Sticking to a Mediterranean diet could be the key to a longer life, according to a major new study.
The study, published in the British Medical Journal, monitored the health of 4,676 middle-aged nurses over more than a decade, analysing the impact of the diet on a component of DNA called telomeres.
Researchers in the US found that those who adhered to the diet, which is based on oily fish, poultry, fresh fruit and vegetables, showed fewer signs of ageing in their cells.
Telomeres are stretches of DNA which protect genetic codes, and have been compared to the plastic tips of shoelaces as they keep chromosones from scrambling. They often shorten as a person grows older.
The Harvard-based researchers concluded there was a link between the Mediterranean diet and longer telomeres, which they suggest can be affected by a person’s lifestyle.
The report said: “In summary, greater adherence to the Mediterranean diet was significantly associated with longer leukocyte telomere length, a marker of biological ageing.
“The results further support the benefits of adherence to the Mediterranean diet for promoting health and longevity.”
Dr Mike Knapton, associate medical director at the British Heart Foundation, said the results added weight to the view that the diet could help prevent age-related illnesses such as cardiovascular disease.
He said: “Longer telomeres may partially explain the link between diet and risk of cardiovascular disease.
“These results reinforce our advice that eating a balanced and healthy diet can reduce your risk of developing heart disease.”
One day you read that the saturated fat in butter is bad for your heart, and the next, new research claims it’s better to eat butter than margarine.
To ease your confusion you have a glass of red wine, which studies have shown to have health benefits. And as you drink it, you read that red wine isn’t nearly as good for you as was thought.
All these so-called health studies can be completely baffling.
Tom Sanders, professor of nutrition and dietetics at King’s College London, points out that many studies are trumpeted to launch a book or report, or are hyped up by press offices to get publicity for universities or particular organisations. But he stresses that the tenets of a healthy diet remain the same - eat more fruit and vegetables, wholemeal bread and wholegrain cereal, and less red meat.
“It’s not rocket science,” he says.
Sometimes, new information is released, which changes the standard views, but it’s misinterpreted in terms of what the public should do. “Often, they can be messages that people like to hear.”
And Durham University public health dietician Dr Amelia Lake points out: “You often have to look behind the headlines at who’s funded the study. Think about the body of evidence, which has taken decades to build up.”
Still unsure? Let the experts reveal their opinions on some of the conflicting messages...
Avoiding saturated fat in foods like butter, cheese and fatty red meat has long been a cornerstone of a healthy diet. Indeed, a large analysis on dietary fat and cardiovascular risk, published by the respected Cochrane Library in 2011, said replacing saturated fat with unsaturated fat led to a “small but potentially important reduction in cardiovascular risk”.
Yet cardiologist Aseem Malhotra received a great deal of publicity last year when he said that butter, cheese and red meat are not as bad for the heart as has been claimed, arguing in the British Medical Journal that saturated fat has been “demonised” and any link with heart disease is not fully supported by scientific evidence.
A study by researchers from the US and Australia, also published in the British Medical Journal last year, showed that men who’d had a heart attack were more likely to die from coronary heart disease when they replaced saturated fats with polyunsaturated fat from safflower oil and safflower oil margarine.
However, the safflower oil in the US study is rarely used in this country, and some modern margarines don’t contain transfats, so consumers could expect to have lower cholesterol from eating them instead of butter.
“Butter isn’t better.” Sanders stresses. “Although a bit of butter is OK, you’d be better off with a reduced-fat spread than a lot of butter. Butter tastes nicer, but the saturated fat in it does raise cholesterol.”
He says it seems red meat and meat products are associated with cancer and heart disease, but some foods that are high in fats, like oily fish and nuts, and possibly dairy, aren’t.
“That’s the confusion,” he says, “but it doesn’t mean you ought to have lashings of cream, or tons of butter on your food. Adding extra fat adds extra calories.”
And Lake says: “There’s no body of evidence that says it’s fine to have saturated fat.
“We should be trying to mirror the Mediterranean diet, which doesn’t include saturated fats like butter, and red meat doesn’t feature strongly.
