Most nuts and seeds are high in fat, but that isn't necessarily bad, as long as you stay in control. Eating portion-controlled amounts of the good kind of fat can placate your cravings and keep you from over-indulging in something far more unhealthy.
This category encompasses some foods that aren't true nuts but have similar nutrition. This includes peanuts (really legumes) and Brazil nuts and cashews, which are technically seeds. Because almost all nuts and seeds are super high in fat, it may surprise you that we are calling them fat-fighting foods. But the fat is unsaturated and may actually aid weight loss and does have disease-fighting properties. As long as you can restrain yourself, nuts and seeds can indeed be fat-fighters and help with weight loss. By taking the place of more traditionalprotein sources, nuts and seeds can actually reduce the saturated fat and calories in your overall diet.
Nuts and grains are high in protein and nutrients, though their fat content (75 to 95 percent of total calories) means you shouldn't eat too many at a time. Macadamia, the gourmet of nuts, is the highest in fat. Walnuts and Brazil nuts are your best bet because they're rich in omega-3 fatty acids.
Of all the nuts, peanuts provide the most complete protein. Other nuts are missing the amino acid lysine. But all are easily complemented by grains. As an alternative protein source, they also provide a good dose of healthy fats, including oleic acid, the healthy fat found in olive oil. Peanuts are rich in antioxidant polyphenols like those found in berries. Studies indicate that roasting actually increases the amount of polyphenol called p-coumaric, making roasted peanuts a true protector of cells.
Research has heartened nut lovers. Studies at Loma Linda University in California found that eating nuts five times a week (about two ounces a day) lowered participants' blood cholesterol levels by 12 percent. Walnuts were used, but similar results have been reported with almonds and peanuts. It appears that replacing saturated fat in the diet with the monounsaturated fat in nuts may be the key. It makes sense, then, to eat nuts instead of other fatty foods, not just to gobble them down on top of your regular fare.
Some nuts, notably walnuts and Brazil nuts, are rich in omega-3 fatty acids, which may contribute further to the fight against heart disease and possibly even arthritis. These healthful nuts also may play a role in weight loss and help you manage your weight better. Also, seeds and some nuts contain significant amounts of vitamin E. As an antioxidant, vitamin E can help prevent the oxidation of LDL cholesterol, which can damage arteries. More heartening news: Seeds are a good source of folic acid. Researchers have found that folic acid helps prevent the buildup of homocysteine. High levels of this amino acid have been linked to heart disease, dementia, and broken bones in people with osteoporosis. Eat plenty of folate to keep your homocysteine levels in check.
Seeds, peanuts, and peanut butter are super sources of niacin. Nuts are chock-full of hard-to-get minerals, such as copper, iron, and zinc. Seeds are among the better plant sources of iron and zinc. Iron helps yourblood deliver oxygen to your muscles and brain, while zinc helps boost your immune system. And nuts do their part to keep bones strong by providing magnesium, manganese, and boron.
One caution: Toxicity problems do not usually occur from eating foods, only from taking too much of a vitamin or mineral in supplement form. However, Brazil nuts contain an astonishingly high amount of selenium: about 70 to 90 micrograms per nut. In 2000 the National Academy of Sciences set the tolerable upper limit (UL) for selenium at 400 micrograms per day for adults. So, go easy on Brazil nuts, eating maybe one or two per day since you get selenium from other food sources, too.
Selection and Storage
Fresh nuts are available in fall and winter. Seeds and shelled nuts are available year-round, but check for a freshness date. If you buy bulk, they should smell fresh, not rancid. Aflatoxin, a known carcinogen produced by a mold that grows naturally on peanuts, can be a problem, so discard those that are discolored, shriveled, moldy, or taste bad.
Aflatoxin ingestion has been virtually eliminated, though, thanks to current storage and handling methods. Plus, the Food and Drug Administration (FDA) enforces a ruling stating that no more than 20 parts per billion of aflatoxin are allowed in foods. If purchasing raw peanuts or grinding your own peanut butter from raw peanuts, check to see that they have been stored in a cool (less than 85 degrees Fahrenheit), dry place. Roasted peanuts have a lower risk of containing aflatoxin. Use dry roasted ones so you don't have less-than-healthy fats mixing with the healthful oils in the peanuts themselves.
Because of their high fat content, you must protect nuts from rancidity. Unshelled nuts can keep for a few months in a cool, dry location. But once they're shelled or the container is opened, refrigerate or freeze them. Seeds with the hulls intact keep for several months if cool and dry; seed kernels don't keep as long.
Preparation and Serving Tips
By using nuts in cooking and baking, you can benefit from their nutrition without overdoing calories, since a little flavor goes a long way. Nuts on cereal can boost your morning fiber intake. Peanut butter on apple wedges or a slice of hearty whole-wheat toast is a superb breakfast or lunch. A sprinkling of seed kernels over pasta, salads, and stir-fries adds crunch and flavor.
Tips: Brazil nuts open easier if chilled first; almonds should be boiled and then dunked in cold water to make peeling them a snap. Roasting brings out flavor. Roast nuts at 180 degrees Fahrenheit for 18-20 minutes to preserve their heart-healthy fats.
Snacking on nuts and seeds is a great way to win the war against the bad kind of fat, and lose weight in the process. Just don't get caught with your finger in the peanut butter jar.