The health benefits of regularly eating nuts and seeds

Last Updated : 19 June 2024

Sprinkled on top of your morning porridge, a tasty crunch to your salads, or a quick and delicious on-the-go snack: adding more nuts and seeds not only brings extra flavour and texture to your meals but also many health benefits. This article explains the difference between nuts and seeds, if nuts and seeds count as 5-a-day, if nuts and seeds are good for you, and if it is okay to eat nuts and seeds every day.

What is the difference between nuts and seeds?

The definition of nuts and seeds varies depending on which classification system is used: botanical, culinary, or nutritional. Botanically speaking, nuts are a type of fruit containing an external inedible hard shell that accommodates the edible seed (kernel). According to this definition, hazelnuts and chestnuts are strictly nuts. However, nutrition research and dietary guidelines do not follow this definition and consider nuts as a broader category, based on their nutrient composition. This includes other nuts that are edible, for example, almonds, Brazil nuts, cashews, hazelnuts, macadamias, peanuts, pecans, pine nuts, pistachios, and walnuts. Coconuts and chestnuts are not included in this definition as chestnuts have a higher carbohydrate content than other nuts and coconuts have a higher amount of saturated fat. Peanuts which are botanically classified as legumes are often included, on the other hand, because they have very similar nutrient profiles to other tree nuts.

Seeds are (botanically speaking) encapsulated embryos of flowering plants. Examples of commonly consumed seeds (nutritional definition) are flaxseeds (linseeds), poppy seeds, pumpkin seeds, sesame seeds, sunflower seeds, and chia seeds. Many seeds are also grown primarily for the production of edible oils, for example, rapeseeds and sunflower seeds.¹

Takeaway

Although classification systems vary between what constitutes as nuts or seeds, they are very similar nutritionally speaking and are therefore often grouped together in dietary guidelines.

Do nuts and seeds count as 5 a day?

While nuts and seeds are nutritious and offer various health benefits, they do not count toward the 5-a-day recommendation. The 5-a-day guideline emphasises the importance of eating a variety of fruits and vegetables to ensure an adequate intake of essential vitamins, minerals, and fibre. Nuts and seeds are excluded from 5-a-day: (1) because of their high protein levels, leading to them being grouped with the meat, fish and ‘alternatives’ group instead of with fruits and vegetables, (2) they were seen as snack foods and intake was low in the early 1990s (when 5-a-day was developed), so the conclusion was that nuts would contribute little to the overall diet, and (3) because portions/serving sizes for nuts were not established at that time.²

However, there have been arguments calling for widening the 5-a-day recommendation to include nuts.²One of the reasons is that nuts are included within the category of fruits and vegetables in nutrient profiling models (e.g., Nutri-Score) which, in the view of the UK Food Standards Agency, recognises their contribution to a healthy balanced diet.³ Other arguments for including nuts and seeds in the recommendation highlight their health benefits and approved health claims.²

What nutrients do nuts and seeds contain?

Nuts and seeds have both a high nutrient-density and high energy-density. This means that although they contain a higher amount of calories per gram, they also have an overall high nutritional value. Nuts and seeds are high in protein, fibre, and monounsaturated and polyunsaturated fats (including omega-3 and omega-6 fatty acids). For example, a small handful of mixed nuts (25 g) contains, on average, 4.5 g of protein, 1.7 g of fibre, and 165 calories. Nuts and seeds are also rich in vitamins and minerals and a range of phytochemicals, such as polyphenolic compounds (e.g., phenolic acids, flavonoids), phytosterols, and carotenoids. Vitamins and minerals abundant in nuts and seeds include, for example, biotin, pantothenic acid, vitamin B6, thiamine, vitamin E, calcium, iron, magnesium, manganese, molybdenum, selenium.^4,5

The amounts and types of nutrients vary between different types of nuts and seeds. Therefore, one type of nut or seed is not better than the other. Because one type of nut contains a bit more iron and the other type a bit more vitamin E, it is recommended to eat a wide variety. Brazil nuts, in particular, are high in selenium. This mineral is, among other things, important for protecting our cells against oxidative damage, supporting our immune system, and keeping the healthy function of our thyroid. With a handful of Brazil nuts, you get more than the Acceptable Daily Intake (ADI) of selenium. However, this is not immediately cause for concern because the ADI has a large built-in safety factor and in practice, consumption above the ADI on one day is more than accounted for by consumption below the ADI on most other days. Another good reason to vary with nuts and seeds!

