Go Nuts for Nuts, but what are nuts?
Nuts have been a part of our diet since prehistoric times (1). The healthiest nuts are very nutrient-dense, rich in unsaturated fat, high-quality protein, fiber, minerals, and phytonutrients (such as tocopherols, phytosterols, and phenolic compounds) (2). They are low in glycemic index and have a relatively low carbohydrate content (3). The consumption of nuts is associated with reduced risk factors for chronic disease (4).
What are the Health Benefits of Eating Healthy Nuts?
They decrease total mortality, decreased cardiovascular disease, and cancer mortality (5, 6, 7). They also reduce the incidence of coronary heart disease and gallstones. Specifically, one daily serving (30 g) of mixed nuts resulted in a 30% reduction in cardiovascular disease (CVD) and a 46% reduction in stroke (8). Compounds in nuts may have antiarrhythmic properties (which suppress abnormal rhythms of the heart (cardiac arrhythmias), such as tachycardia), which is preventive of sudden cardiac death (9). This is similar to the effect of polyunsaturated fats (PUFAs) found in fish oil. These compounds are mainly found in walnuts (10) and (11).
Nut intake has a cholesterol-lowering effect. Many studies have found beneficial effects of all nut types on cholesterol, with a dose-dependent decrease in total and LDL cholesterol (12). Nuts can reduce the risk of metabolic diseases such as diabetes. They modulate glucose and insulin metabolism and can positively influence Type 2 Diabetes (13). They contain fiber, fat, minerals, and other bioactive molecules that modulate several gene mechanisms at the cellular level, which explains some of their favorable effects (14). Nuts are helpful for metabolic syndrome, by showing a modest decrease in triglycerides and fasting glucose and a tendency to smaller waist circumference (15). Nuts have favorable effects on hypertension, cancer, and inflammation.
There is an inverse association between nut consumption and total cancer risk, i.e., the more nuts eaten resulted in lower cancer risk (16). Nuts have beneficial effects on oxidative stress, inflammation, and vascular reactivity. Blood pressure, abdominal fat, and metabolic syndrome appear to be positively influenced by nut consumption. Nuts are unlikely to contribute to obesity and may even help in weight loss, despite being high in calories (17) and (18). The lack of weight gain after consuming nuts is likely due to their very satiating effect (19). Nuts are anti-aging and have been shown to increase cognitive function (20). Consuming walnuts at least once per week was associated with 19% lower risk of CVD and at 17% lower risk of stroke (21). This suggests that walnuts prevent the formation of fatty deposits in the arteries, probably due to the alpha-linolenic acid content (22). Eating peanuts (not peanut butter) at least twice per week was associated with a 13% lower risk of CVD and a slight reduction in stroke risk (23). Peanut butter is not typically cardioprotective because it is often processed with added sugars.
Tree vs. Ground Nuts
Most nuts grow on trees and bushes, but some nuts grow underground. Tree nuts include almonds, Brazil nuts, cashews, chestnuts, macadamia nuts, hazelnuts, pecans, pine nuts, pistachios, walnuts, pili nuts, and baruka nuts. Groundnuts grow underground. Peanuts are a legume, grow underground, and are not considered a tree nut (24). Tiger nuts are tubers, like sweet potatoes, and grow in the ground.
Which are the Healthiest Nuts?
Most studies of healthy nuts have looked at the benefits of all nuts on CVD risk and overall health, so there is little information on specific nut types (25). We mentioned earlier the specific benefits of walnuts and peanuts for CVD health and stroke risk. We recommend getting a good variety of all the different and delicious types of nuts. There is no need to focus on one or two nuts only. In nutrition, variety is the healthiest approach to eating.A few exciting and lesser-known nuts are pili nuts, tiger nuts, and baruka nuts.
Pili nuts have monounsaturated fats and, like other nuts, can lower bad cholesterol and reduce the risk for heart disease (26). They contain the highest source of magnesium of nearly any nut, which can help with blood pressure and bone health. They also contain phosphorous, another mineral involved in bone health, which makes them one of the world’s healthiest nuts. Tiger nuts are tubers rich in fibers, vitamins, minerals (calcium, magnesium, potassium, sodium, phosphorous, and zinc), and other beneficial plant compounds. Baruka nuts are a great source of fiber and vitamin E, with 32% of the daily recommended intake of each. They contain magnesium, potassium, iron, and zinc and are high in antioxidants.
