I used to regularly visit a nut shop downtown run by a lively old lady whose claim to health and longevity was that she snacked on the nuts she sold all day long. Since then, nuts have always been my guilty pleasure. I eat them every morning with yogurt. I love their crunch and their endless variety -- cashews, hazelnuts, almonds, macadamias, walnuts. From pecans to pine nuts to pistachios -- I love them all.
What I haven't loved is their bad reviews. That old lady was the only one who stood by her nuts, while everybody warned her that nuts are high fat, artery cloggers, pound-packers, and as bad as butter. Those nut naysayers had a point: Anyone who has ever dieted knows that the first thing on your do-not-eat list is nuts, nuts, nuts.
The old lady, who lived until she was 94, never knew the popularity of health-boosting products such as almond milk and coconut water. During her years, nut sources -- like almonds and coconuts -- were dismissed as merely fillers for candy bars and toppings for cakes.
I only wish she were around today because nuts really are good for you. The U.S. FDA has already recognized tree nuts for their ability to lower LDL (the bad) cholesterol. But according to a paper published today by Dr. John Sievenpiper, a researcher in the Clinical Nutrition and Risk Factor Modification Centre of St. Michael's Hospital in Toronto, tree nuts do more than that.
Contrary to our common perception of nuts as unhealthy, Dr. Sievenpiper found a modest decrease in blood fats known as triglycerides and blood sugars among people who added tree nuts to their diets compared to those who ate a control diet. Dr. Sievenpiper, himself a nut-lover, said that in his past work on developing clinical guidelines for diabetes, he and his colleagues wanted to examine the role of nuts in the diet: "We knew there was some benefit, but we didn't have enough information to know if there was an actual clinical benefit," he told me.
His study, published today in the journal BMJ Open, looked at 49 randomized control trials with 2,000 participants in order to examine the effect of tree nuts on metabolic syndrome. Metabolic syndrome (a group of factors that raise the risk for heart disease, diabetes and stroke) is present if someone has three of the following risk factors: Low levels of good cholesterol, high triglycerides, high blood pressure, high blood sugar, or extra weight around the waist.
Eating tree nuts (not peanuts as they are legumes) helps to reduce two of the five markers for metabolic syndrome, says Dr. Sievenpiper. Yet in North America, likely because of our fat phobia, we consume on average less than one serving of tree nuts per day. "Yes, the issue with nuts has been that they are considered high in fat and we have been fat phobic for a long time." In the randomized control studies, patients ate about 1 1/2 servings or about 50 grams -- salted and unsalted; one serving is about 1/4 cup or 30 grams.
Dr. Sievenpiper said the biggest reductions in triglycerides and blood glucose were seen when tree nuts replaced refined carbohydrates rather than saturated fats. Nuts have a high fat content, but the good unsaturated kind of fat. "Fifty grams of nuts can be easily integrated into a diet as a snack or as a substitute for animal fats or refined starches like rice, bread, potatoes and crackers," he explained. Try them in salads, stir fries, or use them as a meat alternative. "Think of your diet as a portfolio that can improve your metabolic health, your blood fat and blood sugar health." Adding nuts is one more positive way to make your diet more healthy.
One interesting aspect of his study was that those who ate nuts gained no extra weight. Dr. Sievenpiper suggests the reason may be that people are managing their intake very well. The other thing about nuts, he says, is that the calories on their label do not necessarily equal the calories that are metabolized by the body or are bio-available, he explains: Once in our digestive system nuts may equal fewer calories than we think. "Nuts fell out of favor when we had all that low-fat dietary advice for such a long time. But I think that nuts are experiencing a kind of renaissance. And yes, they are definitely heart-healthy."
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