were overlooked. Nonetheless, the authors feel that this approach provides a broad overview of the evidence base available on whole grains in Southeast Asia.