Cooking and storage of fats

Polyunsaturated oils are easily damaged by heat, not only increasing the risk of trans fat production but also producing damaging substances called free radicals.

Free radicals are disruptive in the body and if in excess can damage not only our cell membranes but also the DNA (genes) in the cells. Free radicals contribute to the ageing process and an excess is strongly linked to all major degenerative disorders.

Free radicals are naturally produced in the body:

• during exercise (excessive exercise can produce harmful quantities of free radicals)
• during food “burning”
• on exposure to radiation, e.g., ultraviolet from sunlight
• when we get infections, to destroy invaders.

Early on in our evolution, we developed sophisticated methods to disarm free radicals before they could do much harm to the body.

Antioxidant nutrients like vitamin A, C, E, zinc and selenium help counteract the damage caused by free radicals in the body. Powerful plant chemicals (phytonutrients) found in darkly coloured fruit and vegetables also act as antioxidants in the body.

Eventually the production of free radicals outweighs the ability of our antioxidant systems to defend us, so we will age. However, a nutrient-rich diet combined with reducing intake of free radicals helps to protect against ageing and degenerative disease.

Free radicals are produced during all combustion processes (baking, frying, roasting, barbecuing and grilling). Cigarette smoke, burnt toast, petrol fumes and ionising radiation are other potent sources of free radicals.

To minimise the risks of damaging fats, polyunsaturated oils should not be heated above 200 degrees C. Most forms of cooking with oil involve temperatures higher than that, therefore it is better to cook with monounsaturated oils, such as olive or canola oil. Polyunsaturated oils should be used cold (for example in salad dressings or home-made mayonnaise). Oils and fats should not be re-used as this increases the risk of free radical production and rancidity.

For storage, oils should always be kept in cool, dark places with as little contact with the air as possible. Dark, narrow bottles are best and if you only use small quantities, it is better to only have small bottles.

Similarly, high fat-content foods, such as nuts and seeds, should be kept in the cool and dark, preferably in air-tight containers.

Learn more about the different types of fat and their effects on our health at Cooking for Health courses held throughout the year in Somerset, UK.

How does what we eat affect how healthily we age? Which foods can help us enjoy decades of active, satisfying life and which foods do the opposite? The answers to these questions will be explored at a Cooking for Health class focused on the Fundamentals of Healthy Eating - Eating for Healthy Longevity.

In this class, we learn about our bodies’ nutritional needs, the evolution of the modern diet and its influence on human health. We look at societies in the world with exceptionally high numbers of healthy elders and learn how to apply their dietary secrets to our own lives.

The class involves 100% hands-on practical cooking in a small, supervised group, combined with teaching of up-to-date information and research findings on the effects of diet on health. Clear, easy-to-follow presentations and handouts are provided with plenty of opportunity for questions and discussion.

Mediterranean diet has beneficial effects on women's bone health

A study from the Harokopio University of Athens (Greece) suggests that adherence to a dietary pattern close to the Mediterranean diet, with high consumption of fish and olive oil and low red meat intake, has a significant impact in women skeletal health.

Results suggest that this eating pattern could have bone-preserving properties throughout adult life.

Diet is one of the modifiable factors for the development and maintenance of bone mass. The nutrients of most obvious relevance to bone health are calcium and phosphorus because they compose roughly 80% to 90% of the mineral content of bone; protein, other minerals and vitamins are also essential in bone preservation.

Traditional analysis has focused on the relation between a specific nutrient (e.g. calcium) and bone health. But, researchers of the Harokopio University of Athens, Greece, carried out a study in two hundred twenty adult Greek women, which is valuable for the understanding of the effect of meals, consisting of several food items, in skeletal mass.

Scientists examined whether adherence to the Mediterranean Diet, rich in plant foods and olive oil, low in meat and dairy products, and with moderate intake of alcohol, or other dietary patterns, have any significant impact on bone mass maintenance in adult Greek women. They determined that adherence to a dietary pattern with some of the features of the Mediterranean diet, i.e., rich in fish and olive oil and low in red meat and products, is positively associated with the indices of bone mass.

These results suggest that this eating pattern could have bone-preserving properties throughout adult life.

Are you struggling with hot flushes, mood swings, depression, osteoporosis, infertility, breast or prostate disease, or simply want to protect yourself from developing these symptoms? Learn more about the factors affecting your hormonal health and how to protect yourself from the adverse effects of hormone imbalance at a Cooking for Health class on Balancing Hormones Naturally.

