- Feeding rats grapeseed flour (GSF) increases their maximum lifespan by 38%.
- GSF supplementation elevates the NAD+/NADH ratio in the brain, heart, liver, and kidney of rats.
- Oxidative stress — an underlying driver of aging — is reduced by GSF supplementation in the brain, heart, liver, and kidney of rats.
It was once thought that molecules called reactive oxygen species (ROS) — which are oxidants — cause the adverse health effects associated with aging. Therefore, consuming anti-oxidants, abundant in plant-based foods, was hypothesized to counteract age-related diseases. While this isn’t the whole story, this theory may not be far from the truth.
In a study published in The Journals of Gerontology: Series A, Tunisian researchers found that grapeseed flour (GSF), rich in antioxidants, increased the lifespan of rats. Jebari and colleagues also showed that GSF improved NAD+ metabolism and reduced ROS-driven damage in multiple organs. These findings suggest that ROS-driven organ damage could at least partially be responsible for driving the aging process.
Grapeseed Flour Counteracts Aging
To determine the effect of GSF on longevity, Jebari and colleagues fed 4 g/kg of GSF to young (1-month-old, equivalent to 3-year-old humans) rats. In terms of maximum lifespan, the results showed that GSF-fed rats lived 38% longer than rats fed a normal diet. These findings demonstrate that consuming large amounts of antioxidant-rich GSF over a lifetime can increase the lifespan of lab rats.
“High dosing GSF increases significantly median life span by 2 months which is equivalent to 4 years in humans and increases maximal life span by 10 months corresponding to 20 years in humans,” said the authors.
NAD+, and NADH (the electron carrying form of NAD+) are important for the production of cellular energy — ATP. A low NAD+/NADH ratio reflects low NAD+ levels, which is associated with disease. Jebari and colleagues showed that compared to young rats, aged rats had low NAD+ levels in multiple organs, as shown by a reduced NAD+/ NADH ratio. However, when fed GSF, the aged rats had a higher NAD+/NADH ratio. Furthermore, this same trend was observed with ATP levels, suggesting that GSF increases ATP production by improving NAD+ metabolism.
When ROS reach excessive levels, they cause damage to cellular components like DNA, proteins, and fats. The damage to fats leads to the production of a compound called MDA (malondialdehyde). To verify GSF’s antioxidant effects, Jebari and colleagues measured MDA from the brain, heart, liver, and kidney of rats.
The results showed that compared to young rats, aged rats had higher levels of MDA in all four organs, suggesting increased oxidative stress — excessive ROS levels. However, treating aged rats with GSF reduced MDA levels in the same organs. These findings suggest that GSF has antioxidant effects that suppress oxidative stress.
Overall, the findings of Jebari and colleagues suggest that GSF increases lifespan by improving NAD+ metabolism and reducing oxidative stress in multiple organs. These benefits could be due to the plant-based compounds found in grapes called polyphenols. The authors note,
“Grape antioxidant properties have been attributed predominantly to their polyphenolics content, largely believed to be responsible for their beneficial health effects.”
However, since GSF contains multiple compounds, it is unclear whether GSFs antioxidant properties are fully responsible. The authors say,
“It is tempting to speculate about the potential effect of GSF in protecting mitochondrial health, hence health span improvement.”
Are Massive Doses of Grapeseed Powder Feasible?
One limitation of Jebari and colleagues’ study is the high dose of GSF used. They say that when translated to humans, this dose would be 240 grams per day, “which is in practice, quite difficult to achieve.” They go on to suggest packaging the antioxidant molecules found in GSF — polyphenols — into nanoparticles, which would likely increase absorption and bioavailability. Until then, consuming polyphenol-rich foods like berries, almonds, and dark chocolate could counteract oxidative stress and potentially mitigate aging.