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General Questions


Can nuts help reduce macular degeneration?

Yes, nuts can help reduce age related macular degeneration (MD). MD is where a small section of the retina called the macula degenerates with age and affects central vision. The macula is a yellow spot and is rich in carotenoids, lutein and zeaxanthins. These carotenoids are carried to the eye on HDL good cholesterol. Regular nut consumption reduces the risk of developing MD (1), with research showing 1-2 handfuls of nuts a week can reduce MD by 35% (2).

References:
1) Seddon JM, Cote J, Rosner B. Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake.Arch Ophthalmol. 2003 Dec;121(12):1728-37.
2) Tan JS, Wang JJ, Flood V, Mitchell P. Dietary fatty acids and the 10-year incidence of age-related macular degeneration: the Blue Mountains Eye Study.Arch Ophthalmol. 2009 May;127(5):656-65.

Published 10 Jan 2017

Can nuts help with cognition and memory?

Yes, nut can help with cognition and memory, specifically improving mild cognitive impairment - the step before Alzheimer's and dementia. The combination of healthy fats and phytochemicals, and nutrients with antioxidant and anti-inflammatory properties in nuts may help protect vital functions of the brain and it's blood vessels. All it takes is a handful of nuts a day.

References:
1) Arab L, Ang A. A cross sectional study of the association between walnut consumption and cognitive function among adult US populations represented in NHANES.J Nutr Health Aging. 2015 Mar;19(3):284-90.
2) Rita Cardoso B, Apolinário D, da Silva Bandeira V, Busse AL, Magaldi RM, Jacob-Filho W, Cozzolino SM. Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial. Eur J Nutr. 2016 Feb;55(1):107-16.
3) O'Brien J, Okereke O, Devore E, Rosner B, Breteler M, Grodstein F. Long-term intake of nuts in relation to cognitive function in older women. J Nutr Health Aging. 2014 May;18(5):496-502.
4) Barbour JA, Howe PR, Buckley JD, Bryan J, Coates AM. Nut consumption for vascular health and cognitive function. Nutr Res Rev. 2014 Jun;27(1):131-58.
5) Martínez-Lapiscina EH et al. Mediterranean diet improves cognition: the PREDIMED-NAVARRA randomised trial.J Neurol Neurosurg Psychiatry. 2013 Dec;84(12):1318-25.

Published 10 Jan 2017

What are antioxidants and do nuts contain them?

Antioxidants are natural plant chemicals or phytochemicals with special properties. They can quelch other natural chemicals called oxidants which may effect body cells negatively. Oxidants may cause aging and chronic diseases through inflammation. It's also thought that oxidants can "oxidise" cholesterol causing it to stick to the walls of arteries leading to atheroschlerosis.

So, phytochemicals with anti-oxidant and anti-inflammatory properties may help reduce chronic disease and aging. Plant foods such as nuts are particularly rich in phytochemicals such as polyphenols or vitamins and minerals with antioxidant functions such as vitamin E, riboflavin, selenium, manganese and copper.

A handful of nuts a day not only improves diet quality by ensuring a good mix of nutrients in the diet, but they also help reduce the risk of developing chronic diseases such as heart disease and diabetes.

Published Jan 2017

What are the healthiest nuts?

All raw, roasted and unsalted nuts are healthy. This may surprise some people because for so long we have been told to eat less fat and nuts have been off the dieters menu. Fortunately this is no longer the case, and nuts with their healthy fats are an essential part of a healthy diet. Those who eat nuts regularly are at less risk of developing heart disease and diabetes, have healthier body weights and are likely to live longer than those who don't. Nut eaters also have greater diet quality because nuts are rich in a unique combination of nutrients such as vitamins, minerals and antioxidants.

It's also OK to eat salted and coated nuts but leave these as your party nuts for special occasions and enjoy raw and roasted unsalted nuts every day.

Published Jan 2017

What vitamins and minerals are in nuts?

Nuts are like nature's own vitamin supplement - a small package of essential nutrients.

Nuts contain a combination of at least 28 different essential nutrients. And similar to fruits and vegetables, each nut has it's own unique combination.

Generally, nuts contain:

Vitamin E - an antioxidant that helps protect tissues from damage
Folate - a B vitamin associated with heart health
Magnesium - a mineral essential for good nerve and muscle function
Zinc - a mineral required for a strong immune system
Iron - a mineral involved in various bodily functions, including the transport of oxygen in the blood.

