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Nuts & Heart Health


Can nuts help with cognition and memory?

Yes, nut can help with cognition and memory, specifically improving mild cognitive impairment - the step before Alzheimer's and dementia. The combination of healthy fats and phytochemicals, and nutrients with antioxidant and anti-inflammatory properties in nuts may help protect vital functions of the brain and it's blood vessels. All it takes is a handful of nuts a day.

References:
1) Arab L, Ang A. A cross sectional study of the association between walnut consumption and cognitive function among adult US populations represented in NHANES.J Nutr Health Aging. 2015 Mar;19(3):284-90.
2) Rita Cardoso B, Apolinário D, da Silva Bandeira V, Busse AL, Magaldi RM, Jacob-Filho W, Cozzolino SM. Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial. Eur J Nutr. 2016 Feb;55(1):107-16.
3) O'Brien J, Okereke O, Devore E, Rosner B, Breteler M, Grodstein F. Long-term intake of nuts in relation to cognitive function in older women. J Nutr Health Aging. 2014 May;18(5):496-502.
4) Barbour JA, Howe PR, Buckley JD, Bryan J, Coates AM. Nut consumption for vascular health and cognitive function. Nutr Res Rev. 2014 Jun;27(1):131-58.
5) Martínez-Lapiscina EH et al. Mediterranean diet improves cognition: the PREDIMED-NAVARRA randomised trial.J Neurol Neurosurg Psychiatry. 2013 Dec;84(12):1318-25.

Published 10 Jan 2017

What effect do nuts have on blood pressure?

The evidence of the impact of nuts on blood pressure is mixed. A 2015 meta analysis combining the effects of several studies found no difference in blood pressure in nut eaters(1). Yet more recent clinical trials have expanded the body of knowledge and eating nuts appears to reduce blood pressure through helping blood vessels stay elastic (endothlial dilation)(2-3). Studies looking at healthy eating patterns that include nuts have also shown improvements in blood pressure(4-6). Overall, they show that adding a handful of nuts to a healthy diet is the key to improving blood pressure.

An interesting new area of research for nuts is whether salted nuts still help reduce blood pressure and the research done to date in pistachios and hazelnuts suggests that they can(3,7,8). It's likely all the nutrients in nuts work together to generate positive outcomes just as all foods in healthy diets work together to generate positive outcomes.

Until there is more research, including unsalted nuts in a healthy daily diet with a variety of foods will help reduce blood pressure. But for now, enjoy salted nuts on special occasion as healthier party foods.

References:
1) Del Gobbo LC et al. Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials.Am J Clin Nutr. 2015 Dec;102(6):1347-56.
2) Dhillon J, Tan SY, Mattes RD. Almond Consumption during Energy Restriction Lowers Truncal Fat and Blood Pressure in Compliant Overweight or Obese Adults.J Nutr. 2016 Dec;146(12):2513-2519.
3) Tey SL et al Do dry roasting, lightly salting nuts affect their cardioprotective properties and acceptability? Eur J Nutr. 2016 Jan 8. [Epub ahead of print]
4) Ndanuko RN et al. Dietary Patterns and Blood Pressure in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Adv Nutr. 2016 Jan 15;7(1):76-89.
5) Jenkins DJ et al. The effect of a dietary portfolio compared to a DASH-type diet on blood pressure.Nutr Metab Cardiovasc Dis. 2015 Dec;25(12):1132-9.
6) Storniolo CE et al. A Mediterranean diet supplemented with extra virgin olive oil or nuts improves endothelial markers involved in blood pressure control in hypertensive women.Eur J Nutr. 2015 Oct 8. [Epub ahead of print]
7) Sauder KA et al. Pistachio nut consumption modifies systemic hemodynamics, increases heart rate variability, and reduces ambulatory blood pressure in well-controlled type 2 diabetes: a randomized trial.J Am Heart Assoc. 2014 Jun 30;3(4). pii: e000873.
8) West SG et al. Diets containing pistachios reduce systolic blood pressure and peripheral vascular responses to stress in adults with dyslipidemia.Hypertension. 2012 Jul;60(1):58-63.

Published 10 Jan 2017

Are salted nuts bad for you?

Salted nuts still contain all the nutrition and health benefits of raw or natural nuts - they just have a higher sodium content.

In general, a diet high in sodium can increase blood pressure which in turn increases the risk of cardiovascular disease (heart attacks and strokes).

Some new research however, has found participants given salted nuts as part of a healthy diet had the same health benefits of unsalted nuts with no rise in blood pressure. It's possible all the other heart healthy nutrients in nuts (healthy fats, arginine, fibre, antixidants: vitamin E, copper, manganese, selenium and polyphenols) offset any negative effects of salt. And because people like the taste of salted nuts, they are likely to consume nuts more often instead of other unhealthy snack foods.

