Beer Hop Extracts May Protect Against Alzheimer’s

Researchers in Italy report that chemicals extracted from hop flowers inhibited clumping of amyloid beta proteins, a phenomenon associated with Alzheimer’s disease (AD).  The findings—published recently in ACS Chemical Neuroscience—suggest a health benefit to “hoppy” beers.

Affecting older adults, AD is a neurodegenerative disease marked by memory loss and personality changes. One of the challenges to treating AD is that several years can pass between the underlying biochemical processes of the disease to begin and onset of symptoms. Irreversible damage to the nervous system occurs before the patient even realizes they may have the disease.

Accordingly, preventative strategies and therapeutics that can intervene before symptoms appear are of increasing interest. One of these strategies involves nutraceuticals—foods that have some type of medicinal or nutritional function. Hop flowers have been explored as one of these potential nutraceuticals, with previous studies suggesting that the plant could interfere with the accumulation of amyloid beta proteins associated with AD.

Cristina Airoldi, with the University of Milano-Bicocca’s Department of Biotechnology and Biosciences, and colleagues set out to determine which chemical compounds in hops had this effect. They created and characterized extracts from four common varieties using a method similar to that used in the brewing process. They found that the extracts had antioxidant properties and could prevent amyloid beta proteins from clumping in human nerve cells.

The most successful extract was from the Tettnang hop, found in many types of lagers and lighter ales. When that extract was separated into fractions, the one containing a high level of polyphenols showed the most potent antibiotic and aggregation-inhibiting activity. It also promoted processes that allow the body to clear out misfolded, neurotoxic proteins.  The team also tested the Tettnang extract in a C. elegans model and found that it protected the worms from AD-related paralysis, though the effect was not very pronounced.

Although the findings may not justify a change in beer preferences, the authors say it shows that hop compounds could serve as the basis for nutraceuticals that combat the development of AD.