Study: Extra-Virgin Olive Oil Preserves Memory and Protects Brain Against Alzheimer’s Disease

The Mediterranean diet, rich in plant-based foods, is associated with a variety of health benefits, including a lower incidence of dementia. Now, researchers at the Lewis Katz School of Medicine at Temple University (LKSOM) have identified a specific ingredient that protects against cognitive decline: extra-virgin olive oil, a major component of the Mediterranean diet. In a study published online June 21 in the Annals of Clinical and Translational Neurology, the researchers show that the consumption of extra-virgin olive oil protects memory and learning ability and reduces the formation of amyloid-beta plaques and neurofibrillary tangles in the brain – classic markers of Alzheimer’s disease.

Temple team also identified the mechanisms underlying the protective effects of extra-virgin olive oil. “We found that olive oil reduces brain inflammation but most importantly activates a process known as autophagy,” explained senior investigator Domenico Praticò, MD, Professor in the Departments of Pharmacology and Microbiology and the Center for Translational Medicine at LKSOM. Autophagy is the process by which cells break down and clear out intracellular debris and toxins, such as amyloid plaques and tau tangles.

“Brain cells from mice fed diets enriched with extra-virgin olive oil had higher levels of autophagy and reduced levels of amyloid plaques and phosphorylated tau,” Dr. Praticò said. The latter substance, phosphorylated tau, is responsible for neurofibrillary tangles, which are suspected of contributing to the nerve cell dysfunction in the brain that is responsible for Alzheimer’s memory symptoms.

Previous studies have suggested that the widespread use of extra-virgin olive oil in the diets of people living in the Mediterranean areas is largely responsible for the many health benefits linked to the Mediterranean diet. “The thinking is that extra-virgin olive oil is better than fruits and vegetables alone, and as a monounsaturated vegetable fat it is healthier than saturated animal fats,” according to Dr. Praticò.

In order to investigate the relationship between extra-virgin olive oil and dementia, Dr. Praticò and colleagues used a well-established Alzheimer’s disease mouse model. Known as a triple transgenic model, the animals develop three key characteristics of the disease: memory impairment, amyloid plagues, and neurofibrillary tangles.

The researchers divided the animals into two groups, one that received a chow diet enriched with extra-virgin olive oil and one that received the regular chow diet without it. The olive oil was introduced into the diet when the mice were six months old, before symptoms of Alzheimer’s disease begin to emerge in the animal model.

In overall appearance, there was no difference between the two groups of animals. However, at age 9 months and 12 months, mice on the extra virgin olive oil-enriched diet performed significantly better on tests designed to evaluate working memory, spatial memory, and learning abilities.

Studies of brain tissue from both groups of mice revealed dramatic differences in nerve cell appearance and function. “One thing that stood out immediately was synaptic integrity,” Dr. Praticò said. The integrity of the connections between neurons, known as synapses, were preserved in animals on the extra-virgin olive oil diet. In addition, compared to mice on a regular diet, brain cells from animals in the olive oil group showed a dramatic increase in nerve cell autophagy activation, which was ultimately responsible for the reduction in levels of amyloid plaques and phosphorylated tau.

“This is an exciting finding for us,” explained Dr. Praticò. “Thanks to the autophagy activation, memory and synaptic integrity were preserved, and the pathological effects in animals otherwise destined to develop Alzheimer’s disease were significantly reduced. This is a very important discovery, since we suspect that a reduction in autophagy marks the beginning of Alzheimer’s disease.”

Dr. Praticò and colleagues plan next to investigate the effects of introducing extra-virgin olive oil into the diet of the same mice at 12 months of age, when they have already developed plaques and tangles. “Usually when a patient sees a doctor for suspected symptoms of dementia, the disease is already present,” Dr. Praticò added. “We want to know whether olive oil added at a later time point in the diet can stop or reverse the disease.”

Source: Temple Health


Today’s Comic

Replacing Saturated Fat with Healthier Fat May Lower Cholesterol in Healthy Diet

The American Heart Association continues to recommend replacing saturated fats with poly- and mono-unsaturated vegetable oil to help prevent heart disease, according to a new American Heart Association advisory, published in the association’s journal Circulation.

Periodically, the evidence supporting limiting saturated fats has been questioned in scientific literature and the popular press. This advisory was commissioned to review the current evidence and explain the scientific framework behind the American Heart Association’s long-standing recommendation to limit foods high in saturated fats.

“We want to set the record straight on why well-conducted scientific research overwhelmingly supports limiting saturated fat in the diet to prevent diseases of the heart and blood vessels,” said Frank Sacks, M.D., lead author of the advisory and professor of Cardiovascular Disease Prevention at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts. “Saturated fat increases LDL – bad cholesterol – which is a major cause of artery-clogging plaque and cardiovascular disease.”

