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Nut Research Group

Nut Research Group

Researchers:
Dr Rachel Brown
Dr Alex Chisholm
Agnes Siew Ling Tey
Andrew Gray (Biostatistician)
Professor Christine Thomson

The Nut Research Group comprises a core group of researchers conducting research investigating the effects of nuts on risk factors of cardiovascular disease, body weight, nutrient status, and acceptance.

The Nut Research Group, University of Otago, led by the Principal Investigator Associate Professor Rachel Brown, has extensive experience in the areas of human nutrition in general and the health effects of nut consumption in particular, sensory assessment, study design, and biostatistics and epidemiology. Group members have been researching this area for approximately twenty years with over 100 publications on nuts. We have conducted a wide range of randomised controlled trials with outcomes including body weight and composition(1), blood lipids and lipoproteins(1,2,3,4,5,6,7,8,9,10), inflammatory markers(8), blood vessel function(8), blood pressure(8,10), glycaemic control(4,11), dietary intakes and compensation(1,12), resting metabolic rate(1), appetite(1), and consumer acceptance(1,6,7,8,9,10,11,13). These studies have also examined different forms and doses of nuts. We were first to address important public health questions regarding whether the recommendation to consume nuts regularly is achievable and sustainable(1,6,7,8,9,10,11,13). Further, we have published a number of epidemiological studies using large datasets (including the 2008/09 New Zealand Adults Nutrition Survey and the UK Women’s Cohort) where we have examined nut consumption patterns, predictors of nut consumption, perceptions of nuts, and the association of nut intake with CVD risk factors and chronic disease(14,15,16,17,18,19). Our research group was invited to write a chapter on “Nut consumption and metabolic syndrome” in the book Nutritional intervention in metabolic syndrome. We were also commissioned by the National Heart Foundation of NZ to write a position statement on the relationship of nuts to heart health(20). Collectively, this research has been used to inform the nut consumption guidelines in the Government published Eating and Activity Guidelines for NZ Adults(21).

Our main research findings
• All forms of raw nuts (ground, sliced, or whole) significantly improve cardiovascular risk factors.
• One of the main barriers to consuming nuts is perceived weight gain due to the fact that nuts are high in fat and energy dense. However we have shown that consuming one serving of nuts a day (30 g), and up to 60 g of nuts per day does not adversely affect body weight, especially when nuts are consumed in place of unhealthy foods.
• Our research shows that, in general, people tend to like nuts, and they continue to like nuts after consuming them daily for a prolonged period. Thus consuming 30g-42g of nuts on a regular basis is an achievable and sustainable behaviour.
• Nuts provide a concentrated source of unsaturated fat, fibre, vitamin E, and a number of other nutrients often in short supply in the typical Western diet. Frequent nut consumption could be an effective way to achieve essential nutrient intakes and maintain general well being.
• Nut consumers have better nutrient intakes than non-nut consumers.
• Adding nuts to bread in different forms decreased the glycaemic response to bread. Adding sliced nuts to bread was an acceptable vehicle for increasing nut consumption.
• Brazil nuts contain substantial amounts of selenium, an essential trace element. Daily inclusion of a couple of Brazil nuts in the diet significantly enhances selenium status and antioxidant activity.

Our research group has been commissioned to write a position paper on the health benefits of nuts by the Heart foundation of New Zealand
Tey, S. L., Brown, R., & Chisholm, A. (2012). Nuts and heart health. Auckland, New Zealand: Heart Foundation of New Zealand. 45p

Our group was incited to author a book chapter
Tey, S. L., Chisholm, A. W.-A. H., & Brown, R. C. (2016). Nut consumption and metabolic syndrome. In I. Dichi & A. Name Colado Simão (Eds.), Nutritional intervention in metabolic syndrome. (pp. 289-312). Boca Raton, FL: CRC Press. doi: 10.1201/b19099-23¬

