1. About Nuts update

This is already the third year of the About Nuts initiative. The goal of the initiative is still to inform consumers and stakeholders about the health aspects of peanuts and nuts, and about the developments emanating from research in this area. However, the scope of About Nuts has been broadened rapidly over the years. At the moment the About Nuts initiative is active in six different countries, and newsletters are sent to the consumer press and stakeholders in the Netherlands, Germany, England, Switzerland and Austria. The newsletters and summaries of the most recent scientific articles about peanuts and nuts can also be found on the website: www.aboutnuts.com.

2. A word from Reint Jan Renes, Associate Professor Health Communication

Most consumers associate (pea)nuts with food allergies. Food-allergic consumers try to buy food that does not cause hypersensitive reactions. To facilitate the consumers’ decision-making process, manufacturers are increasingly including more and more visual aids (i.e. logos) on the packaging of their food products. Do these logos affect consumers’ choice of products? Do we - for safety’s sake - buy more food products with ‘no-nuts’ logos than without? Three consumer experiments that have been conducted in association with Dr. Wendy van Rijswijk of the University of Dundee showed that a trustworthy allergy logo (“no peanuts!”) indeed affects the product choice of consumers, but only when consumers are worried about food allergies. More than 90% of the participants in our experiment who were asked to buy a product for an allergic friend (‘worry’ situation) chose the food product with a ‘no-nuts’ logo instead of the (identical) non-logo product, while participants asked to buy a product for a non-allergic friend (‘no-worry’ situation) did not show any preference. Furthermore, when making their decision, participants confronted with an untrustworthy ‘no-nuts’ logo relied less on the logo and read additional ingredient information to a greater extent than participants who were confronted with a trustworthy logo. So, a ‘no-nuts’ logo will affect only those consumers who trust the logo and for whom the information is relevant.

3. Effects of pistachios and macadamias on LDL-cholesterol

For years cardiovascular diseases (CVD) have been among the leading causes of death worldwide. High levels of LDL cholesterol and triglycerides are important risk factors for developing CVD. Changing the daily diet can influence these risk factors in a positive way. Two recent studies evaluated the effects to relevant serum lipid and lipid protein levels of including macadamia nuts or pistachio nuts in the daily diet.

One portion of macadamias a day

In previous studies, it has been proved that macadamias reduce LDL cholesterol when given in high doses. In the most recent study Griel et al. studied the effect of one dose of macadamias (43 grams of nuts) in mildly hypercholesterolaemic (4.7 to 6.1 mmol/l) persons. During this study, 25 subjects either had a controlled diet that included macadamias or a controlled average American diet for 5 weeks. The groups switched diet s after a two-week rest period. The inclusion of macadamia nuts resulted in a diet higher in monounsaturated fats and lower in saturated fat. Blood analyses were carried out to determine the differences in serum levels.

Pistachio diet

Pistachio nuts have a favourable fatty acid composition and therefore potentially exert heart health benefits. Sheridan et al. studied this potential effect by replacing 15 energy per cent (en%) with pistachio nuts in the daily diet of 15 moderately hypercholesterolaemic (cholesterol > 6,2 mmol/l) subjects. These subjects were randomly assigned to eat either their regular diet or a diet that incorporated 15 en% pistachio nuts. Both groups followed this diet for 4 weeks, after which they switched to the other diet. The inclusion of pistachio nuts resulted in a diet higher in fibres and monounsaturated fats. Differences in serum levels were determined by the analysis of blood samples

Results

Both studies found favourable effects on risk factors for CVD. Inclusion of macadamias in the diet accounted for significant reductions in total cholesterol (-9.4%, p 0.05) and LDL cholesterol (-8.9%, p<0.05) compared to the average diet. Additionally, total cholesterol/HDL cholesterol and LDL/HDL cholesterol ratios declined significantly, although triglyceride levels did not show a significant reduction.

Incorporating pistachio nuts in the daily diet also decreased the total cholesterol/HDL cholesterol (-9%, p < 0.001) and LDL/HDL cholesterol (-14%, p 0.004) ratios successfully. Although other risk factors - among which total cholesterol, LDL cholesterol and apo-lipoproteïn concentrations - were not significantly reduced.

Heart healthy nuts

Both studies showed that including nuts in the daily diet can have significant heart health benefits. The American Food and Drug Administration (FDA) therefore allowed a heart health claim for tree nuts. However, currently this cannot be claimed for macadamia nuts as these nuts exceed the 4 grams of saturated fat per 50 grams of nuts, which was set as a cut-off point by the FDA. Nonetheless, the heart-health effects for macadamias proved significant in this latest study.

Sources:
1) Griel et al. A macadamia nut-rich diet reduces total and LDL-cholesterol in mildly hypercholesterolemic men and women. Journal of Nutrition 2008 138(4):761-767.
2) Sheridan et al. Pistachio Nut Consumption and Serum Lipid Levels Journal of the American College of Nutrition 2007 26(2):141-148.