Go Nuts!
by Dana Denis, MSPH., RD (topic expert: nutrition)

Nuts. Once shunned as a high fat, high calorie food to avoid, nuts are now considered one of the "superfoods" to include daily as part of a healthy diet.

Did you know eating nuts dates back to the Stone Age of 7000 BC?[1] Through time, nuts were stored and then eaten during harsh winter months. Currently, in the United States nuts are consumed primarily as a snack food, but the Food Guide Pyramid (FGP) categorizes them as a meat alternative, due to their high protein content. The FGP suggests 1/2 ounce of nuts to replace one ounce of meat.

Studies have shown that a daily intake of 1 to 1.5 ounces of nuts (tree nuts or peanuts) provides protection against heart disease. In 2003, the Food and Drug Administration approved a health claim for nuts stating, "Scientific evidence suggests but does not prove that eating 1.5 ounces (42 g) per day of most nuts, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease."

Although nuts are high in fat, they are rich in the "healthy fats" - monounsaturated and polyunsaturated fats, which lead to reduced cholesterol levels as well as other risk factors associated with heart disease. However, it is more complex than that. Nuts also contain "phytochemicals" that help protect against disease. Phytosterols, high in peanuts and pistachios, help lower cholesterol. Carotenoids, also high in pistachios, but missing in peanuts, is an antioxidant. Phenols, found in most nuts and especially high in walnuts and almonds, are another group of antioxidants.

Nuts are also nutrient dense. In addition to being a good source of protein and fiber, they also contain many vitamins and minerals, especially Vitamin E and magnesium. Most Americans do not meet the recommended intake of these important nutrients. Vitamin E is a strong antioxidant that helps protect the immune system and magnesium is necessary for metabolism of nutrients as well as many of the pathways that keep our body functioning properly.

But aren't nuts still fattening? Nuts are very calorie dense and high in fat. However, in research studies of large populations (epidemiologic studies), those who ate nuts on a regular basis had a lower body mass index (BMI) than those that did not. In clinical research trials, participants were instructed to add nuts to their diets daily and the researchers expected a certain amount of weight gain due to the increase in calories. This was not the case. Nearly all the studies resulted in either no or little weight gain.

The reason may be cumulative of three mechanisms. 1. Eating nuts creates increased satiety which results in eating less food at the next meal. 2. Our bodies are not very efficient at absorbing the energy or calories from the nuts (have you ever eaten too many nuts and ended up in the bathroom more than usual ... well..enough said). 3. Eating nuts on a regular basis may also result in increased resting energy expenditure. In other words, even when you are resting you would be burning more calories. More research is needed to solidify and confirm these mechanisms.

That being said, more is not necessarily better. Because of the high caloric content of nuts, the recommendation is 1 to 1.5 ounces per day.

So how much is one ounce of nuts?
47 pistachios
28 peanuts or 2 tablespoons of peanut butter
24 almonds
20 pecan halves
18 cashews
14 walnut halves
11 macadamias

Now, how can I incorporate nuts into my diet?
Add walnuts, pecans or sliced almonds to salads.
Add pine nuts or hazelnuts to cooked pasta.
Try peanuts, cashews or almonds in stir fry dishes
Put slivered or sliced almonds, pine nuts or pistachios in vegetables.
Stir in slivered or sliced almonds to rice at the end of cooking.
And don't forget the nuts in your baked goodies!

Added tip: Toasting nuts in the oven or in a pan on top of the stove for a few minutes brings out their wonderful flavor!

So, go nuts!

1. King JC, Blumberg J, Ingwersen L, et al. Tree nuts and peanuts as components of a healthy diet. J Nutr 138: 1736S-1740S, 2008.
2. Mattes RD, Kris-Etherton PM, Foster GD. Impact of peanuts and tree nuts on body weight and healthy weight loss in adults. J Nutr 138: 1741S-1745S, 2008.
3. Davis PA, Jenab M, Vanden Heuvel JP, et al. Tree nut and peanut consumption in relation to chronic and metabolic diseases including allergy. J. Nutr 138: 1757S-1762S, 2008.
4. USDA nutrient database accessed on April 26th, 2009 at http://199.133.10.140/codesearchwebapp/(jidursnujqqr4zby0bds4ibx)/codesearch.aspx
5. Yaeger, V. Inside the shell. Today's Dietitian. 11(3): 49-53, 2009.