The concept of ‘superfood’ refers to some foods which are thought to have certain health benefits. There are many debatable opinions about what a superfood is and their effects on a person’s health, with claims that superfoods can boost intelligence and physical ability, lighten depression or slow the aging process (1).
The food industry exploits the fear of a non-healthy lifestyle and of chronic diseases such as heart disease, stroke or cancer, atrying to convince us that eating a single fruit or vegetable containing a certain chemical will automatically improve our health (1).
A lot of research in this area was done on chemicals and extracts in concentrations not found in food in its natural state (1). Despite the inconclusive evidence, having a balanced and diversified diet that includes these superfoods, will provide the nutrients our body needs and the health claims of these superfoods could quickly add up (1).
Here are eight of the claimed superfoods and the health benefits believed to go with them.
Blueberries
Including fibre and manganese, blueberries are a good source of Vitamin K and C (4). Vitamin K helps blood to clot if you cut yourself in order for a wound to heal (2). Vitamin C – also known as ascorbic acid – does a number of things:
- Protects and maintains healthy cells
- Is needed in order to maintain our connective tissue healthy
- Aids wound healing (3)
Vitamin C cannot be stored in the body so we need it to be part of our daily diet (3).
A 2012 study found that participants, who ate three or more portions of blueberries and strawberries a week, had a 32% less risk of a heart attack than the participants who ate them once a month or less. (4)
While the evidence is inconclusive, it is thought that blueberries can encourage blood vessel walls to relax. This can help reduce the amount of atherosclerosis in your body. Atherosclerosis is a condition whereby arteries become blocked with fatty plaques. Reducing the amount of Atherosclerosis in the body could therefore possibly lessen the risk of clogged arteries. (4)
Goji berries
Goji berries contain Vitamins C, B2 and A, as well as iron and selenium (5a).
Vitamin B2 is also known as riboflavin. It dissolves in water and helps to break down proteins, fats and carbohydrates as it goes through the bloodstream. It can also help to maintain the mucus membranes in our digestive systems (5b).
Vitamin A is useful to the immune system and helps us maintain healthy vision (6).
A 2008 US study, where participants took a daily drink of 120ml of goji berry juice for two weeks, showed that goji berries could improve the general well-being and digestion (7). However, due to having only 34 participants, the test was inconclusive in making claims for the population as a whole.
Dark Chocolate
Despite milk chocolate having a notorious reputation as an unhealthy food, due to its high fat and sugar content, dark chocolate (with at least 70% cocoa) can actually have certain health benefits when eaten in small portions (8).
Dark chocolate is considered to be a powerful source of antioxidants (8) which can protect your cells against the effects of free radicals, produced in the oxidation process of your cells, known to lead to cell damage (8).
The Oxygen Radical Absorption Capacity (ORAC) is the measurement of the antioxidant activity of foods. Under test conditions, the raw cocoa bean had one of the highest ORAC of the foods that were tested (8). This can be questioned though as it was tested in a lab and not in the body.
Some of the compounds found in dark chocolate are called flavanols. These can encourage the endothelium – the lining of the arteries in the body – to produce a gas called Nitric Oxide (NO) (8). NO sends a signal to the arteries to relax, lowering resistance of blood flow and in some cases lowering blood pressure (8). A 2012 review of the existing research reached the same conclusion about the effects of chocolate on blood pressure, however, as most of these research studies were short-term, there is a need for longer-term trials to strengthen the existing results (9).
Oily fish
Fillets of fatty fish such as trout, salmon, mackerel, herring or sardines can contain up to 30% oil (10) which is usually made up of two main ingredients: DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). These are both Omega-3 fatty acids (10).
The Omega-3 oils have been found to have a number of health benefits if part of a regular diet. In 2004, the UK Scientific Advisory Committee on Nutrition produced a report that stated: 'A large body of evidence suggests that fish consumption, particularly of oily fish, reduces cardiovascular disease risk' (12). Other studies have found that oily fish may also help improve working memory in young adults or have a positive effect on fetal development (10).
Oily fish contains more vitamin A and D than other white fish (10). Vitamin D controls the amount of calcium and phosphate absorbed by your body, keeping bones and teeth healthy. Children with Vitamin D deficiency can be at risk of developing symptoms of rickets (a condition that can cause bone deformation) (11).
Beetroot
Beetroot is healthy for the body as raw leaves or juice. It is rich in calcium, Vitamin A and C, as well as number of other components including Folic Acid (14).
Folic Acid is a type of Vitamin B. It works together with Vitamin B12 to form red blood cells. It also helps to reduce the risk of developing central nervous system complications in unborn babies (13).
A 2010 US study suggests that beetroot juice could increase blood flow around the brain, although further research would be needed for definitive results (14).
Green Tea
Green tea contains a number of nutrients including Vitamin B, caffeine and catechins (15).
Catechins are antioxidants found in many foods but in higher quantities in tea, thought to help the body burn more calories (15). A 2013 review of 11 studies involving 821 people suggests that a daily consumption of green tea could aid in lowering cholesterol and blood pressure because of the catechins (15). Further research is needed to back up the findings.
Quinoa
Quinoa is a type of grain similar to cereal and comes in three types: red, white and black.
The grain has been claimed to help control blood sugar levels. Foods which have a high glycemic index stimulate hunger, which can make people want to eat more, and can in some cases contribute to obesity. Quinoa has a low glycemic index which will make you feel full quicker and also provide your body with high levels of protein and fiber.
Pomegranate
Pomegranate is a Middle Eastern fruit that is rich in Vitamin A, C and E (16).
There have been a number of research studies into the fruit's health benefits. In 2006, a small study found that a daily intake of pomegranate juice could significantly slow the progress of prostate cancer in men with the recurring cancer (16).
Another 2004 study found that patients with carotid artery stenosis – narrowing of the arteries – could experience a reduction of damage to their arteries by nearly half, including reducing the build-up of cholesterol (16).
As with most superfoods above, the evidence around the health benefits of pomegranate are inconclusive and further tests and research needs to be carried out to strengthen the results.
Conclusion
Although the term ‘superfood’ is not scientifically recognised, there are a number of foods that have naturally occurring nutrients and chemicals which can be beneficial to our health. Further research, however, is needed to fully understand the specifics of such benefits.
References
1. NHS Choices: What are superfoods? Available here
2. NHS Choices: Vitamin K. Available here
3. NHS Choices: Vitamin C. Available here
4. NHS Choices: Blueberries: antioxidant powerhouse? Available here
5a. NHS Choices: Do goji berries deserve their A-list status? Available here
5b. Medical News Today: Vitamin B2. Available here
6. NHS Choices: Vitamin A. Available here
7. NCBI: Clinical study of general effects of goji berry juice. Available here
8. Authority Nutrition: Dark Chocolate benefits. Available here
9. NHS Choices: Chocolate's health claims. Available here
10. Medical News Today: Fish Oils. Available here
11. NHS Choices: Vitamin D. Available here
12. UK Scientific Advisory Committee on Nutrition: 2004 report on fish consumption and benefits. Available here
13. NHS Choices: Vitamin B. Available here
14. NHS Choices: Beetroot. Available here
15. NHS Choices: Green Tea. Available here
16. NHS Choices: Pomegranate. Available here