With "nuts" we mean all shelled fruits (such as walnuts, hazelnuts, almonds, etc.). Examples of oil seeds are pumpkin seeds, sesame, sunflower, flax, which have nutritional characteristics to similar nuts, so the two types of food are brought together in the same group.
It is worth mentioning here that in the adult VegPyramid, nuts and oil seeds were placed in the protein food group and in the group of fats, and did not constitute a group by themselves. This decision was supported by the fact that the protein content of this group is notable. However, the amount of food normally consumed in this group is very low, and this limits the contribution to the total amount of protein in the diet. In addition, regular consumption of this food group in the context of a healthy diet (vegetarian or otherwise) is extremely important. So, in VegPlate, nuts and oilseeds have assumed the dignity of their own group, a fact that helps to differentiate VegPlate from the “parent” VegPyramid, which is now effectively archived.
On the market, different kinds of nuts and oilseeds can be found:
The foods in this group are an important source of unsaturated fatty acids, with the absence of cholesterol and limited saturated fat, the latter of which instead abound in animal foods. They also contain protein, fiber, vitamins and minerals (iron, calcium, zinc, magnesium and selenium), phytochemicals, and among the polyunsaturated fatty acids, essential fatty acids.
The richness in unsaturated fatty acids of these foods makes them excellent for the production of oils (the best known are those of peanuts and sunflower, while the most valuable is that of flaxseed). In particular, they are a prime source of polyunsaturated fatty acids, among which we also find omega-3 fatty acids, useful in the prevention of vascular diseases related to atherosclerosis.
Plant proteins provided by this group are of excellent quality, even if they contain small amounts of lysine, an amino acid that, however, is contained in other plant foods that you normally consume in a varied diet. It should however be considered that the amount of protein in fact supplied by this food group diet is small, given that the quantities to be eaten during the day is limited to an average of 60 grams.
The foods in this group also provide complex carbohydrates and fiber.
They also contain high amounts of vitamin E, of which are especially rich sunflower seeds, almonds and hazelnuts. They are also rich sources of iron, calcium and especially zinc.
Lastly, nuts and oil seeds are good sources of selenium, magnesium and phytochemicals.
The consumption of nuts and oilseeds is important for good health, whatever be the diet followed, vegetarian or omnivore, as it reduces the risk of chronic diseases. International dietary guidelines recommend the intake for their contribution of proteins, and especially of mono and polyunsaturated fatty acids, the latter to be given preference when compared to animal fats.
Today’s omnivorous diets are based on mass consumption of animal foods, rich in harmful saturated fats, which increase the level of LDL-cholesterol in the blood (the bad cholesterol), with the consequent increased risk of cardio-vascular disease (atherosclerosis, coronary heart disease and stroke). Eating instead dried fruit and seeds, the fats consumed are monounsaturated fats (called for the sake of abbreviation MUFAs) and polyunsaturated (PUFAs), that are protective against the above diseases.
In any healthy diet, vegetarian or omnivorous as it may be, it should be precisely these fats consumed. In particular, certain PUFAs, omega-6 and omega-3 family, are essential because the body is unable to produce them, and must be consumed in the diet.
MUFAs and PUFAs can be obtained precisely from the consumption of nuts and oilseeds.
Regarding the omega-6 fatty acids, their content is high in the various seed oils, and their consumption must be limited, because they interfere with the utilization of the omega-3 fats.
Walnuts and flax seeds (ground or in the form of oil) are excellent sources of omega-3 (in the form of ALA, alpha-linolenic acid), while other foods rich in vitamin E protect the omega-3 from oxidation (almonds , hazelnuts, sunflower seeds).
The omega-3 fats may be protective against certain cancers and cardiovascular diseases, because they become part of cell membranes and help to maintain their fluidity. They are also precursors of molecules that play important regulatory functions.
Vegetable fat sources are always preferable, because they do not contain cholesterol and allow to drastically decrease the intake of saturated fat.
Nuts and oil seeds are very versatile in the kitchen: they can enrich breakfast (for example, in the form of muesli) or provide a nutritious snack, can be ground and sprinkled on pasta or soups or on plates made of cooked cereal grains (risotto or the same made with other grains). Peeled almonds ground together with cashew nuts and pumpkin seeds or sunflower or sesame, with the addition of some salt, are an excellent substitute for Parmesan cheese on pasta.
Hazelnut, peanut, almond, or other creams can be spread on bread for a good breakfast or snack, while sesame (tahin) cream can also be used in various salted recipes.
A product ready for seasoning salads or pasta is gomasio, based on ground sesame seeds and salt, sometimes with the addition of broken algae. It can also be prepared at home, using less salt, since it is too rich.
It is better to consume nuts and seeds in their natural state, not toasted, salted, or sugared.
Smaller seeds (sesame and flax) can’t, as opposed to larger ones (pumpkin and sunflower), be effectively crushed by our teeth and therefore, to assimilate their nutrients, they must be ground in a grinder and pulverized. Flaxseed can then be used on cold dishes, so as not to denature the precious omega-3 fatty acids.