Are Pistachios the King of Nuts? 🤔
You are probably already well aware that nuts are a generally healthy class of food. They are good sources of essential nutrients, as well as fiber and polyphenols, and eating nuts has been shown to be associated with lower all-cause mortality, lower risk of heart disease, lower risk of some cancers, and all sorts of other benefits.
If you take a closer look at the literature in this area, you will notice that it is kind of dominated by walnuts and almonds, and to a lesser extent peanuts (which aren’t even technically nuts but I digress). However, a newly published review suggested that the less-popular pistachios may have been underappreciated in nutrition science.
And as you’ll see from the studies below, they may even surpass other nuts in terms of the most important and well-established health benefits.
This Week's Research Highlights
🩸 Adding pistachios to the diet can result in substantial improvements in blood lipids and other biomarkers.
Researchers in Turkey recruited 32 healthy young men (mean age of 22) whose normal diet, as well as their blood work at baseline, were unremarkable. For four weeks, a Mediterranean diet was administered to them through their school kitchen, consisting of whole foods and high in vegetables and fish. Then, for another four weeks, the participants continued to receive the Mediterranean foods, but 60-100 grams of roasted unsalted pistachios was added in as an appetizer.
Compared with the Mediterranean diet alone, the Mediterranean diet augmented with pistachios resulted in significant reductions in LDL (−23.2 ± 11.9%), total cholesterol (−21.2 ± 9.9%), and triglycerides (−13.8 ± 33.8%). Furthermore, the pistachios resulted in lower fasting glucose (−8.8 ± 8.5%), as well as increased the ability of blood vessels to widen in response to blood flow (+30% relative increase in endothelium-dependent vasodilation). Finally, adding in the pistachios led to increased markers of antioxidant potential and lowered markers of oxidative stress, which is always a good thing. As previously mentioned, many studies have found that nuts in general have favorable effects on the lipid profile, but a recent meta-analysis of clinical trials suggested pistachios may produce better results than most other nut-enriched diets.
Researchers at Penn State recruited 30 adults with well-controlled type 2 diabetes, and enrolled them in a controlled feeding study with all meals prepared at the university’s metabolic kitchen. For 4 weeks, the participants consumed a control diet based on the AHA's Therapeutic Lifestyle Changes diet. Then, after a 2 week washout period, the subjects were switched to a diet that contained the exact same number of calories as the control diet, but integrated pistachios as 20% of the total daily energy (59-128 grams). The pistachio diet led to reduced total peripheral resistance (−3.7±2.9%), meaning the resistance of the vasculature to blood flow, accompanied by increased cardiac output (+3.1±2.3%). As a result, systolic ambulatory blood pressure was also lower after the pistachio diet (−3.5±2.2 mm Hg), with even greater reductions during sleep (−5.7±2.6 mm Hg). Finally, after eating the pistachios, these participants showed improvements in heart rate variability (HRV), or the difference in time between each heartbeat, indicating better balance in the autonomic nervous system (which would in turn also lead to better vascular function and BP). This, too, may distinguish pistachios from other tree nuts; one meta-analysis of 21 randomized controlled trials found that pistachios had the strongest beneficial impact on blood pressure out of all nut types.
Researchers in Spain analyzed data from a nutrition intervention trial (very similar to the ones described above) that examined how pistachio intake affected various health markers in people with impaired blood sugar control. Forty-nine prediabetic subjects spent 4 months consuming a pistachio-supplemented diet (57 g per day) and another 4-month interval consuming a control diet containing the same number of calories but without pistachios. The pistachio diet resulted in reductions in 8-OHdG, a residue that is generated when reactive oxygen species attack DNA (mean −3.5%), while the control diet elicited an increase in the same marker (+6.34%). Additionally, expression of two genes that are responsible for components of the enzyme telomerase (TERT and WRAP53) rose substantially (+164% and +53% respectively) after the pistachio diet. Telomerase is responsible for maintaining our telomeres, which are particularly vulnerable to damage through oxidative stress. Telomere shortening is a hallmark of the aging process, and decreasing the rate of telomere attrition could delay or prevent the onset of chronic disease (in other words, boosting healthspan).
Random Trivia & Weird News
🧮 Eccentric mathematician (seriously read this dude’s wikipedia page) Paul Erdős won a bet with colleague that he couldn’t quit amphetamines.
A fellow mathematician wagered $500 that he could not stop using the drugs for a full month. Erdős wound up pulling it off, but complained that the wager came at a cost to their field: "You've showed me I'm not an addict. But I didn't get any work done. I'd get up in the morning and stare at a blank piece of paper. I'd have no ideas, just like an ordinary person. You've set mathematics back a month.”
Vindicated, he promptly returned to Ritalin and Benzadrine thereafter.
Podcasts We Loved This Week
- Norman Temple: Can science answer diet-health questions? Via Sigma Nutrition Radio.
- Mike Joyner: Exercise, VO2 max, and longevity. Via The Drive.
Products We Are Enjoying
The major perceived disadvantage of nuts, including pistachios, is their caloric density, which could make them into a perilous snack if you’re not careful (although it is worth noting that the subjects in the studies I described above did not gain weight, despite adding up to 550 calories of nuts).
One effective way to manage this is to buy them with their shells intact. In a study where students were offered either shelled or unshelled pistachios, those who ate the in-shell pistachios wound up consuming 41% fewer calories, compared to those who had shelled nuts.
Plus some people, myself included, find removing the shells to be oddly satisfying. 😌
humanOS Catalog Feature of the Week
Thanks for reading, enjoy the weekend, and we'll see y'all next week!