Are Pistachios Good for Weight Management?

In moderation. A registered dietitian nutritionist explains.

Medically reviewed by Suzanne Fisher, RD

Pistachios are essential sources of both macronutrients and micronutrients. They are particularly notable for their high levels of monounsaturated and polyunsaturated fatty acids and carotenoids.

Pistachios and other tree nuts have been studied for their effects on weight, blood sugar, the cardiovascular system, and overall gut health.

The following article covers pistachios' history and origin, nutritional value, health benefits, and potential safety considerations.

What Are Pistachios?

Pistachio nuts (Pistacia vera) belong to the Anacardiaceae family. Other plants in this family include cashews, mangoes, sumac, and poison ivy.

There are, in fact, many members of the Pistacia genus, but only Pistacia vera produces pistachio nuts, which are edible for humans. The remainder of the species is used for oil, timber production, and carpentry.

Pistachio trees are native to western Asia, particularly in the area of the former Persian empire, which is now modern-day Iran. Due to centuries of trading, pistachio trees are now grown widely around the globe.

There is evidence of pistachios being used in many ancient cultures, and they are one of the only two nuts mentioned in the Bible. They are significant parts of the culinary tradition of many Middle Eastern cultures and those of Italy and North Africa.

In the United States, pistachios are most popular as a snack. They are almost exclusively grown in California; American pistachio production accounts for almost half of worldwide production.

Pistachio Nutrition

Below is a detailed breakdown of the macronutrient (protein, fat, carbohydrate) and micronutrient (vitamin and mineral) content of pistachios.

One serving of pistachios is approximately 25 grams (g).

Pistachios are rich sources of protein, fiber, and healthy fats. They also contain high levels of many vitamins, especially:

• Carotenoids

• Vitamin B6

• Vitamin E

• Folate (vitamin B9)

They also contain minerals such as:

• Potassium

• Magnesium

• Calcium

• Selenium

Pistachios are lower in calories per serving than many other tree nuts. Additionally, they contain a high proportion of monounsaturated fats ("healthy" fats) to saturated fats. Compared to other tree nut varieties, they are also high in carotenoids (beta-carotene, lutein, and zeaxanthin).

The Research on Pistachios

Weight Management

Pistachios and other nuts have great potential to aid in weight management due to their protein, fiber, and healthy fat content. Several studies have supported the role of pistachio consumption in promoting satiety (a satisfied feeling of fullness) when consumed as a snack.

However, a systematic review and meta-analysis did not show clear overall evidence for nut consumption leading to long-term weight loss for individuals at higher weights.

One 12-week randomized control trial found that adding pistachios as a daily snack decreased hunger. They also increased satiety more than other commonly consumed snacks higher in carbohydrates. Additionally, it was found that higher pistachio consumption also improved the participants' daily diet and overall nutrient intake.

A different year-long study found that increasing the daily intake of several nuts, including pistachios, reduced waist circumference and decreased overall daily caloric intake. This further suggests that pistachios and other nuts can aid in weight management.

They Are Heart Healthy

Heart health is a category that examines the various factors associated with a robust cardiovascular system. This includes measures such as cholesterol, blood pressure, triglycerides, and the occurrence of heart disease and heart failure.

Pistachios are high in monounsaturated and polyunsaturated fatty acids. Of particular note are the oleic and linoleic fatty acids, which comprise more than half of the pistachio fat content.

Polyunsaturated fats have long been studied for their heart health benefits. A review in Nutrients asserts that polyunsaturated fats, particularly oleic and linoleic fatty acids, lowered cholesterol and cardiovascular disease risk.

A 2017 systematic analysis found several studies in which pistachio consumption improved lipid profiles by reducing low-density lipoprotein (LDL) cholesterol (“bad cholesterol”) and increasing high-density lipoprotein (HDL) cholesterol (“good cholesterol”).

Additionally, pistachio consumption reduced cardiovascular risk in adults who consumed them regularly. Outcomes included reduced blood pressure and improved inflammatory blood markers and lipid levels.

