A study published earlier this year in the Archives of Internal Medicine looked at the effects of nut comsumption on blood cholesterol and triglyceride levels. The news is very good for those of us who are nuts for nuts: looking at data from 583 people in 25 trials conducted in 7 countries, the authors found "the best evidence yet that eating nuts reduces LDL cholesterol and improves the blood lipids profile," according to co-author Dr. Joan Sabaté, chair of the nutrition department at the Loma Linda University School of Public Health.
They found a dose-dependent effect where nuts lowered total cholesterol levels, improved the ratio of HDL (good) to LDL (bad) and total cholesterol, and reduced high triglyceride levels. The effect was the same for all types of nuts -- walnuts, almonds, peanuts (botanically, not a nut, but fakes it well enough), pecans, hazelnuts, macadamias and pistachios. They also found that the cholesterol lowering effect is greater then found when nuts replace saturated fats than when they replace olive oil or carbohydrates.
Now, there is such a thing as too much of a good thing: nuts are a great source of energy, as any trail-mix chomping hiker knows, so overdoing them can pack the diet with too many calories. The highest daily intake of nuts looked at in the trials reviewed was 132 grams -- 4.66 ounces, which is probably a little high. Sabaté recommends a limit of 3 ounces a day.
According to the FDA, "scientific evidence suggests but does not prove that eating 1.5 ounces of most nuts per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease."
As a snack, I love to cut up an apple or a pear and sprinkle on some almonds or walnuts. It's great raw, or sprinkle on some cinnamon and briefly bake, or heat it up in the microwave for a minute -- yum!