Nut health and nutrition Q&A with leading Dietitian Helen Bond

Nut health and nutrition Q&A with leading Dietitian Helen Bond

Have nuts supported our health and wellbeing amid a pandemic?

Following on from our September article, which investigated how the UK grocery retail sales of nuts was affected during the national Covid-19 lockdown (during April, May and June), we now turn to explore the nutritional and health benefits of nuts in a special Q&A feature. Specifically, we pinpoint some of the key nut health research, and health claims, which may help develop messaging, allowing nut growers and brands to connect more with consumers.

To get the latest and authoritative view about the nutritional and health benefits of nuts we have enlisted the contribution of leading Dietitian Helen Bond, BSc (Hons), RD, MBDA. Helen is a Registered Dietitian with 24 years’ experience in food, diet and its relationship to health. She is an active spokesperson for the British Dietetic Association (BDA) and is also fully registered with the Freelance Dietitians Group and the Health and Care Professions Council.

We put a series of nut health related questions to Helen to help extract exactly what it is about nuts that makes them a game changer.

We’ve gone nuts for nuts, especially during the recent pandemic UK national lockdown.

We’ve all gone nuts for nuts during lockdown – and for good reasons! But there are a series of questions, which need to be considered to understand why nuts should be an essential part of our daily diet. How can eating nuts help safeguard our health? How many should we be eating? And which nuts are the healthiest? We delve deeper into nut nutrition with Registered Dietitian Helen Bond and look at the reasons why nuts can benefit our health in so many ways.

The sales of nuts increased by a staggering 20 per cent over the COVID-19 lockdown period, according to recent grocery data released by the consumer research group Kantar (see the US-AgriEu article). The nations love affair with nuts during the national lockdown was at least in part, due to home baking, staying and cooking at home, but also because of the fight against cardiovascular disease (coronary heart disease is one of the most common pre-existing conditions for deaths involving Corona virus) and the weight of scientific evidence that has found them to be beneficial to our health and wellbeing.

Let’s get the Q&A started. Note, a full list of the references can be found at the bottom of the article and also here.

Q1 Can a handful of nuts a day help keep the cardiologist away?

Helen Bond (HB): Even doctors describe them as  “natural health capsules”, as Harvard researchers found that people who eat a handful of hazelnuts, cashews, pistachios or brazil nuts five or more times a week can cut their risk of heart disease by up to a quarter (Ref 1).  Several other studies including the Adventist Study (Ref 2), the Iowa Women’s Health Study (Ref 3), the Nurses’ Health Study (Ref 4) and the Physicians’ Health Study (Ref 5), have also shown a consistent 30 to 50 per cent lower risk of heart attacks, sudden cardiac death or cardiovascular disease associated with eating nuts several times a week (Ref 6). Although this type of study can’t actually prove that it was definitely the nuts that made the difference!

So perhaps the most compelling and established findings about the benefits of eating nuts for heart health comes from the landmark PREDIMED trial (Ref 7).  This large clinical trial among 7,000 Spanish people aged 55-80 years who were at a high risk of cardiovascular disease, but had no symptoms, were put into one of three diet groups and followed for a median of 4.8 years. The three diet groups were:

  • A Mediterranean diet plus 15g walnuts, 7.5g almonds and 7.5g hazelnuts a day.
  • A Mediterranean diet supplemented with at least 50g extra-virgin olive oil daily.
  • A low-fat diet control group.

The Mediterranean diet that included nuts was associated with a 30 per cent lower risk of heart attacks and strokes, when compared to the low fat diet. So compelling is the evidence, they are one of the few foods that have a medical backing as a health aid. Indeed, the US Food and Drug Administration (FDA) now allows some nuts and foods made with them to carry this health claim: “Eating 1.5 ounces per day of most nuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease”. And closer to home, the European Food Safety Authority (EFSA) has approved the following health claim for walnuts: “Eating 30g of walnuts per day has been found to improve the elasticity of blood vessels” (Ref 8).

Health authorities including the US Department of Agriculture (USDA) and the World Health Organisation (WHO) specifically advocate eating nuts as part of a healthy, balanced and varied diet, as their nutritional benefits are plentiful.

Q2 Aren’t nuts packed full of fat and fattening?

HB: Although nuts are high in fat, it’s mainly ‘good’ unsaturated fats, which may in part explain their beneficial effects on cardiovascular health. Research has shown that swapping out saturated fats (found in full fat dairy products, butter and fatty cuts of meat) with unsaturated fats has a positive impact on cholesterol levels (Ref 9) and in turn our heart and circulatory health. In fact, the UK’s Healthy eating model, the Eatwell Guide encourages us to reduce saturated fat intake and in particular, shift food choices from those high in saturated fats to those rich in unsaturated fats.  Walnuts are also an excellent source of the plant-based omega-3 polyunsaturated fat- alpha-linolenic acid or ALA, which is considered an essential fat because it cannot be produced by our body and so must be obtained from our diet

Many of us still think of nuts as ‘fattening’ and an enemy to our weight because of their fat and high calorie content, but these people are not seeing the whole picture. Studies have shown that adults who eat nuts tend to gain less weight over time than nut avoiders, and that careful consumption of nuts can help us control our weight (Ref 10).  This may be down to the fat, protein and fibre content in nuts helping us to feel fuller for longer and help keep our cravings in check. Even the texture may be involved – they’re crunchy, so take some effort to eat, and help to slow down the eating occasion.