Nuts and seeds high in protein

Including a variety of nuts and seeds in your diet can be an excellent way to boost your plant-based protein intake. By incorporating a mix of nuts and seeds into your daily snacks or meals, you ensure that you not only enjoy the benefits of their protein content but also get a wide range of vitamins, minerals, and antioxidants. Also, including a variety of protein sources (like pulses, whole grains, nuts, seeds and soy products) throughout the day will allow you to combine and complement the different amino acids in the right balance.^6,7

Nuts and seeds high in fibre

Nuts and seeds are high in dietary fibre. Vary, for example, with almonds, chia seeds, flaxseeds, and walnuts to help you reach the recommended daily intake of fibre of 25 grams per day. Fibre gets fermented by our gut microbiota, producing short-chain fatty acids. These protect our health by improving insulin sensitivity and ensuring lower levels of glucose and lipids in our bloodstream. Over the long-term this might improve energy balance which indirectly protects against cardiovascular diseases, obesity, and type 2 diabetes.^8.9Fibre also plays an important role in improving gut health, maintaining the intestinal barrier integrity, and protecting against the risk of colorectal cancer.

Nuts and seeds high in iron

Many nuts and seeds are good sources of iron. For example, a portion (25 g) of poppy seeds, pumpkin seeds, or cashew nuts contributes 21%, 18%, and 15% to our dietary reference value (11 mg of iron per day), respectively. However, the type of iron found in plants and plant-based foods is mainly non-haem iron. Our bodies can absorb this type of iron less effectively than animal-based iron. Combining nuts and seeds with a source of vitamin C (e.g., an orange, raw pepper, kiwi) is a helpful strategy to better absorb their iron.

Nuts and seeds high in omega 3 fatty acids

Some nuts and seeds are high in essential omega-3 fatty acids, including walnuts, flaxseeds, chia seeds, hemp seeds, and rapeseeds (usually processed as rapeseed oil). However, the form of omega-3 fatty acids they provide is primarily alpha-linolenic acid (ALA). ALA is a precursor to the longer-chain omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), which are more readily available in sources like fatty fish and algae oil. DHA and EPA are considered important for various aspects of health, especially for brain health, eye health, and cardiovascular health.

Our body can convert ALA into EPA and DHA, but the conversion rates are relatively low. Therefore, while nuts and seeds contribute to omega-3 intake, they may not provide as much EPA and DHA as direct sources like fatty fish and algae oil. Therefore, supplementation may be required if you are solely relying on nuts and seeds are sources of omega-3 fatty acids to meet bodily needs.¹⁰

Table 1 – Nutritional composition of nuts and seeds: almonds (blanched), almonds (with skin), Brazil nuts, cashew nuts, chia seeds, flaxseeds, hazelnuts, hemp seeds, macadamia nuts, mixed nuts, peanuts, pecan nuts, pine nuts, pistachio nuts, poppy seeds, pumpkin seeds, sesame seeds, sunflower seeds, walnuts.⁵

Nuts and seeds	Kcal per 100 g of food	Grams of protein per 100 g of food	Grams of dietary fibre per 100 g of food	Milligrams of iron per 100 g of food	Grams of omega-3 fatty acids (ALA) per 100 g of food
Almonds (blanched)	631	21.7	7	3.3	0
Almonds (with skin)	622	25.4	10.2	3.3	0
Brazil nuts	687	14.3	7.5	3.1	0.02
Cashew nuts	615	21.2	3.8	6.7	0.05
Chia seeds	443	16.5	34.4	7.7	17.85
Flaxseeds	477	19	34.8	5.7	16.61
Hazelnuts	670	16.4	9	3.6	0.09
Hemp seeds	592	31.6	4	8	8.69
Macadamia nuts	753	7.8	8	2.7	0.2
Mixed nuts	658	18.1	6.7	6.7	0.3
Peanuts	627	25.2	6.8	1.9	0.05
Pecan nuts	721	9.2	9.6	2.5	0.98
Pine nuts	675	16.5	6.3	5.5	0.8
Pistachio nuts	592	23.8	9.5	4.3	0.18
Poppy seeds	455	19.2	24	9.4	0.23
Pumpkin seeds	574	30.3	8.5	8	0.14
Sesame seeds	632	22.7	8.9	5.8	0.15
Sunflower seeds	647	18	7.4	4.9	0.06
Walnuts	706	15.9	4.6	3.4	6.54

Are nuts and seeds good for you?

