Glossary - "G"
​
Gaba – is a neurotransmitter, a chemical messenger in your brain. It slows down your brain by blocking specific signals in your central nervous system (your brain and spinal cord). It is known for producing a calming effect. It is thought to play a significant role in controlling nerve cell hyperactivity associated with anxiety, stress, and fear. It is present in some fermented foods, including kimchi, miso, and tempeh. It is also found in green, black, and oolong tea. Other foods that contain it or boost its production in your body include brown rice, soy and adzuki beans, chestnuts, mushrooms, tomatoes, spinach, broccoli, cabbage, cauliflower, Brussel sprouts, sprouted grains, and sweet potatoes.
Galactooligosaccharides – prebiotics made up of plant sugars linked in chains. They are found in dairy products, beans, and certain root vegetables. Prebiotics act as food for "good" bacteria in the intestine. They pass undigested into the colon, increasing bowel mass and promoting certain bacteria's growth. People use it for eczema, colic, hay fever, food allergies, constipation, obesity, and many other conditions, but there is no good scientific evidence to support most of these uses.
Ginko Biloba – the extract from ginkgo leaves is promoted as a dietary supplement for many conditions, including anxiety, allergies, dementia, eye problems, peripheral artery disease (when a buildup of plaque narrows the blood vessels that carry blood to the head, organs, and limbs), tinnitus, and other health problems. However, these claims have yet to be validated by the FDA. Side effects may include headache, stomach upset, dizziness, palpitations, constipation, and allergic skin reactions. If you have a known bleeding risk, consult a physician before consuming it.
Ginseng – an herbal supplement used for centuries in Chinese medicine. It is commonly touted for its antioxidant and anti-inflammatory effects. It could also help regulate blood sugar levels and benefit certain types of cancer. However, these claims have yet to be validated by the FDA. People with high blood pressure should only take ginseng if they are under the supervision of a doctor.
Gluconic Acid – a mild, organic acid that is non-toxic, biodegradable, and occurs naturally in fruit, honey, and wine. As a food additive, it is used as an acidity regulator (a compound that alters or maintains a product's proper pH).
Glucosamine Hydrochloride – a nutritional supplement which, in animal studies, has shown can delay the breakdown of and repair damaged cartilage. However, these claims have yet to be validated by the FDA.
Glucose – a natural, simple sugar that is an important energy source in living organisms and a component of many carbohydrates. It is about ¾ the sweetness of sugar. It has a high glycemic index. It is found in various foods, including fruits, vegetables, whole grains, and dairy. It is a popular sweetener for many beverages and has about the same caloric count as sugar. See the definition for "sweeteners" for further information and comparison to other options.
Glucuronolactone – is commonly used in "energy" drinks to increase attention and improve athletic performance, but no good scientific evidence supports it. Levels of glucuronolactone in energy drinks can far exceed those found in the rest of the diet. Research is too limited to assert claims about its safety.
Glutamine – the most abundant amino acid found in the body. It is made in the muscles and transferred by the blood into different organ systems. Glutamine is a building block for making proteins in the body. It is also needed to make other amino acids and glucose.
Glutathione – made from the amino acids glycine, cysteine, and glutamic acid. It is produced by the liver and involved in many body processes, including tissue building and repair, making chemicals and proteins needed in the body, and immune system function.
Gluten – is a protein found in many grains, including wheat, barley, and rye. It is common in bread, pasta, pizza, and cereal. It helps food maintain its shape by providing elasticity and moisture. It also allows bread to rise and provides a chewy texture. Gluten provides no essential nutrients. People with celiac disease have an immune reaction that is triggered by eating gluten. They develop inflammation and damage in their intestinal tracts and other body parts when they eat gluten-free foods. Current estimates suggest that up to 1% of the population has this condition. However, all the marketing hype about it makes it seem like the impact is much higher. As a result, 20% to 30% of the US population follows a gluten-free diet (or has done so in the past).
