A long-term study on diet and health showed that a high flavonoid intake reduces the risk of Alzheimer’s disease and dementia by up to 40%.
Can drinking tea and eating berries reduce your risk of developing Alzheimer’s disease and dementia? A team of scientists in Boston have shown this to be the case, and it is most likely due to the flavonoids found in many plants. In fact, high flavonoid intake reduces the risk of Alzheimer’s disease and dementia (two neurological diseases that affect your ability to think, reason and remember) by up to 40%.
Flavonoids are a family of compounds that are found in most plants, including fruits and vegetables. There are different types of compounds in the flavonoid family, but most of them have similar beneficial properties. These properties include antioxidants, which can help reduce cell damage in your body, and anti-inflammatory properties which help control your immune system and prevent damage to your body due to inflammation.
Some of the most common sources of flavonoids include brightly coloured fruits like berries, oranges and apples, vegetables like onions and parsley, drinks like tea and wine, and dark chocolate. Different types of foods have different flavonoids, so it is always best to try and eat a large variety of fruits and vegetables in order to ensure you get all different kinds of flavonoids in your diet.
So how much can flavonoid intake affect your chances of developing cognitive (thinking) issues like Alzheimer’s disease or other types of dementia? A study in the American Journal of Clinical Nutrition attempted to figure that out. They used a long-term study in the town of Framingham, Massachusetts, where over 5000 participants have been part of a long-term health and nutrition study since 1948. The children of these participants are also participating in their own version of the study, giving a good bank of people to study the relationships between nutrition and many common diseases.
The Boston scientists took a detailed look at participants who were at least in their fifties and were without any signs of dementia or Alzheimer’s disease (AD) while participating in the study. The researchers then looked at both the participants’ diets and whether they had developed these neurological problems over the years. The scientists also took into account other risk factors such as obesity, smoking, levels of education and some genetic factors to see if they would affect the results.
In total, about 2,800 people from the study were eligible for further analysis. First, the scientists looked into their detailed diet records and calculated their total flavonoid intake over the years. The study participants were divided into four groups of flavonoid intake, ranging from low to high. Then, the researchers looked at the number of people who had developed either AD or another type of dementia in each group.
What they found was that the group that had the highest intake of flavonoids had a 40% reduction in the risks of developing Alzheimer’s disease or dementia when compared with the group that had the lowest flavonoid intake in their diet. They found that the more flavonoids that were eaten, the lower the chances were that people in those groups developed a neurological disorder like AD or dementia. This is very encouraging news, and further proof that a healthy diet with lots of fresh fruits and vegetables is an excellent way to prevent some neurological problems.
However, there were some limitations to this study. First of all, the population number is small, which means that more subtle effects caused by high or low flavonoid consumption and/or risk factors might not have been observed. A larger population study could help improve the observations. Also, the population in Framingham is mostly white and of European descent, so different ethnic backgrounds were not studied. Since genetic differences between ethnicities can affect study results, the researchers suggest that further studies in other populations would help to get a clearer overall picture of the effects of flavonoids on brain health.
However, the research clearly showed that high flavonoid intake reduces the risk of Alzheimer’s disease and dementia significantly.
Written by Nancy Lemieux
1. Shishtar, E., 2020. Long-Term Dietary Flavonoid Intake And Risk Of Alzheimer Disease And Related Dementias In The Framingham Offspring Cohort. [online] academic.oup.com. Available at: <https://academic.oup.com/ajcn/advance-article/doi/10.1093/ajcn/nqaa079/5823790> [Accessed 31 May 2020].
2. En.wikipedia.org. 2020. Flavonoid. [online] Available at: <https://en.wikipedia.org/wiki/Flavonoid> [Accessed 31 May 2020].
3. Szalay, J., 2020. What Are Flavonoids?. [online] livescience.com. Available at: <https://www.livescience.com/52524-flavonoids.html> [Accessed 31 May 2020].
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