All nuts also contribute protein, good fats (monounsaturated and polyunsaturated) and fibre.

For a complete list of all the nutrients that each nut contains see our Nut Nutrient Ready Reckoner

Last update October 2016

What are the health benefits of cashews?

Cashews, like other tree nuts, contain healthy unsaturated fats plus a broad range of vitamins, minerals and phytochemicals which are all essential for good health.

Like other nuts, cashews:
- Help reduce heart disease risk - eating a handful of nuts at least 5 times a week can reduce heart disease risk by 30-50% (1-5).
- Help with weight management - although high in fat, research has shown nuts help with weight management and can prevent weight gain. Those eating nuts are also more likely to have a lower BMI (6,7).
- Help reduce the risk of type 2 diabetes (5,8). Cashews have a low GI of 25 (9) and a low-GI diet can also help manage insulin levels. Cashews are:
- rich in healthy monounsaturated fats
- a source of low GI carbohydrate
- a good source of plant protein
- a source of zinc, magnesium and copper
- good for vegetarians as they contain plant iron.

Resources:
1) Ellsworth JL, et al. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Womens Health Study. Nutr Metab Cardiovasc Dis.2001;11(6):372-377.
2) Fraser GE, et al. A possible protective effect of nut consumption on risk of coronary heart disease. The Adventist Health Study.Arch Intern Med. 1992;152(7):1416-1424.
3) Hu FB, et al. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. BMJ.1998;317(7169):1341-1345.
4) Li TY, et al. Regular Consumption of Nuts Is Associated with a Lower Risk of Cardiovascular Disease in Women with Type 2 Diabetes. J Nutr. 2009;6:6. 5) Afshin A, et al. Consumption of nuts and legumes and risk of incident ischemic heart disease, stroke, and diabetes: a systematic review and meta-analysis. Am J Clin Nutr. 2014 Jul;100(1):278-88.
6) Neale E. et al. The effect of nut consumption on heart health: a systematic review of the literature. 2015 Unpublished. Nuts For Life, Sydney.
7) Flores-Mateo G. et al. Nut intake and adiposity: meta-analysis of clinical trials. Am J Clin Nutr. 2013;97(6):1346-55.
8) Livesey G. et al. Glycemic response and health - a systematic review and meta-analysis: relations between dietary glycemic properties and health outcomes. Am J Clin Nutr. 2008;87(1)258s-268s.
9) www.glycemicindex.com

Last update October 2016

What are tree nuts?

The tree nut family includes (but is not limited to) almonds, brazil nuts, cashews, chestnuts, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts. Tree nuts are different to peanuts as they are from a different family. As the name suggests, tree nuts grow on trees and are a hard-shelled fruit, whereas peanuts are a legume and grow underground.

Published December 2016

Are pecans paleo?

Yes, pecans are paleo. In fact, all nuts are paleo. Lets take a look at what paleo means.

The Palaeolithic diet (also called the Caveman diet) works on the principle that the human body should eat the same diet as our hunter gatherer ancestors. This includes meat, fish, birds, roots, wild fruits and vegetables, and nuts. It claims that the introduction of agriculture around 10,000 years ago works against human genetic makeup and leads to the development of obesity and chronic diseases. Foods therefore, that are the products of agriculture such as grains, legumes, all dairy products, oils, salt and sugar are all excluded.

The theory behind the paleo movement is that our modern 'Western' diet is associated with obesity, diabetes, heart disease and cancers. The paleo diet claims that by reverting to a paleo diet, for which they claim our bodies were designed, these modern diseases would cease to exist.

Several studies have investigated the effects of eating a paleo diet on risk factors of chronic disease such as blood pressure, cholesterol, fasting blood glucose and waist circumference, with results suggesting greater short-term improvements (1,2,3). However, studies are relatively short term, so long-term benefits are yet to be determined.

Should we go paleo then? When we way up the research for the paleo diet against the body of evdience for eating dairy products and legumes - clearly these foods are core to a healthy diet.

All Australians should eat less sugar, refined carbohydrates, energy dense and nutrient poor foods as well as eat more fruits, vegetables and nuts. So we can agree on that.

