Q. I have heard walnuts are good for me. Aren't all nuts the same?
A. Tree nuts and peanuts are quite different nutritionally. Walnuts are unique compared to other nuts because they are predominantly composed of polyunsaturated fatty acids (PUFA) rather than monounsaturated fatty acids (MUFA), which are predominant in most other nuts. Walnuts are the only nut that contain a significant amount of alpha-linolenic acid (ALA), the plant-based source of omega-3 fatty acids. A one-ounce serving of walnuts provides 18 grams of total fat of which 13 grams are PUFA and 2.5 grams are ALA, as well as other health-promoting nutrients and bioactive components. For more nutritional information about the omega-3 content of walnuts visit our page about Alpha-Linolenic Acid. Nearly two decades of research, at renowned universities worldwide have shown the effect of walnuts in such areas as heart health, diabetes, cancer, cognition, aging and metabolic syndrome.
Q: Where do walnuts fit into the 2010 USDA Dietary Guidelines?
A. Some of the key messages of the 2010 Dietary Guidelines include adding good fats and plant-based protein sources to your diet, while limiting your sodium intake. The new recommendations urge Americans to consume more polyunsaturated fat and less saturated and trans fat as part of a healthy diet. In fact, Health.gov recommends that twenty to thirty-five percent of all calories consumed should be in the form of fat that comes from fish, nuts and vegetable oil sources. Consuming walnuts can help you meet these guidelines. In addition to being an excellent source of alpha-linolenic acid (ALA), the plant-based form of omega-3 fatty acids, walnuts provide protein (4 grams per ounce) and are naturally sodium and cholesterol free. Looking for new ways to include walnuts on your plate? Check out our recipe section.
Q. What cancer fighting foods should I be eating?
A. According to the American Institute for Cancer Research (AICR), the best diet for preventing cancer is a predominantly plant-based diet that includes a variety of brightly colored vegetables and fruits, whole grains, beans and nuts, such as walnuts. In fact, the AICR recommends that two-thirds of the plate be filled with these plant-based foods. More information about the role that walnuts can play in fighting cancer is available on our Walnuts and Health Page.
Q: I read a lot about the Mediterranean Diet, what exactly is it?
A: The Mediterranean Diet is actually many diet patterns that hail from various countries surrounding the Mediterranean Sea. According to the American Heart Association, the common Mediterranean dietary pattern has these characteristics:
• High consumption of fruits, vegetables, bread and other cereals, potatoes, beans, nuts and seeds
• Olive oil is an important monounsaturated fat source
• Dairy products, fish and poultry are consumed in low to moderate amounts, and little red meat is eaten
• Eggs are consumed up to four times a week
• Wine is consumed in low to moderate amounts—up to one five-ounce glass of wine per day for women and up to two five-ounce glasses for men.
• Walnuts are a traditional component in this dietary pattern Research has suggested that this is a heart-healthy pattern of eating. PREDIMED is a landmark Spanish study that has been investigating specific benefits of this eating style. Preliminary published findings have found that consuming Mediterranean ingredients, including walnuts, is linked to heart health benefits including lowering LDL “bad” cholesterol and inflammatory markers.
Q. When grocery shopping, I have seen a Heart-Check mark on specific foods. What does this logo mean and how might it help me?
A. The Heart-Check mark easily identifies foods, such as walnuts, that meet the nutritional standards set by the American Heart Association and provides consumers a quick and reliable way to identify heart-healthy foods. When you see the Heart-Check mark on food packaging, you'll instantly know the food has been certified to meet the American Heart Association's guidelines for a heart-healthy food. As a whole food certified with the Heart-Check mark, walnuts are an ideal choice in a sensible eating plan.
Q. I have heard about the DASH Diet. What is it and does it include walnuts?
A. The Dietary Approaches to Stop Hypertension diet – known at the DASH diet – is an eating program that was developed through research sponsored by the U.S. National Institute of Health (NIH) that is aimed at reducing blood pressure and cholesterol. It includes eating a fruits, and vegetables, low-fat or non-fat dairy, nuts, including walnuts, and whole grains. It includes high fiber, and low to moderate fat, and is rich in potassium, calcium and magnesium. Recent DASH studies have shown benefits of lowering sodium intake on blood pressure. Not only have studies shown walnuts associated with improved blood pressure and cholesterol levels, but walnuts are naturally sodium-free and thus are a perfect food for those following the DASH diet guidelines.
