Nutrition 101 - Glossary - P
Paired Testing – Definition – Testing blood sugar (glucose) before and after an activity or event, such as eating or exercise. Relevance – This before/after testing enables a person with diabetes to see the effect of an activity on blood sugar. It can provide insights into how to improve blood sugar.
Palmitic acid – Definition – A saturated fatty acid (identified chemically as C16:0). It is found in higher amounts in palm oil and animal fats. Relevance – The majority of saturated fat we consume is from palmitic acid. It is associated with raising LDL (bad) cholesterol levels and increased heart disease risk.
Pantothenic acid – Definition -Pantothenic acid, or vitamin B5, is a water-soluble vitamin that is found in meat, vegetables, grains, dairy, eggs, and legumes. Relevance - Pantothenic acid is found in the body as a component of coenzyme, which is involved in key life-supporting reactions; it is commonly used to treat numerous conditions, although there is not enough scientific evidence to determine if it is effective for anything other than pantothenic acid deficiency.
Parboiled rice – Definition - Parboiled rice (sometimes called converted rice) has been soaked, steamed and dried before milling. Relevance - This process allows the inner kernel to absorb some of the nutrients from the outer layers of the grain, so not as many nutrients are lost in the processing of white rice. It can also delay rancidity. When cooked, it has a firmer texture.
Pectin – Definition -Pectin is a fibrous material found in the peel and pulp of plants. Relevance - Pectin is used as a treatment for high cholesterol and reducing cancer risk, as well as diarrhea; in the food industry, it is sometimes used to gelatinize foods and is naturally found in apples and citrus fruits.
Periodic fasting – Definition – A form of intermittent fasting in which people generally fast (eating 25% or less of their daily calorie needs) on two non-consecutive days a week. On the other five days of the week, they eat as they normally would. Relevance – The 5:2 fasting diet regimen is an example of periodic fasting that has become popular in recent years. A preliminary small human trial suggests it may promote weight loss similar to a traditional reduced-calorie diet, but more research is needed.
Periodontal disease – Definition – Inflammation of the gums that, if severe, can lead to the loss of tissues that hold your teeth in place. It is caused by plaque. Relevance – To help prevent periodontal disease, remove plaque by brushing twice a day and flossing daily.
Peripheral neuropathy – Definition – Nerve damage causing numbness and pain, usually in the hands and feet. Relevance – Damage may be permanent, especially if the condition is not detected and treated early. It can be caused by many different conditions, such as diabetes and vitamin B12 deficiency.
Phenolics – Definition -Phenolics are compounds found in all plants that are secondary metabolites, meaning that they are produced but not necessary for growth and development. Relevance - Phenolics have been shown to confer health benefits via antioxidant activity and may be protective against cancer and other chronic diseases.
Phosphorus – Definition -Phosphorus is an essential mineral that comprises 1% of body weight and is found in all body cells, but mostly the bone and teeth. Relevance - Phosphorus is critical to formation of bones and teeth, protein synthesis, and the body's use of fats and carbohydrates for energy; meat and dairy are the major dietary sources of phosphorus because although it is present in grains, they contain a storage form that is not bioavailable.
Phloem – Definition – The intermediate layer of a carrot, immediately below the peel. Relevance – The phloem contains appreciable amounts of vitamin C and beta-carotene (the plant form of vitamin A), as well as about 40% of the phytochemicals of a carrot.
Phytic acid – Definition - Phytic acid is a storage unit for the phosphorus present in most grains and seeds. Relevance - Phytic acid is thought to be a natural phytooxidant and has been studied for lowering cholesterol and decreasing the risk of cetain colon cancers; it is used as a preservative in foods.
Phytochemical – Definition - lPhytochemicals are plant chemicals that may affect health, found in fruits, vegetables, nuts, legumes, and grains. Relevance - Plant-based foods are complex and replete with vitamins, minerals, and other active compounds, so studying the effect of individual phytochemicals on health is difficult.
Phytoestrogens – Definition – Naturally-occurring plant compounds that are similar in structure and/or function to human estrogen (but are comparatively weaker). They’re found in a variety of foods, most notably soy products. Relevance – The health effects of phytoestrogens are uncertain but may include benefits for menopausal health and bone health, among others
Phytonutrients – Definition - Phytonutrients are plant components that are believed to have beneficial effects on human health. Relevance - Sources of phytonutrients include fruits, vegetables, grains, legumes, tea and nuts and include classes such as carotenoids, flavonoids, lignans, phenols, terpenes, and more.