References:
1) Manheimer EW et al. Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. Am J Clin Nutr. 2015 Oct;102(4):922-32.
2) Otten J et al. Benefits of a Paleolithic diet with and without supervised exercise on fat mass, insulin sensitivity, and glycemic control: a randomized controlled trial in individuals with type 2 diabetes.Diabetes Metab Res Rev. 2016 May 27. [Epub ahead of print].
3) Whalen KA. et al. Paleolithic and Mediterranean Diet Pattern Scores Are Inversely Associated with Biomarkers of Inflammation and Oxidative Balance in Adults.J Nutr.2016Jun;146(6):1217-26.

Last Update December 2016

Can eating nuts help me live longer?

A new study published in the December 2016 issue of BMC Medicine, found a 20g handful of nuts everyday can cut the risk of developing coronary heart disease by almost 30 per cent, the risk of developing cancer by 15 per cent and the risk of premature death from all causes by 22 per cent. So yes, eating nuts every day can help you live longer.

The research also found an average of at least 20g of nuts was associated with a reduced risk of premature death from respiratory diseases by about half, and diabetes by 40 per cent.

About the research

The research included all tree nuts as well as peanuts, and was led by the Imperial College London and the Norwegian University of Science and Technology and published in the journal BMC Medicine.

The researchers analysed 20 published studies from around the world, involving 819,000 participants, including more than 12,000 cases of coronary heart disease, 9,000 cases of stroke, 18,000 cases of cardiovascular disease and cancer, and more than 85,000 deaths.

Why 20g and not 30g of nuts?

The research refers to at least 20g of nuts, which is less than the 30g handful the Australian Dietary Guidelines and Nuts for Life recommends as the daily serving size. This is because the study is a meta-analysis of 20 individual studies. The actual journal paper shows the researchers assessed a one ounce serving of nuts (which is 28g, and which we round up to 30g) and found at this serving size, 30g a day reduces heart disease by 29%, cancer by 15% and premature death by all causes by 22%.

The researchers did another statistical analysis to determine the minimum amount of nuts to get the best effect and they found it was 20g. This doesn’t mean you can’t eat more than 20g - it just means that this research didn’t see much additional benefit in reducing premature death from a specific health cause with more than 20g a day.

Putting this into context of the full body of evidence, which for instance shows that to reduce blood cholesterol we need 60g of nuts a day – eating at least a 30g serving size is appropriate. Especially when Australians on average are eating just 6g of nuts a day (ABS data).

Published December 2016

Are nuts expensive?

What is the cost of good health? Nuts are no more expensive than other snack foods. They can sometimes appear to be more expensive, because we often buy them in the fresh produce section of the supermarket, as a price per kilo. Whereas groceries in other aisles are priced per pack.

What if all products were sold as a price per kilogram?

Nuts in fresh produce - $9-15/kg

Nuts in cooking/snack aisles - $25-40/kg depending on seasonal availability

Chocolate coated biscuits - $13/kg

Muesli Bars - $13-23/kg

Potato crisps - $10-35/kg

Snack biscuits and cream cheese - $19-36/kg

Kids sweet biscuits e.g. Teddies - $16-20/kg

So, nuts are competitively priced compared to other snack foods, and they provide a bigger bang for your buck when it comes to NUTrition. Just remember that value for money is not always value for health.

We should also be aware of the true costs to produce food. It can take 5-10 years for nut trees to grow enough to bear a commercial crop of nuts. This means that nut growers have to invest in their trees for many years before they can make a profit. And what if the climate and weather don't work in your favour? Droughts, floods, frosts, fungal growths can all impact on the quality of the crop that is grown and will impact the following season too. Cheaper produce does not reflect the true costs of producing food nor the returns to nut growers. Nut growers need to earn a living too.

Prices based on average of two online supermarket stores July 2016

Last updated July 2016

Nuts contain phytates – what are they?

Phytates are the salts of phytic acid or inositol hexaphosphate. This is a storage compound which binds minerals such as iron, zinc, calcium, magnesium and phosphate, and is found in plant seeds. During germination, phytates are broken down by phytase enzymes, released when in water. The minerals released are used by the plant for the developing shoot and root.

"Activating" grains, nuts and seeds by soaking them for 10—12 hours to start the germination process and reduce the impact of phytates on the absorption of these minerals is a recent trend. Phytates have this reputation as an anti-nutrient for humans but the reality is quite different.

For some people, such as those in developing countries that rely on only a few staple foods, it's possible higher levels of phytates in their diets can impact on mineral absorption resulting in deficiencies. However, for those eating a diet with a wide variety of foods, these mineral deficiencies are rare, even for vegetarians.

