A neurodegenerative disorder characterized by progressive memory loss, spatial disorientation, cognitive dysfunction, and behavioral changes. The pathological hallmarks of Alzheimer's disease include amyloid-beta plaques, tau tangles, and reduced brain glucose uptake. Most cases of Alzheimer's disease do not run in families and are described as "sporadic." The primary risk factor for sporadic Alzheimer's disease is aging, with prevalence roughly doubling every five years after age 65. Roughly one-third of people aged 85 and older have Alzheimer's. The major genetic risk factor for Alzheimer's is a variant in the apolipoprotein E (APOE) gene called APOE4.

One of three common genetic variants of the APOE (apolipoprotein E) gene. The APOE4 allele, which is present in approximately 10-15% of people, increases the risk of developing Alzheimer's disease and lowers the age of onset. Having one copy of E4 increases risk 2- to 3-fold, while having two copies increases risk as much as 15-fold.

A chemical produced in the liver via the breakdown of fatty acids. Beta-hydroxybutyrate is a type of ketone body. It can be used to produce energy inside the mitochondria and acts as a signaling molecule that alters gene expression by inhibiting a class of enzymes known as histone deacetylases.

A measurable substance in an organism that is indicative of some phenomenon such as disease, infection, or environmental exposure.

An amino acid having aliphatic side-chains with a branch (a central carbon atom bound to three or more carbon atoms). Among the proteinogenic amino acids, there are three BCAAs: leucine, isoleucine and valine.

A general term referring to cognitive decline that interferes with normal daily living. Dementia commonly occurs in older age and is characterized by progressive loss of memory, executive function, and reasoning. Approximately 70 percent of all dementia cases are due to Alzheimer’s disease.

Any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalyst in specific biochemical reactions.

A type of water-soluble B-vitamin, also called vitamin B9. Folate is critical in the metabolism of nucleic acid precursors and several amino acids, as well as in methylation reactions. Severe deficiency in folate can cause megaloblastic anemia, which causes fatigue, weakness, and shortness of breath. Certain genetic variations in folate metabolism, particularly those found in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene influences folate status. Inadequate folate status during early pregnancy increases the risk of certain birth defects called neural tube defects, or NTDs, such as spina bifida, anencephaly, and other similar conditions. Folate deficiency and elevated concentrations of homocysteine in the blood are associated with increased risk of cardiovascular disease. Low folate status and/or high homocysteine concentrations are associated with cognitive dysfunction in aging (from mild impairments to dementia). The synthetic form of folate is called folic acid. Sources of folate include most fruits and vegetables, especially green leafy vegetables.

The genetic constitution of an individual organism. The combination of genotype and environment determine an organism's physical characteristics – known as the phenotype.

A blood test that measures the amount of glycated hemoglobin in a person’s red blood cells. The hemoglobin A1c test is often used to assess long-term blood glucose control in people with diabetes. Glycation is a chemical process in which a sugar molecule bonds to a lipid or protein molecule, such as hemoglobin. As the average amount of plasma glucose increases, the fraction of glycated hemoglobin increases in a predictable way. In diabetes mellitus, higher amounts of glycated hemoglobin, indicating poorer control of blood glucose levels, have been associated with cardiovascular disease, nephropathy, neuropathy, and retinopathy. Also known as HbA1c.

An amino acid present in the blood. Homocysteine is produced during the metabolism of methionine. Abnormalities in methionine metabolism can lead to elevated homocysteine levels, a condition called hyperhomocysteinemia. Elevated homocysteine levels can contribute to arterial plaque formation and increase the risk of clot formation. Some evidence suggests that elevated homocysteine levels double the risk of developing Alzheimer’s disease. Homocysteine levels vary according to dietary intake, with highest levels associated with consumption of animal protein. Variants in the genes that encode for the enzymes that metabolize homocysteine, specifically MTHFR, or methylenetetrahydrofolate reductase, markedly increase the risk of developing a wide array of diseases, including cardiovascular disease, Alzheimer’s disease, and cancer. High intake of dietary folate (present in leafy greens and other fruits and vegetables) can modulate the harmful effects associated with MTHFR.

