A handful of nuts a day may be just the thing to get your heart in shape. A new study out of the University of Rovira i Virgili in Reus, Spain, found that subjects who consumed two tablespoons of mixed nuts daily in combination with a Mediterranean diet were 70 percent more likely to reduce symptoms of "metabolic syndrome" than subjects who ate a low-fat diet. Metabolic syndrome refers to a constellation of symptoms -- including hypertension, excess belly weight, high cholesterol, glucose intolerance and elevated blood sugar -- that lead to high risk for cardiovascular disease and diabetes. In the US, the condition affects over 50 million individuals.
The subjects in this study included 1,224 Spanish men, ages 55 to 80, all with risk factors for heart disease. Subjects were divided into three groups. The control group followed a traditional low-fat diet. A second group followed the Mediterranean diet, which is rich in fruits, vegetables, and whole grains and low in meat, dairy, and sugar. This diet typically includes a glass or so of red wine daily and some fish, and relies heavily on virgin olive oil. The third group also followed a Mediterranean diet, but added a daily helping of three walnuts, eight almonds, and seven hazelnuts. In all three groups, subjects were allowed to eat as much as they wanted, without calorie restrictions -- and not surprisingly, the subjects did not lose weight. Even so, subjects lost belly fat and all the groups showed improvement in cardiovascular risk factors by the end of the year -- although the amount of improvement varied greatly from one group to the next.
In the low-fat diet group, the rate of metabolic syndrome decreased by a marginal two percent. In the non-nut Mediterranean diet group, the improvement was 6.7, but it was 13.7 percent in the Mediterranean diet group that supplemented with nuts. In other words, the nut-eating participants were 700 percent healthier than those who followed the low-fat diet, and 200 percent healthier than those who simply followed the Mediterranean diet. And remarkably, once again, these benefits came without the subjects losing weight or restricting the quantity of food they ate.
As Dr. Joann Manson of Harvard's Brigham and Women's Hospital said, "What's most surprising is they found substantial metabolic benefits in the absence of calorie reduction or weight loss." She also notes that it's not just the nuts that did the magic -- it was nuts in combination with the Mediterranean diet. Dr. Manson cautions that eating lots of nuts on top of a junk-rich diet will simply lead to weight gain and other health complications.
It may seem a bit counterintuitive that nuts have such a positive impact on cardiovascular risk since they're so high in fat, but as study director Dr.Jordi Salas-Salvado points out, "Nuts are rich in anti-inflammatory substances, such as fiber, and antioxidants, such as vitamin E. They are high in unsaturated fat, a healthier fat known to lower blood triglycerides and increase good cholesterol." He noted that nuts make you feel full at the same time that they increase the body's ability to burn fat. (Note: It's not mentioned in the study, but almond consumption in particular has been associated with a reduced risk of heart disease, diabetes, and cancer. Also, sprouting nuts dramatically improves their nutrition level and health benefits, while reducing the possibility of any adverse reactions.)
It's again important to restate that the nutty benefit comes only in combination with the Mediterranean diet, a diet that has been shown to have significant other health advantages in previous studies. A study published a few months ago in the British Medical Journal found an 83 percent reduction in incidence of diabetes in subjects following the diet. A 2006 study from Columbia University Medical Center found that following the diet reduced Alzheimer's risk by up to 40 percent. Other studies have found that the diet significantly reduces the incidence of respiratory disease, Parkinson's disease, cancer, and various forms of cardiovascular disease, and that it significantly increases lifespan.
And now this new study shows that just tweaking the diet slightly amps up the benefits even more. As I've written in the past, other modifications to the traditional Mediterranean diet help keep it even healthier -- using olive oil mostly for salads rather than for cooking, for example, since olive oil breaks down at high temperatures. Instead, cook with avocado oil or rice-bran oil, which withstand high-heat better than olive oil does. Also, while some versions of the Mediterranean diet rely heavily on pasta and rice, you might do better to make sure you use whole grain wherever possible. Also, you'll multiply the benefits if you add an exercise routine and supplements to the diet.
As a side note, while the Mediterranean diet clearly offers spectacular health advantages, it also beats the pants off of most diets in terms of culinary splendor. As Dr. Salas-Salvado notes, "Traditionally, dietary patterns recommended for health have been low-fat, high-carbohydrate diets, which generally are not palatable. The results of the present study show that a non-energy-restricted traditional Mediterranean diet enriched with nuts, which is high in fat, high in unsaturated fat and palatable, is a useful tool in managing the metabolic syndrome."
One of the success factors enjoyed by those who follow the Mediterranean diet is that, to paraphrase an old commercial, "it's delicious and nutritious." In other words, it's a diet that's tasty and varied enough to stick with, as opposed to the punishing, austerity, weight-loss diets that have been so popular (and unsuccessful) in the US.