Trials by the US Department of Agriculture (USDA) have also found that because of the rigid make-up of nut’s cells, our bodies don’t process or absorb all of the fat from nuts, so we may ingest fewer calories than previously thought (Ref 11). Roasted and unroasted nuts actually provide up to a fifth fewer calories than commonly listed on nutrition labels and databases (Ref 12). Which is all great news for any weight-conscious nut lovers out there! Nevertheless, it’s not a green light to overindulge!

Q3 Is portion control a consideration and required?

HB: Most studies uncovering benefits are based on a daily intake of about 30g of whole nuts, with their skins still intact (and of course make sure you’re choosing unsalted and unsweetened varieties) – put simply, that means keeping your portion size to a small handful. This amount of nuts generally contains 180 to 224 kcals depending on the type of nuts (see table one). That’s more than a packet of crisps and less than a 51g Mars Bar, but with lots more nutrients than either, making them a weight-wise snack option at any time of the day. Buy large bags to keep pennies down, and for example you can store walnuts in the fridge to stop them going rancid. So, yes, it’s a good idea to portion control and separate them into 30g portions so that you’re not tempted to gorge on the lot!

Q4 Good things come in small packages but what other health benefits can nuts offer us?

HB: The many health benefits of eating nuts aren’t just limited to thefact they they’re rich in monounsaturated and/or polyunsaturated fats. They’re also an important source of many nutrients that help to keep us healthy and free from disease. They provide fibre, which helps keep our gut healthy by feeding some of our good gut bugs, such as bifidobacteria and making our stools large and soft, so they move easily through the large intestine. This in turn, may protect against constipation and bowel cancer.

Nuts also supply a range of vitamins and minerals, such as magnesium, potassium, iron, zinc, selenium, copper, vitamin E and B vitamins with the exact types and amounts differing according to the nut variety. Table one presents the macronutrient and micronutrient composition per 30g serving showing the large variation between nuts.

Nuts also provide naturally occurring phytochemicals – that’s just a sciencey name for a group of plant chemicals. The main role of phytochemicals is to help plants thrive and protect them from disease, so concentrations are often highest in the outer skin layers of nuts. But large amounts of research also show that phytochemicals probably have an array of health benefits. Many of the phytochemicals found in nuts, such as polyphenols and tocopherols – of which there are reportedly thousands, with many more still to be discovered – act as antioxidants and so may help protect our cells from free radical damage that’s linked to disease. Some studies suggest that it’s the unique package of nutrients in nuts that work together to protect our health as we age – though more research is needed to confirm the benefits of phytochemicals for our overall health, mental and physical wellbeing.

Nevertheless, it’s clear that nuts are an Aladdin’s Cave of nutrients, so it’s no wonder that some people call them ‘Nature’s own nutritional supplement’. 

Q5 Ok, so eating nuts is good for you, but are they good for the planet too? 

HB: Yes. Eating plant-based protein sources, rather than meat and dairy, has been recommended as a way of eating that is both beneficial for our health and more sustainable for our planet – nuts are increasingly important for people who are attempting to make the switch to a more plant-based diet and are particularly useful for vegetarians and vegans as they provide some of the nutrients present in meat and fish, like iron and zinc.

Q6 What are the best nuts for health?

HB: As shown in Table one (click here), each nut has its own combination of nutrients, including vitamins and minerals.

Below offers a summary of some of their nutrition and health benefits:

  • In terms of calories and fat, they’re all fairly similar. Peanuts – they are technically legumes (like chickpeas), but they are worth a mention here as they are a nutty favourite of us Brits – have the least calories, and macadamia nuts have the most.
  • Most nuts are primarily a source of unsaturated fat but do contain some saturated fat as well – brazil nuts are the highest in saturated fat, whereas almonds are the lowest. Walnuts have the highest amounts of polyunsaturated fat and are the only nut that has a significant source of omega-3 ALA (2.7g of ALA per 30g serving), whereas macadamia nuts supplies the most monounsaturated fat.
  • Almonds have the highest amounts of gut healthy fibre, providing 2.9g per 30g serving – that’s nearly 10 per cent of our daily 30g fibre needs.
  • Pistachios are the richest sources of potassium, important for maintaining a healthy blood pressure – a 30g serving provides 312 mg, or 15 per cent of our daily goal. And they are also packed with the not-very-well-known nutrient chloride at 243mg per 30g serving, which is 30 per cent of our daily target.
  • Almonds are one of the richest sources of non-animal calcium, needed for strong bones and teeth. A 30g serving gives us 72mg, which is 9 per cent of our daily calcium needs. And the B vitamin riboflavin, needed for healthy vision and skin.
  • Brazil nuts are the richest nut sources of energy-giving magnesium and selenium that is essential for strong immunity.
  • Pine nuts are the edible seeds of pine and are brimming full of bone-friendly phosphorus, zinc and manganese.
  • Cashew nuts have good amounts of iron. A 30g portion provides 1.9g, which is 14 per cent of our daily target to help reduce tiredness and fatigue. They are also the nut highest in copper, needed for a healthy nervous system and normal skin and hair pigmentation.
  • Hazelnuts are good sources of the antioxidant vitamin E, with a 30g portion supplying 63 per cent of our daily goal, and iodine too, which is needed to make thyroid hormones. They also contain the highest amounts of vitamin B1 or thiamin, which supports healthy heart function, and biotin for healthy hair and skin.
  • Peanuts have the best amounts of the B vitamins niacin, B6 and B5, which all support our bodies’ energy-producing mechanisms, and folate for healthy blood. They also contain more protein than any other classified tree nut.