There is growing evidence that eating nuts and seeds regularly as part of a healthy diet and lifestyle may help to reduce the risk of many common diseases. A low intake of nuts and seeds (below 21 g/day) is one of the major leading dietary risk factors for the number of years lost due to ill-health, disability, or early death in Europe (ranked after diets low in whole grains, legumes, fruits and diets high in sodium and red meat). In 2019, a diet low in nuts and seeds was attributable to over 3.1 million disability-adjusted life years (or 1.02% of total disability-adjusted life years), a metric which represents the total burden of disease – both from years of life lost and years lived with a disability.¹¹ In other words, over 3.1 million years of healthy life were lost due to diets low in nuts and seeds.

Much of the literature has so far been focused on the health benefits of nuts. Seeds are often not assessed in observational studies and, to an even lesser extent, trials. However, due to their comparable nutrient profile to nuts, their health benefits are likely to be very similar.1 Regularly eating nuts and seeds is associated with a lower risk of premature deaths and various non-communicable diseases, including cardiovascular diseases, cancers, type 2 diabetes, and respiratory disease-mortality, and infectious-disease mortality.^1,12,13

Cardiovascular disease

Nuts and seeds are recommended to be eaten regularly to reduce cardiovascular disease (CVD) risk as they lower low-density lipoprotein cholesterol (LDL cholesterol) and improve the overall lipoprotein profile.13 High LDL cholesterol in blood is linked with an increased risk of CVD.15 Observational studies show that eating more nuts and seeds (~15-20 g/day) is associated with a lower risk of cardiovascular diseases (CVD) and CVD-related mortality, coronary heart disease and coronary heart disease-mortality, stroke mortality, and atrial fibrillation risk (compared to low consumption).^1,12,13,14

Nuts and seeds reduce several CVD risk factors such as blood lipids (e.g., total cholesterol, LDL cholesterol, triglycerides, and Apolipoprotein B), blood pressure, inflammation, and markers of glycaemic control, among others.^12,13 They may also be beneficial for weight management. The cardioprotective effects of nuts and seeds may be attributed to their unsaturated fatty acids, plant protein, phytosterols, fibre, vitamin, mineral, phenolic and bioactive content.

The European Food Safety Authority (EFSA) has also authorised a health claim for walnuts. This health claim states, ‘walnuts contribute to the improvement of the elasticity of blood vessels.’ Elastic, flexible blood vessels are a sign of a healthy cardiovascular system, while more stiff, inflexible blood vessels are a risk factor for disease. EFSA recommends a 30 g daily portion (in the context of a balanced diet).¹⁶

Cancer

Diets rich in fibre – found in foods such as nuts and seeds – help to lower the risk of developing bowel cancer.¹⁷ Diets high in nuts and seeds (~28 g/d) are also associated with a lower cancer-related mortality (compared to diets low in nuts and seeds). This is likely due to slight favourable improvements in inflammatory markers.¹²

Sometimes nuts may be contaminated by aflatoxins which is a mycotoxin produced by different types of moulds found especially in areas with hot and humid climates. There is strong evidence that foods contaminated by aflatoxins increase the risk of liver cancer. However, the EU and EFSA have set strict rules on the maximum levels of aflatoxins nuts can contain, and on the processing and distribution so that exposure to aflatoxins are minimised.¹⁸ As consumers, we can also minimise the risk from mycotoxins by storing our food properly. Aflatoxins are very stable chemical compounds and once they are formed they cannot be eliminated from the food.

Type 2 diabetes

There are some conflicting findings regarding the relationship between eating nuts and the risk of developing type 2 diabetes.¹² However, these associations might be influenced by differences in body weight. Nuts and seeds have been found to slightly reduce body weight, body mass index (BMI), and waist circumference. Weight gain is the most important risk factor for type 2 diabetes. Analyses that did not consider BMI found that eating nuts and seeds was associated with a lower risk of diabetes. This implies that the positive effect of eating nuts on diabetes risk might be partially explained by its potential role in reducing body weight. Other studies also show that nuts and seeds can improve other risk factors for type 2 diabetes such as blood glucose concentrations, glycaemic control, and insulin sensitivity.^12,19

