An apple a day may keep the reaper away — especially when enjoyed with a cup of hot tea. A new study finds that eating foods rich in flavonoids, a compound found in high concentrations in foods like apples and beverages such as tea, lowers one’s risk of death, particularly among heavy drinkers and smokers.
Researchers from Edith Cowan University’s School of Medical and Health Sciences analysed data from the Danish Diet, Cancer and Health cohort that assessed the diets of 53,048 Danes over 23 years.
They found that people who habitually consumed moderate to high amounts of foods rich in flavonoids, compounds found in plant-based foods and drinks, were less likely to die from cancer or heart disease.
The study titled “Flavonoid intake is associated with lower mortality in the Danish Diet Cancer and Health Cohort” was published Tuesday (August 13) in the journal Nature Communications.
Lead researcher, Dr. Nicola Bondonno, said while the study found a lower risk of death in those who ate flavonoid-rich foods, the protective effect appeared to be strongest for those at high risk of chronic diseases due to cigarette smoking and those who drank more than two standard alcoholic drinks a day.
“These findings are important as they highlight the potential to prevent cancer and heart disease by encouraging the consumption of flavonoid-rich foods, particularly in people at high risk of these chronic diseases,” she said.
“But it’s also important to note that flavonoid consumption does not counteract all of the increased risks of death caused by smoking and high alcohol consumption. By far the best thing to do for your health is to quit smoking and cut down on alcohol.
“We know these kinds of lifestyle changes can be very challenging, so encouraging flavonoid consumption might be a novel way to alleviate the increased risk, while also encouraging people to quit smoking and reduce their alcohol intake.”
Participants consuming about 500mg of total flavonoids each day had the lowest risk of cancer or heart disease-related death.
“It’s important to consume a variety of different flavonoid compounds found in different plant-based food and drink. This is easily achievable through the diet: one cup of tea, one apple, one orange, 100g of blueberries, and 100g of broccoli would provide a wide range of flavonoid compounds and over 500mg of total flavonoids”.
Bondonno said while the research had established an association between flavonoid consumption and lower risk of death, the exact nature of the protective effect was unclear but likely to be multifaceted.
“Alcohol consumption and smoking both increase inflammation and damage blood vessels, which can increase the risk of a range of diseases,” she said.
“Flavonoids have been shown to be anti-inflammatory and improve blood vessel function, which may explain why they are associated with a lower risk of death from heart disease and cancer.”
Bondonno said the next step for the research was to look more closely at which types of heart disease cancers were most protected by flavonoids.
The ECU study was a collaboration with researchers from the Herlev & Gentofte University Hospital, Aarhus University, as well as the Danish Cancer Society Research Centre, Aalborg University Hospital, the Universities of Western Australia and the International Agency for Research on Cancer.
Meanwhile, pioneering research in America has revealed that drinking apple juice and eating apples can reduce the risk of heart disease.
The clinical trial involved healthy adults drinking 12oz of 100 per cent apple juice daily or eating two apples.
The time it took for cholesterol in the body to oxidise, or break down, increased by up to 20 per cent after just six weeks of following the apple diet.
It turns out that apples contain phytonutrients or phytochemicals (compounds found in plants) which act as antioxidants against LDL (low-density lipoproteins), the damaging portion of cholesterol in the bloodstream.
Apples are also rich in pectins, which are soluble fibres which have been demonstrated are effective in lowering cholesterol levels.
Dianne Hyson, a registered dietician and lead researcher of the study, said: “Previous studies have shown that eating fruits and vegetables is associated with a reduced risk of coronary artery disease, but this is the first clinical study to show the potential benefits of active compounds in apple juice and apples.
“A very moderate intake of apple juice or apples has the potential to reduce risk factors for heart disease in a fairly short period of time. These small diet changes might play an important role in a heart-healthy diet.”
Volunteer, father of two Jack Farrell said: “If I can get this result from just drinking 12ozs of apple juice a day, it’s definitely worth making part of my daily routine.”