Phytates can be considered a nutrient in their own right as they have antioxidant and anti-inflammatory effects, may have anti-cancerous effects, may affect carbohydrate metabolism and glucose control, improve bone mineral loss and possibly prevent calcification and kidney stones.

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 nuts, grains and seeds to reduce phytates. In fact, phytates may provide the very protection we need to avoid certain health conditions such as bowel cancer.

References:
1) Schlemmer U et al. Phytate in foods and significance for humans: Food sources, intake, processing, bioavailability, protective role and analysis. Mol. Nutr. Food Res. 2009, 53, S330 –S375.

This has been adapted from Lisa Yates' phytate article in Medical Observer https://www.medicalobserver.com.au/news/is-activating-a-vital-step

Last updated July 2016

Does processing nuts (grinding, flaking etc) affect the nutrients?

There are many ways nuts are processed so here are a few methods and some thoughts on the affects of processing on NUTrition:

Soaking nuts

It is thought nuts need to be soaked overnight to reduce the level of phytate - a natural phytochemical that can bind to minerals such as iron and zinc. There is no evidence however, that soaking nuts releases more nutrients. There is some evidence that soaking grains and legumes reduces phytates but not all studies show a subsequent rise in nutrient availability. What's also interesting is that phytates themselves are considered a nutrient with antioxidant capabilities, so we don't necessarily want to reduce the level of it in our diets. For most Australians eating a wide variety of foods, micronutrient deficiencies are rare, so soaking nuts is unnecessary. However if you like the taste and texture of soaked nuts, then go for it as it is far better to be eating a handful of nuts a day, anyway you like them. For more information and references see our other FAQ on Activated Nuts in the General FAQ category.

Whole nuts vs. nut butters/pastes

Research shows that more fat is absorbed from nut butters/pastes than whole nuts. It's likely the fat is trapped in the fibrous structure of the nuts and is excreted from the body. Although the more you chew nuts, the more fat is released(1-3). This is not to say you should avoid eating nut butters/pastes - a large study found eating 1 tablespoon of nut butters a day reduced the risk of developing diabetes, similarly to whole nuts(4). Smooth nut butters are also in the perfect form for infants when introducing solids from around 6 months of age(5).

Nut milks

It's trendy right now to avoid animal milks and drink milk substitute beverages such as those from grains (oat milk, rice milk), legumes (soy milk) and nuts (almond milk, macadamia milk). It's important to keep in mind that the actual level of nuts in these milks is small - only 2-10%, and much of the nutrients in nuts are left behind in the fibrous "pulp". If you make nut milks at home be sure to use the "pulp" as an ingredient in cooking - don't discard it. If you are buying commercial milk substitutes make sure they are fortified with calcium - about 120mg per 100mL. Nut milks are general low in fat (less than 3g total fat per 100mL) whereas whole nuts are rich in the healthy fats - 49-74% fat. If you enjoy nut milks continue to use them, but just know they are not a substitute for a handful of nuts a day.

Ground nuts or nut meals

When nuts, such as almonds, chestnuts, hazelnuts and macadamias, are ground or milled into a coarse flour, they still contain the nutrients of whole nuts, although the fibre content can be reduced if the nuts are blanched before milling. Because all nuts are gluten free, nut meals are a good alternative to grain based flours for those with Coeliac Disease or gluten intolerance.

Blanched nuts

Blanched nuts are temporarily soaked in hot water to soften the seed coats for removal. This reduces the fibre content, as the coat is a good source of fibre and is also thought to have a prebiotic effect i.e. as a source of food for probiotic bacteria in the large intestine(6). Blanched nuts are often used in cooking or for decoration but where you can, use and eat the whole nut - skin included.