Nuts and seeds for weight loss

Nuts and seeds can be included in a diet to support weight loss. Although nuts and seeds are relatively energy-dense foods, eating a handful of nuts per day is unlikely to contribute to overweight and obesity.²⁰ In fact, nuts have actually been found to contribute positively to feelings of fullness and reducing hunger. This is a likely explanation as to why nuts have been associated with a lower risk of overweight/obesity.¹² It is important, however, to be mindful of portion sizes. Another systematic review and meta-analysis concluded that a daily intake of 42.5 g of nuts could be included in the diet without contributing to weight gain.²¹

Takeaway

What type of nut or seed you choose, whether it’s almonds, walnuts, peanuts, pumpkin seeds, or sunflower seeds, all varieties appear to be similarly positively associated with health outcomes. So, opt for a variety of nuts and seeds that are affordable and available to you to reap their many benefits!

Is it okay to eat nuts and seeds every day?

Almost all European food-based dietary guidelines (FBDGs) recommend including nuts and seeds in your diet.²¹ The recommendations range from a daily intake to eating nuts and seeds one to two times per week. Most recommend a daily intake of approximately 30 g/day. This is equal to a small handful. The European Society of Cardiology and European Atherosclerosis Society also recommend eating nuts and seeds as a regular part of the diet due to their LDL-cholesterol lowering effect and overall lipoprotein benefits.²²

When choosing nuts and seeds, opt for unsalted and unsweetened varieties. To control portion size, it can be useful to take some out of the packet and put the rest away if you think you will be tempted to eat more. Nut/seed butter (e.g., peanut butter, almond butter, cashew butter, etc.) also counts towards your daily consumption of nuts and seeds as long as they contain no added salt, sugar or oils. This is because beneficial health associations are not seen for peanut butter, likely, because of added salt, sugar and/or oils which could negatively impact their health benefits as compared with whole sources of peanuts.¹³ Some plant-based milk alternatives are also based on nuts (e.g., almond drink, cashew drink), however, the actual amount of nuts they contain is very small so they are unlikely to contribute significantly to your daily nut or seed consumption.

Summary

Incorporating a variety of nuts and seeds into your diet provides numerous health benefits (for people without allergies to nuts). Nuts and seeds have a high nutrient-density, offering proteins, fibres, monounsaturated and polyunsaturated fats, and various vitamins, minerals, and phytochemicals. Despite being excluded from the 5-a-day recommendations, their positive impact on various non-communicable diseases and in weight management make them valuable additions to a healthy balanced diet.

Most European food-based dietary guidelines emphasise eating (unsalted and unsweetened) nuts and seeds in their recommendations. The key is to embrace variety to reap all their benefits.

Some helpful tips to include more nuts and seeds in your diet include:

• Take them in small containers as an easy on-the-go snack
• Sprinkle them on top of your breakfast: on porridge, yoghurt, or low-sugar cereal
• Add them as a topping to salads, curries, soups, or stir-fries
• Spread nut/seed butter on wholegrain bread or crackers, apple slices, or celery sticks
• Add a tablespoon of nut/seed butter in smoothies
• Add them into baked goods

References

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2. Public Health England. (2015). External reference group – 5 a day. Accessed 16 January 2024.
3. Department of Health. (2011). Nutrient Profiling Technical Guidance. Accessed 16 January 2024.
4. Balakrishna, R., Bjørnerud, T., Bemanian, M., Aune, D., & Fadnes, L. T. (2022). Consumption of Nuts and Seeds and Health Outcomes Including Cardiovascular Disease, Diabetes and Metabolic Disease, Cancer, and Mortality: An Umbrella Review. Advances in Nu
5. Dutch Food Composition Database (NEVO). (2021). NEVO-online version 2021/7.1. Accessed 16 January 2024.
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7. Grossmann, L., Weiss, J. (2021). Alternative Protein Sources as Technofunctional Food Ingredients. Supplemental Material: Annu. Rev. Food Sci. Technol. 12.
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11. HME. (2019). Global Burden of Disease.
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13. Glenn, A. J., Aune, D., Freisling, H., Mohammadifard, N., Kendall, C. W., Salas-Salvadó, J., ... & Sievenpiper, J. L. (2023). Nuts and Cardiovascular Disease Outcomes: A Review of the Evidence and Future Directions. Nutrients, 15(4), 911.
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