Nuts about Nuts? Should nuts be consumed to reduce risk of chronic disease?
In a Nutshell discusses whether or not nuts are all they are cracked up to be. Nuts are advertised as a great source of protein and unsaturated fats. Although this may be true, other sources of protein have much fewer calories, such as beans, tofu, Greek yogurt, milk, fish, and poultry. Due to its caloric density, serving size recommendations for nuts may just seem nuts. Just one serving of brazil nuts (6-8 nuts) equates to 150 to 200 . So maybe we shouldn’t be nuts about nuts.
Reasons to go nuts about nuts. Nuts are known to be a good source of protein, especially for those who do not consume animal protein. An ounce of most nuts has 4 to 6 grams of . Nuts are also a good source of dietary fiber, polyunsaturated fats (also known as the “good” type of fat), and antioxidants, such as vitamin E. Such a nutrient dense composition may reduce risk of cardiovascular disease by reducing insulin resistance, cholesterol concentrations, lipid peroxidation, and oxidative . “Nuts also contain other bioactive compounds…which may reduce cancer risk by inducing cell cycle arrest, apoptosis, inhibiting cell proliferation, migration, invasion, and angiogenesis”.
A randomized controlled trial design, comparing participants on either a control diet or a Mediterranean diet, with either nuts or olive oil, found the lowest total mortality risk associated with those who were on a Mediterranean diet, consuming nuts greater than 3 servings/week at . However, who is to say that this association was attributed to the Mediterranean diet and not the actual nut consumption?
The New England Journal of Medicine published the findings of a cohort study, which examined the association between nut consumption and total mortality amongst nurses and other health . This study found that nut consumption was inversely associated with total mortality among both women and men. Specifically, significant inverse associations were observed between nut consumption and deaths due to cancer, cardiovascular disease, and respiratory . In agreeance with Bao et al. (2013), Aune et al. (2016) found a reduced risk of developing cancer, specifically colorectal cancer. Furthermore, current literature suggests a reduced risk of coronary heart , and type 2 diabetes
Research also demonstrates an association between nut consumption and blood cholesterol—specifically lowering LDL, or the “bad” , and elevating HDL, or the “good” cholesterol.
O’Neil et al. (2015) conducted a cross-sectional study, examining the association between nut consumption, weight, and cardiovascular risk factors. Findings indicated a lower BMI and waist circumference, and a lower likelihood of obesity in those consuming tree nuts. To further strengthen these findings, Aune et al. (2016) also found a better weight status among those who consumed tree nuts.
Although it is safe to say that much of the current research supports the notion of “going nuts for nuts”, it is important to realize the limitations of existing studies and other contradictory findings. For example, O’Neil et al. (2015) states that previous research has shown inconsistencies in the association of tree nut consumption with risk factors for cardiovascular disease and metabolic syndrome. With that being said, nut consumption and reduced risk of chronic disease is not a “black and white” issue—hence its ongoing controversy.
Not-so-nutty tips for nut eaters. Rather than eating nuts out of a bag, grab a quick handful, put the bag away, and be done with it. Also, purchase nuts low in sodium and sugar. Look for words such as, “unsalted” or “lightly salted” and try to avoid nuts smothered in chocolate or yogurt. Nuts can also serve as a good substitute for less healthful foods. For example, instead of croutons, sprinkle toasted nuts on your salad. Or, replace a sugary cereal with a whole grain cereal, and add your own nuts and fresh
References
(1) Hurley J and Liebman B. In a Nutshell: Are nuts all they’re cracked up to be? Nutrition Action Health Letter. October 2015.
(2) Aune D, Keum N, Giovannucci E, et al. Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies. BMC Medicine; 2016: 14: 207-220.
(3) Guasch-Ferre M, Bullo M, Martinez-Gonzalez AM, et al. Frequency of nut consumption and mortality risk in PREDIMED nutrition intervention trial. BMC Medicine. 2013; 11: 164. Abstract Only.
(4) Bao Y, Han J, Hu FB, Giovannucci E, Stampfer MJ, Willett WC, et al. Association of nut consumption with total and cause-specific mortality. N Engl J Med. 2013; 269: 2001-2011. Abstract Only.
(5) O’Neil Ce, Fulgoni VL, Nicklas TA. Tree nut consumption is associated with better adiposity measures and cardiovascular and metabolic syndrome health risk factors in US Adults: NHANES 2005-2010; Nutrition Journal. 2015; 14: 64-71. Abstract Only.
Written by Nicole Lindel ~ Nutrition Education Master’s Student at Columbia University