Nutrition

The acceptable daily intake, or ADI, is the amount of a substance a person can consume every day across a whole lifetime without appreciable risk to health. It is expressed per…

Acesulfame K is the potassium salt of an oxathiazinone dioxide, coded E 950 in the EU and often labelled acesulfame potassium. It is roughly 200 times sweeter than table sugar,…

Alpha-lipoic acid (ALA) is a sulfur-containing fatty acid. It is an essential helper (cofactor) for two mitochondrial enzyme complexes (pyruvate dehydrogenase and α-ketoglutarate…

Apigenin is a plant flavone, found in parsley, celery, chamomile, and dried oregano. In a 2013 Diabetes paper, Escande and colleagues found that apigenin inhibits CD38, an enzyme…

Aspartame is the methyl ester of the dipeptide aspartyl-phenylalanine, coded E 951 in the EU. It is roughly 200 times sweeter than table sugar. Gram for gram it yields 4 kcal,…

Astaxanthin is a red-pink pigment (a ketocarotenoid). It is made mainly by a microalga (Haematococcus pluvialis). It then travels up the food chain into crustaceans, salmon, and…

Blue Zones are regions reported to have unusually many centenarians. The popular list (from Buettner) includes Okinawa (Japan), Sardinia (Italy), Nicoya (Costa Rica), Ikaria…

The branched-chain amino acids (BCAAs) are leucine, isoleucine, and valine. They are essential amino acids, rich in meat, dairy, eggs, and the protein supplements you might buy.…

Caffeine is a methylxanthine alkaloid, found in coffee, tea, and cocoa. It works by blocking your adenosine A1 and A2A receptors. Normally, adenosine signaling makes you drowsy…

Carnosine is a dipeptide (beta-alanine plus L-histidine), concentrated in your skeletal muscle and nerve tissue. It works through four mechanisms. It buffers pH inside cells…

Choline is a water-soluble nutrient. The US Institute of Medicine officially recognized it as essential in 1998. It set Adequate Intakes of 425 mg a day for adult women and 550…

Coenzyme Q10 (also called ubiquinone) is a fat-soluble molecule. It is essential for mitochondrial electron transport and ATP production, and it acts as an antioxidant inside…

Collagen peptides are also called hydrolysed collagen or collagen hydrolysate. They are made by enzymatically breaking down animal collagen into small fragments, about 2 to 5…

Creatine is a compound your body makes in the liver and kidneys. It builds it from the amino acids arginine, glycine, and methionine. You also get creatine from red meat, fish,…

Curcumin is the main polyphenol in turmeric (Curcuma longa). It tunes several inflammatory and oxidative pathways, including NF-kB and Nrf2. But there is a big practical problem.…

Dietary fiber is the plant carbohydrate your gut enzymes cannot break down. It comes in two main types. Soluble fiber (like pectin, beta-glucan, and inulin) dissolves in water…

Dietary nitrate (NO₃⁻) is abundant in beetroot, leafy greens, and celery. Your body converts it to nitric oxide (NO) in a two-step cascade. First, your salivary glands…

EGCG (epigallocatechin gallate) is the most abundant catechin in green tea. It is a polyphenol. It has antioxidant, anti-inflammatory, and AMPK-tuning activity. Observational…

Ergothioneine is a sulfur-containing compound (a histidine betaine), mostly in its 'thione' form. Only fungi, certain bacteria, and cyanobacteria can make it. You get it from…

Erythritol is a four-carbon sugar alcohol, or polyol, used as a bulk sweetener and coded E 968 in the EU. It is about 70 percent as sweet as table sugar and carries essentially…

Fisetin is a flavonoid (a plant compound) found in strawberries, apples, and persimmons. So you already eat a little. In aged mice, one study (Yousefzadeh et al., 2018,…

Flavonoids are a big subclass of plant polyphenols, built on a 15-carbon backbone. They come in six families. Flavonols (quercetin, kaempferol; onions, kale). Flavan-3-ols…

The glycemic index (GI) ranks foods by how fast their digestible carbs raise your blood sugar, compared with pure glucose (GI = 100). A GI of 55 or under is low, 56 to 69 is…

Glycine is the smallest, simplest amino acid. It is 'non-essential' under normal conditions. But it is 'conditionally essential' in aging, pregnancy, and disease. In those…

GlyNAC is the combined supplement of glycine plus N-acetylcysteine (NAC). The aim is to refill both building blocks of glutathione (the tripeptide γ-Glu-Cys-Gly), which falls…

