From the BBC on down, in the past few days the headline “Alchohol Makes Fruit Healthier” has been highlighted in nearly every news venue.
The fruit contains compounds [antioxidants] that can protect against cancer, heart disease and arthritis.
But having them with alcohol, such as in a daiquiri, boosts these antioxidant properties, the Journal of the Science of Food and Agriculture says.
Nutritionists said the “detrimental effects” of such drinks could cancel out such benefits.
As a college student, no one takes this sort of study more seriously than I. Alcohol as health food? Surely you jest!
This deserved a bit more investigation.
UPDATE: I was threated by the publishers of the Journal of the Science of Food and Agriculture with legal action if I didn’t take down the one chart and one graph from the published results. Seems ironic since they release one million press releases. Anyway, I complied and formally requested permission. Hopefully they will grant it!
UPDATE TWO: At the suggestions of commenters, I have reproduced the data charts and graph in Excel. While not as pretty, you’ll get the point much better than nothing at all. And I’m not stepping on any legal toes.
UPDATE THREE: I put the original figures back up. I also include a link to the abstract, as someone suggested.
(Continued below the fold…..)
The study that all these ‘blurby’ news briefs are referring to is a brand-spankin’-new paper published in the Journal of the Science of Food and Agriculture entitled ‘Natural volatile treatments increase free-radical scavenging capacity of strawberries and blackberries‘ by Chanjirakul et al. Quite the mouthful (forgive the pun). The paper was a collaboration between the USDA Fruit Labs and Produce Quality Labs, and the Dept of Horticulture in Thailand.
As many people know, certain fruits contain large amounts of healthful compounds called antioxidants which “scavenge” cell-damaging free-radicals in our bodies. Strawberries and blackberries fall into this category, both naturally containing high amounts of antioxidants such as anthocyanin and phenolic acid. These compounds interact with reactive oxygen species (ROS), which are byproducts of metabolic processes, and prevent them from damaging DNA and cells.
The other side of this is that improving the antioxidant levels in fruit not only increases healthful benefits to the people that ingest them, it increases the shelf life of fruit by slowing down decay. So obviously there is interest in getting fruit to last longer and reducing waste and allowing increases in transit time.
So the researchers tested whether treating strawberries and blackberries with natural volatile compounds (methyl jasmonate, allyl isothiocyanate, ethanol, and tea tree oil) would be effective in reducing decay in the berries. Natural volatiles occur naturally in some fruits, and were thought to have evolved as an antimicrobial and antifungal defense mechanism. But would they increase antioxidant activity as well?
The method was simple. Include a piece of soaked blot paper (saturated with a natural volatile) within a closed container of berries and wait 7 and 14 days at 4 degrees C. Antioxidant levels were examined before and after, and decay was measured visually. Results of treatment conditions and decay are below.
Compared to controls, allyl isotholcyanate treatment resulted in the least decay in both berry types. Ethanol treatment provided the little to no protection against decay.
As for antioxidant activity, that was measured by ‘ORAC’ test (Oxygen Radical Absorbance Capacity, no not Orac). Results are below, which show that compared to controls, all the natural volatiles except the allyl isotholcyanate provided modest increases in antioxidant activity. Methyl jasmonate (MJ) treatment provided the largest increase in antioxidant activity (see below) in both the 7 day and 14 day groups.
The group tested the quantities of specific reactive oxygen species and, overall, consistently found that methyl jasmonate treatment provided the best protection against ROS but that the other natural volatiles (ethanol included) provided some beneficial effect too. Take home message was that a combination of methyl jasmonate (to increase antioxidants) and allyl isotholcyanate (to reduce decay) would maximize shelf life.
So really, a dash of methyl jasmonate in your daiquiri might leave you healthier, but I can’t say what that would do for the taste and fun of your beverage.