Unsaturated fats: what they are, benefits and the richest nuts

Fats have had a bad reputation for decades, but science has spent years correcting itself. Not all fats are the same, and unsaturated fats —found naturally in nuts— are today recognised as one of the most valuable nutrients for the body. If you've been hearing about them for a while but aren't quite sure what sets them apart from saturated fats, this article explains it with data and no fluff.

Unsaturated fats are fatty acids characterised by having one or more double bonds in their molecular chain. That structure gives them unique properties that saturated fats —the ones abundant in processed animal products— don't have. Their origin is mainly plant-based, and nuts are one of their best representatives in the Mediterranean diet. If you've already read our article on omega-3 in nuts, you'll know that part of the magic of walnuts has to do precisely with this type of fat.

Within unsaturated fats there are two large families: monounsaturated fats —with a single double bond— and polyunsaturated fats —with two or more. Both are beneficial, but they have distinct profiles, sources and functions that are worth understanding separately. In this article you'll find the full picture; in the articles dedicated to each type, the detail you need to optimise your intake.

At nutnut we've spent years selecting nuts for their nutritional quality, and unsaturated fats are one of the main reasons this food deserves a permanent place in your diet. The artisanal roasting process we use is designed to preserve exactly that lipid profile that makes nuts so special.

What unsaturated fats actually are

Chemically, an unsaturated fat is a fatty acid with at least one double bond between carbon atoms. At room temperature these fats are liquid or semi-liquid —think of olive oil—, whereas saturated fats are solid —think of lard. In nuts they're integrated into the food's matrix, but their profile is just as favourable.

Monounsaturated fats have a single double bond; polyunsaturated fats have two or more. Both are known as "good fats" because the body can't synthesise them in sufficient quantity and needs to obtain them from the diet. When you replace saturated fats with unsaturated ones, cardiovascular health markers improve consistently, as shown by the scientific literature built up around the Mediterranean diet.

Benefits of unsaturated fats backed by science

The most documented benefit is the improvement of the lipid profile. Unsaturated fats help to lower LDL cholesterol —the so-called "bad" one— and to maintain or raise HDL —the "good" one. That rebalancing reduces the risk of arteriosclerosis and cardiovascular disease, which remain the leading cause of death in Western countries.

Beyond the heart, these fats have notable anti-inflammatory effects, especially the polyunsaturated fats of the omega-3 family. Chronic low-grade inflammation lies behind many metabolic diseases, from type 2 diabetes to certain types of cancer. Including regular sources of unsaturated fats is one of the dietary strategies with the most evidence for keeping it in check.

The nervous system also benefits. The cell membranes of neurons are partly made up of unsaturated fatty acids. A diet rich in these nutrients is associated with better cognitive function, better memory and a lower risk of neurological decline with age. If you do sport, these fats also improve insulin sensitivity and contribute to more efficient muscle recovery —aspects we also develop in the article on BCAAs in nuts.

Finally, unsaturated fats aid the absorption of fat-soluble vitamins: A, D, E and K can't be absorbed properly without fat. Eating nuts alongside other plant foods boosts the bioavailability of many micronutrients throughout the day.

Which nuts have the most unsaturated fats (ranking per 100 g)

The following ranking includes the sum of monounsaturated and polyunsaturated fats per 100 grams of nut. The figures are approximate, as they vary depending on variety, origin and processing.

1. Macadamia: ~60.4 g/100 g

Macadamia tops the ranking thanks to its very high content of oleic acid —the same fat that makes olive oil famous. More than 95% of its fats are unsaturated, with a profile very similar to that of extra virgin olive oil. A nutritional luxury in the form of a nut.

2. Walnuts: ~56.1 g/100 g

Walnuts are the reference nut for polyunsaturated fats, especially omega-3. With almost 47% of their weight in polyunsaturated fats, they have no rival in that category. They're the perfect complement to nuts rich in monounsaturated fats for achieving a complete lipid profile.

3. Hazelnuts: ~53.6 g/100 g

Hazelnuts combine a very high content of oleic acid —almost 46 g/100 g— with a good presence of vitamin E, which protects those same fats from oxidation. They're one of the most efficient nuts if you want to maximise the monounsaturated profile.

4. Pine nuts: ~53.1 g/100 g

Pine nuts are a surprise in this ranking. They have a very balanced profile between monounsaturated (~19 g) and polyunsaturated (~34 g) fats, which makes them a versatile source for diversifying the type of unsaturated fats you take in.

5. Almonds: ~43.9 g/100 g

Almonds are the most popular nut and have a very solid unsaturated fat profile, with oleic acid as the protagonist. Their combination of monounsaturated fats, vitamin E and magnesium makes them one of the most complete options for cardiovascular health.

6. Peanuts: ~40.3 g/100 g

Peanuts have a very balanced unsaturated profile and are, in addition, the nuts with the highest protein content. An ideal combination for those looking for satiety and dense nutrition in a single source.

7. Pistachios: ~38.2 g/100 g

Pistachios have a solid content of unsaturated fats, but their real differentiating value lies in the breadth of their nutritional profile: they provide protein, fibre, potassium, vitamin B6 and antioxidants such as lutein in proportions that no other nut can match all at once. Nutritionally, they're among the most complete.

8. Brazil nut: ~33.7 g/100 g

The Brazil nut combines its unsaturated fats with the highest natural concentration of selenium known in the diet. Just 2-3 pieces a day cover the daily requirement of this antioxidant mineral, and its lipid profile combined with methionine —as we saw in the article on methionine in nuts— makes it a unique complement within any mix.

9. Cashews: ~31.8 g/100 g

Cashews close the ranking with a profile oriented towards monounsaturated fats, similar to almonds but with a creamier flavour. They're excellent for sauces and preparations where other nuts don't fit as well.

Unsaturated fats vs. saturated fats: not all fat is the same

The current recommendation from the main public health bodies is clear: replace saturated fats with unsaturated ones whenever possible. That doesn't mean eliminating all saturated fat —they also serve functions in the body—, but rather shifting the balance in favour of unsaturated fats.

Nuts do this naturally. A handful of almonds or pistachios provides mostly unsaturated fats with a small saturated fraction. Processed meat, industrial pastries or full-fat dairy, on the other hand, have the inverse balance.

Trans fats —the worst for cardiovascular health— are not present in nuts. They're a product of the industrial hydrogenation of vegetable oils. Avoiding them is as simple as prioritising foods in their most natural possible state.

How to incorporate unsaturated fats into your daily routine

The good news is that you don't need to calculate anything. A couple of handfuls of nuts a day already places you in an optimal intake range according to Mediterranean diet guidelines.

Breakfast: add almonds or hazelnuts to your bowl of oats or yoghurt. Their fat slows down the absorption of sugars and provides you with sustained energy throughout the morning.

Mid-morning or afternoon snack: pistachios or a mix of walnuts and cashews. Filling, natural and with a very complete unsaturated fat profile.

Post-workout: combine Brazil nuts with almonds. As well as unsaturated fats, you get selenium, magnesium and protein for muscle recovery.

Dinner: walnuts on a salad or worked into a sauce. Their omega-3 fatty acids —polyunsaturated— have an anti-inflammatory effect that's especially interesting during the night-time hours, when the body repairs tissues.

nutnut's nuts are roasted artisanally in small batches, with no added oils and no additives. That process preserves the unsaturated fat profile that makes them so valuable —and that you now know how to identify and make the most of.