Health Research

For over 30 years, the California Walnut Commission (CWC) has supported health-related research on walnuts through research grants and the provision of walnuts. Research priorities are identified in consultation with our Health Research Advisory Group. More than 170 CWC-supported, peer-reviewed papers have been published examining the effect of walnut consumption on heart health, bone health, cognition, cancer, diabetes, metabolic syndrome, body weight & composition, reproductive health, in addition to studies to ascertain walnut micronutrients and bioactive composition.  Additional CWC funding has supported the inclusion of walnuts in healthy diets, such as the Mediterranean diet. The CWC is committed to building a strong foundation of high-quality scientific evidence, from in vitro and animal research in the early stages of exploration to observational epidemiological and clinical intervention studies that determine the health effects of walnut consumption in people.

The CWC has invested approximately $20 million in health research in 10 countries working with more than 65 institutions and universities. The results support health claims in the EU and the US.

To explore the California Walnut Commission supported research publications: 

Health and Nutrition Claims

Heart health*

Since 1993, published research has been investigating how eating walnuts affects various heart health biomarkers and risk markers. Due to the evidence supporting the cardiovascular benefits of walnuts, the U.S. Food and Drug Administration approved one of the first qualified health claims for a whole food in March of 2004: “Supportive but not conclusive research shows that eating 1.5 ounces of walnuts per day, as part of a low saturated fat and low cholesterol diet, and not resulting in increased caloric intake may reduce the risk of coronary heart disease.” The European Union has also acknowledged walnuts‘ contribution to cardiovascular health with the following exclusive walnut health claim: “Walnuts contribute to the improvement of the elasticity of the blood vessels.”

High cholesterol is a risk factor in the development of coronary heart disease. Research specific to ALA and its contribution to health benefits continues to evolve, but it indicates that they can help maintain heart health and lower cholesterol levels. Walnuts are a rich source of the plant-based essential omega-3 alpha-linolenic acid (ALA) and heart healthy polyunsaturated fats. Replacing saturated fat with unsaturated fats has been shown to reduce blood cholesterol and contributes to the maintenance of normal blood cholesterol levels. Linoleic acid also contributes to the maintenance of normal blood cholesterol levels.

Walnuts are a source of potassium which contributes to the maintenance of normal blood pressure.

Walnuts are a rich source of thiamin which contributes to the normal function of the heart.

Walnuts are a rich source of Vitamin B6 and folate which contribute to normal homocysteine metabolism.

California Walnuts have the heart healthy seal of approval from the heart health charity, Heart UK.  www.heartuk.org.uk

Cognitive Health

Walnuts are a rich source of thiamin, vitamin B6 and a source of magnesium and biotin which contribute to normal psychological function.

Walnuts are a source of Pantothenic acid which contributes to normal mental performance.

Walnuts are a source of iron and zinc which contributes to normal cognitive function. Iron also contributes to the normal cognitive development of children.

Diabetes

A portion (30g) of walnuts contains 1g of carbohydrate, is a source of fibre and is a heart healthy, low GI choice.

Gut health

Walnuts are a source of fibre and have the potential to act as prebiotics.1 One portion of walnuts provide 1.4g of fibre (5% of recommended daily target of 30g/day for adults).

Reproductive health

Walnuts are a rich source of Vitamin B6 which contributes to normal red blood cell formation and the regulation of hormonal activity.

Walnuts are a rich source of folate which contributes to maternal tissue growth during pregnancy, normal amino acid synthesis, normal blood formation and folate has a role in the process of cell division.

Walnuts are a rich source of magnesium which contributes to normal protein synthesis and has a role in the process of cell division.

Walnuts are a source of iron which contributes to normal formation of red blood cells and haemoglobin, has a role in the process of cell division.

Walnuts are a source of zinc which contributes to normal DNA synthesis, normal fertility and reproduction, the maintenance of normal testosterone levels in the blood, normal protein synthesis and has a role in the process of cell division.

Weight loss/maintenance

Walnuts are a source of fibre.

Walnuts provide 4.4g protein per 30g portion.

A portion of walnuts provides 206kcal.

Bone health

Walnuts are a rich source of magnesium, phosphorus and manganese and a source of zinc – all of which contribute to the maintenance of normal bones.

Magnesium and phosphorus also contribute to the maintenance of normal teeth.

Phosphorus is needed for the normal growth and development of bone in children.

Immune system

Walnuts are a rich source of Vitamin B6, folate, copper and a source of iron and zinc which all contribute to the normal function of the immune system.

Nervous system

Walnuts are a rich source of thiamin, vitamin B6, magnesium and copper and a source of biotin and potassium which all contribute to the normal functioning of the nervous system.

Skin and hair

Walnuts are a rich source of copper which contributes to normal hair and skin pigmentation.

Walnuts are also a source of biotin and zinc which contribute to the maintenance of normal hair and skin. In addition zinc contributes to the maintenance of normal nails.

Vision

Walnuts are a source of zinc which contributes to the maintenance of normal vision and biotin which contributes to the maintenance of normal mucous membranes.

Tiredness and fatigue

Walnuts are a rich source of folate and magnesium and a source of pantothenic acid and iron which all contribute to the reduction of tiredness and fatigue.

Iron and vitamin B6 contribute to the normal formation of red blood cells and iron contributes to the normal formation of haemoglobin and normal oxygen transport in the body.

Anti-oxidants

Walnuts are a rich source of the anti-oxidants vitamin E, copper, manganese and a source of zinc which all contribute to the protection of cells from oxidative stress.

Exercise and sport

Walnuts are a rich source of thiamine, vitamin B6, magnesium, phosphorus, copper, manganese and a source of iron and pantothenic acid which all contributes to normal energy-yielding metabolism.

Vitamin B6 also contributes to normal protein and glycogen metabolism.

Magnesium also contributes to electrolyte balance and normal muscle function.

Potassium also contributes to normal muscle function.

Zinc also contributes to normal protein synthesis.

Walnuts are rich in both manganese which contributes to the normal formation of connective tissue and copper which contributes to maintenance of normal connective tissues.

NB. All nutrition and healths claims are made as part of a healthy, balanced diet and lifestyle. Ref: https://ec.europa.eu/food/safety/labelling_nutrition/claims/register/public/?event=register.home

Except:

{1] Lauri O. Byerley, Derrick Samuelson, Eugene Blanchard, Meng Luo, Brittany N. Lorenzen, Shelia Banks, Monica A. Ponder, David A Welsh, Christopher M. Taylor. Changes in the Gut Microbial Communities Following Addition of Walnuts to the Diet. The Journal of Nutritional Biochemistry, 2017; DOI: 10.1016/j.jnutbio.2017.07.001

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