Could Fruit Polyphenols Be The Secret To Improving Athletic Endurance?

Marathon runners and triathletes may want to stock up on fruit as new research suggests that along with supporting overall recovery, polyphenols from apples and grapes may help to boost endurance. 

What are Polyphenols?

As plant compounds, Polyphenols include flavonoids and phenolic acid, that can benefit the human body in many ways and help to fight disease. They can be subdivided into flavonoids, phenolic acid, polyphenolic amides, and other polyphenols.

As a category of compounds, polyphenols may be found in fruits, herbs, spices, tea, dark chocolate and wine. 

What The Study Shows 

The double-blind study published in the journal Nutrients, recruited 48 active men from the ages of 25 to 37 to perform three high-intensity cycling tests. In the first test, the men cycled at 70% of their predetermined maximum aerobic power for as long as possible until exhaustion. 

In the second test, the men were given a 500mg supplement with a polyphenol profile similar to apples and grapes, the evening before and just one hour prior to a cycling test. 

During the cycling test, the men cycled until exhaustion at 70% of their maximum power. For the third test one week later, the men swapped treatments and cycled until exhaustion at 70% of their maximum power. 

During these three tests, researchers timed how long it took the men to reach exhaustion, as well as physical parameters such as blood pressure, heart rate, breathing rate, and oxygen use. Additionally, the men used a scale to report on the perceived level of exertion every four minutes while cycling. 

Researchers found that when compared with the placebo, men cycled for an average of 9.7% longer after receiving the polyphenol supplement. 

Those taking a polyphenol supplement also saw a 12.8% average increase in time to reach their maximum perceived level of exertion. While none of the physical parameters measured during exercise were affected by the polyphenol supplement, taking a supplement was associated with longer respiratory recovery time, which may be due to the longer exercise time. 

Polyphenols For Exercise Recovery 

The findings of the study suggest that polyphenols can help endurance athletes to improve their game. While polyphenols from eating fruit are different from polyphenol supplements because the body may absorb them differently, it’s recommended to include apples and grapes as they make great snack choices, especially post-exercise if you need more energy. 

Depending on the variety, an apple has about 136mg of polyphenols, and around ⅔ of a cup of blue-black grapes has about 169mg of polyphenols.

Other Health Benefits Of Taking Polyphenols 

Along with improving physical endurance for athletes, there are many other great health benefits to taking polyphenols. Some of these many reasons include…

• May Lower Blood Sugar Levels and Contribute To A Lower Risk Of Type 2 Diabetes 

This is partly because polyphenols may prevent the breakdown of starch into simple sugars, lowering the chances of blood sugar spikes after meals. Various studies suggest that polyphenol-rich diets are linked with lowering fasting blood sugar levels, higher glucose tolerance, and increased insulin sensitivity – all important factors in lowering your risk of Type 2 Diabetes. [1]

• May lower your risk of heart disease

Two recent reviews have linked taking polyphenol supplements to lower blood pressure and LDL (bad) cholesterol levels, as well as higher HDL (good) cholesterol. [2, 3]

• May prevent blood clots

Polyphenols may help with reducing the risk of developing a blood clot. Polyphenols may help with reducing platelet aggregation process, thereby preventing the formation of blood clots. [4]

• May protect against cancer

Research shows that diets rich in plant foods may help to lower the risk of cancer. Polyphenols have strong antioxidant and anti-inflammatory effects, both of which can be beneficial for cancer prevention. [5]

• May promote healthy digestion

Polyphenols can benefit your digestion by promoting the growth of beneficial gut bacteria, while fending off harmful ones. It’s been shown for instance that there is evidence suggesting that polyphenol-rich tea extracts can help promote the growth of beneficial bifidobacteria. [6]

• May promote brain function

Polyphenol rich foods may boost your focus and memory. One study has found that drinking grape juice which is naturally rich in polyphenols, helped to significantly boost memory in older adults with mild mental impairment in as little as 12 weeks. [7]

Similarly, polyphenol rich plant extracts such as Gingko Biloba appear to boost memory, learning and concentration. This has also been linked with improved brain activity and short-term memory in people with dementia. [8]

Anyone wanting to boost their polyphenols may want to consider eating dark-skinned berries as they are rich in antioxidants, along with being generally lower in sugar. While taking a supplement with polyphenols can help to provide the above benefits, as part of a healthy lifestyle. 

References:

[1] https://pubmed.ncbi.nlm.nih.gov/28785373/

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359281/

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5727797/

[4] https://pubmed.ncbi.nlm.nih.gov/27475864/

[5] https://www.sciencedirect.com/science/article/abs/pii/S2214799316300133

[6] https://pubmed.ncbi.nlm.nih.gov/16962743/

[7] https://pubmed.ncbi.nlm.nih.gov/16962743/

[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372091/

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