Blood Sugar Regulation

The 2017 systematic review of several randomized control studies mentioned above found a fair amount of evidence to support the beneficial effects of pistachio consumption on blood sugar control and insulin sensitivity (your body's ability to respond to insulin effectively to reduce blood sugar levels).

One study within the review found that consuming pistachios along with a slice of bread reduced the glycemic response (how food changes blood sugar levels in your body after eating it) of the bread. This suggested that pistachios can help regulate blood sugar levels.

A different study found that two servings of pistachios per day significantly decreased the hemoglobin A1c and fasting blood glucose levels of individuals with diabetes. These are two essential blood measures in determining blood sugar stability and overall health for people with diabetes.

An eight-week study involving participants with prediabetes (a state at risk of developing diabetes) consuming two servings of pistachios per day showed improved glucose metabolism and reduced insulin resistance (when the body doesn't reduce blood sugar as effectively) by the end of the study.

The studies further serve to demonstrate the potential beneficial implications of consuming pistachios for individuals with diabetes or those at risk of developing the condition.

Antioxidant Effects

Oxidative stress (when free radicals aren't effectively removed from the body) is considered to be an essential underlying factor contributing to several common illnesses, including type 2 diabetes, cardiovascular disease, and some types of cancer.

A meta-analysis examined the relationship between an increase in overall dietary levels of antioxidants, including carotenoids, and the risk of all-cause mortality, including the above-mentioned diseases. This review found that increased dietary and blood levels of antioxidants decreased overall mortality risk.

Pistachios are the nut that contains the highest levels of antioxidant carotenoids, including beta-carotene, lutein, and zeaxanthin.

Beyond the overall antioxidant benefits of carotenoids, the consumption of pistachios, in particular, has been found to decrease several markers of oxidative stress and inflammation. These include interleukins and cytokines.

Nutrient Absorption and Gut Health

Pistachios provide a rich source of both polyunsaturated and monounsaturated fatty acids. These fatty acids act as a carrier for other important nutrients contained within the pistachio nut, such as the fat-soluble vitamins A, D, E, and K, as well as antioxidant-promoting polyphenols.

There has been interest in pistachio and other nuts' effect on gut health and the gut microbiome (bacteria in your gut). Because nuts are high in fiber as well as poly and monounsaturated fatty acids, there is a belief that nuts could act as a prebiotic (a beneficial fiber) once digested, thereby creating a more robust microbiome.

Two systematic reviews and meta-analyses came to somewhat conflicting evidence of whether nut consumption improves the gut microbiota. One found a modest association between nut consumption and microbiota diversity (a measure of gut health), especially an increase in bacteria that produce short-chain fatty acids.

The other analysis found fewer clear associations across multiple studies, thus necessitating further exploration into whether nut consumption produces a positive impact on gut health.

Are Pistachios Good for Me?

The evidence above suggests that pistachios are indeed good for you. They can be a healthful addition to just about any diet.

However, it is essential to avoid pistachios if you're allergic to them or their components (parts). Seek immediate medical attention if you have a severe allergic reaction (itching, hives, shortness of breath). Those with known tree nut allergies should avoid consuming pistachios.

Summary

Pistachio nuts are members of the Pistacia genus, which belongs to the Anacardiaceae family. There is evidence of pistachios being used in many ancient cultures, and they are one of the only two nuts mentioned in the Bible.

Pistachios are rich sources of protein, fiber, and healthy fats. They also contain high levels of many vitamins, particularly carotenoids, vitamin B6, vitamin E, and folate. They also contain minerals like potassium, magnesium, calcium, and selenium.

As far as health benefits, pistachios are very heart-healthy. Additionally, they aid in weight management and blood sugar regulation. The carotenoids in pistachios reduce oxidative stress, and the fiber and fats in pistachios benefit nutrient absorption and, possibly, gut health.

The evidence above suggests that pistachios are indeed good for you. They can be a healthful addition to just about any diet. Those with known tree nut allergies should avoid consuming pistachios.

Read the original article on Verywell Health.