This Week: Blueberries!

Why are blueberries good for you?

Blueberries are small, round, bluish-purple fruits or berries.There are many varieties growing in different regions of the world; the berries grow in clusters on shrubby bushes and can range in size. The blueberry (vaccinium myrtillus) was one of the first foods to be titled a ‘superfood’.

Cultivated blueberries are sweeter than wild berries; however, they all share the same characteristic deep blue-purple colour, thin translucent skin and
tiny seeds.

Blueberries have one of the highest antioxidant levels among commonly consumed fruit and vegetables. They are extremely rich in naturally occurring plant compounds called phytochemicals, such as ellagic acid and anthocyanidins. These phytochemicals are responsible for the blue, indigo and red colouring of the berry. They have also been extensively researched for their protective properties.

Research has shown that anthocyanidins, which are found in berry fruits, may support the cardiovascular system. They appear to do this by supporting the health
of blood vessels and reducing the arterial stiffness associated with ageing. This is especially useful for post-menopausal women.

In conjunction with helping manage blood pressure, the phytochemicals in blueberries have been seen to prevent oxidative damage to cholesterol. Being rich in phytochemicals, vitamins and fibre, blueberries support the health of the gut, which is home to 70 per cent of our immune system.

Research demonstrates a beneficial effect on the gut microbiota, the community of beneficial bacteria that live in our gut and play an important role in the induction and training of the immune system. Studies suggest the polyphenol and fibre content of blueberries may help relieve gut symptoms and improve general well-being in those with abdominal symptoms from gut disorders.
Observational studies also suggest that diets rich in anthocyanins may help lower the risk of heart attacks – however more studies are needed to confirm these findings.

Berries contain antioxidants, which help keep free radicals under control. Free radicals are unstable molecules that are beneficial in small amounts but can damage your cells when their numbers get too high, causing oxidative stress. One study showed that blueberries, blackberries, and raspberries have the
highest antioxidant activity of commonly consumed fruits, next to pomegranates.

In fact, several studies have confirmed that the antioxidants in berries may help reduce oxidative stress.
One study in healthy men found that consuming a single, 10-ounce (300 gram) portion of blueberries helped protect their DNA against free radical damage.

​A number of studies suggest that both whole blueberries, their juice and the concentrated powdered form may help reduce oxidative damage. Such damage is an inevitable part of everyday life, but is a key driver in ageing and the development of disease.

Many people turn to berries such as cranberries to help prevent urinary tract infections (UTI). Blueberries contain similar compounds to those in cranberries. These compounds may help prevent the bacteria responsible
for UTIs from adhering to the bladder wall; however, this is not effective for all people, and studies suggest there may be other mechanisms at play.

Blueberries are both low in sugar and a good source of fibre; as a result, they have a low glycaemic index (GI). This, together with their high flavonoid content, may help improve insulin sensitivity, which is important for managing blood sugar levels.

Including blueberries in your diet regularly may improve vision and guard against age-related macular degeneration. This is thought to be thanks to the improved blood and oxygen flow to the eyes, and the antioxidant protection that may help reduce the likelihood of cataract and macular degeneration.

Strenuous physical activity or exercise may lead to soreness and inflammation. Consuming blueberries in a smoothie, for example, before and after such an event may help promote recovery and reduce inflammatory
markers.

While it's clear that blueberries make a healthy addition to any diet, they might not be suitable for those with sensitivities or allergies.  Blueberries contain salicylates, natural chemicals found in aspirin and many fruits and vegetables, some people are sensitive to these compounds, and may experience an allergic reaction, including skin rash and swelling.

When taken by mouth: Blueberry whole fruit, juice, and powders are commonly consumed in foods. Drinks made with freeze-dried blueberries might cause constipation, diarrhea, nausea, or vomiting in some people.

While blueberries are nutritious and provide many health benefits, it's better to eat a varied diet to achieve good health. If you are concerned about food allergies, please consult your GP or registered dietitian for guidance.

The fiber, potassium, folate, vitamin C, vitamin B6, and phytonutrient content in blueberries supports heart health. The absence of cholesterol from blueberries is also beneficial to the heart. Fiber content helps to reduce the total amount of cholesterol in the blood and decrease the risk of heart disease.

Nutrient-rich and low in calories, as long as you do not have an allergy to the fruit, blueberries make a valuable addition to your diet. Enjoy fresh when in season, or try frozen or dried.