Study: Lemons For A Long Life
A study published last year in the journal Nature looked at the effects of consuming lemons – and their abundant polyhenols – over a lifetime. Most studies focus on immediate or short term effects, but the Japanese researchers who authored the study wanted to go a step further and look at how eating lemons affected aging, and in particular, the intestinal microbiome.
The researchers analyzed the lemons they used to identify the polyphenols that were present, including six flavanone glycosides and three flavone glycosides, using both fruit and peel. The most common included:
• eriocitrin, 21.7;
• hesperidin, 3.5;
• eriodictyol-7-glycoside, 1.2;
• eriodictyol, 0.4.
Eriocitrin showed the highest content of polyphenols in lemons.
A Study On Mice
The study was completed using special senescence-accelerated resistant mice, or Senescence Accelerated Mouse-Prone 8 (SAMP8). This means the mice have been identified as having a naturally occurring genetic marker for accelerated aging. These mice displayed early age-related symptoms such as senile amyloidosis, impaired immune response, and impaired motor function. Another group were SAMP8 resistant, meaning they had natural anti-aging abilities.
The mice in this study were examined without sacrificing their lives, except to old age. The researchers used non-invasive methods to measure the results.
At the end of the experiment, the mice – who were prone to early aging, but who ingested the lemon polyphenols – had a longer lifespan of about 3.7%.
Other anti-aging findings in the mice that consumed lemon polyphenols:
• An increase in anti-oxidative activities;
• There was a significant decrease in age-related symptoms such as coarseness of hair and hair loss, and periophthalmic (eyelid) lesions;
• The ability to move without dysfunction was also much lower in the group that ingested lemons, even preventing atrophy associated with aging;
• Many of the positive changes were observed to actually increase with age.
Lemon polyphenols are related to gut bacteria. Eriocitrin, for example, is metabolized by intestinal bacterial, and then absorbed into the blood, where it contributes to both anti-oxidant and anti-inflammatory activity in the body.
When it comes to the bacteria in the stomach, the researchers focused on the phylum Bacteroidetes/Firmicutes, which has been associated with obesity. While all test groups saw an increase in this bacteria with aging, the mice that regularly ingested lemon polyphenols saw a significantly lower increase.
Lemons for Life
Good eating habits should be established for a lifetime. It’s clear that the study’s authors understood that concept. They note that more studies need to be performed to evaluate the effects of lifelong eating habits.
When it comes to lemons, it’s clear that there are benefits associated with consuming the fruit/juice and peel – and maybe even a longer life, with fewer signs of aging.