At this stage, until more research is undertaken we recommend making raw/dry roasted unsalted nuts your everyday nut choice, and enjoy salted nuts as a healthier party food alternative.

References:
1) Sauder KA et al. Pistachio nut consumption modifies systemic hemodynamics, increases heart rate variability, and reduces ambulatory blood pressure in well-controlled type 2 diabetes: a randomized trial.J Am Heart Assoc. 2014 Jun 30;3(4). pii: e000873.
2) West SG et al. Diets containing pistachios reduce systolic blood pressure and peripheral vascular responses to stress in adults with dyslipidemia.Hypertension. 2012 Jul;60(1):58-63.
3) Tey SL et al. Do dry roasting, lightly salting nuts affect their cardioprotective properties and acceptability? Eur J Nutr. 2016 Jan 8. [Epub ahead of print]

Published 10 Jan 2017

Are peanuts good for people with heart disease?

While “nut” is in their name, peanuts are in fact legumes. Peanuts grow underground, as opposed to nuts like walnuts, almonds, etc. that grow on trees (and are referred to as "tree nuts"). However, peanuts have a very similar nutrient composition to tree nuts, and therefore share many of the properties and health benefits of tree nuts.

The large population (epidemiology) studies which show benefits in eating nuts for reducing the risk of heart disease include tree nuts (1-5). A review conducted in 2008 (6) concluded that "there is impressive evidence from epidemiological and clinical trials of the beneficial effects of nut (and peanut) consumption and their constituents on the risk of cardiovascular disease (CVD), including sudden death".

So, it appears that a well balanced diet that includes nuts and peanuts can markedly benefit health and reduce CVD risk.

Nuts for Life is a nutrition and health education initiative established for the Australian Tree Nut industry to provide information about the nutrition and health benefits of tree nuts.

References:
1) Albert CM et al. Nut consumption and decreased risk of sudden cardiac death in the Physician’s Health Study. Arch Intern Med 2002;162(12):1382-7.
2) Ellsworth JL et al. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women’s Health Study. Nutrition Metabolism and Cardiovascular Disease 2001;11(6):372-7.
3) Hu FB et al. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. British Medical Journal 1998;317(7169):1341-5.
4) Fraser GE et al. A possible protective effect of nut consumption on risk of coronary heart disease. Arch Intern Med 1991; 152: 1416-24.
5) Blomhoff R. et al. Health benefits of nuts: potential role of antioxidants. Brit J Nutr 2007;96(SupplS2):S52-S60.
6) Kris-Etherton PM et al. The role of tree nuts and peanuts in the prevention of CHD: multiple potential mechanisms. J Nutr. 2008 Sep;138(9):1746S-1751S.

Last update October 2016

Can eating nuts help me live longer?

A new study published in the December 2016 issue of BMC Medicine, found a 20g handful of nuts everyday can cut the risk of developing coronary heart disease by almost 30 per cent, the risk of developing cancer by 15 per cent and the risk of premature death from all causes by 22 per cent. So yes, eating nuts every day can help you live longer.

The research also found an average of at least 20g of nuts was associated with a reduced risk of premature death from respiratory diseases by about half, and diabetes by 40 per cent.

About the research

The research included all tree nuts as well as peanuts, and was led by the Imperial College London and the Norwegian University of Science and Technology and published in the journal BMC Medicine.

The researchers analysed 20 published studies from around the world, involving 819,000 participants, including more than 12,000 cases of coronary heart disease, 9,000 cases of stroke, 18,000 cases of cardiovascular disease and cancer, and more than 85,000 deaths.

Why 20g and not 30g of nuts?

The research refers to at least 20g of nuts, which is less than the 30g handful the Australian Dietary Guidelines and Nuts for Life recommends as the daily serving size. This is because the study is a meta-analysis of 20 individual studies. The actual journal paper shows the researchers assessed a one ounce serving of nuts (which is 28g, and which we round up to 30g) and found at this serving size, 30g a day reduces heart disease by 29%, cancer by 15% and premature death by all causes by 22%.

The researchers did another statistical analysis to determine the minimum amount of nuts to get the best effect and they found it was 20g. This doesn’t mean you can’t eat more than 20g - it just means that this research didn’t see much additional benefit in reducing premature death from a specific health cause with more than 20g a day.

Putting this into context of the full body of evidence, which for instance shows that to reduce blood cholesterol we need 60g of nuts a day – eating at least a 30g serving size is appropriate. Especially when Australians on average are eating just 6g of nuts a day (ABS data).

Published December 2016

What nuts are good for lowering cholesterol?

All nuts can lower cholesterol levels. In fact, the results of a recent review concluded that the major determinant of cholesterol lowering was nut dose rather than nut type (1).

Results of recent studies suggest that around 60g of nuts/day lowers cholesterol:

  • A large analysis combining the results of 25 cholesterol lowering studies involving nuts found that around 67g or two handfuls, each day lowered total cholesterol by about 5%, LDL cholesterol by around 7% and triglycerides by about 10% (2).
  • A review of 61 controlled studies concluded that tree nut intake lowers total and LDL cholesterol, with stronger effects observed at intakes of greater than 60g of nuts/day (1).

