Guest Post, Sally Marchini, Dietitian
Nuts are a fascinating food, and for us with diabetes they tick so many of our healthy eating boxes – fibre, nutrients, good fats, satiety and more! Today we’ll take a closer look at the reasons behind all those good stories with a focus on our D-health (remembering to choose unsalted ones). It’s important to remember with blogs like this that focus on one food type, that foods should be incorporated into a healthy varied diet. I like these words of David L. Katz to illustrate this point: “Eat a diet of wholesome foods reliably associated with good health across a vast and stunningly consistent literature.”
Recently I was chatting with Nuts for Life Accredited Practising Dietitian, Lisa Yates, who suggested the key messages for us with diabetes are:
- People with diabetes can and should eat nuts (unless you’re allergic of course!)
- Nuts are a healthy snack that will help control BGLs as they have a GI lowering effect when eaten with carbs due to their healthy fat content
- Cashews and chestnuts are the only nuts that contain enough carbs to be GI tested (needs a minimum 10g carbs per serve) and they have a low GI. Cashews average GI 25 and chestnut meal has been GI tested and was 54. Since GI is related to particle size it makes sense that whole chestnuts not grounded will also be low GI
- Nuts also help with improving insulin sensitivity
- People with diabetes have an increased risk of heart disease and eating a daily handful of nuts will help reduce the risk of heart disease while managing weight and cholesterol
- People who are overweight can eat nuts they will not cause weight gain and if eaten in a calorie controlled diet will help with weight loss. This is because we don’t absorb all the fat in nuts about 20% is excreted as trapped in the fibrous structure of chewed nuts. Nuts eaters have more fat in their stools than non nut eaters. Nuts also contain fibre, protein and fat which all work on various aspects of appetite control. 30g per day is the recommended daily amount = #healthyhandful
I’ll look closer at some of these claims and the evidence behind them, as well as explaining how nuts fit within the Australian Dietary Guidelines (hereafter called ‘the guidelines’) and provide you with some recipe ideas to help include nuts on a daily basis.
According to the guidelines nuts fit into the protein foods section and 30g (a healthy handful) is one serve. If you’d like to read more about Protein and diabetes you can check out a previous blog here.
In terms of definition of a nut the guidelines offers this one: “A nut is a simple dry fruit with one or two seeds in which the ovary wall becomes very hard (stony or woody) at maturity, and where the seed remains attached or fused with the ovary wall. Most nuts are indehiscent (not opening at maturity). Any large, oily kernel found within a shell and used in food may be regarded as a nut. Examples include almonds, pecans, walnuts, brazil nuts, cashew nuts, chestnuts, hazelnuts, macadamia nuts, pine nuts and pistachio nuts. The term ‘nut’ is applied to many seeds that are not botanically true nuts. These may include cape seed, caraway, chia, flaxseed, linseed, passionfruit, poppy seed, pepita or pumpkin seed, sesame seed and sunflower seed.” Lots of choices here then!
The guidelines tell us: “There is evidence to suggest that consuming nuts (65–110g per day) is not related to risk of weight gain in the short term”, and that “consumption of nuts and seeds may help reduce the risk of heart disease and is not associated with weight gain if total energy (kilojoule) intake is controlled.”
It goes on to explain a key point that I was keen to make in this blog, that: “Nuts and seeds are rich in energy (kilojoules) and nutrients, reflective of their biological role in nourishing plant embryos to develop into plants. In addition to protein and dietary fibre, they contain significant levels of unsaturated fatty acids and are rich in polyphenols, phytosterols and micronutrients including folate, several valuable forms of vitamin E, selenium, magnesium and other minerals.
They are nutritious alternatives to meat, fish and eggs, and play an important role in plant-based, vegetarian and vegan meals and diets.” There’s an awesome ready reckoner for nuts available from Nuts for Life that lists all the different nuts and the levels of nutrients each of them contains per 100g. It’s one of my favourite resources that I give to clients to help them understand more about the food they’re eating.
Further on the topic of helping with cholesterol, the guidelines say, “Nut consumption provides benefits by enhancing anti-inflammatory processes and lowering serum cholesterol possibly due to the presence of phytosterols, which reduce cholesterol re-absorption and/or the effects of shifting dietary fat quality, notably replacing saturated with unsaturated fat.
Nut consumption is also associated with increased levels of adiponectin, which has anti-inflammatory and anti-atherogenic properties. Early work suggests that the delivery of components such as tocopherols and phenolic acids may help to reduce lipid peroxidation and oxidative DNA damage, and there is some indication that walnuts with a relatively high content of the amino acid L-arginine may have an effect on vasodilation through nitrous oxide pathways.
Other nuts are also significant sources of arginine. Proposed mechanisms for effects on weight control include increased satiety, increased faecal fat excretion, increased thermogenesis and increased fat oxidation.”
Pretty impressive facts to encourage nut consumption I’d say!
The guidelines advice for pregnant women and young children
It’s also important to note that “Nuts are a problem for small children as their size and consistency increases the risk of inhalation and choking. For this reason, they should not be given to children aged less than 3 years.” And that, “Pregnant and breastfeeding women do not need to avoid consuming nuts for fear of causing an allergic reaction in their babies. Only women who are allergic to these foods themselves need to avoid them.”
On the topic of improving insulin sensitivity, it’s a little complicated to explain in depth at this point other than to say it’s related to evidence about increased amounts of the anti-inflammatory mono-unsaturated fats in nuts that reduce inflammatory processes in the body, thereby allowing improved insulin sensitivity combined with lowering the GI of other carbs and increased satiety leading to weight loss. I have lots of research papers on the topic if you’d like to learn more – perhaps improving insulin sensitivity could be the topic of a whole blog one day? Please let me know if you’re interested and I’ll add it to my list! 🙂
Specifically related to Lisa Yates’ points about how they related to us with diabetes, Nuts for Life offers a free downloadable fact sheet entitled, ‘Nuts and Diabetes’ where you can read more at your leisure. They also have many other fact sheets and resources, as well as some delicious recipes. It’s definitely a site worth bookmarking as Lisa advised me this week that there are some great additions to it on their way in the near future.
There’s a FAQ page on the Nutrition Australia site that you may also like to view that includes some other interesting points that I haven’t gone into here.
Remember that it’s a good idea to check with your Accredited Practising Dietitian before making changes to your diet and to learn what the right amount of nuts for you personally is, and it’s good to go armed with some factual information. You can find an APD near you via the Dietitian’s Association of Australia website
Wishing you improved D-health! Please let me know if you have any questions as usual, and I would love to hear how you include nuts in your day! Sally 🙂
Sally is owner of her private practice (Marchini Nutrition), and has had type 1 diabetes for close to 40 years and coeliac disease for many years too.