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Nuts — A Guide to Each One

A daily handful of nuts is one of the most evidence-backed habits in nutrition. But each nut has its own strength — from the walnut's omega-3 to the Brazil nut you should ration. Here's what each one is really good for.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden) Last reviewed June 2026 Reference guide

Nutrition basicsNutsHeart health

Nuts pack unsaturated fat, plant protein, fibre, vitamin E, magnesium and polyphenols into a small package. In the large PREDIMED trial, a Mediterranean diet enriched with 30 g of mixed nuts a day cut major cardiovascular events,1 and large cohort studies link regular nut eating to lower mortality.2 They genuinely help lower LDL when they replace less healthy snacks (see LDL & your heart).

How much? A portion is about a small handful (~30 g) a day. Choose raw or dry-roasted, unsalted where you can — heavily salted or sugar/honey-glazed nuts undo a lot of the benefit. Whole nuts beat nut "snacks." And yes, nuts are calorie-dense (~160–200 kcal per handful) — but in trials they rarely cause weight gain, partly because they're filling and some fat isn't fully absorbed.

Almond

Vitamin E championMagnesium · fibre
A bowl of raw whole almonds, one split open showing the pale interior
Raw almonds — skin-on "natural" almonds keep the most polyphenols.

Richest in: vitamin E — a handful gives most of a day's needs — plus magnesium, fibre and plant protein. Mostly monounsaturated fat.

Good for: lowering LDL cholesterol, blood-sugar steadiness and skin (vitamin E is a key antioxidant). One of the best all-round everyday nuts.

Note: the skin holds many of the polyphenols, so "natural" (skin-on) beats blanched. Almond flour is a useful low-carb baking swap.

Walnut

Plant omega-3 (ALA)Brain & heart
Walnut halves and a cracked walnut in its shell
Walnuts — the top plant source of omega-3 ALA among nuts.

Richest in: ALA omega-3 — by far the highest of any common nut — plus polyphenols and the antioxidant ellagic acid.

Good for: heart health and the one most studied for brain/cognition. The ALA is a plant omega-3, though the body only partly converts it to the EPA/DHA you get from oily fish.

Note: that omega-3 makes walnuts oxidise (go rancid) faster than other nuts — store cool and sealed, ideally in the fridge.

Brazil nut

Extreme seleniumRation: 1–2/day
Shelled Brazil nuts with two still in their dark shells
Brazil nuts — a single kernel can cover a full day of selenium.

Richest in: selenium — to an extreme. A single Brazil nut can contain ~70–90 µg, already around or above a full day's requirement (~55–70 µg).

Good for: thyroid function and antioxidant defence (selenium feeds glutathione peroxidase). One or two nuts is a tidy way to top up selenium.

Caveat — this matters: because they're so concentrated, eating a handful daily can push you toward selenium toxicity (the upper limit is ~300–400 µg/day) — hair loss, brittle nails, nausea, nerve issues. Stick to 1–2 a day, not a bowlful.3

Cashew

Copper · magnesium · ironLower in fat
Raw cashew kernels piled in a small bowl
Cashews — creamy texture, more carbohydrate than most nuts.

Richest in: copper, magnesium, iron and zinc — a good mineral nut. Creamier and slightly higher in carbohydrate, lower in fat than most nuts.

Good for: minerals (useful plant iron/zinc source) and making smooth dairy-free sauces and "cheeses."

Note: always sold shelled and roasted — the raw shell contains an irritant oil (related to poison ivy). The slightly higher carb content is worth knowing if you watch blood sugar.

Hazelnut

Monounsaturated (oleic)Vitamin E · folate
Hazelnuts in shells and shelled round kernels
Hazelnuts — rich in monounsaturated fat, vitamin E and folate.

Richest in: oleic acid (the same monounsaturated fat as olive oil), plus vitamin E, folate, manganese and copper.

Good for: heart-friendly fats and a favourable LDL effect. Antioxidant-rich, especially with the skin on.

Note: mostly met in sugary chocolate spreads — those are confectionery, not health food. Whole or as pure 100% hazelnut butter is the way to get the benefit.

Pistachio

Protein · potassiumEye antioxidants
Pistachios in split shells revealing green kernels
Pistachios — shelling them slows you down, a built-in portion brake.

Richest in: protein and potassium for a nut, plus lutein and zeaxanthin — the antioxidants that protect the eyes — which most nuts lack.