Roasting nuts

One of the most common questions we get asked is, 'Does roasting affect the nutrients in nuts - especially the fat content'. Whether dry or oil roasted, the nutrient content varies only a little when compared to raw natural nuts. For instance, heating reduces the water content so the mineral content appears higher. B group vitamins are not heat stable so they will be reduced in roasted nuts. Also, oil roasted nuts tend to be salted so the sodium content will be higher than raw nuts. Think of these nuts as your party nuts for special occasions, and raw and dry roasted nuts for everyday use. Roasting can also cause the nut skins to fall off and since they are a good source of fibre and antioxidant compounds, consuming the skins is a good idea. When it comes to the fat content, oil roasted nuts are slightly higher in fat but only by 2-5%. This is because nuts are so dense and they are unable to absorb much more fat. Unlike a potato chip which is a lot more porous and able to absorb more fat when fried in oil. There's not a lot of research but what there is says there is little evidence that heating will cause major changes to the fatty acid profile.(7)

Nut storage

While not a processing method per se, storage length and location could have effects on the nutrients. Like any food, the longer nuts are stored in higher temperatures and humidity, the more likely the fats in nuts will turn rancid. For this reason, we recommend that nuts are stored in air tight containers or resealable bags to reduce oxygen levels and keep moisture out. Nuts are best stored in the fridge or freezer. Bring nuts back to room temperature or warm slightly in the microwave before eating to bring back the volatile oils that give nuts their nutty taste.

References:
1)Cassady BA et al Mastication of almonds: effects of lipid bioaccessibility, appetite, and hormone response.Am J Clin Nutr. 2009 Mar;89(3):794-800.
2)Hollis J et al. Effect of chronic consumption of almonds on body weight in healthy humans.Br J Nutr. 2007 Sep;98(3):651-6.
3)Casas-Agustench P et al Effects of one serving of mixed nuts on serum lipids, insulin resistance and inflammatory markers in patients with the metabolic syndrome. Nutr Metab Cardiovasc Dis. 2011 Feb;21(2):126-35.
4)Jiang R et al Nut and peanut butter consumption and risk of type 2 diabetes in women. JAMA. 2002 Nov 27;288(20):2554-60.
5)National Health and Medical Research Council (2012) Infant Feeding Guidelines.Canberra:National Health and Medical Research Council.
6) Liu Z et al Prebiotic effects of almonds and almond skins on intestinal microbiota in healthy adult humans.Anaerobe. 2014 Apr;26:1-6.
7) Alasalvar C et al Effects of roasting on oil and fatty acid composition of Turkish hazelnut varieties (Corylus avellana L.).Int J Food Sci Nutr. 2010 Sep;61(6):630-42.

Last updated July 2016

Do nuts cause gallstones or kidney stones?

There have been two population based studies investigating the relation of frequent nut consumption and the risk of gallstones (1,2).

Men consuming five or more 30g serves of nuts per week had a significantly lower risk of gallstone disease (30% risk reduction) than men who never ate or who ate less than one serve per month(1).

Data from the Nurses' Health Study (2) showed that for women, frequent nut consumers (≥5 times/wk) had a 25% reduced risk of needing cholecystectomy (removal of the gallbladder) than women who never ate nuts or who ate less than one serve a month.

These outcomes remained true despite the type or content of fat in the diet(1,2). Thus, it appears that the frequency of nut consumption is equally protective of gallstone disease in both sexes.

There is less evidence for the role of nuts in reducing the risk of kidney stones. Consumption of a DASH style diet - which is rich in fruit, vegetables, legumes, nuts and wholegrains; moderate in low fat dairy products; and low in sweetened beverages, salt and processed meat is associated with a 40% reduced risk of kidney stones(3).

References:
1)Tsai CJ et al. A prospective cohort study of nut consumption and the risk of gallstone disease in men. Am J Epidemiol. 2004 Nov 15;160(10):961-8.
2) Tsai CJ et al. Frequent nut consumption and decreased risk of cholecystectomy in women. Am J Clin Nutr. 2004 Jul;80(1):76-81.
3) Taylor EN et al. DASH-style diet associates with reduced risk for kidney stones.J Am Soc Nephrol. 2009 Oct;20(10):2253-9.

Last updated July 2016

I’m vegetarian – Are nuts a source of iron?

Vegetarians avoiding animal products need to seek alternative plant sources of iron. Nuts in general contain around 1-5mg iron per 100g, depending on the nut variety, with cashews containing the most iron (5mg/100g) and chestnuts the least (0.8mg/100g). However this non-haem, plant iron is difficult to absorb as it is bound by the antioxidant phytate. One way to help the absorption of plant iron is by eating these foods with a source of vitamin C (ascorbic acid) such as citrus fruits, tomato, capsicum or avocado. Vitamin C helps to break down phytate, making the iron more bioavailable. Soaking nuts may also reduce the phytate, although there is no evidence that more iron is made available.

Last updated July 2016

Do nuts cause gout?