A peptide hormone secreted by the beta cells of the pancreatic islets cells. Insulin maintains normal blood glucose levels by facilitating the uptake of glucose into cells; regulating carbohydrate, lipid, and protein metabolism; and promoting cell division and growth. Insulin resistance, a characteristic of type 2 diabetes, is a condition in which normal insulin levels do not produce a biological response, which can lead to high blood glucose levels.

A diet that causes the body to oxidize fat to produce ketones for energy. A ketogenic diet is low in carbohydrates and high in proteins and fats. For many years, the ketogenic diet has been used in the clinical setting to reduce seizures in children. It is currently being investigated for the treatment of traumatic brain injury, Alzheimer's disease, weight loss, and cancer.

Molecules (often simply called “ketones”) produced by the liver during the breakdown of fatty acids. Ketone production occurs during periods of low food intake (fasting), carbohydrate restrictive diets, starvation, or prolonged intense exercise. There are three types of ketone bodies: acetoacetate, beta-hydroxybutyrate, and acetone. Ketone bodies are readily used as energy by a diverse array of cell types, including neurons.

An infectious disease caused by bacteria of the Borrelia type which is spread by ticks. The most common sign of infection is an expanding non-painful area of redness on the skin, fever, headache and feeling tired. Lyme disease is the most common disease spread by ticks in the Northern Hemisphere and is estimated to affect 300,000 people a year in the United States and 65,000 people a year in Europe.

A class of saturated fats. Medium-chain triglycerides are composed of medium-length fatty acid chains (six to 12 carbons long) bound by a glycerol backbone. They occur naturally in coconut oil, palm oil, and butter, but they can also be synthesized in a laboratory or food processing setting. Evidence suggests that MCT therapy improves cognitive function in older adults with Alzheimer's disease.^[1] Examples of MCTs include caprylic acid (C8), capric acid (C10), and lauric acid (C12).

A gene coding for an enzyme that converts homocysteine into methionine; a critical step in the methyl cycle. Natural variation in this gene is common among healthy people, however, some variants have been reported to influence susceptibility to occlusive vascular disease, neural tube defects, Alzheimer’s disease and other forms of dementia, colon cancer, and acute leukemia.

A test in which a person's glucose and sometimes insulin is tested before and at multiple intervals after having consumed a measured dose of glucose. Depending on the protocol, blood may be drawn for up to 6 hours afterward.

A health condition in which blood glucose levels are higher than normal, but not high enough to indicate a diagnosis of type 2 diabetes. Prediabetes can be halted or reversed with dietary and lifestyle modifications, including weight loss, exercise, and stress reduction.

A glycoprotein that binds to sex hormones, and is produced mostly by the liver. Testosterone and estradiol circulate in the bloodstream bound mostly to SHBG. Only around 1-2% is unbound or "free", and thus biological active. The relative binding affinity of various sex steroids for SHBG is dihydrotestosterone (DHT) > testosterone: androstenediol> estradiol> estrone.

A change in one nucleotide DNA sequence in a gene that may or may not alter the function of the gene. SNPs, commonly called "snips," can affect phenotype such as hair and eye color, but they can also affect a person's disease risk, absorption and metabolism of nutrients, and much more. SNPs differ from mutations in terms of their frequency within a population: SNPs are detectable in >1 percent of the population, while mutations are detectable in <1 percent.

The primary male sex hormone. Testosterone is critical to the maintenance of fertility and secondary sexual characteristics in males. Low testosterone levels may increase risk of developing Alzheimer’s disease.

A molecule composed of a glycerol molecule bound to three fatty acids. Triglycerides are the primary component of very-low-density lipoproteins (VLDL). They serve as a source of energy. Triglycerides are metabolized in the intestine, absorbed by intestinal cells, and combined with cholesterol and proteins to form chylomicrons, which are transported in lymph to the bloodstream.