SHERYL AFONSO e D’SOUZA
CLINICAL NUTRITIONIST (NORBERT’S FITNESS STUDIO) & ASST. PROFESSOR (POST GRADUATE DEGREE STUDIES, CARMEL COLLEGE)
Yeast has been in use for more than 5000 years, first for leavening bread and then to produce alcoholic beverages. The scientific name for yeast is Saccharomyces cerevisiae, and the two commonly used industrial forms are Brewer’s yeast and Baker’s yeast. Brewer’s yeast is a brewery by-product, made from dead yeast cells left over from the brewing process. It has a very bitter taste but can be consumed as a nutritional supplement as it is a source of the B-complex vitamins, amino acids, and a few minerals. Brewer’s yeast is also purchased alive, and is used to brew beer. Baker’s yeast is purchased alive – it is dried at low temperatures so that the yeast is not killed. It is used to leaven bread; the yeast is killed during baking, but its presence adds an earthy flavor to bread.
Nutritional yeast is yeast that has been specifically grown to be used as a consumable food product. It is a species of Saccharomyces cerevisiae, but is not technically the same as Baker’s or Brewer’s yeast. To produce nutritional yeast, S. cerevisiae cells are grown for several days on a sugar-rich medium such as molasses. The yeast is then deactivated with heat, harvested, washed, dried, crumbled into flakes, granules, or powder, and packaged for distribution. Nutritional yeast cannot be used for brewing or baking because it is ‘inactive’ or ‘dead’. It is, instead, used in cooking and has a cheesy, nutty or savory flavor often used to emulate cheese in vegan dishes, thicken sauces and dressings, and act as a nutritional supplement. There are two types of nutritional yeast:
- Unfortified, which does not contain any added vitamins or minerals, but only the micro-nutrients that are naturally produced by the yeast cells as they grow
- Fortified, which contains synthetic vitamins added during the manufacturing process to boost its nutritional value
Nutritional yeast is known by various other names – nooch, yeshi, brufax, savory yeast flakes – across the world. Loaded with a host of B vitamins – folate, thiamine, riboflavin, niacin – as well as trace minerals such as selenium, chromium and zinc, protein, vital food factors such as lipoic acid, GABA, glutathione, and ?-glucans, nutritional yeast is often called a ‘super food’.
Best suited for vegans, nutritional yeast is a complete protein since it contains all the 9 essential amino acids; the only other known foods that can boast of the same are flesh foods and dairy products. It also helps prevent Vitamin B12 deficiency in vegans. Vitamin B12 is needed for a healthy nervous system, DNA production, energy metabolism and the creation of red blood cells, and is only found naturally in animal products. Hence, vegans are often deficient in this vital nutrient, and consuming nutritional yeast can be an effective way to prevent vitamin B12 deficiency while on a vegan diet. Below are some of the other proven benefits of consuming nutritional yeast as part of a balanced diet:
- Enhanced Immunity: due to the presence of immune-boosting ?-1, 3 glucan, trehalose, ?-mannan and glutathione in nooch.
- Tissue Repair: due to the presence of selenium and zinc. The powerful antioxidants glutathione and selenomethionine present in nutritional yeast also protect cells from damage caused by free radicals and heavy metals, thereby eliminating one of the major causes of cancer, cardiovascular disease, and premature ageing.
- Decreased Serum Cholesterol: a result of the dietary fibre ?-1, 3 glucan present in nooch.
- Improved Digestion: due to the presence of probiotics in nutritional yeast.
- Healthy Hair, Skin and Nails: a result of the B vitamins, especially niacin, biotin and vitamin B5.
- A Healthy Pregnancy: the abundance of folate in nutritional yeast makes it ideal for preventing neural tube defects in the foetus.
Concerns about allergies to the product abound. However, it must be noted that the yeast is completely deactivated, and so will not give rise to any sensitivities. In fact, people often sensitive to active yeast found in bread can consume this variety safely and with no repercussions. Nutritional yeast is also said to contain compounds similar to MSG (monosodium glutamate) – an excitotoxin present in the much talked about ajino moto. Yeast is a natural source of glutamate, from which it derives its umami flavour, unlike the artificially manufactured MSG. Hence, the glutamate in yeast comes ‘bound’ to other chemicals and fibre, which the body is naturally inclined to regulate. Any excess glutamic acid is passed off as waste, and not stored in your body, contrary to what happens with MSG. The only downside of nutritional yeast is its tendency to raise serum uric acid levels, and hence people with gout are advised to limit its intake to not more than 2 tbsp per day.
Nutritional yeast – which is neither plant nor animal, but rather fungus, like mushroom – can certainly be a beneficial dietary addition, suited to people of all ages and eating habits.