Good news for nut lovers: if you’re trying to lower cholesterol, eating nuts – in moderation – may just do the trick. A new study published in the May 10, 2010 issue of Archives of Internal Medicine finds that eating a third of a cup of nuts per day may help reduce cholesterol and triglyceride levels.

The authors say that the effect of nuts was dose-dependent, meaning that the more nuts were consumed, the greater the effect on cholesterol and triglycerides. Of course, there is an upper limit to this phenomenon

Joan Sabaté and colleagues at Loma Linda University reviewed 25 earlier studies that included 583 male and female participants. They found that eating about 67 grams, or 2.4 oz., of nuts per day was associated with a 5.1% reduction in total cholesterol level (that is, both “good” HDL and “bad” LDL varieties). LDL cholesterol by itself was lowered by 7.4%, which made the LDL-HDL ratio (bad-to-good) increase by 8.3%, which is an healthy improvement. Finally, triglyceride levels were reduced by over 10% in people who had high levels to start, but similar changes were not seen in people with normal levels of the blood fats.

The authors say that the effect of nuts was dose-dependent, meaning that the more nuts were consumed, the greater the effect on cholesterol and triglycerides. Of course, there is an upper limit to this phenomenon: since nuts are high in fat and calories, eating too many would eventually negate their beneficial effects. The authors found that the effect of nuts was the greatest in people who had normal body mass indexes (BMIs) but had high LDL cholesterol levels to start. It was also most pronounced in people who typically ate Western-style diets – in other words, high-fat diets – rather than low-fat, Mediterranean-style diets.

Interestingly, the kind of nut did not seem to matter, since a large variety of nuts was shown to effect cholesterol and blood fats in a similar way. Sabaté and his team underline the many other health benefits of nuts, which they say “are a nutrient-dense food rich in plant protein (10%-25%) and fat (50%-75%), mostly unsaturated fatty acids.” It is likely these unsaturated fats that are responsible for nuts’ cholesterol-lowering effect. The authors add that nuts include a wide array of other necessary nutrients, like fiber, vitamins, minerals, and antioxidants.

The authors conclude that their findings “support the inclusion of nuts in therapeutic dietary interventions for improving blood lipid levels and lipoproteins and for lowering [coronary heart disease] risk.”