A Nutty Evolution: 10 Things You Didn't Know About Nuts

Aug. 2, 2012
Nuts, once shunned as a high-fat ingredient, are concentrated sources of phytochemicals.

Our view of nuts, in particular tree nuts, as dietary components has undergone an evolution. Nuts are an essential ingredient in many formulations because of their richness and subtle flavors. But that richness is due to fat content, which can be 80 percent of the calories in most nuts. If you are counting calories, that’s a whopping 800 per cup, give or take a few. So dieters had to eat nuts with caution.

Recently, the reputation of nuts soared with the dual realization that not all fats are equal (and the fats in nuts happen to be among the healthiest) and that nuts are a rich source of phytochemicals, including some with strong antioxidant action.

Understanding Antioxidants

In theory, antioxidants help to protect the body from the biological equivalent of rust: oxidation. It happens when byproducts of living and doing business in an oxygen environment, often referred to as Reactive Oxygen Species (ROS), attempt to share their unpaired electrons with body proteins, membranes or even DNA itself, resulting in damaging links that negatively affect health. Data from large observational studies consistently reveal a link between nut consumption and lowered the risk of several diseases where oxidative stress may play a role. For example, four major epidemiological studies, including the Nurses’ Health Study, the Physicians’ Health Study, the Iowa Women’s Health Study and the Adventist Health Study, have all shown that frequent nut consumption is associated with a decreased risk of coronary heart disease events.

Bolling concludes, “[clinical studies that] examine separately the impact of nut components such as the skin, meat and oil, while incorporating appropriate control groups could provide important new information in this regard and should be undertaken.”

One such study was reported last year in Clinical Nutrition, titled “Neuroprotective effects of almond skins in experimental spinal cord injury.” This study looked at the potential of almond skins to protect against injury secondary to spinal cord injury in mice. These secondary complications include inflammation, microvascular dysfunction at the site of injury, free radicals formation, lipid peroxidation and accumulation of excitatory neurotransmitters, leading to further neural damage. Treatment with natural almond skins one and six hours after spinal cord injury reduced all parameters of inflammation as neutrophil infiltration, suggesting treatment with compounds from almond skins to reduce the development of inflammation and tissue injury could be useful in the treatment of spinal cord injury in the future.

  • A dominant fatty acid in nuts is monounsaturated oleic acid, the same as in olives and avocadoes. Oleic acid had the reputation of lowering LDL cholesterol without lowering HDL cholesterol.
  • Pine nuts and walnuts are rich in omega-6 fatty acids. 
  • Walnuts are a source of omega-3 fatty acids. 
  • Many studies confirm that nuts are a wise choice in a diet to reduce the risk of heart disease. 
  • In an article published last year in Nutrition Research Reviews, Bradley Bolling of the Department of Nutritional Sciences at the University of Connecticut noted that tree nuts contain a variety of phytochemicals, including carotenoids, phenolic acids, phytosterols and polyphenolic compounds such as flavonoids, proanthocyanidins and stilbenes. Carotenoids, phenolic acids and flavonoids function as powerful antioxidants.
  • Flavonoids, a subclass of phenolics, includes flavonols, flavones, flavanones, flavan-3-ols (the primary flavonoids in nuts), anthocyanidins and isoflavones. Flavanones and isoflavones are also found in nuts, but in smaller quantities. 
  • Proanthocyanidins (PACs) are related to anthocyanidins and include catechins, epicatechin, and epigallocatechins — all found in hazelnuts, pecans and pistachios. They also include afzelechin (almonds). The A-type PAC have been found only in almonds.
  • The antioxidants in nuts vary with species and preparation method. Total phytochemical content is affected by environment, cultivation practice, climate, processing and storage. The value is further subjected to the methods used to separate and measure them. According to Bolling, almonds, hazelnuts, pecans and pistachios have higher contents of PAC than do other tree nuts, ranging from 184 to 501mg per 100g. 
  • Flavonoids have been detected in all tree nuts, but pecans, macadamias, almonds and pistachios have the highest concentrations (25 to 2,713mg per 100g). Pecans and walnuts are rich sources of phenolic acids and aldehydes, with 2,052 and 39mg per 100g, respectively.
  • Almond skins are the subject of specific study. According to Sam Cunningham, food technologist and co-owner of Nut-trition Inc. (www.nut-trition.com), Hughson, Calif., "At least 33 bioavailable flavonoids and polyphenolic compounds have been identified in almond skins so far. Almond Bran is a rich source of almond sterols and essential minerals such as magnesium, calcium, phosphorus and potassium. The total antioxidant capacity of Almond Bran is more than 13 times greater than that of almonds alone, and it contains less than half the fat and nearly four times the dietary fiber."

Sponsored Recommendations

Revolutionizing Healthcare: The Impact of Digitalization in Biopharma Innovation

Biopharma enables an entirely new level of innovation that’s simply not possible in conventional drug development. It’s an approach that can fundamentally change the way healthcare...

Navigating the Automotive Industry's Electric Future

The automotive industry is at a turning point. Bloomberg estimates that by 2040, 54% of new vehicle sales will be electric. And by 2030, we’re looking at 100% of passenger vehicles...

Unified Process Control Brings Operational Clarity

Inland Empire Utilities Agency replaces its SCADA enterprise system with the PlantPAx Distributed Control System and reduces complexity for operators

PlantPAx DCS Improves Operational Reliability

KC Water calls on R.E. Pedrotti to replace obsolete wastewater SCADA solution with a unified Modern Distributed Control System (DCS).