Whilst there is not a lot of evidence, a recent study among the Chinese population, demonstrated that higher consumption of poultry and fish/shellfish is associated with an increased risk of gout, whereas eggs, nuts, seeds and grain products was not (1). Similarly, two other studies have shown that eating nuts as well as low-fat dairy products, purine-rich vegetables, grains and legumes and less sugary fruits reduces the risk of developing gout. Red meat, fructose-containing beverages and alcohol was shown to increase the risk of gout (2,3).

References:
1) Teng GG et al. Food sources of protein and risk of incident gout in the Singapore Chinese Health Study. Arthritis Rheumatol. 2015 Jul;67(7):1933-42.
2) Torralba KD et al. The interplay between diet, urate transporters and the risk for gout and hyperuricemia: current and future directions.Int J Rheum Dis. 2012 Dec;15(6):499-506.
3) Choi HK. A prescription for lifestyle change in patients with hyperuricemia and gout.Curr Opin Rheumatol. 2010 Mar;22(2):165-72.

Last updated July 2016

Do nuts contain sugar?

Yes raw, natural nuts contain natural sugars and depending on the nut variety, contain between 2.1 and 5.9g sugars per 100g. Pistachios contain the most sugar (5.9g/100g) and Brazil nuts the least (2.1g/100g). The type of sugar found naturally in nuts is sucrose - the same type that is in sugar cane and crystallised as white, brown or raw sugar. There's so much hype about sugars at present but there's no need to be concerned about the natural sugar content of nuts. If we avoided all foods that contain sugars, there'd be little left to eat as many plant foods contain some level of natural sugars.

Despite their natural sugar content, nuts help to reduce the glycemic index of a meal, reducing the rise in blood glucose following a meal containing carbohydrate foods(1-4). The protein, healthy fats and fibre content of nuts helps to slow their digestion.

Some nuts are coated in sugar (Vienna almonds), honey (honey coated) or chocolate coated. These products will be higher in added sugars and are best left as party nuts on special occasions.

References:
1) Kendall CW et al The glycemic effect of nut-enriched meals in healthy and diabetic subjects.Nutr Metab Cardiovasc Dis. 2011 Jun;21 Suppl 1:S34-9.
2) Parham M et al. Effects of pistachio nut supplementation on blood glucose in patients with type 2 diabetes: a randomized crossover trial. Rev Diabet Stud. 2014 Summer;11(2):190-6.
3) Blanco Mejia S et al. Effect of tree nuts on metabolic syndrome criteria: a systematic review and meta-analysis of randomised controlled trials.BMJ Open. 2014 Jul 29;4(7):e004660.
4) Kendall CW et al. The impact of pistachio intake alone or in combination with high-carbohydrate foods on post-prandial glycemia. Eur J Clin Nutr. 2011 Jun;65(6):696-702.

Last updated July 2016

Do nuts cause acne?

There is no evidence to suggest that nuts cause acne. There is some evidence to suggest that diets based on products with a high glycemic index (GI) leads to hyperinsulinemia (elevated insulin levels) (1,2). Elevated insulin levels stimulate the secretion of androgens and cause an increased production of sebum, which plays a fundamental role in the cause of acne. Nuts can help to reduce the GI of a meal containing carbohydrates due to their healthy fat content. The healthy fats take longer to digest, and slow the rise in blood glucose.

References:
1) Kucharska A et al. Significance of diet in treated and untreated acne vulgaris. Adv Dermatol Allergol 2016; XXXIII (2): 81–86.
2) Smith RN et al. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007 ul;86(1):107-15.

Last Update July 2016

Brazil nuts are very high in selenium – Isn’t selenium toxic? Are Brazil nut healthy?

Brazil nuts are one of the highest natural sources of selenium. A 100g serve of Brazil nuts contains 1917 micrograms of selenium, equivalent to 575 micrograms per 30g serve (1). However, this can vary quite significantly within the range of 0.4 - 158 micrograms per gram of Brazil nut (2).

Selenium is also found in seafood, poultry and eggs and to a lesser extent, other muscle meats. The contribution of plant sources (e.g. sunflower seeds and wheat germ) depends on the location, as selenium levels in soil vary. Low soil selenium levels in New Zealand mean that dietary intakes and selenium status are lower than in many other countries (3).

