Leslie's Corner: Japanese Sweet Potato - Where to Buy & How to Cook Them

Spermidine is a vital, naturally-occurring molecule called a polyamine, which is a type of protein. It is known for inducing autophagy, the body's cellular "clean up" and recycling process, and targeting the root causes of aging.

We naturally produce spermidine when we are young, but this declines with age, making us much more reliant on food-derived sources of spermidine, like Primeadine.

Human clinical trials using food-derived spermidine have shown it to support cognition and heart health, promote hormonal balance, improve hair growth and fullness (including eyelashes and brows), increase collagen synthesis, and strengthen nails.

Studies have correlated higher plant-derived spermidine levels with a longer life. They have also shown its potential in improving fertility and restoring sleep by regulating the body's internal clock (aka circadian rhythm).

Other benefits noticed by our clients include deeper, sounder sleep, gray hair reversal, enhanced energy levels, brighter, more supple skin, and improved gut health. Read our Reviews to find out more.

While we can’t speak directly about the formulation of other spermidine products, here are some of the main differentiators of Primeadine®/Oxford Healthspan.

• We source our raw materials from Japan, which is known for its Nobel Prize-winning scientific leadership on autophagy, or cell renewal. Japan has the most rigorous quality control and testing policies in the world, meaning our ingredients have the most advanced extraction process and meet the incredibly high standards of the Japan Health Food and Nutrition Food Association. They are tested for heavy metals, mold, fungi, and bacteria at the Japan Food Research Lab (JFRL), a third party independent testing lab.
• Every single batch is tested for its amount of food-derived spermidine so we ensure it contains the minimum effective dose of 1mg stated on our labels.
• Primeadine® is manufactured in Japan in an FDA-registered and -inspected facility with ISO22000 standards, the highest in food quality control. It is then encapsulated in an FDA cGMP facility in the USA and undergoes purity testing there as well at Eurofins or Delta.
• Our capsules and tablets do not contain any synthetic ingredients, whereas other supplements typically contain magnesium stearate (of which circa 80% has hydrogenated fats in it; the supplement industry is not legally required to get rid of hydrogenated oils the way the processed food industry has been mandated by law to), shellac, talc and glycerin. Our products are all suitable for vegans. Learn more about our sourcing, quality, and testing standards.
• The Primeadine® Original formulation includes a special type of prebiotic fiber, called FOS (fructooligosaccharide), that selectively feeds the friendly, spermidine-producing bacteria in the gut microbiome. The idea is to increase both supplemental, or 'exogenous' spermidine, as well as encourage your own body's natural ability to produce spermidine in your gut microbiome.
• Primeadine® GF comes from a sub-strain of chlorella singled out from over 100 others because it alone contains a high level of spermidine and also contains putrescine, the precursor polyamine to both spermine and spermidine. Our chlorella is grown in the nutrient-abundant longevity islands of Okinawa, Japan, and exposed to sunlight to increase the chlorophyll and other nutrient content, such as vitamins D and K, which together help drive calcium to the bones. We combine the chlorella with two other anti-inflammatories and autophagy inducers, Okinawan turmeric and nobiletin (from Okinawan "Shikuwasa" citrus lime peel).
• We do not use liposomes in Primeadine® because this is unnecessary for absorption and would prevent the benefits that happen when spermidine is exposed directly to the gut lining. There is no evidence that spermidine cannot be taken up by the cells on its own. Similar to amino acids, polyamines do not need a liposome to cross into the cell or to be taken up with epithelial cells. The process of creating a liposomal version also creates unnecessary expense.
• We do not synthetically enrich our product with synthetic spermidine. Be wary of labels that say "wheat germ with spermidine" as this indicates that the wheat germ has been soaked in synthetic spermidine, thereby increasing the overall amount of spermidine but meaning it is no longer a natural source.
• We do not use doses beyond what the European Food Safety Authority (EFSA) has mandated as safe for human consumption, which is 6mg daily. Please note that this is related to food-derived spermidine. Synthetic spermidine and synthetically enriched spermidine have never been tested in humans for safety or efficacy and are being sold without regulatory oversight. 
• We work closely with our scientific and clinical advisers at the University of Oxford and abroad, all of whom take our product and share it with their loved ones. Learn more about our scientific advisory board here.
• We are also the only non-Japanese member of the Japan Autophagy Consortium, whose Senior Adviser is the 2016 Nobel Prize Winner in Medicine or Physiology, Prof Yoshimori Ohsumi, and whose Director is Prof Tamotsu Yoshimori, Osaka University. Prof Yoshimori conducted all of the mammalian research in autophagy that helped underpin Prof Ohsumi's work in yeast cells. Find out more about our story here.

• We take great care to use the highest quality ingredients available and to keep out the 'nasties' commonly found in the supplement manufacturing process. We take the same approach that we do when baking a birthday cake for our children: we use the highest quality ingredients - no industrial seed oils such as wheat germ oil that oxidizes rapidly and wreaks havoc in our cells, no magnesium stearate to make the powder flow faster through automated encapsulation equipment (approximately 80% of all magnesium stearate used as 'flow agents' contain hydrogenated industrial seed oils), and no talc to make the powder denser and fit more compactly into fewer capsules. 
• We also do not use synthetic spermidine, which is very cheap and often 'cut' into products stating they contain 'wheat germ with spermidine.'  
• We choose food-derived spermidine, sourced and manufactured in Japan, which has one of the strictest food and supplement regulatory regimens in the world. Our products undergo rigorous third party lab testing to ensure they are of the purest and most effective quality. Yes, it is more costly, just as the best cake ingredients for your child's birthday cake would be too. It's a choice and philosophy we wholeheartedly believe in and follow every step of the way.

To date, most studies have been conducted using a daily dose of 1mg of food-derived spermidine, which is the amount present in Primeadine.

The US FDA has not ruled on a safe upper limit for food-derived spermidine, but the European Union's European Food Safety Authority has deemed 6mg of supplemental food-derived spermidine to be the safe upper limit.

Synthetic spermidine has not been tested for safety in humans.