Gluten-Free – a gluten-free diet is for people with celiac disease or other health conditions that make it hard for their bodies to process gluten. Many food items are gluten-free, including some whole grains (e.g., quinoa, brown rice, wild rice, tapioca, etc.), some fruits (e.g., citrus, bananas, apples, berries, peaches, pears), some vegetables (e.g., cauliflower, broccoli, leafy greens, potatoes, corn, squash, peppers, mushrooms, onions, carrots, radishes, green beans), some proteins (legumes, nuts + seeds, red meat, poultry, seafood, tofu, edamame), some dairy products (milk, butter, cheese, cream, cottage cheese, sour cream, yogurt), some fats and oils (e.g., butter, olives, olive oil, avocados, avocado oil, coconut oil, vegetable and seed oils), some beverages (e.g., water, 100% fruit juice, coffee, tea, lemonade, wine, hard ciders, and many types of sports drinks, soda, and energy drinks – but check their labels).
Glycemic Index (GI) – measures how quickly a food can raise blood sugar (glucose). Only foods that contain carbohydrates have a glycemic index. Not all carbohydrates work the same in the body. Some trigger a quick spike in blood sugar, while others work more slowly, avoiding significant or rapid rises in blood sugar. The glycemic index addresses these differences by assigning a number to foods that reflect how quickly they increase blood glucose compared to pure glucose (sugar). The glycemic index scale goes from 0 to 100. Pure glucose has the highest GI and is given a value of 100. Eating low-GI foods can help you gain tighter control over your blood sugar. Paying attention to the glycemic index of foods can be another tool to help manage diabetes, along with carbohydrate counting. Following a low-GI diet also may help with weight loss. When consuming beverages, especially multiple beverages, in a short period, you should pay particular attention to the impact of sweeteners on your blood sugar levels. Many ready-to-drink products that are thought to contain a single serving might contain multiple servings. Always read labels carefully.
Glycerine – a carbohydrate known as a sugar alcohol or a polyol. This odorless liquid has a sweet taste and a syrupy consistency. While glycerin occurs naturally in plants through the fermentation of sugars, most of the glycerin used in commercial products today is produced from the hydrolysis of fats and oils. It has about 70% of the sweetness of sugar and a zero glycemic index. See the definition for "sweeteners" for further information and comparison to other options.
Glyvia – a plant-based, zero-calorie supplement patented by Biologic Pharmamedical, and approved by Health Canada. It is a blend of plant glycosides and amino acids that provide a full-mouth flavor like sugar without the bitter aftertaste of substitute sweeteners. It is five times sweeter than sugar. It has zero calories, zero carbohydrates, and a zero glycemic index. See the definition for "sweeteners" for further information and comparison to other options.
Golden Root Extract (Rhodiola Rosea) – a natural tonic, referred to as an "adaptogen" used to promote good health, strength, endurance, physical performance, and mental performance. However, these claims have yet to be validated by the FDA.
Gout – a type of inflammatory arthritis that causes joint pain and swelling, usually as flares that last for a week or two, and then resolve. Gout flares often begin in your big toe or a lower limb. Avoid foods that may trigger a gout flare. These foods include those high in purines (like a diet rich in red meat, organ meat, and seafood, as well as alcohol, including beer and hard liquor).
Grape Seed Extract (Vitis Vinifera) – in their natural form, the seeds of grapes contain fiber, minerals, protein, water, and oil. They are rich in numerous minerals, but their most potent nutrients are antioxidants like Vitamin E, Linolenic Acid, Potassium, Copper, Phosphorus, Calcium, Zinc, Magnesium, and Iron.
Green Coffee Bean Extract – unroasted coffee beans that contain caffeine and are rich in antioxidants. Some studies show that the caffeine in green coffee beans may be helpful for weight loss. Still, since caffeine is a stimulant, children, people with heart issues, and women who are pregnant or nursing should avoid consuming it, as it can cause insomnia, nervousness, restlessness, nausea, and an increased heart rate.
Green Tea Extract – a concentrated form of green tea that is an excellent source of antioxidants. These have been credited with various health benefits — from promoting heart, liver, and brain health to improving skin and even reducing cancer risk. However, these claims have not been validated by the FDA. Green tea extract contains caffeine, a stimulant, which is not recommended for children, people with heart issues, and women who are pregnant or nursing, as it can cause insomnia, nervousness, restlessness, nausea, and an increased heart rate.
Guarana – a plant native to the Amazon. It is a common ingredient of energy drinks and can be unsafe in large amounts. It contains caffeine. Caffeine works by stimulating the central nervous system, heart, and muscles. Guarana also contains theophylline and theobromine, which are chemicals like caffeine. People consume it for weight loss, athletic performance, mental performance, to increase energy, and for many other reasons, but no good scientific evidence supports these uses.
​