Tag Archives: Alzheimer’s disease

Nutrition Spotlight: Caffeine and L-theanine in Tea

2 Jan

According to a Unilever study recently reported in a Food Navigator-USA article, there is evidence to support the notion that compounds in tea, primarily caffeine and L-theanine, can be beneficial for one’s mood and mental focus.

Despite the European Food Safety Authority’s recent rejections of two Unilever health claims petitions (13.1 and 13.5) which linked black tea consumption to improved mental focus, the company is continuing its extensive research on the many benefits of tea consumption. Suzanne Einother and Vanessa Martens, employed at Unilever Research and Development, Vlaardingen (the Netherlands), are responsible for a recent review in the American Journal of Clinical Nutrition which, concerning a number of studies of tea consumption, notes “particularly consistent evidence for improved attention” throughout. They added that tea “consistently improved self-reported alertness and arousal” among subjects.

“These studies,” they said, “showed the validity of laboratory findings by supporting the idea that tea consumption has acute benefits on both mood and performance in real-life situations.”

The review was first formally presented on September 19th, 2012, at the Fifth International Scientific Symposium on Tea and Human Health in Washington, D.C.

Scientific research of tea has long focused on green tea, the benefits of which are well-documented and include improving oral and cardiovascular health, aiding in weight-management and reducing the risks of Alzheimer’s disease and some forms of cancer.

Black tea is simply green tea which is oxidized by fermentation, and contains between 3% and 10% of water-extractable polyphenols; original green tea, by comparison, contains between 30% and 40%. Fresh tea leaves contain four primary extractable polyphenols: epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate.

Unilever’s research, however, has focused more on L-theanine, an amino acid extracted from tea leaves, and caffeine. L-theanine is believed to help reduce stress while improving one’s quality of sleep. Since it is found in very low concentrations (less than 2%) in tea leaves, drinking tea cannot deliver effective dosage levels of 100 to 200 milligrams per day.

In the past, L-theanine has been linked to other various health effects, including improved attention, relaxation and certain “neuro-protective” effects. For example, it has been suggested that the amino acid is responsible for increased alpha activity during rest (as shown in EEG models), which can improve relaxation.

In the new review, Einother and Martens used data from randomized control trials focusing on tea’s effects on attention and mood.

“From the totality of research on tea summarized,” they wrote, “[…] it can be concluded that consumption of black tea may improve attention and self-reported alertness. These conclusions are further supported by studies on caffeine and on theanine and caffeine in combination.”

They are quite clear, however, about the pockets of uncertainty which remain for the time being: “Research on the benefits of tea is promising for attention and alertness, although questions remain regarding the scope and magnitude of impact as well as the sensitivity of different individuals. Whereas the bioavailability of both caffeine and theanine has been established, as well as the [suggested] mechanisms of action in the brain, they extent to which they actually cross the blood-brain barrier in humans and how much this is associated with [individual] changes in subsequent performance and mood measures are as yet unknown.”



Ingredient Spotlight: Curcumin’s Health Benefits

22 Jul

Two new studies, one from the University of Colorado and the other from Selcuk University in Turkey, have found many potential health benefits in curcumin, the natural pigment that makes the spice turmeric yellow. The studies suggest that curcumin in daily supplements could not only support healthy aging, but also be beneficial to cognition and arterial aging.

Many studies reviewed by Power Brands have examined the potential benefits of curcumin in recent years. It has been suggested to help protect against ailments such as arthritis, diabetes, Alzheimer’s and even prostate cancer.

The study conducted by scientists from the University of Colorado, led by Bradley Fleenor, was published in Experimental Gerontology. The researchers used aging lab mice to find a link between curcumin and improved vascular health. The wrote that the chow for the mice, supplemented with 0.2% curcumin, “ameliorates age-associated large elastic artery stiffening, NO-mediated vascular endothelial dysfunction, oxidative stress and increases in collagen […] in mice.” Per day, the mice were given what is equal to 14 grams for an average-sized adult.

“Because of curcumin’s poor absorption and rapid metabolism,” the researchers explained, “clinical trials in humans have also used high doses of curcumin (8 to 12 g) similar to the amount our old mice consumed, while observing only infrequent, minor side effects.”

“Our results provide the first evidence that dietary curcumin supplementation ameliorates two clinically important markers of arterial dysfunction with aging: large elastic artery stiffening and endothelial dysfunction.” The team wrote in conclusion, “Given its accessibility and safety, these pre-clinical findings provide the experimental basis for future translational studies assessing the potential for curcumin to treat arterial dysfunction with aging and reduce CVD risk in humans.”

The second study of curcumin, performed by researchers from Selcuk University, was published in Biogerontology. These researchers focused more on curcumin’s effects on cognitive functions, a potential link which many Power Brands-reviewed studies have explored. Old female rats were used for the study; the rats were given either corn oil or curcumin for seven days, and then for another five days while they were tested with the Morris water maze. According to the results, curcumin supplementation decreased the rats’ total distance traveled, as well as the time required for the rats to reach the platform.

“In addition to the behavioral testing,” the researchers said, “biochemical results showed that MDA levels decreased in brain tissue by curcumin supplementation.” MDA, formerly known as “malondialdehyde,” is a known marker of oxidative stress.

According to Power Brands, the researchers reached a definite conclusion: “It may be concluded that curcumin supplementation improves cognitive functions by decreasing the lipid peroxidation in brain tissue of aged female rats.”