References

1. Brown RC, Tey SL, Gray AR, et al. (2014) Patterns and predictors of nut consumption: results from the 2008/09 New Zealand Adult Nutrition Survey. Br J Nutr 112, 2028-40.
2. Brown RC, Tey SL, Gray AR, et al. (2015) Association of Nut Consumption with Cardiometabolic Risk Factors in the 2008/2009 New Zealand Adult Nutrition Survey. Nutrients 7, 7523-42.
3. Brown RC, Tey SL, Gray AR, et al. (2016) Nut consumption is associated with better nutrient intakes: results from the 2008/09 New Zealand Adult Nutrition Survey. Br J Nutr 115, 105-12.
4. Chisholm A, Mann J, Skeaff M, et al. (1998) A diet rich in walnuts favourably influences plasma fatty acid profile in moderately hyperlipidaemic subjects. Eur J Clin Nutr 52, 12-16.
5. Chisholm A, McAuley K, Mann J, et al. (2005) Cholesterol lowering effects of nuts compared with a canola oil enriched cereal of similar fat composition. Nutr Metab Cardiovasc Dis 15, 284-292.
6. Chisholm AW, Brown RC and Tey SL. (2011) Are nuts good for you? Journal
7. Devi A, Chisholm A, Gray A, et al. (2015) Nut-enriched bread is an effective and acceptable vehicle to improve regular nut consumption. Eur J Nutr
8. Pearson KR, Tey SL, Gray AR, et al. (2016) Energy compensation and nutrient displacement following regular consumption of hazelnuts and other energy-dense snack foods in non-obese individuals. Eur J Nutr
9. Tey SL, Brown R, Chisholm A, et al. (2011) Current guidelines for nut consumption are achievable and sustainable: a hazelnut intervention. Br J Nutr 105, 1503-1511.
10. Tey SL, Brown R, Gray A, et al. (2011) Nuts improve diet quality compared to other energy-dense snacks while maintaining body weight. J Nutr Metab 2011, 357350.
11. Tey SL, Brown RC, Chisholm AW, et al. (2011) Effects of different forms of hazelnuts on blood lipids and α-tocopherol concentrations in mildly hypercholesterolemic individuals. Eur J Clin Nutr 65, 117-124.
12. Tey SL, Brown RC, Gray AR, et al. (2012) Long-term consumption of high energy-dense snack foods on sensory-specific satiety and intake. Am J Clin Nutr 95, 1038-1047.
13. Tey SL, Delahunty C, Gray A, et al. (2015) Effects of regular consumption of different forms of almonds and hazelnuts on acceptance and blood lipids. Eur J Nutr 54, 483-487.
14. Tey SL, Gray AR, Chisholm AW, et al. (2013) The dose of hazelnuts influences acceptance and diet quality but not inflammatory markers and body composition in overweight and obese individuals. J Nutr 143, 1254-1262.
15. Tey SL, Robinson T, Davis H, et al. (2015) The effect of regular hazelnut consumption on cardiovascular risk factors and acceptance in Maori and European. J Nutrients 2, 39-53.
16. Tey SL, Robinson T, Gray AR, et al. (2016) Do dry roasting, lightly salting nuts affect their cardioprotective properties and acceptability? Eur J Nutr
17. Thomson CD. (2011) Brazil nuts (Bertholletia excelsa): improved selenium status and other health benefits. Journal 245-252.
18. Thomson CD, Chisholm A, McLachlan SK, et al. (2008) Brazil nuts: an effective way to improve selenium status. Am J Clin Nutr 87, 379-84.

Our research group has been commissioned to write a position paper on the health benefits of nuts by the Heart foundation of New Zealand
Tey, S. L., Brown, R., & Chisholm, A. (2012). Nuts and heart health. Auckland, New Zealand: Heart Foundation of New Zealand. 45p

Our group was incited to author a book chapter
Tey, S. L., Chisholm, A. W.-A. H., & Brown, R. C. (2016). Nut consumption and metabolic syndrome. In I. Dichi & A. Name Colado Simão (Eds.), Nutritional intervention in metabolic syndrome. (pp. 289-312). Boca Raton, FL: CRC Press. doi: 10.1201/b19099-23¬

Our research group has received a considerable amount of media attention. Some highlights are below:

• A Radio Interview, Radio NZ, Simon Morton, “Activating nuts” 2017, Available from: http://www.radionz.co.nz/national/programmes/up-this-way/audio/2018627766/is-nut-activation-nuts
• A magazine article, Consumer NZ, Plant milks, April 2018, Available from: https://www.consumer.org.nz/articles/plant-milks
• A magazine article, Listener, “Nuts to activation”, March 17, 2018, Available from: (https://www.noted.co.nz/health/nutrition/why-the-claims-made-for-activated-nuts-dont-stack-up/

• An online news article to review the health effects of nut consumption (21st October, 2012)
http://www.nzherald.co.nz/lifestyle/news/article.cfm?c_id=6&objectid=10841980
• A newspaper article to encourage nut consumption for health (20th October, 2012)
http://www.3news.co.nz/Go-nuts-for-health-say-experts/tabid/420/articleID/273455/Default.aspx
• A live TV interview on the health benefits of nuts (19th October, 2012)
http://www.ch9.co.nz/node/63491
• Article on the health benefits of nuts in the New Zealand Listener (16th May, 2011)
http://www.listener.co.nz/lifestyle/nutrition/are-nuts-good-for-you
• An article on the European Food Information Council website to encourage Brazil nut consumption as a means to improve Selenium status
http://www.eufic.org/page/en/show/latest-science-news/fftid/Brazil-nuts-may-be-effective-in-improving-selenium-status