Q. Are walnuts gluten-free?
A. Walnuts are naturally a gluten-free food. If you have Celiac Disease or are sensitive to gluten, please be sure to check the packaging to ensure that the product was not processed in a facility with products that contain gluten.
Q. Does heating (i.e toasting, boiling or frying) affect the nutrient content of walnuts?
A. The nutrient profile of walnuts changes insignificantly when roasted, toasted or baked for short periods of time. For information on the proper way to toast walnuts, see “How to Toast Walnuts”.
Q. Are all omega three fatty acids the same?
A. The omega-3 fatty acid alpha-linolenic acid (ALA) is the precursor or “parent” to the two long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Walnuts contain ALA and fatty fish contain EPA and DHA. Metabolic reactions enable ALA to be converted into EPA and DHA. A recent study published in the American Journal of Clinical Nutrition looking at whether walnuts (providing ALA) and fatty fish (providing EPA and DHA) have similar effects on specific blood markers associated with Coronary Heart Disease. The study found that a diet including walnuts was more powerful in reducing total and LDL (bad) cholesterol when compared to fatty fish. Healthy individuals who consumed walnuts reduced their total cholesterol by 5.4% and LDL by 9.3% translating to an 18.6% decrease in risk of Coronary Heart Disease (CHD). When they consumed fatty fish, HDL (good) cholesterol increased and triglycerides decreased.
Q. What foods are highest in antioxidants?
A. Research has suggested that antioxidants may help to protect from certain chronic diseases of aging, including cardiovascular, neurological and carcinogenic ailments due to their ability to control free radicals – known to negatively influence healthy aging. Walnuts are known for their high antioxidant content (13.126 mmol/100 grams).
A 2011 study published in the journal Food and Function found that the quality and quantity of antioxidants in walnuts ranked higher than any other nut. Researchers from The University of Scranton in Scranton, Pa., compared the amount of powerful antioxidants called polyphenols in nine types of roasted and raw nuts and two types of peanut butter in an attempt to “crack” the antioxidant code. Dr. Vinson’s research concluded “Nuts are high in fiber, low in saturated fats, high in beneficial unsaturated fats, and very high in antioxidants. Nuts are a nutritious snack and food additive providing both nutrients and bioactive antioxidants which provide significant health benefits to the consumer.”
A 2010 study investigating the antioxidant activity of different dry fruits found walnuts to exhibit the best antioxidant properties. Additional research testing 1113 different foods for antioxidant levels reported walnuts rank second only to blackberries in terms of antioxidant content. Ellagic acid and gamma tocopherol, a form of vitamin E, are two antioxidants that are thought to have anticarcinogenic properties; both are found in walnuts. Melatonin, an antioxidant known for its sleep regulating properties is also naturally found in walnuts. Research, led by melatonin expert Russel Reiter, PhD4, published in the September 2005 issue of Nutrition: The International Journal of Applied and Basic Nutritional Sciences, reported the calculated concentrations of melatonin in walnuts was 3.5 +/- 1.0ng/g.uts:
The ONLY Nut
1 Biogerontology. 2004;5(5):275-89.
2 Food Chem Toxicol. 2010 Dec;48(12):3316-20.
3 Am J Clin Nutr. 2006 Jul;84(1):95-135.
4 Nutrition. 2005 Sep;21(9):920-4.gnificantly High in Omega-3s (ALA)
Q. Can walnuts be used for weight management?
A. Walnuts can be an important food for weight management. According to recent studies when eaten in combination with a healthy and active lifestyle, consuming walnuts can help manage symptoms of metabolic syndrome, as well as reduce central obesity (accumulation of fat around the internal organs.) Furthermore, research has shown that eating walnuts does not result in weight gain. In fact, people often report feeling more satisfied when including walnuts in their diet.