Regardless of who issues them, guidelines for health promotion and disease prevention universally recommend diets that are largely plant-based, meaning those that include plenty of fruits, vegetables, grains, beans, and nuts. The U.S. dietary guidelines also recommend foods in the “protein” category. Grains, beans, and nuts are good sources of protein, but the guidelines use “protein” to mean low-fat dairy, lean meats, and fish. Recommended eating patterns include all these foods, relatively unprocessed, but with minimal addition of salt and sugars. Such patterns provide nutrients and energy in proportions that meet physiological needs but also minimize the risk of obesity, type 2 diabetes, and other chronic diseases. One more definition: “Patterns” refer to diets as a whole, not to single foods. No one food makes a diet healthful. The healthiest diets include a wide variety of foods in each of the recommended categories in amounts that balance calories.
In their largely unprocessed forms, foods from the earth, trees, or animals are healthful by definition. So why, you might ask, would the producers of foods such as cranberries, pears, avocados, or walnuts fund research aimed at proving that these particular foods—rather than fruits, vegetables, or nuts in general—have special health benefits? Marketing, of course. Every food producer wants to expand sales. Health claims sell. The FDA requires research to support health claims and greatly prefers studies that involve human subjects rather than animals.
All of this explains why Royal Hawaiian Macadamia Nut petitioned the FDA in 2015 to allow it to say in advertisements that daily consumption of macadamias—along with eating a healthy diet—may reduce the risk of heart disease. The 81-page petition cited several studies done in humans, one of them funded by the Hershey Company, which sells chocolate-covered macadamias. The FDA ruled that it would permit a qualified health claim for macadamia nuts with this precise wording: “Supportive but not conclusive research shows that eating 1.5 ounces per day of macadamia nuts, as part of a diet low in saturated fat and cholesterol and not resulting in increased intake of saturated fat or calories may reduce the risk of coronary heart disease.” Can a statement this cumbersome help sell macadamia nuts? Definitely, with a little help from the press: “Go nuts, folks! FDA declares macadamia nuts heart healthy.”