    References:
    1) Del Gobbo LC et al. Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose response of 61 controlled intervention trials. Am J Clin Nutr. 2015;102(6):1347-56.
    2) Sabate, et al. Nut consumption and blood lipid levels: a pooled analysis of 25 intervention trials. Arch Intern Med 2010;170(9):821-7.

    Last update October 2016
  • How is blood cholesterol made?

    Humans and animals make cholesterol in their liver. Cholesterol is an important part of many of the body’s processes (1).There are two types of cholesterol – low density lipoprotein or LDL cholesterol and high density lipoprotein or HDL cholesterol. Cholesterol can’t dissolve into the blood so it has to be transported on protein carriers called lipoproteins. LDL cholesterol is considered the bad kind that gets sticky and can block arteries, whereas HDL is considered the good kind as it helps to 'mop up' any build up in the arteries.

    Plants do not contain cholesterol, so you won’t find cholesterol in natural plant foods such as nuts or avocados.

    References:
    1) Essentials of human nutrition 2007. Oxford University Press, 3rd Edition. Mann J and Truswell AS (Eds).

    Last Update September 2016

    Can nuts lower blood cholesterol?

    Eating nuts regularly can improve blood fats, particularly by lowering LDL (bad) cholesterol (1,2). A large analysis combining the results of 25 cholesterol lowering studies involving nuts found that an average serve of nuts (around 67g or two handfuls) each day lowered total cholesterol by about 5%, LDL cholesterol by around 7% and triglycerides by about 10% (1). More recently, a review of 61 controlled studies concluded that tree nut intake lowers total and LDL cholesterol, with stronger effects observed at intakes of greater than 60g of nuts/day (3).

    Reference:
    1) Sabaté J et al. Nut consumption and blood lipid levels: a pooled analysis of 25 intervention trials. Arch Intern Med 2010;170(9):821-7.
    2) Greil AE et al. Tree nuts and the lipid profile: a review of clinical studies. British J Nutrition 2007;96(S2):S68-S78.
    3) Del Gobbo LC et al. Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose response of 61 controlled intervention trials. Am J Clin Nutr. 2015;102(6):1347-56.

    Last Update September 2016

    Can nuts help reduce the risk of heart disease?

    Nuts are on the “must eat” food list if we want to reduce the risk of developing heart disease. Studies show eating a daily handful of nuts (about 30g) can significantly reduce the risk of developing heart disease by 30-50% (1-5). Even people who only eat nuts once a week have less heart disease than those who never eat nuts (4).

    References:
    1) Albert CM et al. Nut consumption and decreased risk of sudden cardiac death in the Physician’s Health Study. Arch Intern Med 2002;162(12):1382-7.
    2) Ellsworth JL et al. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women’s Health Study. Nutrition Metabolism and Cardiovascular Disease 2001;11(6):372-7.
    3) Hu FB et al. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. British Medical Journal 1998;317(7169):1341-5.
    4) Fraser GE et al. A possible protective effect of nut consumption on risk of coronary heart disease. Arch Intern Med 1991; 152: 1416-24.
    5) Blomhoff R. et al. Health benefits of nuts: potential role of antioxidants. Brit J Nutr 2007;96(SupplS2):S52-S60.

    Last Update October 2016

    How do nuts affect good and bad cholesterol?

    Research has shown that around two handfuls (approx 60g) of nuts a day can significantly reduce total and LDL (bad) cholesterol by 5% and 7% respectively (1). Some studies have shown that nuts increase levels of HDL (good) cholesterol, however there is a lack of consistent effects.

    References:
    1) Sabaté J et al. Nut consumption and blood lipid levels: a pooled analysis of 25 intervention trials. Arch Intern Med 2010;170(9):821-7.

    Last Update October 2016

    What is the difference between dietary cholesterol and blood cholesterol?

    Dietary cholesterol is the cholesterol present in foods such as eggs and shellfish, whereas blood cholesterol is what is made by your body by the liver. We used to think that eating foods high in dietary cholesterol increased blood cholesterol, but we now know this is not the case. For most people, cholesterol in foods doesn't get directly absorbed and converted into cholesterol in your blood, and so has a very small effect. Blood cholesterol is affected mainly by the fats you eat - in particular saturated fats (found in animal foods) and trans fats. Your liver then makes cholesterol from these saturated fats. Saturated fats increase LDL (bad) cholesterol (1).

    References:
    1) National Heart Foundation 2009. Q & A: Dietary fats, dietary cholesterol and heart health. https://www.heartfoundation.org.au/sites/HealthyEating/SiteCollectionDocuments/DietaryFats%20QA.pdf Accessed 22/12/10.

    Last Update October 2016

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