How to slow down ageing: Eat fewer calories but more food
That's no typo. Nutrition researchers have found a tummy-satisfying secret to good health: pile your plate high with vegetables and fruits, add beans and whole grains, and downplay high-calorie fare such as burgers.
Priming the body for survival
“Ounce for ounce, people on Okinawa Island, Japan, eat more food by weight than people who eat a Western-style diet,” says Bradley Willcox, MD, of the Pacific Health Research Institute in Honolulu and lead researcher of the Okinawa Longevity Study.
“They eat a lot of produce and grains and smaller portions of higher-calorie, higher-fat foods. It's the combination of high nutrition and lower calories that gives them a tremendous health advantage: their risk for dementia, heart attacks, strokes and cancer are among the lowest in the world.”
Okinawans aren't starving. They eat about 1,800 calories a day. (In contrast, in many Western cultures, the average adult eats close to 2,500.) “Slight calorie restriction seems to prime the body for survival,” Dr Willcox says.
“Just cutting back by 10 per cent can have a dramatic effect. The theory is that this throws genetic ‘master switches’ so that more maintenance work gets done: your cells invest more time and energy in repairing DNA; there's less oxidation, and insulin, the hormone that tells cells to absorb blood sugar, becomes more effective.”
Refocus your food priorities
We're not talking about starvation diets. Yes, eating extremely low-calorie diets has extended the lives of earthworms in labs, but the jury's out on whether this impractical and even dangerous practice lengthens human life.
Simply refocusing your food priorities by eating smaller portions of calorie-dense foods and copious amounts of plant-based foods is all you need to do.
Researchers at the University of Cambridge have shown in a study of more than 19,000 healthy people aged 45 to 79, that waist to hip ratio is inversely associated with blood levels of vitamin C, independent of body mass index.
In other words, no matter how heavy you are, if you have low vitamin C levels you're more at risk of abdominal obesity—the belly fat that's especially hazardous.
The dangers of inflammation
Meanwhile, University at Buffalo researchers have found that a single high-calorie meal boosts the body's production of unhealthy free radical molecules.
These rogue oxygen molecules damage cells and cause low-level inflammation throughout the body.
This type of inflammation has been linked with a higher risk of diabetes, heart disease, high blood pressure, stroke and even breast and prostate cancers. You can read more guides on health benefits of low calorie and high fat foods on sites like www.supplementlexicon.com.
The scientists found that a fast-food breakfast sent a rush of free radicals into the bloodstream that stayed at high levels for the next 3 to 4 hours.
“A high-fat, high-calorie meal temporarily floods the bloodstream with inflammatory components, overwhelming the body's natural inflammation-fighting mechanisms,” says Buffalo’s Ahmad Aljada, PhD.
“People who experience repeated, short-lived bouts of inflammation resulting from many such unhealthy meals can end up with blood vessels in a chronic state of inflammation, a primary factor in the development of atherosclerosis.”
So what's happening?
Digesting food requires oxygen. The more calories you eat, the more your body must digest and the more free radicals are produced as a side effect.
Foods loaded with saturated fat, trans fats and refined carbohydrates seem to ratchet up free radical production. In contrast, the antioxidant vitamins and minerals in fruit and vegetables actually mop up damaging free radicals.
When Dr Aljada's team tested the blood of volunteers who ate a fruit and fibre-packed meal, there was no increase in inflammatory free radicals.
Scientists now know that free radicals can exacerbate or even cause conditions that become more common in later life, such as cancer, vascular disease, macular degeneration in the eye and possibly neuro-degenerative diseases such as Parkinson's or Alzheimer's disease.
Because the antioxidants in fruit and vegetables help to counteract free radical formation, Help the Aged dubs them the ‘anti-ageing remedy’.
What's more, by dumping calorie-dense ‘junk’ for fruit and vegetables, you can eat much bigger portions while still taking in fewer calories. “That's a tremendous dietary advantage,” Dr Willcox says.
“You're loading up on the foods that provide you with the most antioxidants, which protect against free radical damage.”
Stone Age diets
Think avoiding fast food, eating brown bread and having muesli for breakfast gives you a more natural human diet? Think again.
Remember, we humans were hunter-gatherers for most of our history, and our body systems evolved to process what our ancestors ate—basically what can be felled with a spear or gathered from plants.
So in the Stone Age, the diet consisted mainly of lean meat, fish, eggs, insects, vegetables, fruit, roots, mushrooms and nuts. Then came agriculture and modern mass-production techniques. On a modern Western diet, we get most of our calories from cereal crops, dairy produce, refined sugar, processed vegetable oils and potatoes.
Some experts believe that such a diet underlies many ‘diseases of civilisation’, such as heart disease, cancer and diabetes, all of them linked to underlying risk factors such as obesity, high blood pressure and high cholesterol.
When scientists at the Karolinska Institute in Sweden put a small group of healthy volunteers on a mock Stone Age diet, they recorded after three weeks an average 36 per cent reduction in calorie intake, with weight loss of 2.3kg (5lb).
They had also lowered their body mass index and blood pressure, and levels of a blood clotting factor posing a risk for heart attacks and strokes.