Nuts are seeds that are covered with a hard shell, most are the seeds of trees. Nuts and seeds are very healthy and nutritious. They are excellent sources of protein, vitamins, minerals, essential fatty acids and fibre. Hence they are an important part of any vegan or vegetarian's diet.
Nuts can be used in cooking many different ways. Whole, flaked, ground and nut butters are widely available. As well as making a great snack, nuts and seeds add texture and flavor to many recipes and can be used in savoury or sweet dishes.
Studies have shown that a diet rich in nuts and seeds helps to reduce the risk of heart disease and cancer:
- Most nuts are high in the amino acid arginine that reduces cholesterol levels and, as a precursor to nitric oxide, dilates blood vessels, thus reducing blood pressure. It also inhibits tumour growth and boosts immunity.
- Most of the fat in nuts consists of the polyunsaturated omega-3 and omega-6 varieties that reduce blood cholesterol levels.
- Many nuts are rich in vitamin E which helps prevent the oxidation of cholesterol that leads to fatty build up in the arteries.
- Vitamin B9 (folate) lowers high blood levels of homocysteine, a strong predictor of heart disease.
- Nuts and seeds are generally rich in calcium, magnesium and potassium, all of which serve to reduce blood pressure.
- The coatings of all nuts and seeds (such as the thin brown papery layer coating almonds and peanuts) are rich in the antioxidant polyphenols. These are associated with reduced risk of heart disease and cancer. Raw nuts and seeds possess greater amounts of antioxidants, therefore use them raw whenever possible.
- Walnuts in particular are high in alpha-linolenic acid, an essential fatty acid that protects the heart and in ellagic acid, the cancer-fighting polyphenol antioxidant.
- Phytic acid found in nuts and seeds serves as a potent antioxidant to help preserve seeds and may reduce the rate of colon cancer.
- Selenium is an antioxidant, abundant in brazil nuts which has cancer preventative properties.
The appetite-suppressing and health benefits of nuts and seeds are lost when they are salted, oiled, roasted, stale, or rancid. The fats in nuts and seeds are susceptible to oxidation after they are shelled and exposed to light and air. They therefore should be bought in small quantities and stored in their shells. It is ideal to store any nuts and seeds in an airtight container in a refrigerator or freezer.
The enzyme inhibitors and phytates in nuts limit the availability of their nutrients. To maximize the nutritional value of nuts, soak nuts in salted water for six to eight hours, drain out the water and oven-dry the nuts on a cookie sheet on low heat. This would stimulate the process of germination, which increases the vitamin C, B, and carotenes (pre-vitamin A) content. It may also neutralize phytic acid which can inhibit some absorption of calcium, magnesium, iron, copper, and zinc. Raw nuts and seeds also contain enzyme inhibitors that are neutralized by germination.