Finnish researchers found that individuals who ate the most apples had the lowest risk of suffering a stroke, due to the benefits of the active compounds called phytonutrients found in apples.
Their conclusion was based on the evaluation of dietary records and health outcomes of 9,208 men followed for 28 years.
British researchers found that apple eaters had better lung function than non-apple eaters.
After analysing the health and dietary records of 2,512 men, scientists discovered a strong link between positive lung function and the number of apples eaten each week.
Although other researchers had suggested that vitamin C from fresh fruit was responsible for improving lung function, this investigation found otherwise.
These researchers believe that it is the consumption of antioxidant-like phytonutrients in apples, such as flavonoids especially one member called quercetin which reduces the risk of cancer and heart attacks. This they say provides an explanation for the healthful effect of apples.
Researchers in Hawaii found that increased consumption of quercetin (from apples and onions) was associated with a reduced risk of lung cancer.
This was supported by epidemiologists from Finland’s National Public Health Institute who concluded that a flavonoid-rich diet (and particularly those flavonoids from apples) was associated with a reduced risk of developing cancer.
Their study of 9,959 cancer-free men and women revealed that people who regularly consumed the most flavonoid-rich foods were about 20 per cent less likely to develop cancer.
The researchers found that lung cancer was 46 percent lower among those on these diets and that high consumption of apples was also directly associated with the lowest risk for coronary mortality.
This conclusion was based on their analysis of diet and health outcomes of an ongoing study of 5,133 Finnish men and women aged 30-69, who were initially free of heart disease when the study began in 1967.
Meanwhile, earlier research, which appeared in the International Journal of Cancer, found an association between drinking tea at very high temperatures and the risk of developing esophageal cancer.
Numerous factors may raise a person’s risk of developing cancer of the esophagus. These include being older than 55, being male, having acid reflux, or eating a diet high in processed meats and low in fruits and vegetables.
Some researchers have also suggested that regularly drinking very hot liquids may also raise the risk of esophageal cancer.
However, most of these studies asked the participants to remember and estimate how much tea they drank and at what temperature. Such an approach may have biased the results. Namely, when participants have to estimate something in retrospect, recall bias may affect their answers. So, a new study aimed to rectify this by measuring tea drinking temperature objectively — that is, in a way that did not depend on a person’s memory, feelings, or opinions.
Researchers, led by Dr. Farhad Islami, the strategic director of Cancer Surveillance Research at the American Cancer Society, also wanted to study tea-drinking habits prospectively rather than retroactively.
Islami and colleagues used data on over 50,000 people included in the Golestan Cohort Study — a “population-based prospective study” — who were 40–75 years old at baseline.
The researchers clinically followed the participants for an average period of 10.1 years, between 2004 and 2017. During this time, 317 people developed esophageal cancer.
The researchers divided tea temperature into “very hot” — meaning a temperature of over 60°C, and “cold [or] lukewarm,” that is, a temperature that is or falls below 60°C.
In their analysis, the researchers also considered a “reported shorter time from pouring tea to drinking” it — that is, on a scale between two and six minutes’ wait, as well as “reported preference for very hot tea drinking.”
Overall, the study found that drinking 700 milliliters (ml) of “very hot” tea per day increased the chances of esophageal cancer by 90 percent compared with drinking the same daily amount of cold or lukewarm tea.
“Our results substantially strengthen the existing evidence supporting an association between hot beverage drinking and [esophageal cancer risk],” conclude the researchers.
Islami and colleagues continue, “It may thus be a reasonable public-health measure to extrapolate these results to all types of beverages, and to advise the public to wait for beverages to cool to [lower than] 60°C before consumption.”
“Many people enjoy drinking tea, coffee, or other hot beverages. However, according to our report, drinking very hot tea can increase the risk of esophageal cancer, and it is, therefore, advisable to wait until hot beverages cool down before drinking.”