In Australia, the recommended dietary intake (RDI) for selenium is 70 micrograms for adult men, and 60 micrograms for adult women (4). This means you only need 2 Brazil nuts a day to get 100% of the RDI for selenium. However this assumes we absorb 100% of the nutrients from the foods we eat, which is not the case - we only absorb about 55-70% of selenium from foods (5).

An upper level of intake (UL) has also been set at 400 micrograms of selenium a day and relates to intakes from food and supplements (4). This is based on studies from China and the US indicating that intakes of 800 micrograms does not cause adverse effects. Studies in native populations of the Brazilian Amazon region have found blood selenium levels ranging from 103 to 1500 micrograms/litre with no signs or symptoms of selenium toxicity (6). However, because of gaps in the body of evidence, a safety factor is applied – resulting in an upper limit of 400 micrograms (equivalent to 20g or approx 6 Brazil nuts).

There is limited data about selenium toxicity in humans but the most common outcomes are brittleness and loss of hair and nail, as well as gastrointestinal disturbance, skin rash, fatigue, irritability and nervous system abnormalities.

So, enjoying a few Brazil nuts/day is safe and is unlikely to cause any significant adverse effects – just don’t eat excessive amounts all at once.

References:
1) FSANZ NUTTAB 2010 online database https://www.foodstandards.gov.au/science/monitoringnutrients/nutrientables/nuttab/Pages/default.aspx.
2) Lemire M et al. Elevated levels of selenium in the typical diet of Amazonian riverside populations. Sci Total Environ. 2010 Sep 1;408(19):4076-84.
3) Thomson CD et al. Brazil nuts: an effective way to improve selenium status. Am J Clin Nutr. 2008 Feb;87(2):379-84.
4) https://www.nrv.gov.au/nutrients/selenium.
5) Whanger PD. Metabolism of selenium in humans. J Trace Elem Exper Med 1998;11:227-40.
6) Lemire M et al No evidence of selenosis from a selenium-rich diet in the Brazilian Amazon. Environ Int. 2012 Apr;40:128-36.

Last Update July 2016

How do I choose fresh nuts?

For nuts in the shell: choose clean nuts free from cracks and holes. Nuts in the shell should be heavy for their size, indicating a fresh, solid kernel.

For nut kernels: choose crisp, plump and solid kernels indicating high quality. Unless you plan to use kernels as a garnish, they do not need to be whole or uniform in size.

Once home, remove nuts from plastic bags and store them in an airtight container in the refrigerator or freezer. Nuts can be refrigerated for up to 4 months and frozen for up to 6 months. Remember to bring nuts back to room temperature before eating so they taste...well....nuttier!

Last Update July 2016

Are organic nuts better than conventionally grown nuts?

Despite claims that organic foods have more nutrients and elicit favourable effects on health, there is actually a lack of scientific evidence to support it. Research published in 2011(1) found that organic foods may contain more vitamin C and phosphorous, however another in 2012(2) showed that organic foods may reduce exposure to pesticides, but there was a lack of evidence that organic foods were significantly more nutritious.

A handful of any type of nut - organic or conventional has benefits for health. So until the evidence is clear, include a daily handful of whichever type of nuts you prefer, as eating any type is better than eating none at all.

References:
1) Hunter D et al. Evaluation of the micronutrient composition of plant foods produced by organic or conventional agricultural methods. Crit Rev Food Sci Nutri 2011;51(6):571-82.
2) Smith-Spangler C et al. Are organic foods safer or healthier than conventional alternatives? A systematic review. Ann Intern Med 2012;157(5): 348-66.

Last Update July 2016

Where are nuts grown?

Tree nuts are grown all over the world, and most types are grown here in Australia. The only nuts that aren’t grown here at all are Brazil nuts.


Almond

Almonds are grown in several regions in Australia and are only second to the US in terms of volume produced. You will find almond orchards along the Murray River Valley, across four main regions: Adelaide and the Riverland (SA), Sunraysia (VIC) and the Riverina (NSW). Some are also imported from California USA.


Brazil nut

Brazil nuts can only grow in South America, as they need the rainforests of the Amazon valley of Brazil, Peru and Bolivia to grow.


Cashew

A native of Brazil, now grown in Vietnam, India, Africa and Brazil, with some small orchards in northern Australia.