Saturated fats are found in meat, full-fat dairy products and tropical oils such as coconut, palm and others. Other types of fats include poly-unsaturated fats, found in corn, soybean, peanut and other oils, and mono-unsaturated fats, found in olive, canola, safflower, avocado and other oils. The advisory reports that:

  • Randomized controlled trials that lowered intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil reduced cardiovascular disease by approximately 30 percent –similar to that achieved by cholesterol-lowering drugs, known as statins.
  • Prospective observational studies in many populations showed that lower intake of saturated fat coupled with higher intake of polyunsaturated and monounsaturated fat is associated with lower rates of cardiovascular disease.
  • Several studies found that coconut oil – which is predominantly saturated fat and widely touted as healthy – raised LDL cholesterol in the same way as other saturated fats found in butter, beef fat and palm oil.
  • Replacement of saturated fat with mostly refined carbohydrate and sugars is not associated with lower rates of CVD.

“A healthy diet doesn’t just limit certain unfavorable nutrients, such as saturated fats, that can increase the risk of heart attacks, strokes and other blood vessel diseases. It should also focus on healthy foods rich in nutrients that can help reduce disease risk, like poly- and mono-unsaturated vegetable oils, nuts, fruits, vegetables, whole grains, fish and others,” Sacks said.

Examples of healthy dietary patterns include the Dietary Approaches To Stop Hypertension (DASH) diet and a Mediterranean-style diet, both of which emphasize unsaturated vegetable oils, nuts, fruits, vegetables, low-fat dairy products, whole grains, fish and poultry and limits red meat, as well as foods and drinks high in added sugars and salt.

Source: American Heart Association


Today’s Comic

What Are Chia Seeds?

When you hear “chia” your first thought may be of the green fur or hair of Chia Pets, collectible clay figurines. But did you know that chia seeds also can be a healthful addition to your diet?

Chia seeds come from the desert plant Salvia hispanica, a member of the mint family. Salvia hispanica seed often is sold under its common name “chia” as well as several trademarked names. Its origin is believed to be in Central America where the seed was a staple in the ancient Aztec diet. The seeds of a related plant, Salvia columbariae (golden chia), were used primarily by Native Americans in the southwestern United States.

Chia seeds have recently gained attention as an excellent source of omega-3 fatty acid. They also are an excellent source of fiber at 10 grams per ounce (about 2 tablespoons), and contain protein and minerals including iron, calcium, magnesium and zinc.

Emerging research suggests that including chia seeds as part of a healthy diet may help improve cardiovascular risk factors such as lowering cholesterol, triglycerides and blood pressure. However, there are not many published studies on the health benefits of consuming chia seeds and much of the available information is based on animal studies or human studies with a small number of research participants.

How to Eat Chia Seeds

Chia seeds can be eaten raw or prepared in a number of dishes. Sprinkle ground or whole chia seeds on cereal, rice, yogurt or vegetables. In Mexico, a dish called chia fresco is made by soaking chia seeds in fruit juice or water. Chia seeds are very absorbent and develop a gelatinous texture when soaked in water making it easy to mix them into cooked cereal or other dishes.

The seeds are not the only important part of the chia plant; the sprouts also are edible. Try adding them to salads, sandwiches and other dishes.

Source: Academy of Nutrition and Dietetics

Red Onions Pack a Cancer-Fighting Punch, Study Reveals

The next time you walk down the produce aisle of your grocery store, you may want to reach for red onions if you are looking to fight off cancer.

In the first study to examine how effective Ontario-grown onions are at killing cancer cells, U of G researchers have found that not all onions are created equal.

Engineering professor Suresh Neethirajan and PhD student Abdulmonem Murayyan tested five onion types grown in Ontario and discovered the Ruby Ring onion variety came out on top.

Onions as a superfood are still not well known. But they contain one of the highest concentrations of quercetin, a type of flavonoid, and Ontario onions boasts particularly high levels of the compound compared to some parts of the world.

The Guelph study revealed that the red onion not only has high levels of quercetin, but also high amounts of anthocyanin, which enriches the scavenging properties of quercetin molecules, said Murayyan, study’s lead author.

“Anthocyanin is instrumental in providing colour to fruits and vegetables so it makes sense that the red onions, which are darkest in colour, would have the most cancer-fighting power.”

Published recently in Food Research International, the study involved placing colon cancer cells in direct contact with quercetin extracted from the five different onion varieties.

“We found onions are excellent at killing cancer cells,” said Murayyan. “Onions activate pathways that encourage cancer cells to undergo cell death. They promote an unfavourable environment for cancer cells and they disrupt communication between cancer cells, which inhibits growth.”

The researchers have also recently determined onions are effective at killing breast cancer cells.

“The next step will be to test the vegetable’s cancer-fighting powers in human trials,” said Murayyan.

These findings follow a recent study by the researchers on new extraction technique that eliminates the use of chemicals, making the quercetin found in onions more suitable for consumption.

Other extraction methods use solvents that can leave a toxic residue which is then ingested in food, said Neethirajan.

“This new method that we tested to be effective only uses super-heated water in a pressurized container,” he said. “Developing a chemical-free extraction method is important because it means we can use onion’s cancer-fighting properties in nutraceuticals and in pill form.”

While we can currently include this superfood in salads and on burgers as a preventative measure, the researchers expect onion extract will eventually be added to food products such as juice or baked goods and be sold in pill form as a type of natural cancer treatment.