Q7 Any final thoughts to leave us with?

HB:  If you eat a range of nuts, you’re most likely to benefit from all of the different nutrients they can provide.  There are many options open to nuts – raw or roasted, whole or crushed and sliced or slivered. Nuts also make delicious and nutritious wholesome snacks, as well as versatile ingredients in a huge range of dishes.

Consumers increasingly want to know exactly what they are eating and how it can positively benefit their health. So, nut growers and brands have the task to creatively develop their product messaging, in line with the key nut health research and approved nutrition and health claims, to both inform and educate.

As a final thought. With the rise of plant-based diets, helping to support planet sustainability, if you haven’t done so already perhaps it’s time to consider how you and your customers can creatively introduce more nuts into the day-to-day diet. Or as most of us seem to prefer these days with our busy lives, just grab a bag of nuts on-the-go instead.

With special thanks to leading Dietitian Helen Bond, BSc (Hons), RD, MBDA for this Q&A information article.

References: 

  1. Marta Guasch-Ferré,Xiaoran Liu, Vasanti S et al. Nut Consumption and Risk of Cardiovascular Disease. Journal of the American College of Cardiology. 2017 Nov 70; (20) 2519-2532.
  2. Fraser GE, Sabaté J, Beeson WL, Strahan TM.A possible protective effect of nut consumption on risk of coronary heart disease: the Adventist Health Study. Arch Intern Med 1992; 152: 1416–24.
  3. Kushi LH, Folsom AR, Prineas RJ, Mink PJ,Wu Y, Bostick RM. Dietary antioxidant vitamins and death from coronary heart disease in postmenopausal women. N Engl J Med 1996; 334:1156–62
  4. Belanger, F.E. Speizer, C.H. Hennekens, B. Rosner, W. Willett, C. Bain The Nurses’ Health Study: current findings Am J Nurs, 80 (1980), p. 1333
  5. Tammy T Hshieh, Andrew B Petrone, J Michael Gaziano, Luc Djoussé. Nut consumption and risk of mortality in the Physicians’ Health Study. Am J Clin Nutr. 2015 Feb; 101(2): 407–412.
  6. Nuts for the Heart. The Nutrition Source. Harvard TH Chan. School of Public Health
  7. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra virgin olive oil or nuts. New England Journal of Medicine. 2018;378(25), e34. DOI: 10. 1056/NEJMoa1800389.
  8. Scientific Opinion on the substantiation of health claims related to walnuts and maintenance of normal blood LDL-cholesterol concentrations (ID 1156, 1158) and improvement of endothelium-dependent vasodilation (ID 1155, 1157) pursuant to Article 13(1) of Regulation (EC) No 1924/2006 (2011) EFSA Journal 9 (4), 2074
  9. Scientific Opinion on the substantiation of health claims related to the replacement of mixtures of saturated fatty acids (SFAs) as present in foods or diets with mixtures of monounsaturated fatty acids (MUFAs) and/or mixtures of polyunsaturated fatty acids (PUFAs), and maintenance of normal blood LDL-cholesterol concentrations (ID 621, 1190, 1203, 2906, 2910, 3065) pursuant to Article 13(1) of Regulation (EC) No 1924/20061 (2011) EFSA Journal 9 (4) 2069
  10. Freisling, H., Noh, H., Slimani, N. et al.Nut intake and 5-year changes in body weight and obesity risk in adults: results from the EPIC-PANACEA study. (2018) Eur J Nutr 57, 2399–2408.
  11. Gebauer SK, Novotny JA. Food Porcessing and Structure Impact the Metabolizable Energy of Almonds. Food and Function. 2016; 7 (10): 4231–4238.
  12. David J Baer, Sarah K Gebauer, and Janet A Novotny. Walnuts Consumed by Healthy Adults Provide Less Available Energy than Predicted by the Atwater Factor. The Journal of Nutrition. November 18, 2015, doi: 10.3945/jn.115.217372

 

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