Hydroxytyrosol is the main antioxidant phenol in olive oil and olive leaves. (It is an ortho-diphenolic compound.) In the fruit and the oil, it sits mostly bound inside a bigger…

Lutein and zeaxanthin are two xanthophyll carotenoids (dihydroxy types). They build up in your macula, the central retina, where they form the 'macular pigment' and filter blue…

Lycopene is an acyclic, fat-loving carotenoid (a plant pigment) that gives tomatoes, watermelon, and pink grapefruit their red color. You absorb it better from heat-processed…

The Mediterranean diet is an eating pattern built around vegetables, fruits, legumes, whole grains, nuts, olive oil, and fish, the kind of meals you can eat every day, with…

Methionine restriction (MR) means cutting the sulphur amino acid methionine in your diet, without an overall cut in calories. Orentreich and colleagues first reported, in 1993,…

The MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay) is a hybrid eating pattern aimed at protecting your brain. It emphasizes leafy greens, berries, nuts,…

N-acetylcysteine (NAC) is a tweaked form of the amino acid cysteine. In the clinic, it loosens mucus and serves as the standard antidote for acetaminophen (paracetamol) overdose.…

NMN is a building block your body uses to make NAD+, a coenzyme that is central to energy, sirtuin activity, and DNA repair. It enters NAD+ production through the salvage…

NR is a form of vitamin B3 and another building block for NAD+, the energy-and-repair coenzyme. Your body converts it through salvage pathways (possibly passing through NMN on…

EPA and DHA are the two key omega-3 fats. EPA is 20:5n-3; DHA is 22:6n-3. Both are long-chain polyunsaturated fats, found mainly in oily fish and fish oil (or algae supplements,…

Polyphenols are a huge, diverse group of plant compounds, over 8,000 of them. They are all built around aromatic rings carrying hydroxyl groups. The major subclasses include…

Pterostilbene is a close cousin of resveratrol (a dimethylated stilbene). It is found naturally in blueberries, grapes, and Indian kino (Pterocarpus marsupium) heartwood. Two…

Quercetin is a flavonoid. You find it in onions, apples, capers, and berries. It has antioxidant and anti-inflammatory activity. It is being studied as a senolytic. (A senolytic…

Resveratrol is a stilbene polyphenol, found in grape skins, red wine, and Japanese knotweed. It is studied as a possible sirtuin (SIRT1) activator and AMPK modulator, with…

Saccharin is a benzoic sulfimide and the oldest synthetic sweetener, discovered in 1879 and coded E 954 in the EU. It is roughly 300 to 500 times sweeter than table sugar,…

Selenium is built into proteins as the amino acid selenocysteine, often called the 21st amino acid. That forms a class of enzymes called selenoproteins, with 25 encoded in the…

Sorbitol is a six-carbon sugar alcohol, coded E 420 in the EU. It occurs naturally in stone fruits and is produced industrially by hydrogenating glucose. It is roughly 60 percent…

Soy isoflavones are plant compounds (polyphenols) that act as weak estrogens. They look structurally similar to your body's estrogen (17β-estradiol). They are concentrated in…

Spermidine is a naturally occurring polyamine, found in wheat germ, aged cheese, soy, and mushrooms, so you already eat some. The content varies a lot by source and processing.…

Stevia is the common name for sweeteners extracted from the leaves of Stevia rebaudiana. The sweet compounds are steviol glycosides, chiefly stevioside and rebaudioside A, coded…

Sucralose is a chlorinated derivative of sucrose, coded E 955 in the EU, in which three hydroxyl groups are replaced by chlorine atoms. It is roughly 600 times sweeter than table…

Sulforaphane is a plant compound (an isothiocyanate). It forms when you chew or chop broccoli, broccoli sprouts, and other crucifers. It activates a pathway called Nrf2. That…

Taurine is a sulfur-containing amino acid, though it is not used to build proteins. Your body makes it from cysteine, through the cysteine sulfinic acid pathway. You also get a…

Vitamin E is a family of eight fat-soluble molecules. There are four tocopherols (α, β, γ, δ) and four tocotrienols (α, β, γ, δ). They share a 'chromanol' ring but differ in…

Menaquinone-7 (MK-7) is a long-chain form of vitamin K2. Its side chain has seven isoprene units, which gives it a longer half-life than vitamin K1 (phylloquinone) or MK-4, so it…

Xylitol is a five-carbon sugar alcohol, coded E 967 in the EU. It is about as sweet as table sugar, gives a cooling sensation on the tongue, and counts as 2.4 kcal per gram under…