Chestnut

Around 70 - 80% of Australian production is located in the North East of Victoria. In the South of the Divide Region of Victoria, chestnuts are grown in the High Country of the Gippsland and the Macedon Ranges. Producers are also located in NSW (around Orange, Canberra, and the Northern Tablelands), Southern Queensland, South Australia, Western Australia and Tasmania.


Hazelnut

Hazelnuts are not native to Australia, and commercial varieties in Australia are cultivars of the European hazelnut. Hazelnuts in Australia are largely imported from Turkey, the USA and Spain. Hazelnuts are grown in South-Eastern Australia, where climatic conditions are temperate. The main production regions are the Central Tablelands of New South Wales near Orange, and north-east Victoria near Myrtleford. They are also grown in central and Eastern Victoria and increasingly in Tasmania.


Macadamia

Macadamias are Australia’s native nut and are grown along the coastal strip of eastern Australia, from the Atherton Tablelands in Queensland to Nambucca Heads in NSW. Around half of the Australian crop is produced in the NSW Northern Rivers district.


Pecan

Well known as a native American nut, pecans are grown from the Hunter Valley and Nelsons Bay on the Central Coast to the Mid North Coast near Kempsey and the North Coast near Lismore. Orchards can also be found in Queensland at Munduberra, Gympie, Bundaberg, the Atherton tablelands and Beaudesert and small plantings in South Australia and Western Australia.


Pine nut

Most pine nuts in Australia are imported from Asia and the Mediterranean but there is a small orchard in Victoria.


Pistachio

The pistachio originated in western Asia and Asia Minor, made its way into Mediterranean Europe and now thrives in the dry climates of suitable areas of inland Australia. A small Australian industry is producing pistachios along the Murray River Valley between Swan Hill in Victoria and Waikerie in South Australia. Further plantings are located in central west Victoria and Pinnaroo, South Australia, with small plantings in Western Australia.


Walnut

A native of the northern hemisphere. Major supplies to Australia come from California, USA and China. However, there are increasing quantities from the growing Australian industry on the east coast of Tasmania and SE mainland in the Goulburn Valley near Shepparton, the Murray Irrigation Area near Kerang and Swan Hill and the Riverina near Griffith in New South Wales. Smaller production from Ovens Valley, Gippsland and Central Regions of Victoria, in the NSW Southern Highlands, in the Adelaide Hills and Riverland regions of South Australia and in south west Western Australia.

Last Update July 2016

Do peanuts count as nuts?

While “nut” is in their name, peanuts are in fact legumes. Peanuts actually grow underground, as opposed to nuts like walnuts, almonds, etc. that grow on trees (and are referred to as "tree nuts"). However, they share many of the properties and health benefits of tree nuts. The large population (epidemiology) studies which show benefits in eating nuts for reducing risks of heart health and diabetes didn’t distinguish between tree nuts and peanuts, so it appears peanuts and tree nuts all have positive health benefits (1-6).

Nuts for Life is a nutrition and health education initiative established for the Australian Tree Nut industry to provide information about the nutrition and health benefits of tree nuts.

References:
1) Albert CM et al. Nut consumption and decreased risk of sudden cardiac death in the Physician’s Health Study. Arch Intern Med 2002;162(12):1382-7.
2) Ellsworth JL et al. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women’s Health Study. Nutrition Metabolism and Cardiovascular Disease 2001;11(6):372-7.
3) Hu FB et al. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. British Medical Journal 1998;317(7169):1341-5.
4) Fraser GE et al. A possible protective effect of nut consumption on risk of coronary heart disease. Arch Intern Med 1991; 152: 1416-24.
5) Blomhoff R. et al. Health benefits of nuts: potential role of antioxidants. Brit J Nutr 2007;96(SupplS2):S52-S60.
6) Jiang R et al. Nut and peanut butter consumption and risk of type 2 diabetes in women. Journal of the American Medical Association 2002;288(20):2554-60.

Last Update July 2016

Is one nut better than all the rest?

Nuts represent a core food in the diet of Australians. Whilst the exact amounts of nutrients varies slightly between tree nuts, they are key sources of at least 28 different essential nutrients and bioactive substances. These include healthy monounsaturated and polyunsaturated fats, protein, fibre, folate, vitamin E, phytosterols and arginine.

So, just as we need a variety of fruits and vegetables, we need to eat a variety of nuts as well. Remember 2 serves of fruit, 5 of veg and a handful of nuts every day. Use nuts as a snack or as ingredients in meals to add interesting textures and tastes.

Last Update August 2016

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