Polyols – Definition -Polyols are low calorie carbohydrates that have a low glycemic index and low digestibility. Relevance - Polyols are often used as a sugar-free alternative in some sugar-free and low-sugar foods, such as chewing gum.
Polyphenols – Definition -Polyphenols are antioxidant phytochemicals that are abundant in the diet and associated with decreased risk of certain degenerative diseases. Relevance - The most abundant antioxidant in the diet, polyphenols have been associated with a reduced risk of developing cardiovascular disease, cancers, and osteoporosis; common sources include fruits and beverages derived from plants, such as tea, coffee, red wine, and fruit juice.
Polyunsaturated fat – Definition -Polyunsaturated Fatty Acids (PUFAs) are fats that contain more than one double bonded (unsaturated) carbon in their chemical backbone and are usually liquid at room temperature. Relevance -In moderation, PUFAs can help reduce blood cholesterol and decrease risk of heart disease, especially when they replace saturated fats and trans fats in the diet, and they also include essential omega-3 and omega-6 fats.
Potassium – Definition - Potassium is a mineral that is essential in the body for regulating homeostasis and is found in meat, fish, soy, and some vegetables. Revelance - In the body, potassium is an electrolyte critical for building muscle and proteins, regulating the electrical activity of the heart, carbohydrate breakdown and controlling pH.
Potassium chloride – Definition -Potassium chloride is a mineral supplement that is used to treat low blood potassium levels and sometimes used as a salt substitute in food. Relevance - Potassium chloride is toxic at high levels and is one of the three substances in the combination used for lethal injection; since it is not palatable, it is often mixed with table salt when it is used as a salt substitute in foods.
Prebiotic – Definition - Prebiotics are indigestible carbohydrates that are fermented by the bacteria in the gut, benefitting the host and the gut microflora. Relevance - Prebiotics are fermented by the 'good' bacteria in the gut to improve digestive health by promoting growth of the gut microflora; they are found in whole grains, artichokes, leeks, onions, garlic and bananas.
Probiotic – Definition -Probiotics are live bacteria or microorganisms that are similar to those found naturally in the gut that confer health benefits, thus often called 'good' bacteria. Relevance - Probiotics can be found in foods fermented by bacteria, like yogurt or kefir, and may treat gastrointestinal problems and boost immunity.
Prolonged nightly fasting – Definition – Also called time-restricted feeding. It’s a form of intermittent fasting in which people generally restrict eating to a shorter time window than typical, such as eight hours a day. Relevance – A person following such a regimen might fast from 8 p.m. at night until noon the next day. During non-fasting periods, they eat as they normally would. Research on this approach in humans is limited.
Prostaglandins – Definition -Prostaglandins are created in the body from fatty acids and act as local messenger molecules, similar to hormones. Relevance - Prostaglandins regulate the contraction and relaxation of smooth muscle cells, regulate calcium and hormone regulation, and control other homeostatic functions; prostaglandins also may have a role in inflammation.
Proteoglycans – Definition - Proteoglycans are present in the matrix surrounding connective tissues, like cartilage. Relevance - Proteoglycans act as a buffer for connective tissue, allowing it to endure compression and physical stress.
Protocatechuic acid – Definition - Protocatechuic acid (PCA) is a phenolic compound found in fruits, vegetables, and nuts. Relevance -PCA is an antioxidant that may have a role is cancer treatment and decreasing carcinogens.
Proton-pump inhibitor – Definition -Proton pump inhibitors (PPIs) are a strong class of drugs that are used to treat stomach acid problems by reducing the amount of stomach acid produced. Relevance - PPIs are used to treat peptic or stomach ulcers, acid reflux or gastroesophageal reflux disease (GERD), and lower esophagus damage caused by acid reflux.
Psyllium husk fiber – Definition – Comes from the Plantago ovata plant. It absorbs water in the gut, making stools softer, bulkier and easier to pass. Relevance – Psyllium fiber supplements are sometimes used in to treat constipation. Supplements are typically available as a powder you mix into liquid or as capsules (which should be taken with at least 8 ounces of water).
Purines – Definition – Compounds found in high amounts in certain animal foods (like meat and seafood) that are converted to uric acid in the body. Relevance – High levels of uric acid in the blood increase gout risk. If you have gout, you may be advised to reduce intake of purine-rich foods to help reduce uric acid levels.