Which Nuts are the Best and Worst for Sustainability?
Hazelnuts are a sustainable nut. They use less water than other nut crops, are drought resistant, and help prevent soil erosion (27). They sequester carbon as their extensive root systems help build and increase organic soil matter, sequestering carbon from the atmosphere (28).
Brazil nuts increase forest diversity in the Amazon because they need to be grown with other plants (29). They don’t grow well without their natural, diverse ecosystem around them, and this diversity is good for the soil and ecosystem (30).
Peanuts are a sustainable crop. They release nitrogen into the soil as they grow, which replenishes the soil. Farmers can use less fertilizer for other crops planted in the same plot (31). They are also a rotation crop and help to reduce soil erosion. Peanuts are also a deep-rooted crop. This allows them to draw water from deep down, decreasing the need for irrigation water (32).
Almonds need a lot of water to grow. It takes approximately 15 gallons of water to produce 16 almonds, making almonds one of the most water-intensive crops in California, where they are grown (33). Pesticides are also used in the production of commercial almonds (34). Residues of 9 pesticides have been found on almonds, 5 of which are toxic to honey bees (35). Not only is this harmful to the environment, but nutritionally, we do not want to be eating foods high in toxic pesticides, which will damage our gut and overall health.
Walnuts and Pistachios are almost equally water-intensive crops, contributing to the issues of water shortage and drought in California (36).
Cashews: production has, in the past, violated human rights. They are primarily grown in India and Vietnam and are challenging harvesting. Cashew nuts have layers that need to be discarded, and those layers are toxic (37). People whose job it is to shuck cashews have frequently suffered permanent damage from the toxic liquid that the shells release (38). It is best to ensure that your cashews come from a fair-trade source that treats its workers well.
Health Concerns with Eating Nuts
High nut calories
Nuts are a little high calorie, so be moderate. The research does say that nuts are highly satisfying and do not cause weight gain (41). What is the correct portion size of nuts? A portion of nuts is 30g or a small, cupped handful, which is about 175 calories. Or you can determine a serving size by measuring out 1.5 oz or 1/4 cup of nuts.
Nut allergies in healthy nuts
Nut allergies are becoming more prevalent and affect approximately 1% of the US population (42, 43, 44). The incidence of food-induced anaphylaxis is also increasing in young children (45). Anaphylactic shock is an immediate and severe allergic reaction to an allergen. It is a critical condition that can be fatal if not treated immediately. In one study done on preschool-age children, the nuts most likely to cause anaphylactic reactions were cashews, walnuts, pine nuts, hazelnuts, and almonds (46).
Anti-nutrients in the healthy nuts
Some of the healthiest nuts contain antinutrients, which interfere with and disrupt the absorption of proper nutrients (47). These are compounds including phytic acid or phytates, lectins, and oxalates. These compounds bind up minerals and reduce the absorption of iron, zinc, magnesium, calcium, and other nutrients. Some people develop a sensitivity to these antinutrients. Peanuts may contain aflatoxins. These are toxins sometimes found on corn, peanuts, cottonseed, and tree nuts. Eating aflatoxin-contaminated food can cause adverse health effects, including liver cancer (48). Nuts that appear moldy, discolored or shriveled are probably affected and are best avoided.
To reduce these antinutrients in healthy nuts, make sure you choose raw, organic, fresh-looking nuts. You can soak them in water overnight and then dry them out on a dishtowel the next day. But be careful that they dry out and don’t go moldy as you don’t want to eat moldy food. Roasting nuts yourself is another option to reduce the phytates and other antinutrients. You can dry, roast them in the oven or in a pan, add a little salt or spices like cumin, turmeric, and others to add some additional flavor. Sprouting and fermenting are other methods of reducing antinutrients, but these are less relevant with nuts. It is better to soak or roast nuts yourself as it is best to eat unprocessed nuts (49). Processed nuts are often made with rancid inflammatory oils and poor-quality salts.
It is impossible to avoid all antinutrients in the diet, and nuts are still healthy food. Just be aware of this fact and be sure to eat a well-rounded diet that includes, but does not solely focus on, nuts.
Nuts are a superfood. They can be part of any healthy diet to protect cardiovascular health, support healthy aging, and provide other benefits. A handful of mixed nuts can be an excellent post-workout or anytime snack. Choose various nuts to get the full benefits and great tastes of all nuts. Go nuts for healthy nuts!