Biochemists from Oregon State University have discovered that lipoic acid, a powerful antioxidant, is integral to the restoration and synchronization of the circadian rhythms found in most life forms. This restoration of the circadian rhythm is particularly important in older organisms in which a disrupted biological clock can have many different negative impacts on health.
Lipoic acid (aka alpha-Lipoic acid) is a type of antioxidant that can be found in abundance in organ meats, spinach, potatoes, and broccoli. Lipoic acid has been studied in a variety of different capacities, including its impacts on memory loss, HIV/AIDS, liver disease, and chronic fatigue syndrome. It also has clinical applications such as chelating (binding up) heavy metals, capturing carcinogenic free-radicals, and improving the conditions of patients with diabetes-associated nerve damage. In addition to these uses, researchers also found that lipoic acid plays an integral role in the regulation of an organism’s circadian rhythms.
“Circadian rhythm” is a term used to describe the changes in physical and mental state that occur regularly over the course of a 24 hour period. They are affected mostly by periods of light and dark, and are considered to be an extension of an organism’s more over-arching biological clock. To date, researchers have produced strong evidence that organisms that experience major disruptions to their circadian rhythm are at a greater risk for developing a wide array of health problems such as heart disease, hormonal imbalance, cancer, and inflammation.
One group in particular that is at a high risk for disrupted circadian rhythms is the elderly. Part of this increased risk is associated with how over time an individual acquires mutations in their DNA. Damaged DNA means that many of the enzymes and other proteins needed to help regulate the body’s natural rhythms cannot be fabricated or are produced with alterations. These altered proteins may have the potential to disrupt an individual’s circadian rhythm and put further stress on the body. It is estimated that a third of all the genes in the genome take cues from the circadian rhythm in some way or another. Therefore a disrupted rhythm can be both caused by and lead to malfunctions in gene expression.
Researchers from Oregon State University were particularly interested in finding ways in which age-related disruptions to the circadian rhythm can be corrected. In previous research, the investigators had discovered that diets high in lipoic acid had an overall depressing effect on the expression of circadian rhythm-regulated genes. In a new series of experiments, they fed one group of rats a diet rich in lipoic acid and compared them to a control group. After two weeks the researchers looked for markers of changed circadian rhythms, such as changes in the cycling of hormones like corticosteroine and other clock-controlled proteins.
The researchers discovered that the lipoic-acid rich diets had an overall effect of correcting the otherwise asynchronous orchestra of carefully timed hormones and proteins. Specifically they found that that lipoic acid has the effect of resetting the circadian rhythms in older rats to a more youthful condition.
As people around the globe continue to live longer and longer, research such as this is important to understand the aging process. In particular research has come to focus on not just increasing human life-span, but also the human “healthspan.” “Healthspan” refers to the longevity with which a person is capable of living in good health and participating in normal activities. Research into lipoic acid and other regulators of the circadian rhythm might one day increase not only the quantity of years lived by a person, but also their quality.
By Sarah Takushi