Healthy Foods – Olive Oil, Honey and Chillies?
Are olive oil, honey and chillies really good for us? If so, how and why? And if they can really affect our bodies, are there any possible side effects?
As we’ve reported elsewhere ‘superfoods’ are a media exaggeration. However, some foods appear to be healthier than others. So what does the evidence suggest here?
Olive oil is as an important part of the Mediterranean Diet. As we report elsewhere the appears to reduce the risk of cardiovascular disease (including heart attacks), possibly reduces the risk of some cancers, slows cognitive decline and may protect against Alzheimer’s.
When researchers examined studies comparing olive oil with other monounsaturated oils in 2014, their conclusion was that only olive oil appears to be associated with a reduced risk of death.
A study of 4,512 women in Spain, reported in 2015, found that a Mediterranean Diet with olive oil appeared to be result in lower levels of breast cancer than a Mediterranean Diet with nuts or a low fat diet, although the authors advised that more research is needed to confirm this.
A systematic review published in April 2017 found that olive oil is ‘a suitable component of a balanced diet’ and has ‘favourable effects’ on people suffering from Type 2 diabetes.
One of the main questions relating to olive oil is the quality of the research evidence so far. For example a 2016 review of published studies into the Mediterranean Diet questioned the quality of much of the existing research and recommended that more rigorous research was needed.
It’s also important to remember that there are different types of olive oil and Extra Virgin Olive Oil is richest in the components believed to help protect our health because it is the least processed.
No health risks have been identified except when olive oil is heated to a high temperature. So it is best consumed uncooked – for instance on salad or vegetables.
Various claims have been made for the medicinal qualities of honey, in particular its ability to kill bacteria and promote healing. However, high quality research into its effectiveness has so far been limited.
This is probably understandable. There is no financial incentive for pharmaceutical companies to research the possible benefits of a natural product. Clinical trials usually aim to compare a medication with a placebo which looks the same, so that neither patients nor researchers know which is which and can be influenced by this. However, the distinctive appearance, consistency and smell of honey makes this approach almost impossible. Also, there are different types of honey, each of which may behave a little differently.
Having said this, factors such as the rise of antibiotic resistance may be leading to an increased interest in the medical potential of honey. What does the limited research which has been conducted so far suggest?
The most researched area so far is the use of honey for treating wounds. A 2015 review of the evidence here concluded that evidence for treating a range of wounds (including ulcers and gangrene) was of low quality. However, honey appears to heal partial thickness burns more quickly than conventional treatment and infected post-operative wounds more quickly than antiseptics and gauze.
The NHS recommends drinking hot lemon with honey as one way to treat a cough and a small-scale study in Iran, published in 2011, suggested that honey and coffee can successfully treat a persistent cough which has continued for weeks after a cold or upper respiratory tract infection.
Might honey, despite its sugar content, help patients with diabetes? That’s a question posed in a 2013 article. This suggests growing evidence and scientific data to support the use of honey in patients with diabetes, by helping manage blood sugar. However, the article concludes by advising that more clinical studies are needed.
So research to date suggests potential in a number of areas. However reliable clinical trials with people are needed to confirm or deny the claimed health benefits. And honey, like many natural products, can vary in quality depending where it comes from.
Few significant adverse side effects have been reported – although honey should not be given to children under one year old, due to a possible risk of botulism poisoning and anyone allergic to pollen should also avoid honey. If you have IBS and are following a low FODMAP diet, then you should also limit how much honey you eat.
Some health claims (and counter claims) about chilli peppers are based on laboratory experiments with animals, rather than clinical trials or population studies with people, so we haven’t included them here.
Some earlier studies had suggested that chillies might increase the risk of stomach and liver cancer. However, a large scale study in China, reported in the BMJ in 2015, concluded that spicy (chilli based) foods, were associated with lower death rates – and there were similar findings from a study of 16,000 people in the US, reported in 2017.
At the same time, we should avoid particularly hot chillies, because of the side effects such as severe stomach pains.
On the research evidence so far we should:
- Include extra virgin olive oil in our diet, alongside other components of the Mediterranean Diet. This is likely to help protect against cardiovascular disease and may also help protect against some cancers and Alzheimer’s.
- Include honey if we like the taste and to help treat coughs. There don’t seem to be any serious health risks for adults (although honey might be one food to avoid if you have IBS).
- Include chillies in moderation if we like the taste. Recent studies suggest potential health value, although more research is needed here.
Reviewed and updated by Karen Rollins, October 2017. Next review date September 2020.