The research — funded by the Almond Board of California— is the first to monitor the effects of dietary change on digestive health and immune function in a parent and child and whether this positively affects immunity, inflammation and general health.
The 14-week, randomised, controlled, crossover study included 29 healthy parent and child pairs.
Parents and children consumed 1.5 and 0.5 ounces of almonds and/or almond butter, respectively, on a daily basis for three weeks, as part of their usual diet, followed by a six-week washout period and another three-week period of following their usual diet with no almonds.
To track progress, adult participants completed daily questionnaires of compliance with nut intake and weekly dietary recalls on behalf of both themselves and their child.
In terms of diet, the researchers noticed an increase in quality, according to the results published in Nutrition Research.
Using the Healthy Eating Index (HEI) score — a measure of adherence to recommended dietary guidance — parents and children increased their scores to 61.4, which is above national averages of 57.4 for adults 31-50 years and 54.9 for children 4-8 years.
HEI scores also increased for fatty acids, total protein, seafood and plant protein and decreased for fruit and empty calories. When eating almonds, participants also consumed more vitamin E and magnesium, two nutrients lacking in the majority of adult and children’s diets.
"The findings suggest that participants replaced some of their empty calorie snacks with almonds, which has important implications since snacking has become so prevalent," said Dr Wendy Dahl, associate professor at the University of Florida and contributing author to the study.
Almond consumption also seemed to change gut bacteria levels in subjects. Although the children consumed one-third of the amount of almonds compared to adults, microbiota was affected to a greater extent in their bodies. No specific changes in immune markers were noted.
“Microbiota was stable at the phylum and family level, but genus level changes occurred with nut intake,” the researchers noted.
Despite the benefits attributed to almonds, the researchers highlighted the study’s limitations. Nutrient intake was assessed using self-reported dietary recall data and parents completed diet and GI symptom records for their child, a technique not scientifically validated.
In addition, parents were unable to accurately determine the foods eaten away from home by their children, as they attended school or day-care.
A brief history
Almonds’ health benefits have long been the subject of scientific studies that have focused on their prebiotic promise. Last year, a study suggested consuming almonds and their skins for six weeks may selectively boost the populations of Bifidobacterium spp. and Lactobacillus spp in the gut.
A similar study carried out in 2010 by the Institute of Food Research (IFR) in Norwich, England found both natural and blanched almond skins increased populations of various gut microbes, including Bifidobacteria.
“These results indicated the stimulation effects of almond skin and almond intake were typical prebiotic effects,” wrote the researchers. “Any food or ingredients that reach the colon without being digested are prebiotic candidates; nondigestible carbohydrates, in particular fructooligosaccharides (FOS), are authentic prebiotics.”
“Almond skins contain approximately 50% dietary ﬁbre and almonds contain about 12% dietary fibre. Dietary ﬁbre is resistant to digestive enzymes and passes undigested to the large intestine where it interacts with the intestinal mucosa and microbiota to enhance gut health.”
Source: Nutrition Research
Vol 36, Iss 1, January 2016, Pp. 80–89, doi:10.1016/j.nutres.2015.11.004
“Diet quality improves for parents and children when almonds are incorporated into their daily diet: a randomized, crossover study”
Authors: A. M. Burnsa, M. A. Zitta, C. C. Rowea, B. Langkamp-Henkena, V. Maib, C. Nieves Jr., M. Ukhanovab, M. C. Christmanc, W. J. Dahl