Nuts and seeds: nutrition, portions, storage, roasting, quality and differences between varieties.
Low-moisture nuts can still deteriorate because their fats oxidize. Airtight packaging, cool temperatures, and protection from moisture and strong odors make a major difference; chopped kernels generally have a shorter shelf life than whole ones.
Nuts freeze very well because they contain little water. At about 0°F (-18°C) in airtight packaging, cold storage greatly slows fat oxidation; UC Davis guidance gives up to roughly two years of good quality for several intact nut types.
Cashews and almonds are close in calories but far apart in fiber and carbohydrate. Per 100 grams, almonds provide about 21 grams protein and 12.5 grams fiber; cashews provide about 18 grams protein and 3.3 grams fiber with substantially more starch.
Rancidity is fat oxidation, not a calendar date. It often shows up as an abnormal odor or flavor—old oil, paint, cardboard, or a harsh lingering bitterness—before there is an obvious visual change. Dark nuts are not automatically rancid, and normal-looking nuts can still taste oxidized.
Pistachios clearly lead in protein and fiber by equal weight; walnuts lead even more dramatically in ALA, the main plant omega-3. A 1-ounce-style serving gives about 6 grams protein from pistachios versus roughly 4.5 grams from walnuts, while walnuts deliver around 2.6 grams ALA.
Flax and chia clearly stand out for ALA omega-3. NIH lists about 2.35 g ALA in a tablespoon of whole flaxseed and 5.06 g in one ounce of chia. Hemp also contributes ALA, but at a lower concentration.
Chestnuts break the usual nut pattern because they contain far less fat and much more water and starch. Among typical high-fat nuts, cashews and pistachios are near the lower end of calories per 100 g.
Hulled hemp is highly concentrated: about 31–32 g protein and 49 g fat per 100 g. One ounce provides roughly 9 g protein, 155 calories, ALA omega-3, and a substantial amount of magnesium.
Pumpkin seed kernels are nutrient-dense: roughly 30 g protein, 49 g fat, and more than 550 mg magnesium per 100 g. A 1-ounce serving is about 8–9 g protein and 160–170 calories.
Almonds and pistachios are closer nutritionally than their reputations suggest. A roughly 1-ounce serving of either delivers about 6 grams of protein; almonds have a little more fiber, while pistachios come in a few calories lower.
The most concentrated plant omega-3 foods provide mainly ALA. A 1 oz serving of flax provides about 6.4 g ALA, chia about 5 g, and walnuts about 2.57 g. The body converts only part of ALA into EPA and DHA; algae oil is a direct non-fish source of DHA and, depending on the product, EPA.
Yes. For most people, a daily 1 oz (28 g) serving of unsalted nuts can fit well in a healthy diet. The American Heart Association uses 1 oz as a standard serving. Depending on the nut, that portion provides roughly 155–200+ calories, so replacing another snack is different from simply adding nuts on top of everything else.