Michael Ristow
Encyclopedia
Michael Ristow is a German
medical researcher who has published influential articles on the metabolic
basis of human diseases, including type 2 diabetes, obesity and cancer, as well as general aging processes. Amongst more than 50 peer-reviewed scientific publications, Ristow published a seminal article describing a genetic mutation associated with extreme human obesity.
Ristow was born in Lübeck
in the North of Germany
. He graduated at the University of Bochum in 1992 and received his M.D. from University of Bochum in 1996. He was appointed to the University of Jena in 2005 as a full professor
in nutritional science.
Ristow’s laboratory has provided direct evidence supporting the so-called Warburg hypothesis
. Specifically Ristow has shown that forced metabolic activity and respiration
of mitochondria efficiently blocks cancer growth as anticipated by Otto Heinrich Warburg
as early as in 1924.
In 2007, Ristow’s group published evidence which could explain the basis of the observed extension of lifespan by restriction of sugar intake. In experiments on a model organism, the worm Caenorhabditis elegans
, they found that lowering the availability of glucose
extended the lifespan of the worms. It has been known since the 1930s that restricting calories while maintaining adequate amounts of other nutrients extends lifespan across a broad range of organisms. The mechanism has been proposed as a change in the activity of the sirtuins. Interestingly, Michael Ristow shows in his article that this effect can also occur independent of sirtuins, since worms deficient for sirtuins still show extended life span in states of sugar restriction..
Most importantly, Ristow's research suggests that this is a mitohormetic effect, as reviewed in . Hormesis
is a controversial concept in which it has been demonstrated that the induction of a stress can lengthen lifespan in some species. Ristow's interpretation was that in response to a decrease in glycolytic
energy production, the worms have to generate ATP
by oxidative phosphorylation
in the mitochondria, leading to increased production of reactive oxygen species
. In response, the organism produces more defenses against oxidative stress
, including increased production of catalase
. Supplementation with antioxidants abolishes the increase in lifespan, and so does disruption of an AMP-kinase but not disruption of sirtuins.
More recently and experiencing significant media attention, Ristow and colleagues have shown that supplementing humans with antioxidants during exercise blocks the health-promoting effects of exercise, suggesting that free radicals produced during exercise are responsible and required for the effects of exercise .
These findings bring into question Denham Harman
's free radical theory of aging, and provide a mechanistic basis to question the application of antioxidants to human health.
Independent of his work on oxidative stress, Ristow has recently shown that increased concentrations of the trace metal
Lithium
contained in drinking water are associated with increased lifespan in Japan suggesting a readily available anti-aging intervention.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
medical researcher who has published influential articles on the metabolic
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
basis of human diseases, including type 2 diabetes, obesity and cancer, as well as general aging processes. Amongst more than 50 peer-reviewed scientific publications, Ristow published a seminal article describing a genetic mutation associated with extreme human obesity.
Ristow was born in Lübeck
Lübeck
The Hanseatic City of Lübeck is the second-largest city in Schleswig-Holstein, in northern Germany, and one of the major ports of Germany. It was for several centuries the "capital" of the Hanseatic League and, because of its Brick Gothic architectural heritage, is listed by UNESCO as a World...
in the North of Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
. He graduated at the University of Bochum in 1992 and received his M.D. from University of Bochum in 1996. He was appointed to the University of Jena in 2005 as a full professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
in nutritional science.
Ristow’s laboratory has provided direct evidence supporting the so-called Warburg hypothesis
Warburg hypothesis
The Warburg effect is the observation that cancer cells exhibit glycolysis with lactate secretion and mitochondrial respiration even in the presence of oxygen....
. Specifically Ristow has shown that forced metabolic activity and respiration
Respiration (physiology)
'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...
of mitochondria efficiently blocks cancer growth as anticipated by Otto Heinrich Warburg
Otto Heinrich Warburg
Otto Heinrich Warburg , son of physicist Emil Warburg, was a German physiologist, medical doctor and Nobel laureate. He served as an officer in the elite Uhlan during the First World War and won the Iron Cross for bravery. Warburg was one of the twentieth century's leading biochemists...
as early as in 1924.
In 2007, Ristow’s group published evidence which could explain the basis of the observed extension of lifespan by restriction of sugar intake. In experiments on a model organism, the worm Caenorhabditis elegans
Caenorhabditis elegans
Caenorhabditis elegans is a free-living, transparent nematode , about 1 mm in length, which lives in temperate soil environments. Research into the molecular and developmental biology of C. elegans was begun in 1974 by Sydney Brenner and it has since been used extensively as a model...
, they found that lowering the availability of glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
extended the lifespan of the worms. It has been known since the 1930s that restricting calories while maintaining adequate amounts of other nutrients extends lifespan across a broad range of organisms. The mechanism has been proposed as a change in the activity of the sirtuins. Interestingly, Michael Ristow shows in his article that this effect can also occur independent of sirtuins, since worms deficient for sirtuins still show extended life span in states of sugar restriction..
Most importantly, Ristow's research suggests that this is a mitohormetic effect, as reviewed in . Hormesis
Hormesis
Hormesis is the term for generally favorable biological responses to low exposures to toxins and other stressors. A pollutant or toxin showing hormesis thus has the opposite effect in small doses as in large doses...
is a controversial concept in which it has been demonstrated that the induction of a stress can lengthen lifespan in some species. Ristow's interpretation was that in response to a decrease in glycolytic
Glycolysis
Glycolysis is the metabolic pathway that converts glucose C6H12O6, into pyruvate, CH3COCOO− + H+...
energy production, the worms have to generate ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
by oxidative phosphorylation
Oxidative phosphorylation
Oxidative phosphorylation is a metabolic pathway that uses energy released by the oxidation of nutrients to produce adenosine triphosphate . Although the many forms of life on earth use a range of different nutrients, almost all aerobic organisms carry out oxidative phosphorylation to produce ATP,...
in the mitochondria, leading to increased production of reactive oxygen species
Reactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
. In response, the organism produces more defenses against oxidative stress
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
, including increased production of catalase
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...
. Supplementation with antioxidants abolishes the increase in lifespan, and so does disruption of an AMP-kinase but not disruption of sirtuins.
More recently and experiencing significant media attention, Ristow and colleagues have shown that supplementing humans with antioxidants during exercise blocks the health-promoting effects of exercise, suggesting that free radicals produced during exercise are responsible and required for the effects of exercise .
These findings bring into question Denham Harman
Denham Harman
Denham Harman , MD, PhD, FACP, FAAA biogerontologist is Professor emeritus at the University of Nebraska Medical Center. Harman is widely known as the "father of the free radical theory of aging".-Background:...
's free radical theory of aging, and provide a mechanistic basis to question the application of antioxidants to human health.
Independent of his work on oxidative stress, Ristow has recently shown that increased concentrations of the trace metal
Trace metal
Trace metals are metals in extremely small quantities that reside in or are present in animal and plant cells and tissue. They are a necessary part of good nutrition, although they can be toxic if ingested in excess quantities....
Lithium
Lithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...
contained in drinking water are associated with increased lifespan in Japan suggesting a readily available anti-aging intervention.