Health authorities around the world recommend eating more plant foods, including nuts, for good health.

Nuts are like nature’s own vitamin supplement – a small package containing a unique combination of at least 28 different essential nutrients.

Regularly eating nuts has been shown to contribute to heart health, reduce overall mortality and the risk of developing type 2 diabetes, assist with weight management, reduce the risk of cancer, improve sperm quality, reduce depression and overall promote good health.

Healthy dietary patterns include nuts 

The traditional Mediterranean dietary pattern, which includes plenty of plant foods (like vegetables, fruits, whole grains, legumes, nut, seeds, and olive oil), is considered to be one of the healthiest in the world. 

The EAT-Lancet Commission on Food, Planet and Health report highlights that a diet rich in plant-based foods confers both health and environmental benefits [1].

It suggests that transforming to healthy diets by 2050 requires global substantial shifts, including more than doubling consumption of healthy foods like nuts, fruit and vegetables, and legumes.

Nuts have long been linked with good health

Their role in heart health was established more than 20 years ago, following the publication of four major population studies [2-5]. Since then, nuts have been linked with a number of health outcomes including: 

• Reduced risk of cardiovascular disease and coronary heart disease [6]
• Preventing type 2 diabetes [7], and managing existing diabetes [8]
• Reduced risk of overweight and obesity [9]
• Reduced all-cause mortality (death) [6]
• Reduced risk of cancer [10]
• Improvements in brain health, including cognition, learning and memory [11-13]
• Improvements in sperm quality [14]
• Decreased risk of depression [15].

What is it about nuts that makes them so healthy?

Nuts are a nutrient-dense food, rich in many essential vitamins and minerals, and also contain mono- and polyunsaturated fatty acids, plant protein and dietary fibre. 

Generally, nuts contain:

• Healthy fats, especially the healthy mono- and polyunsaturated fats – essential for regulating blood cholesterol and serve as a carrier of fat-soluble vitamins. The majority of the fat in nuts is unsaturated, averaging over 85% of total fat.
• Omega-3 polyunsaturated fats. Omega-3 alpha-linolenic acid (ALA) is an essential fat which must be obtained from the diet and is necessary for growth and development, brain and nerve function, maintaining cell membranes and in regulating inflammation.  
  • Walnuts are particularly rich in ALA, with smaller amounts in pecans, hazelnuts and macadamias.
• Protein – required throughout life to create, maintain and renew body cells. It also plays a role in satiety, helping to satisfy hunger.
  • Nuts provide approximately 10-20g of protein per 100g
• Fibre – essential for maintaining a healthy bowel, helping to satisfy hunger, managing blood glucose levels and helping to lower blood cholesterol.
  • Nuts provide approximately 8g of fibre per 100g
• Vitamin E – an antioxidant that helps protect tissues from damage.
  • An average 30g serve of nuts provides around 20% of the RDI
• Folate – a B-group vitamin associated with heart health, and involved in cell structure.
• Magnesium – a mineral essential for good nerve and muscle function.
• Zinc – a mineral required for a strong immune system and healing and protecting the skin.
• Iron – a mineral involved in various bodily functions, including the transport of oxygen in the blood.

Most nuts also provide phytochemicals

Phytochemicals are the biologically-active compounds found in plants, including polyphenols, carotenoids, phytosterols, phytates, and lignans.

Studies have shown that these phytochemicals have antioxidant, anti-inflammatory, anti-mutagenic, and anti-cancer properties. This broad range of bioactivity of phytochemicals helps in preventing or slowing down aging and age-related diseases [16]. 

In addition to polyphenols, the presence of phytosterols, tocopherols, folic acid, L-arginine, low sodium, high calcium, magnesium, and potassium, and a good ratio of omega-3/omega-6 fatty acids among many other nutrients in nuts contribute to enhanced health and an increased lifespan.

How many nuts do we need?

The evidence supports dietary recommendations to eat a handful of nuts a day. And here in Australia, the Australian Dietary Guidelines define a serving of nuts as 30g.

Many studies on nuts and health have investigated a one ounce serving, or increments of an ounce serving of nuts (where an ounce is equivalent to 28g). And a major review concluded that a minimum of around 20g of nuts per day is linked with most of the disease risk reduction seen in research studies [6].

So, 30g (or a handful) of nuts a day is a good target.