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.
This article looks at some of the evidence for the health benefits of three natural products we often cook with or add to our foods.
- Olive oil
Cardiovascular disease, some cancers, and cognitive decline
Olive oil is as an important part of the Mediterranean Diet. It appears to:
- reduce the risk of cardiovascular disease (including heart attacks)
- reduce the risk of some cancers
- slow cognitive decline and possibly 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 ‘all-cause mortality’ (the death rate from all causes of death over a given time).
Type 2 diabetes
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 question relating to olive oil is that it is a natural product whose composition – and presumably its health benefits – may vary, depending for instance on where, when and how it was produced and stored. It is also important to remember that there are different types of olive oil.
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 associated with olive oil, except when it is heated to a high temperature. So, olive oil 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 to promote healing. However, high quality research into its effectiveness has so far been limited.
The lack of high-quality research is probably understandable as there is no financial incentive for pharmaceutical companies to research the possible benefits of such a natural product. Clinical trials usually aim to compare a medicinal product with a placebo – which looks the same – so that neither patients nor researchers know which is which, and so cannot be influenced by its appearance. 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 have different effects.
Anti-bacterial effects and wound healing
Having said this, factors such as the rise of antibiotic resistance may be leading to an increased interest in the medical potential of honey, as a number of studies suggest it can help with wound healing where conventional approaches have failed.
The most researched area so far is the use of honey for treating wounds. For example, a 2021 review of the evidence concluded that medical grade honey (MGH) is a promising wound-healing agent because it has a broad spectrum of antimicrobial efficacy with no known resistant pathogens. The review recommended that MGH should be considered as a potential alternative to antibiotics or as a complementary therapy for treating locally infected wounds such as infected diabetic ulcers.
The Mayo Clinic recommends drinking hot lemon with honey as one way to treat a cough.
In addition, a 2018 review of the evidence concluded that honey probably relieves cough symptoms to a greater extent than diphenhydramine (a sedating antihistamine), a placebo, or no treatment, and has a similar effect compared to dextromethorphan (a typical over-the-counter cough suppressant).
Might honey, despite its sugar content, help patients with diabetes? That’s a question considered by researchers. For example, a 2018 review of the evidence concluded that honey had a protective effect for patients with obesity, type 2 diabetes, and hypertension.
However, a review by Healthline suggested caution until more research has been conducted, and warned that honey, like other sugars, should be consumed only in moderation.
Research-to-date suggests a number of potential areas where honey might have effective medical uses. However, more clinical trials with people are needed to confirm or deny the claimed health benefits. And honey, like many natural products, can vary greatly 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 the amount of honey you eat.
Some health claims (and counterclaims) about chilli peppers and their active ingredient capsaicin are based on laboratory experiments with animals, rather than on clinical trials or population studies with people. These claims have not been included in this article.
Studies with people suggest that chillies, applied clinically as a patch or as a cream, may help with weight management.
Pain relief through a clinically administered capsaicin patch or by applying lower strength capsaicin cream has been found to be effective and can last for several months after application. Research is also being done on the use of injectable capsaicin as a treatment for pain conditions such as arthritis and other musculoskeletal conditions.
Creams and patches containing capsaicin have also been used to help with fibromyalgia (widespread pain and extreme tiredness), migraines, joint conditions like rheumatoid arthritis and osteoarthritis, and even to relieve pain after surgery.
Some earlier studies had suggested that chillies might increase the risk of stomach and liver cancer. However, a 2021 review of published research concluded there was an association between chilli pepper consumptions and lower risk of all-cause, cardiovascular and cancer-related deaths. This was in line with previous studies, including a 2015 study in China, a 2017 study in the US, and a 2019 study in Italy, all of which concluded there was an association between regular consumption of chilli peppers and a lower risk of total and cardiovascular death.
Prostate cancer cells
The American Association for Cancer Research reports that capsaicin is able to kill prostate cancer cells by causing them to undergo apoptosis (the body’s natural way of eliminating unwanted cells).
We should avoid particularly hot chillies, because of the potential side effects such as vomiting and severe stomach pains.
However, this refers to unusually hot peppers, with a high rating on the Scoville scale i.e. the digestive equivalent of pepper spray. It does not refer to the type of chilli peppers you would typically get in food or in sauces like Tabasco.
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 in our diet 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 you like the taste. Recent studies suggest potential health value, provided we avoid the superhot varieties.
Reviewed and updated by Michael Baber, July 2022. Next review date June 2026.
Other relevant articles on the Age Watch website:
- Diet: Healthy foods – garlic, green tea and oily fish
- Diet: What is the Mediterranean diet?
- Diet: Mediterranean diet health benefits
- Diet: Top foods
- Diet: Healthy eating on a budget
- Diet: How to ensure that we eat more healthily
- Diet: What determines our food choices – and how does this affect our health?