Guest Post by Sally Marchini, Dietitian
It’s been more than a year since I wrote about grains. Recently there has been a research push involving grains and microbiota that people with diabetes should really know about for cardiovascular health, insulin resistance management and improved mortality. The Dietitians Association of Australia’s (DAA) annual conference was held in Perth last week, and there were some fascinating statistics shared on Twitter (#DAA2015) that have inspired me to try and inspire you to include more grains in your diet.
People with diabetes (regardless of type) often tell me that they are cutting back on grains because of the carbohydrate content. I encourage you to consider cutting back on processed grain foods if you feel like this, but do what you can to include the recommended serves of whole grains according to the Australian Dietary Guidelines. Aside from whole grains generally taking longer to break down to glucose in your bloodstream in the short term, the long-term health benefits are big winners!
Perhaps some of you aren’t sure what a ‘whole grain’ is, so we’ll start with a quick definition then look at a brief overview from that first blog on grains. Lastly we’ll move onto the latest research that builds on the benefits of grains for diabetes management, avoidance of cardiovascular disease and minimising insulin resistance.
Definition of a whole grain
The Grains and Legumes Nutrition Council reminds us that:
“Foods labelled as whole grain vary considerably in whole grain content from 1.4g whole grain to 75g whole grain per serve. As a result some foods contribute significantly more than others to the whole grain Daily Target Intake of 48g.”
This means that it’s important when you’re reading labels to try to choose foods that have more whole grain content, rather than refined grains which are higher in carbohydrate and lower in the nutrients that will bring us health benefits.
That first blog on grains talked about the Australian Dietary Guidelines and the evidence behind the grains and cereals recommendations, which alone is excellent evidence for including them and features cardiovascular disease, excess weight and some cancers. It goes into detail about the important plant nutrients found in grains. It looks at the different types of grains, how much we should aim to include, how to include them and how to count the carbohydrates in them. It’s really worth a refresher read!
Onto the latest research!
Firstly there is a recent study published in BMC Medicine. That study examined the diets of 367,442 people over 14 years – participants from the prospective NIH-AARP Diet and Health Study. Researchers found a diet high in cereal fibre (10.22g) reduced the risk of premature death from a range of chronic diseases including cancer (15%), heart disease (20%), respiratory disease (21%) and diabetes (34%). This was compared to people with the lowest cereal fibre intakes (2.02g). Researchers stated that cereal fibre may provide multiple protective properties, including anti-inflammatory effects, and that the protective effects of whole grains may be due, at least in the main part, to its cereal fibre component.
Then we move into one of my personal passions as a dietitian – the latest nutritional research that’s coming to light on gut microbiota, or the good bacteria in your large bowel. In the recent Diabetes Counselling Online blog on yogurt, we discussed the importance of getting those good bacteria (probiotics) in there in the first place. The other side of the coin, of course, is feeding them to keep them well (prebiotics) so they can actively work towards your better overall health.
I saw a tweet from Accredited Practising Dietitian Sue Radd from the DAA conference that shared a slide from one of the presentations she was attending. That really hit home for me, when I hear of so many people with diabetes who avoid grains. The tweet read:
This statement came from research into grains and relates to how the whole-grains make it through to the large bowel to feed those good bacteria. The paper that was discussed at the conference ‘Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews.’ by Fardet, Anthony; Boirie, Yves; Nutrition Reviews, 2014, is not yet available for public viewing but undoubtedly provides further evidence to support these important developments in our understanding of CVD, insulin resistance and metabolic conditions. The longer term implications of the foods we eat!
This article though provides a good discussion for us to consider along those lines: “‘The way to a man’s heart is through is gut microbiota’ – dietary pro- and prebiotics for the management of cardiovascular risk” by Tuohy, Fava and Viola from the Proceedings of the Nutrition Society (2014). In this particular paper, I’d like to select a few quotes to help you appreciate just how those cereal whole grains are so important for our diabetes and heart health:
From the intro:
“CVD (cardiovascular disease) risk is also shaped by a number of modifiable largely environmental risk factors often linked to diet and lifestyle, e.g. smoking, chronic low-grade systemic inflammation, dyslipidaemia, high blood pressure, diabetes and insulin resistance, metabolic syndrome, overweight/obesity. Recent studies in animal models and in human subjects have identified another extra-genomic contributor to CVD risk, the gut microbiota.”
And for those of us with type 2 diabetes (and some type 1s with metabolic syndrome) where insulin resistance plays such a key role in the progression of the condition, the article explains how the by-products of the good bacteria (short-chain fatty acids) have been shown to help regulate “gut hormone production, thereby controlling satiety and food intake”. These same acids also stimulate the production of another gut hormone, “which can impede the uptake of inflammatory compounds…. from the gut lumen that trigger the low-grade chronic inflammation and subsequent insulin resistance associated with obesity and CVD.” And that’s just the tip of the iceberg!
The article covers a whole lot more info, including the probiotics, before it gets to a section called ‘Reducing CVD with prebiotics’ and this is where it becomes clear that the fibre from grains is so critical in our diets in addition to reducing the foods that reduce the gut microbiota including high fat, high red meat and low fibre diets.
It is an exciting area of research for us with diabetes and certainly lots more fascinating studies and reviews are being undertaken in this area.
The take-away from this for all people with diabetes, and those working on avoiding it, is to ensure that most of the grain foods you choose are whole grain for your longer-term health, rather than avoiding grains altogether for a short term carb avoidance strategy. Following the Australian Dietary Guidelines is a great way to go.
If you’re unsure about what you should aim for personally, I recommend a visit with an Accredited Practising Dietitian for individualised medical nutrition therapy. Sally 🙂
Sally is owner of her private practice (Marchini Nutrition), has had type 1 diabetes for close to 40 years and coeliac disease for many years too.