Nuts and cholesterol: which ones help lower it

Few nutritional recommendations have as much scientific backing as including nuts in your diet to manage cholesterol. This is neither a fad nor an exaggerated headline: it is one of the most consistent lines of research in cardiovascular nutrition from the last thirty years, with studies conducted in Spain as well. At nutnut, we believe it is worth explaining the "why" in detail, going beyond the simple headline that "eating nuts lowers cholesterol."

This article does not replace the assessment of a cardiologist or an endocrinologist: if you have high cholesterol, diet is an important tool, but it must be part of medical follow-up, especially if you are already taking lipid-lowering medication.

A quick note on LDL and HDL cholesterol

LDL cholesterol, popularly known as "bad cholesterol," transports cholesterol to the tissues and, in excess, tends to deposit on arterial walls, contributing to the formation of atheroma plaques. HDL cholesterol follows the reverse path, removing cholesterol from the tissues and transporting it back to the liver, which is why adequate levels are considered protective. The goal of a heart-healthy diet is not to eliminate cholesterol, but to improve the balance between the two.

How nuts help improve the lipid profile

Substituting saturated fats with unsaturated ones

The most direct mechanism is also the simplest: when nuts replace foods rich in saturated fats in the diet (pastries, processed meats, fried snacks), the overall fat profile of what you eat improves. The monounsaturated and polyunsaturated fats in nuts tend to reduce LDL cholesterol when they take the place of those saturated fats, rather than just being added to the usual diet.

Soluble fiber

A portion of the fiber in nuts is soluble, and this fraction binds to bile acids in the intestine, forcing the liver to produce more from the cholesterol circulating in the blood. This is a modest mechanism on its own, but it adds to the other factors.

Phytosterols

Nuts contain phytosterols, plant compounds with a structure very similar to cholesterol that compete with it for absorption in the intestine, thus reducing the amount of cholesterol that ends up in the blood. Pistachios are among the nuts with the highest phytosterol content.

Antioxidants and polyphenols

LDL cholesterol is only particularly harmful to the arteries when it becomes oxidized. The antioxidants present in nuts, especially in the skins of almonds and walnuts, help protect LDL particles against this oxidation, a mechanism that complements, rather than replaces, the reduction of total cholesterol levels.

What scientific evidence says: the PREDIMED study

The PREDIMED (PREvention with DIeta MEDiterránea) trial, conducted in Spain with more than 7,000 participants at high cardiovascular risk, is one of the most cited nutrition studies worldwide. It compared a Mediterranean diet supplemented with extra virgin olive oil or a daily handful of nuts (walnuts, almonds, and hazelnuts) against a low-fat control diet.

The results, published in the New England Journal of Medicine, showed a significant reduction in the risk of suffering a serious cardiovascular event in the group that followed the Mediterranean diet with nuts, along with improvements in the lipid profile. To date, it is one of the most solid foundations for recommending the regular consumption of nuts as part of a Mediterranean diet pattern, and it has the added value of having been conducted specifically in the Spanish population.

Unsaturated fats in nuts: ranked from highest to lowest

The following ranking shows the grams of total unsaturated fats (monounsaturated plus polyunsaturated) per 100 grams of nut—the type of fat that, when substituting saturated fat, contributes most to improving the lipid profile. This is not a direct measure of "how much" each variety lowers cholesterol, but rather of the main mechanism behind that effect.

1. Macadamia: ~60 g/100 g

Macadamia tops the ranking in total unsaturated fats, with a profile especially rich in monounsaturated fat, similar to that of olive oil.

2. Walnuts: ~56 g/100 g

Walnuts are, by far, the nut with the most scientific evidence published specifically on LDL cholesterol reduction, also thanks to their content of plant-based omega-3s.

3. Hazelnuts: ~54 g/100 g

Hazelnuts stand out for their high content of monounsaturated fat, added to their richness in vitamin E, an antioxidant that protects LDL from oxidation.

4. Pine nuts: ~53 g/100 g

Pine nuts combine a good supply of unsaturated fats with habitual presence in the traditional Mediterranean diet.

5. Brazil nuts: ~48 g/100 g

Brazil nuts add an exceptional selenium content to their fat profile, a mineral with antioxidant function.

6. Almonds: ~44 g/100 g

Almonds, widely studied alongside walnuts in clinical trials on cholesterol, combine unsaturated fat with soluble fiber and vitamin E.

7. Peanuts: ~40 g/100 g

Although botanically legumes, peanuts provide a notable amount of unsaturated fat, with studies supporting their role within a heart-healthy diet.

8. Pistachios: ~37 g/100 g

Pistachios, despite not topping this specific ranking, are among the nuts with the highest content of phytosterols, the most specific mechanism for reducing intestinal cholesterol absorption.

9. Cashews: ~35 g/100 g

Cashews close the ranking in total unsaturated fats, though they still provide an interesting mineral profile of iron and magnesium.

How to incorporate nuts if you are concerned about cholesterol

• Breakfast: walnuts or almonds, the two varieties with the most specific clinical studies on cholesterol, on yogurt or oatmeal.
• Mid-morning snack: pistachios, for their phytosterol content, instead of ultra-processed snacks.
  
• Lunch: chopped hazelnuts on a salad, instead of dressings with saturated fats.
  
• Light dinner: a small handful of macadamia or Brazil nuts, within the recommended daily serving of 25-30 grams.

The key point, beyond choosing one variety or another, is substitution: the benefit to cholesterol occurs primarily when nuts take the place of foods with saturated fats, not when they are simply added to a diet that does not change. At nutnut, we roast each variety artisanally and without added oils, so that this favorable fat profile reaches your plate intact.