Does Grape Seed Extract Boost Your Testosterone Levels?
Written by Ben Bunting: BA, PGCert. (Sport & Exercise Nutrition) // British Army Physical Training Instructor // S&C Coach.
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Your testosterone levels will naturally decrease as you get older. You may lose muscle strength and endurance as your testosterone levels decrease.
This can affect athletic performance. You'll also notice that you have a lower libido, a decrease in sexual performance, and heightened risk for long-term illnesses.
You should do everything you can to maintain testosterone levels by exercising hard, eating healthy and adding nutrients to your diet that stimulate and regulate the production of testosterone.
In the latest scientific research, a number of nutrients have shown to increase T in even the most rigorous studies. There are some supplements which contain nutrients that don't work.
This article will look at the grape seed extract to see if it is worth your money or not.
What is grape seed extract?
The grape seed extract is made from ground up seeds. It's a common by-product of wine-making.
Wine making is a centuries-old tradition, yet only recently did manufacturers start to consider GSE as a food resource rather than an unwanted byproduct of wine production.
The grape contains a few bioactive substances, such as procyanidins. Depending on where the grape is grown, the levels can be up to 81%.
GSE, although found in grapes and grape juices, is not the same as resveratrol. Procyanidins, in fact, are chains of catachin molecules. This means it has more similarities to the green tea extract ECGC rather than red wine.
Red grapes contain vitamins, minerals, and resveratrol. However, oil extracts have less nutritional value. GSE contains very little resveratrol, as it is only found on the skin of grapes.
A tablespoon of GSE contains around 120 calories and 14g fats. Around 70% of these fats are polyunsaturated, and only 16% is monounsaturated. Omega-6 fatty acid content is high. The oil is a micronutrient-free product, except for vitamin E.
Despite the lack of vitamins, marketing companies continue to promote it as a healthier alternative. Science doesn't confirm many of the benefits.
The key point is that grape seed extract contains a high amount of omega-6 polyunsaturated fats and a moderate level of vitamin E.
Does it improve health?
It is important to note that grape seed oil does not come in the same quality. Pressing the seeds first is necessary to get the oil out of them. This can affect the quality.
Two main extraction methods are available. Cold pressing is a healthier option. It involves using an hydraulic press to remove the oil, enzymes and fiber from the seeds. It requires no chemicals.
GSE may also be obtained using industrial methods involving chemicals like hexane. It is common to use this method in order to increase the amount of oil contained within the extract. However, it can leave behind a residue of hexane.
It is important that you only consume cold-pressed GSE oils to improve your health. You can either do that, or risk consuming a contaminated extract which could be toxic. If it does not say cold-pressed on the packaging of a product, then it has been chemically pressed.
Research on GSE's health benefits has mixed results. Studies show that seed oil reduces inflammation through the inhibition of a white blood cell known as a macrophage. However, other studies have shown that seed oils rich in polyunsaturated omega-6 oils increase inflammation, inflammatory diseases, and heart disease risk.
Research shows GSE can reduce blood pressure. However, it does not affect blood sugar or lipid levels. The blood pressure was reduced by 1.45mmHg, a small but significant amount. The study used metabolically ill participants, so caution is needed when applying these findings to healthy individuals.
Only high doses of grape seed supplementation seem to improve blood flow. Researchers have found that 2-4g of grape seed extract can increase blood flow, or "vasodilation", especially in people at risk for heart disease.
GSE has been used as a supplement for a long time, but in the past few years it's become more popular as a booster of testosterone. Does science support these claims? Find out!
The key point is that grape seed oil doesn't have the same health benefits as other oils. Some aspects of autonomic functions may be improved in clinical populations, but they are rare.
Does Grape Seed Extract Boost Testosterone?
It's true that grape seed extract is a nutrient which has been understudied. Studies that link the two don't seem to be very convincing, which is why you may wonder why companies sell it as T-boosters in the first instance.
Some evidence suggests that GSE can help slow the damage caused to testes by alcohol and other toxins. Researchers found in a Molecular and Cellular Biochemistry study [5] that 75mg of GSE per kilogram body weight reduced the decrease in testicular mass from 36% to 12% over a 10 week period.
It may reduce the damage to testicular tissue, but it won't raise testosterone.
A couple of studies have shown that GSE inhibits aromatization, the conversion process in the body from testosterone into the estrogen hormone.
One study [6] showed that procyanidin in the extract of seeds inhibited the aromatase on a dose-dependent basis.
It is beneficial to keep estrogen in check, but does not mean that testosterone will increase. Only the conversion rate of male hormones into female hormones may be slowed. It is not true that grapeseed extract increases testosterone.
It is still too early to be confident that grape seed can boost testosterone, as no human studies have been conducted that directly link the two. While inhibiting aromatization may be a good thing, GSE can't compete with other nutrients like zinc, D-apartic Acid or Vitamin D which are known to directly boost testosterone levels.
The key point: Although grape seed extract may reduce aromatization, and improve blood circulation, there are currently no studies that show it increases testosterone.
Conclusion
The grape seed oil comes from the after-products of red grapes. The oil is rich in omega-6 polyunsaturated fatty acids and procyandins, but it contains very few micronutrients other than vitamin E.
GSE is marketed as a product that promotes health, but the manufacturers have done very little to support their claims.
Some studies found it improved autonomic function, while other studies showed that seed oil can increase inflammation.
There is even less evidence to support its effectiveness as a testosterone booster.
Its only benefit may be that it can act as an estrogen inhibitor, and it could improve blood circulation.
Other, more reliable supplements that directly affect your testosterone levels would be far superior.
References
- Calder, PC et al. n−3 Polyunsaturated fatty acids, inflammation, and inflammatory diseases. Am J Clin Nutr. 2006; 83(6): S1505-1519S
- Rose, GA et al. Corn oil in treatment of ischaemic heart disease. Br Med J. 1965; 1(5449): 1531-1533
- Sivaprakasapillai, B et al. Effect of grape seed extract on blood pressure in subjects with the metabolic syndrome. Metabolism. 2009; 58(12): 1743-6
- Clifton, PM. Effect of Grape Seed Extract and Quercetin on Cardiovascular and Endothelial Parameters in High-Risk Subjects. J Biomed Biotechnol. 2004; (5): 272-278
- Ye, X et al. The cytotoxic effects of a novel IH636 grape seed proanthocyanidin extract on cultured human cancer cells. Mol Cell Biochem. 1999; 196(1-2): 99-108
- Kijima, I et al. Grape seed extract is an aromatase inhibitor and a suppressor of aromatase expression. Cancer Res. 2006 1; 66(11): 5960-7