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NutENews November 2014


2014 – a year of fads

What an interesting year we’ve had diet-wise. Fads a plenty – paleo, sugar free, gluten free and in a year of comic book heroes on the big and small screen we have our own superhero Activated Nuts and its villian the “Anti-nutrient” Phytate.

Let’s dispell the myths, uncover the truth and shine some light on these fads.
Cheers
Lisa Yates
Program Manager and Dietitian
Nuts for Life


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Paleo eating

Those following the Paleo diet believe we should only eat foods available during the Paleolithic era,  2.6 million to about 10,000 years ago,  before the neolithic period when domestication of animals and agriculture began. Available foods during the paleolithic were eggs, insects, birds, reptiles, mammals, fruits, berries,  honey,  tubers, roots, and nuts.
Since many Paleolithic foods are no longer available or are modified by breeding, proponents of the modern Paleo diet avoid grains, legumes and dairy in the belief that modern breeding techniques have made grains less digestible and that our genes have not evolved to digest these foods, leading to chronic diseases.

The modern Paleo diet includes meat, fish, seafood, eggs, vegetables, nuts and seeds, with or without fruit. Advocates also suggest avoiding refined sugars, oils, potatoes, salt and processed foods. The modern Paleo diet appears to be a low-carb, low-sugar, high-protein diet by another name.
While the idea of eating more plant based foods and less highly processed foods is a good one, there is not a lot of convincing research on the health benefits of paleo eating.
There are eight clinical trials (1-9) comparing a paleo diet with other diets and while these preliminary results are intriguing (improvements in weight, blood glucose, blood cholesterol, insulin sensitivity and blood pressure) some of these studies have flaws which may impact the results:

  • small participant numbers so under represented,
  • most had short time frames (2 weeks to 3months) and although one study lasted 2 years it had a 30% drop out rate,
  • lack of control groups,
  • lack of consistency re what foods are included in a paleo diet – some allowed fruit even alcohol,
  • diets not kilojoule controlled so any weight loss could have improved the biomarkers listed above and not the actual paleo diet or foods chosen.

Further longer term, larger studies are needed to reproduce these preliminary results.
In the mean time Mediterranean, vegetarian and low GI diets — which include nuts, wholegrains, legumes and dairy — have been more extensively researched and show positive effects on risk reduction and treatment of chronic diseases including heart disease, diabetes, obesity, and cancer.(10-20) The weight of evidence suggests wholegrains, legumes and dairy should be included in the diet.
But for those who are still going to eat the paleo way consider this – one in 12 Australians will get bowel cancer before the age of 85 years (21) and removing wholegrains and legumes from the diet also removes those nutrients which can help reduce the risk of bowel cancer. If you have a family history of bowel cancer you may like to reconsider the paleo diet.
Are you for or against following a paleo diet?


Phytate – the misunderstood good guy

One of the reasons paleo inspired people think they need to avoid wholegrains and legumes, and “activate” or soak nuts is because of the villianous “anti-nutrient” phytate. Such extreme ideas always make me wonder what the other side of the story is. Is phyate really that bad? Why is it in the very foods we need to survive? Does it have any health benefits?
 
Here’s what I found….
Phytates are the salts of phytic acid (also known as inositol hexaphosphate). This is a storage compound which contains calcium, magnesium and phosphate and is found in plant seeds. During germination, phytates are broken down by phytase enzymes and the minerals released are used by the plant for the developing shoot and root. Because phytate binds to minerals it makes them less available for absorption by the body. For some people who rely solely on only a few types of food this could lead to mineral deficiencies. Culturally however there are ways to process foods to naturally reduce phytates such as soaking, malting, leavening and fermenting. These processes either increase the level of phytase to break down phytate or they contain other compounds that help do that such as lactic acid. Of course for most people eating a varied diet mineral deficiencies are rare, even for vegetarians relying on plant foods rich in phytates such as wholegrains, legumes and nuts.
On the flip side phytates actually have many health benefits and preliminary research is undercovering more such as having antioxidant and anticancerous effects, improving carbohydrate metabolism, reducing calcium kidney stones, reducing bone mineral loss and possibly even reducing oxidative stress in the brain.(23-39)
To demonise phytates based on their negative impact on mineral bioavailability alone means ignoring the evidence for their health benefits. Australians following well-balanced diets do not need to ‘activate’ their grains and seeds to reduce phytates. But if you like the flavour and softer texture of soaked nuts that’s OK too. Just remember to eat a handful of nuts a day, legumes a few times a week and choose mostly wholegrains.
Does it surprise you that phytates are not the villain but the good guy?


I won’t quit sugar – here’s why

I find it distressing that proponents of eating sugar-free are selling sugar-free cook books which in fact still use sugars in their recipes. Those sugars may not be traditional white, brown or raw crystallised sugars but instead they suggest using the more expensive rice malt syrup, barley malt syrup, dextrose (just another word for glucose) and other types of sugars. It’s misleading and deceptive to suggest that sugars are different when they all provide a similar energy content, and that somehow their “sugar-free” cake recipes are any healthier than any other sugar laden cake recipes.

Did you know that nuts naturally contain sugars?
Yes depending on the nut variety nuts contain about 2-6g sugars per 100g and that the type of sugar they contain is sucrose. Sucrose is the type of sugar found in abundance in sugar cane which is juiced and crystallised to white, raw or brown sugar.

Does this mean we should avoid eating nuts because they contain sugars?
Not at all – nuts are seeds and the sugars are naturally present in nuts to help the seed when it germinates. Sugars provide energy to grow a root and shoot. These sugars also help give flavour characteristics to the “nuttiness” of nuts.
Nuts can also affect our blood glucose levels. Adding nuts to meals with carbohydrate can also reduce the rise in blood glucose levels after eating so nuts have a Glycemic Index (GI) lowering affect. Only two nuts have been GI tested because they contain enough carbohydrate to be tested: cashews and chestnuts and both are low GI. Low GI meals and diets provide sustained energy, helping to control appetite.
Raw natural nuts are a great every day nut choice so remember to eat a handful a day. Nuts that contain added sugars such as: chocolate coated, caramelised, vienna and honeyed nuts are a great choice for parties and festive occasions such as Christmas.

Are you concerned that sugar-free cookbooks still suggest using sugars?

This blog has been adapted from my articles on these topics in Medical Observer – the GP magazine – visit https://www.medicalobserver.com.au/clinical-review/nutrition
 


References

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  2. Osterdahl M et al Effects of a short-term intervention with a Paleolithic diet in healthy volunteers. Eur J Clin Nutr. 2008 May;62(5):682-5.
  3. Frassetto LA et al Metabolic and physiologic improvements from consuming a Paleolithic, hunter-gatherer type diet. Eur J Clin Nutr. 2009 Aug;63(8):947-55.
  4. Lindeberg S et al A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia. 2007 Sep;50(9):1795-807.
  5. Jönsson T et al A Paleolithic diet is more satiating per calorie than a Mediterranean-like diet in individuals with ischemic heart disease. Nutr Metab (Lond).2010 Nov 30;7:85.
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  20. Schwingshackl L et al Long-term effects of low glycemic index/load vs. high glycemic index/load diets on parameters of obesity and obesity-associated risks: a systematic review and meta-analysis. Nutr Metab Cardiovasc Dis. 2013 Aug;23(8):699-706.
  21. https://www.bowelcanceraustralia.org/bca/
  22. National Health and Medical Research Council (2013) Australian Dietary Guidelines. Canberra: National Health and Medical Research Council.
    Click Here
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Belinda

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