Source: University of Guelph


Today’s Comic

Is Apple Cider Vinegar a Miracle Food?

Leslie Beck wrote . . . . . .

If you believe what you read on the Internet, apple cider vinegar is a pretty darn powerful natural health product. It’s claimed to do everything from controlling diabetes to lowering cholesterol to boosting weight loss.

Made by fermenting crushed apples, the vinegar is also touted to prevent constipation, ease arthritic joints, reduce heartburn, banish acne and treat eczema, among numerous other things. That’s a whole lot of health benefits.

But here’s the deal: Most claims are untested and, therefore, unfounded. The few health claims that do have (limited) scientific backing are often overhyped. Here’s what we know so far about apple cider vinegar – and what we don’t.

Speeds up weight loss

There’s not much to go on here. Only one small study, published in 2009, has tested the effectiveness of apple cider vinegar on weight loss in people. And the results weren’t that impressive.

For the study, 175 obese but otherwise healthy Japanese adults, aged 25 to 60, were assigned to drink, once daily, a 500-ml beverage that contained either one tablespoon of apple cider vinegar (low dose), two tablespoons (high dose) or no vinegar (placebo) for 12 weeks.

At the end of the study, participants who consumed the vinegar drinks achieved greater weight loss than those who got the placebo drink. What’s more, people who drank the beverage that contained two tablespoons of apple cider vinegar lost more weight than those who consumed the lower dose.

But don’t get too excited. After three months, the high-dose vinegar group lost 4.1 pounds compared to the low-dose group, who lost 2.6 pounds. In either case, it’s hardly a dress (or pant) size. And four weeks after the study ended, most had gained back the weight.

Apple cider vinegar may help increase feelings of satiety but, as research suggests, this is likely due to a queasy stomach from drinking the solution.

Research conducted in mice has suggested that acetic acid – the acid that gives vinegar its characteristic sour taste – may prevent the buildup of body fat by activating fat-burning genes.

All in, don’t count on apple cider vinegar to help you slim down.

Controls blood glucose levels

There’s more promising evidence to support the claim that apple cider vinegar helps lower blood sugar. And that seems to be particularly so in people with prediabetes.

If you have prediabetes, your blood glucose level is higher than normal, but not high enough to be diagnosed as full-blown diabetes. People with prediabetes are at increased risk of developing Type 2 diabetes within 10 years if lifestyle changes are not implemented.

In a study published in the journal Diabetes Care (2004), researchers from Arizona State University asked people with pre-diabetes and Type 2 diabetes to consume 20 g of apple cider vinegar (about four teaspoons) diluted in water immediately before eating a high carbohydrate meal.

Doing so blunted the after-meal rise in blood sugar. It also improved how the body used insulin, the hormone that clears sugar from the bloodstream. These improvements were significant in participants with prediabetes but only slight in those with diabetes.

Acetic acid in apple cider vinegar is thought to slow the digestion of starch – e.g., carbohydrates in bread, rice, pasta, quinoa, oats, potatoes and other starchy foods – preventing some of it from being absorbed into the bloodstream and raising blood glucose levels.

All vinegars, though, contain acetic acid and can dampen the rise in blood glucose after eating a starchy meal. That means balsamic, red wine, white wine or flavoured and distilled white vinegars will also do the trick.

Prevents heart disease, stroke, cancer

Studies in rodents fed a high fat diet have demonstrated that apple cider vinegar can help lower blood cholesterol, blood triglycerides and blood pressure. But research has not been conducted in humans.

Nor have there been any human studies to substantiate apple cider vinegar’s purported anti-cancer effects.

There’s also not a stitch of evidence that a daily dose (or two) of the vinegar – or any vinegar for that matter – guards against arthritis, digestive upset, acne or eczema.

Still, is apple cider vinegar worth taking?

When it comes to blood sugar and weight control, apple cider vinegar is by no means a magic bullet. Focus your efforts on diet and exercise, strategies proven to help shed excess pounds and guard against Type 2 diabetes.

If you decide to add apple cider vinegar to the mix, I recommend consuming it in a homemade salad dressing made with at least one tablespoon of the vinegar.

If you prefer to drink it, dilute a tablespoon of apple cider vinegar in eight ounces of water and drink it at the beginning of a meal, once or twice daily.

Apple cider vinegar is sold filtered and pasteurized or unfiltered and unpasteurized. The unfiltered vinegar is cloudy and retains the “mother” bacteria that fermented the apples, which some experts contend is full of beneficial probiotic organisms.

Precautions

Do not drink apple cider vinegar straight. Undiluted vinegar – in liquid or pill form – can irritate the throat and esophagus and increase stomach acidity. Sipping it plain can also damage tooth enamel.

Prolonged large doses of apple cider vinegar can lead to dangerously low potassium levels in the body.

Since apple cider vinegar may reduce blood sugar and insulin levels, it could potentially amplify the blood-sugar-lowering effect of anti-diabetes drugs. Inform your doctor if you decide to try apple cider vinegar.

Some people with diabetes have delayed stomach emptying, a disorder caused by prolonged high blood sugar levels. Apple cider vinegar could make this problem worse.

Source: The Globe and Mail