The Effects of Genetic Variants and Calorie Restriction on Aging

(image: By Nazrul Islam Ripon (Own work) [CC BY-SA 4.0 (], via Wikimedia Commons)


While aging is something that happens to everyone, scientists have been trying to determine the causes of aging, how to slow down the process, and ways to improve quality of life. There has been some interesting new research. First up, scientists, led by Paola Sebastiani out of the Boston University School of Public Health, have identified single nucleotide polymorphisms (SNPs) and new variants in chromosomes that seem to be associated with longevity and reduced risk of Alzheimer’s and cardiovascular disease. They looked at population and genetic data of individuals considered to have extreme longevity (those living past 95 in males and past 100 in females). Their meta-analysis confirmed the role of SNPs in the Apolipoprotein E gene on longevity that had been seen in previous studies. The team also discovered new longevity-associated variants (LAVs) on chromosomes 7 and 12 with genome-wide and nearly genome-wide significance.1

Next, a review on aging, led by Marie Amitani out of the Kagoshima University in Japan, explored the role of ghrelin on aging. Ghrelin is typically an orexigenic peptide known for its role in regulating energy balance and hunger. However, when calories are restricted, ghrelin levels increase, signaling a feeling of satiety. Research, starting as far back as 1935, has seen that calorie restriction contributes to longevity by decreasing oxidative stress. Levels of circulating ghrelin have also been shown to decrease with aging.2Perhaps, restricting calories will increase circulating ghrelin and decrease oxidative stress, thereby slowing the aging process.



  1. P. Sebastiani et al., J Gerontol A Biol Sci Med Sci, 00 (00), 1 (2017). doi:10.1093/gerona/glx027
  2. M. Amitani et al., Int. J. Mol. Sci., 18, 1511 (2017). doi:10.3390/ijms18071511


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Denise Karounos

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Denise Karounos joined Peptides International in October 2016. After completing her BS in chemistry from West Virginia University, she spent time as an organic chemist at Bachem Bioscience synthesizing peptides and amino acid derivatives. Denise has experience with both solid and solution-phase peptide synthesis, and has worked under both research and cGMP settings. After completing her MBA from Saint Joseph’s University, Denise transitioned into product management of peptides and amino acid derivatives. In her marketing role, she had many duties including but not limited to product management, market research, creating and producing marketing materials, handling US catalog distribution and customer database, email marketing, quoting and inside sales, sales calls, and coordinating and attending trade conferences. 

At PI, Denise's duties encompass both sales and marketing, bringing to bear her extensive lab and sales support experience. Contact her today and see how Denise can assist you with your peptide research project.