Good for: heart health, blood pressure (potassium) and eye health. Lower in calories per nut than most.

Note: buying them in the shell is a built-in portion brake — the effort and the pile of empty shells naturally slow you down.

Pecan

Very high antioxidantsMonounsaturated
Pecan halves and a whole pecan in its oval shell
Pecans — among the highest antioxidant loads of any nut.

Richest in: polyphenol antioxidants — among the highest of all nuts — and mostly monounsaturated fat, with manganese and zinc.

Good for: antioxidant intake and heart-healthy fats.

Note: rich and buttery, with one of the higher fat (and calorie) contents — easy to over-eat, and usually drowned in sugar as pecan pie. Enjoy them plain.

Macadamia

Most monounsaturatedHighest calories
Creamy macadamia kernels with one nut in its round shell
Macadamias — the highest monounsaturated-fat share of all nuts.

Richest in: monounsaturated fat — the highest proportion of any nut, including rare omega-7 (palmitoleic acid). Low in carbs and protein.

Good for: a keto/low-carb favourite thanks to the high fat, low carb profile, and good for heart-friendly fats.

Note: the most calorie-dense common nut (~200+ kcal per small handful) — portion awareness matters. Also toxic to dogs, so keep them away from pets.

Peanut

High protein · cheapTechnically a legume
Peanuts in pods and shelled kernels with red skins
Peanuts — botanically a legume, nutritionally a nut.

Richest in: protein (the highest of the "nuts"), niacin (B3), folate and the polyphenol resveratrol. Botanically a legume, but nutritionally it sits with the nuts.

Good for: an affordable, protein-rich option with the same heart benefits as tree nuts in studies. Choose 100% peanut butter (just peanuts ± salt), not the kind with added sugar and palm oil.

Caveats: a common, sometimes severe allergen; and poorly stored peanuts can carry aflatoxin (a mould toxin) — buy from reputable brands and discard any that taste musty or look mouldy.

Pine nut

Vitamin E · vitamin KMagnesium
Pine nut kernels in a wooden spoon beside a small pine cone
Pine nuts — the small kernels behind pesto, rich in vitamin E and magnesium.

Richest in: vitamin E and vitamin K, magnesium and the antioxidant lutein. Delicate and buttery (think pesto).

Good for: a flavourful garnish that adds healthy fats and fat-soluble vitamins to salads and pasta.

Note: expensive, and some people (usually after certain imported varieties) get "pine mouth" — a harmless but odd metallic/bitter taste lasting a few days. It passes on its own.

At a glance

NutStands out forBest for
AlmondVitamin E, magnesiumAll-round daily nut, LDL
WalnutALA omega-3Brain & heart
Brazil nutSelenium (extreme)Thyroid — 1–2/day only
CashewCopper, iron, zincMinerals, creamy cooking
HazelnutOleic fat, vitamin EHeart-friendly fats
PistachioProtein, potassium, eye antioxidantsBP, eyes, portion control
PecanAntioxidantsAntioxidant intake
MacadamiaMonounsaturated fatKeto/low-carb (high cal)
PeanutProtein, niacin (cheap)Budget protein
Pine nutVitamin E & KFlavour garnish

Sensible cautions: tree nuts and peanuts are among the most common serious allergens — never push nuts on anyone with a known allergy. Whole nuts are a choking hazard for young children (use nut butters thinly spread instead). Ration Brazil nuts for the selenium. And favour unsalted versions — salted nuts add a lot of sodium.

Bottom line: a daily handful of mixed, unsalted nuts is a genuinely evidence-backed habit for the heart. Variety wins — almonds for vitamin E, walnuts for omega-3, pistachios for potassium and eyes — with Brazil nuts the one exception you keep to one or two a day.

✓
Bodil Isaksson, Licensed Biomedical Scientist (Sweden)

At Food Health Lab we explain what the science says in plain language, and we cite our sources so you can check for yourself.

References

  1. Estruch R, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts (PREDIMED). N Engl J Med, 2018. NEJMoa1800389
  2. Aune D, et al. Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis. BMC Medicine, 2016. BMC Medicine
  3. National Institutes of Health, Office of Dietary Supplements. Selenium — Health Professional Fact Sheet (Brazil-nut selenium content and tolerable upper intake level). ods.od.nih.gov

This guide summarizes nutrition evidence for education. It is not a substitute for individual medical or allergy advice.

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