“A bit of butter on your toast occasionally might be OK, but it’s the behaviours you repeat on a daily basis that can cause problems.”
Red wine has often hit the headlines as being the ’healthiest’ alcohol choice, with studies claiming that when drunk in moderation, the tipple can help protect the heart, and reduce ’bad’ cholesterol.
Indeed, the regular drinking of red wine has been suggested as the explanation for the relatively low incidence of coronary atherosclerosis (blocked arteries) in France, compared with other Western countries, despite the generally high intake of saturated fat in the French diet.
Some of red wine’s purported health benefits are thought to come from a chemical it contains called resveratrol, and researchers at the University of Leicester have found that a daily amount of resveratrol, equivalent to two glasses of wine, can halve the rate of bowel tumours.
However, US research published earlier this year suggests red wine may not be as good for you as was thought. The study of nearly 800 men and women from the Chianti region of Italy found dietary resveratrol didn’t translate into fewer deaths, cancers or heart problems.
“Alcohol, including red wine, increases blood pressure,” says Sanders, who points out that, conversely, studies do show wine to be associated with a lower risk of heart disease in moderate drinkers.
But heavy reds like Merlot are known to be associated with migraine, he says, and stresses: “The downside of alcohol is that it increases the risk of cancers of the upper digestive tract, and probably contributes to colorectal cancer and liver problems.
“You shouldn’t feel there’s a recommended amount of wine to drink per day. If you drink it moderately and with food, it’s OK, but it’s probably not a good idea to drink every day.”
Lake adds: “There’s completely convincing evidence that alcohol is related to cancer. Can it ever be good for you? I would argue ’no’.”
An international study led by researchers from Newcastle University earlier this year concluded that organic food has more antioxidants, which are linked to better health, than regular food, plus lower levels of toxic metals and pesticides.
But an earlier study examining 50 years’ worth of scientific articles about the nutrient content of organic and conventional foods found that organically and conventionally-produced foods aren’t significantly different in their nutrient content.
The 2009 London School of Hygiene and Tropical Medicine study, commissioned by the Food Standards Agency, concluded there was no reason to buy expensive organic food for nutritional reasons.
“If you buy organic food, you’re making a lifestyle choice,” says Sanders.
“In terms of salt, saturated fat, sugar and vitamin levels, it’s not really any different at all. You might have slightly lower levels of pesticides, but they’re barely detectable in ordinary produce, and they’re not at a level that causes harm.
“The bottom line is that there’s not really any substantial difference – it doesn’t convince me nutritionally.”
And Lake adds: “While there’s a growing body of evidence that seems to indicate organic might be related to better health, at the moment, that’s of less importance than getting people to eat fruit and vegetables.
“Organic is more of a lifestyle choice for people who can afford it.”
In the past, coffee has been blamed for many ills – from aggravating pre-existing conditions, such as migraines and heart arrhythmias, to causing sleep problems and anxiety, as well as claims that it causes heart disease and cancer.
But more recent research suggests coffee may not be so bad after all.
A Harvard study involving more than 130,000 people found no relationship between coffee consumption and increased risk of death from any cause, or death from cancer or cardiovascular disease, even in those who drank up to six cups of coffee a day.
Other studies have suggested coffee may protect against type 2 diabetes, Parkinson’s disease, liver cancer and cirrhosis. In addition, research just published by the Institute for Scientific Information on Coffee found that drinking three to five cups of coffee a day could help to significantly lower the risk of developing Alzheimer’s disease.
“Coffee’s OK,” Sanders says. “But tea is a better beverage overall.”
He reveals that the way coffee is brewed is important, as stronger, unfiltered coffee can raise blood cholesterol. If coffee is filtered, terpenes in it (which are thought to raise cholesterol) are removed.
Lake points out that certain groups, such as pregnant and breastfeeding women, and people with particular heart problems, probably shouldn’t drink coffee.
She adds: “We already have a pretty good idea of which foods are healthy. People need to use common sense, and be wary of the headlines, because there haven’t been that many groundbreaking discoveries in terms of diet and health recently.
“If you hear something that sounds too good to be true, it probably is.”