Conflicting caffeine research confuses consumers

It’s safe to say the argument over the health implications of caffeine is far from over, leaving consumers increasingly confused about what to believe.

“While highly studied and approved for safe use by the US Food and Drug Administration (FDA), European Food Safety Authority (EFSA), and many other global regulatory agencies, caffeine remains a controversial ingredient and a heated topic of discussion,” says a spokesperson for nutrition and food safety group, Food Insight.

FoodNavigator recently reported on research, presented at American College of Cardiology’s ACC Asia 2024, ​suggesting that consuming over 400 milligrams of caffeine each day could increase the risk of cardiovascular disease​.

The study, which analysed the effects of caffeine on young, ‘healthy’ adults, found that regular intake at this level disrupts the autonomic nervous system. And this disruption leads to increased heart rate and blood pressure. The research team concluded that these findings highlight the importance of moderating caffeine consumption to reduce the risk of hypertension and related cardiovascular conditions.

“Regular caffeine consumption could disturb the parasympathetic system, leading to elevated blood pressure and heart rates,” says Nency Kagathara, lead author on the study. “Due to its effect on the autonomic nervous system, regular caffeine consumption could put otherwise healthy individuals at risk of hypertension and other cardiovascular events.”

Now research, published in Rheumatology by Oxford University Press, suggests that increased caffeine intake could in fact improve vascular health.

So who’s right?

Is caffeine good for vascular health?​Researchers from the Sapienza University of Rome believe patients with vascular health issues could improve their condition by consuming caffeine.

According to the study, caffeine actively supports endothelial progenitor cells – the group of cells help regenerate the lining of blood vessels and are involved in vascular growth.

This research could prove a major breakthrough for healthcare professionals and vascular patients as, until now, recommendations to reduce vascular issues were focused on the avoidance of risk factors such as smoking and high-cholesterol foods. But could including caffeine in a patients’ diet also be added to the list of recommendations in the future?

Foods rich in vitamin D such as oily fish and eggs, vitamin A such as mangos and carrots, and polyunsaturated fatty acid have been associated with decreased inflammation in the body. The research team wanted to know if the caffeine could also have the same effect.

Besides the well-known stimulant effect on the body, caffeine also exerts an anti-inflammatory effect, as it binds with the receptors expressed on the surface of immune cells. They carried out a study on 31 lupus patients, without traditional cardiovascular risk factors, using a seven-day food questionnaire. After a week the investigators took the patients’ blood, to measure blood vessel health. The team found that patients who consumed caffeine had better vascular health, as measured through endothelial cells, which form the important inner layer of blood vessels.

Is caffeine damaging to vascular health? GettyImages/izusekFurther research required​It’s important to note, this is a limited study, carried out over a short period of time, with a small study group. Further investigation is therefore required.

“The present study is an attempt to provide patients with information on the possible role of diet in controlling the disease,” said Fulvia Ceccarelli, the paper’s lead author. “It will be necessary to confirm the results through a longitudinal study, aimed at assessing the real impact of coffee consumption on the disease course.”

With that in mind, it’s likely consumers will continue to follow guidance from the European Food Safety Authority (EFSA), which advises caffeine intake of up-to 400 milligrams per day, saying this level does not raise safety concerns for healthy adults in the general population, with the exception of pregnant women. Though, this advice may come under review, at a later date.

However, while advice on caffeine intake levels may at some point change, it’s highly unlikely that EFSA will recommend against the consumption of caffeine altogether. And not just because it’s so widely enjoyed, but because it also offers the consumer some health benefits.

Despite the clear association with tea and coffee, caffeine is actually present in a variety of foods and beverages, including some soft drinks and energy bars. GettyImages/Betsie Van der MeerWhat are the benefits of consuming caffeine?​Caffeine is a natural substance, found in the leaves and fruit of more than 60 plants, most notably, tea and coffee plants. However, despite the clear association to tea and coffee, caffeine is actually present in a variety of beverages, including some soft drinks, as well as some foods, including energy bars.

As a natural ingredient, caffeine offers a variety of health benefits, with studies from Johns Hopkins Medicine in the United States associating it with a reduced risk of Alzheimer’s disease, diabetes and kidney disease.

Caffeine also offers potential mental and emotional benefits when enjoyed in the form of a cup of tea or coffee.

“Coffee provides a great ritual, and really brings people together in their daily routines,” Howey Gill, head of coffee at coffee brand Grind, told FoodNavigator. “Sitting down in a buzzing café, chatting, with the noise of espresso machines, customers and music – people love this vibe. At home, it provides this amazing ritual for us. Regardless of what’s going on in our lives it provides this little moment of constancy where we take a second to do whatever it is we do to make our cup of coffee. For me that’s pouring a big v60 for me and my partner in the exact same spot in the kitchen.”

Furthermore, many consume caffeine, as it’s a natural stimulant, meaning it increases activity in the brain and nervous system. It also increases the circulation of chemicals such as cortisol and adrenaline in the body, helping the consumer to stay alert and active.

There are multiple benefits to consuming caffeine. GettyImages/alvarezSource: Caffeine improves systemic lupus erythematosus endothelial dysfunction by promoting endothelial progenitor cells survival
Published online: 9 October 2024
DOI: doi.org/10.1093/rheumatology/keae453
Authors: Valeria Orefice, Fulvia Ceccarelli, Cristiana Barbati et al.