Not sure if California walnuts are gluten-free? Wondering about the health benefits of walnuts? Curious about omega-3s? Here you'll find the answers to these and many more frequently asked questions.
California-grown walnuts are not genetically modified.
The California walnut industry understands consumer concerns regarding genetically modified foods. Therefore, we work closely with the University of California’s walnut breeding program to release new walnut varieties for planting that have been developed through conventional breeding methods. The California Walnut Board does not anticipate production of genetically modified walnuts in California in the foreseeable future.
Research has suggested that health benefits from eating walnuts do not come at the expense of weight gain1. However, large and longer-term studies are needed to address the effects of walnut consumption on CVD risk and body weight. Portion control is also important when monitoring weight. The recommended portion size for walnuts is 1 ounce, or ¼ cup. Check our Weight and Walnuts page for published research, recipe ideas, and more.
1Banel DK, Hu FB. Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review. Am J Clin Nutr. 2009;90(1):56-63. doi: 10.3945/ajcn.2009.27457.
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 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 that eating walnuts is associated with improved blood pressure and cholesterol levels, walnuts are naturally sodium-free and thus are a perfect food for those following the DASH diet guidelines.
The Mediterranean Diet is actually comprised of 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.
The 2015 Dietary Guidelines encourage a shift from current eating patterns to a healthy eating pattern that includes nutrient-dense foods and beverages in place of less healthy choices. Among other things, a healthy eating pattern includes a variety of protein foods, including nuts and seeds along with seafood, lean meats and poultry, eggs, legumes and soy products. The Guidelines also emphasize the importance of reducing saturated fats intake to less than 10 percent of calories per day and shifting food choices from those high in saturated fats to those high in polyunsaturated fats. Consuming walnuts can help you meet these guidelines. In addition to providing polyunsaturated fat (13 grams per ounce), which includes an excellent source of alpha-linolenic acid (ALA), the plant-based form of omega-3 fatty acids (2.5 grams per ounce), a serving of walnuts (1 oz), as part of a healthy diet, provides 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.
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.
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 investigated 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 study participants consumed fatty fish, HDL (good) cholesterol increased and triglycerides decreased.
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.
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.
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.
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.