When you’re looking for a snack, do you grab a bag of chips? Skip the chips and reach for a handful of nuts, one of the most nutrient-dense snacks you can eat. Beyond being a source of nutritional goodness, research finds that snacking on nuts lowers the risk of cardiovascular disease and all-cause mortality.
In fact, a study showed that munching on as little as 10 grams of nuts daily was associated with a 23% lower risk of mortality. They were also:
- 47% less likely to die from degenerative diseases of the nervous system
- 30% less likely to die from diabetes
- 21% less likely to die from cancer
- 17% less likely to die from cardiovascular disease
Those are good reasons to make nuts your “go-to” snack! When you buy nuts, you have two options. You can buy raw, uncooked nuts or roasted ones. You’ll probably discover the roasted ones taste better, but which is better for you?
All Nuts Have Health Benefits
All nuts are a source of healthy fats and fiber. Plus, they contain protein for added satiety. Another perk: Despite their high calorie content, studies show people who munch on nuts are less likely to be overweight or obese. In fact, research shows we don’t absorb all the fat in nuts, so the calorie content of nuts, like almonds and pistachios, is 15% to 20% lower than the quantity listed on the label.
Plus, the fats in nuts are the heart-healthy kind that is less likely to clog your arteries. Macadamia nuts are especially high in heart-healthy fats called monounsaturated fats.
Raw vs Roasted Nuts
Should you choose raw or roasted? Roasting nuts doesn’t significantly change their overall nutritional value. The fiber and protein content of raw and roasted nuts is similar. However, roasting nuts may subtly change their fats. Monounsaturated fats are relatively stable to heat, but polyunsaturated fats, the predominant fats in pecans and walnuts, oxidize when roasted at a high temperature.
One concern is that the oxidized fats might react with the inner walls of blood vessels through a process called lipid peroxidation and damage them, thereby increasing the risk of heart disease or stroke. However, this is more of a theoretical concern since studies link eating nuts with a lower risk of cardiovascular disease, regardless of whether they’re raw or roasted.
The longer a nut is roasted, and the higher the temperature, the more likely there is to be oxidation of the polyunsaturated fats in nuts. So, avoid buying nuts that are roasted to the point they’re dark in color since their fats may be oxidized. You won’t encounter this problem with raw nuts since they’re not exposed to heat. In fact, one study found that roasting walnuts to a high temperature increased fat oxidation by 17 times above the level in raw walnuts.
Roasted Nuts and Acrylamides
Another problem with roasted nuts is they’re higher in acrylamides, substances that form when you expose foods that contain the amino acid asparagine to high temperatures. Since nuts, particularly almonds, contain asparagine, roasting almonds increases the number of acrylamides you take in when you munch on them. One study found that almonds are highest in acrylamides, while hazelnuts have the lowest acrylamide content.
Why are acrylamides a problem? Studies link them with a higher risk of cancer in animals and are likely carcinogenic in humans too. Since raw nuts aren’t heated, acrylamides aren’t a problem. Acrylamides usually don’t form until the temperature rises above 240 degrees Fahrenheit.
Plus, some nuts are “roasted” in oil, but the term roasting is a misnomer. When you see oil in the ingredient list on a can of nuts, it usually means they’re “fried” in oil and may retain a lot of oil. The oils manufacturers use to make nuts aren’t typically healthy either. One way to avoid this is to look for dry roasted nuts. If nuts are dry roasted, you shouldn’t see oil listed in the ingredients.
Does Roasting Affect the Antioxidant Content of Nuts?
Some health benefits of nuts come from their high antioxidant content. How does roasting affect these free-radical fighters? It’s a mixed bag. Studies show roasting reduces the antioxidant activity of nuts slightly, but other antioxidants form during the roasting process. So, with roasted nuts, you lose some antioxidant benefits but also gain some. Depending on the roasting temperature, roasted nuts may contain slightly less vitamin B1 and vitamin E, although the loss varies with the type of nut.
The Bottom Line
Eating all types of nuts is better than munching on chips, but there are some advantages to buying raw nuts rather than roasted. You don’t have to worry about acrylamides or damaged fats with nuts in the raw, and there are no added oils. Raw nuts may also have slightly higher quantities of vitamin E and vitamin B1.
If you buy raw nuts, keep them in a dark, airtight container to protect them from light. Even light may cause slight fat oxidation. Also, look for nuts without added salt. You can add your own spices at home for salt-free flavor and enjoy them as a substitute for carbier snacks, like potato chips. Your body will thank you!
References:
- MedLinePlus.gov. “Facts about polyunsaturated fats”
- Nematollahi, A., Kamankesh, M., Hosseini, H. et al. Investigation and determination of acrylamide in 24 types of roasted nuts and seeds using microextraction method coupled with gas chromatography–mass spectrometry: central composite design. Food Measure 14, 1249–1260 (2020). https://doi.org/10.1007/s11694-020-00373-9.
- HealthLine.com. “Raw vs Roasted Nuts: Which Is Healthier?”
- Schlörmann W, Birringer M, Böhm V, Löber K, Jahreis G, Lorkowski S, Müller AK, Schöne F, Glei M. Influence of roasting conditions on health-related compounds in different nuts. Food Chem. 2015 Aug 1;180:77-85. doi: 10.1016/j.foodchem.2015.02.017. Epub 2015 Feb 11. PMID: 25766804.
- Amaral JS, Casal S, Seabra RM, Oliveira BP. Effects of roasting on hazelnut lipids. J Agric Food Chem. 2006 Feb 22;54(4):1315-21. doi: 10.1021/jf052287v. PMID: 16478254.
- Science Daily. “Eating nuts can reduce weight gain, study finds”
- Berkeley Wellness. “Are Nut Calorie Counts Wrong?”
- Prevention.com. “The Exact Number Of Nuts You Should Eat Every Day”
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