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Friday 1 March 2019

Hazelnuts the new multivitamin?

Hazelnoten
Hazelnuts, we don’t eat enough of them. Researchers have recently discovered that eating hazelnuts significantly increases the vitamin E and magnesium levels in older adults. In their recent article published in the Journal of Nutrition, the researchers described that this is associated with health benefits. 


In the Netherlands, it is recommended that at least 15 grams of unsalted nuts are eaten daily. Food consumption surveys have revealed that just six percent of the population meet this guideline. On average, older adults eat just 3 grams of unsalted nuts a day (Netherlands National Institute for Public Health and the Environment - RIVM).


Inadequate intake of macronutrients

The guidelines are equally not met in America. Researchers at the Oregon State University mention the inadequate intake of vitamin E and magnesium in older adults and associated age-related diseases, such as Alzheimer’s disease. The aim of their study was to find out to what extent hazelnuts increase the vitamin E and magnesium status in older adults (Michels, 2018). 


Favourable levels

Thirty-two older adults participated in the study. They ate on average 57 grams of hazelnuts every day for 16 weeks. Blood and urine samples were taken at the start and end of the intervention. Determined from these samples were the differences in serum magnesium, plasma α-tocopherol (vitamin E), α-carboxyethyl hydroxychromanol in the urine, a metabolite of vitamin E (Michels, 2018).


Following the intervention, the concentration of the metabolite had increased significantly. The serum magnesium levels had also risen. Furthermore, glucose and LDL cholesterol levels had fallen.The scientists found no significant differences in blood pressure and serum insulin, C-reactive protein, triglycerides, HDL cholesterol and α-tocopherol (Michels, 2018).


The researchers used a metabolite as a marker for vitamin E because it would be difficult to measure the α-tocopherol levels in the blood of older adults as they tend towards elevated cholesterol levels, which goes hand-in-hand with elevated serum α-tocopherol. The breakdown product would therefore be a better biomarker. The researchers confirmed that α-carboxyethyl hydroxychromanol in the urine increases if the body gets enough vitamin E (MedicalXpress, 2019).


A varied diet

Hazelnuts are therefore a good source of vitamin E and magnesium and can help to improve the dietary status of older adults. Hazelnuts contain many more micronutrients and macronutrients that are important for the health. One hundred grams of hazelnuts contain 69 grams of fat, the majority of which is unsaturated, 14 grams of proteins and few carbohydrates. Furthermore, they contain a whole host of vitamins, minerals and trace elements, including calcium, phosphorus, potassium, copper, selenium, beta carotene, vitamin A, B6 and folic acid (RIVM, 2016). 


The researchers say that hazelnuts are a natural form of multivitamins (MedicalXpress, 2019). That feels somewhat far-fetched. A varied diet is, of course, key, but in the case of older adults, it is for good reason that extra supplementation of, for example, vitamin D is recommended. Hazelnuts do not contain vitamin D. Furthermore, the 57 grams given in this study equates to approx. 400 kilocalories which would soon satiate someone (RIVM, 2016). We wonder whether, for example, 25 grams, which is more likely in a varied diet, would produce the same effects. It remains to be investigated whether hazelnuts can reduce the risk of, for example, Alzheimer’s disease, but they are most certainly part of a healthy and varied diet. 

 

Sources

[1] MedicalXpress (2018). Hazelnuts improve older adults' micronutrient levels. Consulted from: https://medicalxpress.com/news/2018-12-hazelnuts-older-adults-micronutrient.html


[2] Michels et al. (2018). Daily Consumption of Oregon Hazelnuts Affects α-Tocopherol Status in Healthy Older Adults: A Pre-Post Intervention Study. The Journal of Nutrition. 148;12 (1924–1930) https://doi.org/10.1093/jn/nxy210


[3] RIVM (2016). NEVO online, voedingsmiddelendetails: hazelnoten. Consulted from https://nevo-online.rivm.nl/ProductDetails.aspx 


[4] RIVM (z.d.). Noten. Consulted from: https://www.wateetnederland.nl/resultaten/voedingsmiddelen/richtlijnen/noten