Just in time for holiday nut bowls, new research has been making the rounds suggesting that people who eat nuts reduce their risk of cancer and heart disease. Indeed the study did find a correlation between eating a handful of nuts and reduced risk. But it wasn’t a controlled experiment and it could be that people who enjoy nuts on a regular basis simply have healthier habits overall.
A fistful of nuts
To reach their conclusions on the protective effect of eating nuts, published in the journal BMC Medicine, researchers from the Norwegian University of Science and Technology reviewed findings from 29 published studies conducted around the world that involved up to 819,000 people.
Among the participants, there were 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. But those who ate an average of at least 20 grams of nuts a day were 30 percent less likely to get heart disease and 15 percent less likely to get cancer than people ate fewer, or no nuts.
A fistful of nuts was also linked to a 50 percent reduction in risk of dying from a respiratory disease, and 40 percent less risk of developing diabetes. The reduction in risk was essentially the same regardless of the type of nuts consumed.
Why would nuts reduce risk of chronic disease? The researchers noted that nuts are rich in fiber, magnesium and polyunsaturated fats, nutrients that are associated with lower cholesterol levels and better cardiovascular health. Nuts are also a high quality, non-animal source of protein. Certain nuts you are most likely to see in nut bowls this time of year, such as walnuts and pecans, are rich in antioxidant compounds that could possibly account for the reduced cancer risk coaxed out of the study.
It’s important to keep in mind, however, that while nuts are nutrient dense, they are also calorie-dense. A palmful of those cancer fighting walnuts or pecans delivers about 150 calories. A cup of mixed nuts from the party bowl contains more than 800 calories. A lot of nuts you will be exposed to in the holiday season are also heavily salted and/or coated in sugar.
It’s widely accepted that nuts should be part of a healthy diet. Like all good things, moderation is the key. Also, nutritional studies focusing on a single food or nutrient tend to obscure the fact that reducing risk of chronic diseases such as cancer and heart disease requires a comprehensive range of healthy behaviors. Simply eating nuts without making a broad range of healthy lifestyle choices isn’t likely to produce the same results.