We will explore what hormones are; how they interact with each other and with mood-regulating chemicals in the body; the rise in hormonal health problems; hormone-disrupting chemicals; what to eat and what to avoid in order to balance hormones naturally; and how to cook with natural ingredients that support our hormone system.

Reference

Kontogianni et al. Association between dietary patterns and indices of bone mass in a sample of Mediterranean women. Nutrition, 2009; 25 (2): 165

Sea vegetables - nature's secret for healthy longevity?

The health benefits of consuming seaweed were recognised over three thousand years ago, particularly in Asia, where marine algae are still prized for their nutritional content. The vast majority of marine algae are edible, with only a few tropical species being poisonous. Some species, however, are specially selected for their appealing flavour, texture or culinary versatility; these include dulse (Palmaria palmata), nori (Porphyra tenera), sea lettuce (Ulva lactuca) kombu (Laminaria japonica), wakame (Undaria pinnatifida), arame (Eisenia bicyclis), hijiki (Hizikia fusiforme) and agar-agar (Sphaerococcus euchema).

Sea vegetables are low in fat, low in calories and rich in essential minerals, vitamins and protein. The mineral content of seaweeds is very significant and is likely to explain many of their beneficial effects on health. Seaweeds provide all of the 56 minerals and trace minerals required for the body’s physiological functions. Indeed, they contain 10 to 20 times the minerals of land plants and an abundance of vitamins and other elements necessary for metabolism. The modern diet is severely depleted of minerals due to a general decline in soil and crop mineral content, and to refining and processing which strips food of minerals and other vital nutrients. Thus, addition of seaweed into the diet is very important to ensure adequate intake of minerals, which are in a highly assimilable form because they are integrated into living plant tissue. Sea vegetables are especially useful for vegetarians and those abstaining from dairy foods because of their high levels of calcium, iron and iodine.

In addition to minerals, seaweeds contain vitamins A, B, C, and E, and Porphyra species are reported to contain vitamin D. Moreover, some seaweeds contain what appears to be vitamin B12, which is normally found only in animal products.

Seaweeds contain 50 to 60% polysaccharides, notably cell wall structural polysaccharides that are extracted by the hydrocolloid industry. Despite this large quantity of carbohydrate, sea vegetables add few calories to the diet; this is because much of their starch consists of a substance called algin. Alginates are not easily digested by the body, acting like soft fibre, soothing and adding bulk to the digestive tract. Scientific studies have shown that alginates inhibit absorption of toxic metals and radioactive isotopes such as strontium-90 in the digestive tract. All sea vegetables contain significant amounts of protein, sometimes as much as 48%.

Lipids represent only 1-5 % of algal dry matter and show an interesting polyunsaturated fatty acid composition, particularly regarding omega 3 and omega 6 acids which are concentrated in the galactolipid fractions.

Sea vegetables have traditionally been used in Asia to treat cancer, heart disease and thyroid problems. Other medicinal uses are currently being investigated. Scientific research aimed at
explaining the positive effects of seaweeds on health is in progress. Some key findings related to breast cancer, heart disease, thyroid problems, immune function, inflammation, and anti-bacterial and anti-viral activity are reviewed in a peer-reviewed paper by Jane Philpott MA (Oxon), MSc, PhD in the Nutrition Practitioner Journal. The paper also includes practical information on how to prepare and cook nori, arame, dulse, kombu, wakame, hijiki and agar-agar is given, as well as some recipes.

For information and practical tuition in cooking and eating sea vegetables, come to a Cooking for Health course, held throughout the year in Somerset, UK.

An apple a day may keep breast cancer away

Six studies published in the past year by a Cornell researcher add to growing evidence that an apple a day -- as well as daily helpings of other fruits and vegetables -- can help keep the breast-cancer doctor away.

In one of his recent papers, published in the Journal of Agricultural and Food Chemistry (57:1), Rui Hai Liu, Cornell associate professor of food science and a member of Cornell's Institute for Comparative and Environmental Toxicology, reports that fresh apple extracts significantly inhibited the size of mammary tumours in rats -- and the more extracts they were given, the greater the inhibition.

"We not only observed that the treated animals had fewer tumours, but the tumours were smaller, less malignant and grew more slowly compared with the tumors in the untreated rats," said Liu, pointing out that the study confirmed the findings of his preliminary study in rats published in 2007.

In his latest study, for example, he found that a type of adenocarcinoma -- a highly malignant tumour and the main cause of death of breast-cancer patients, as well as of animals with mammary cancer -- was evident in 81 percent of tumors in the control animals. However, it developed in only 57 percent, 50 percent and 23 percent of the rats fed low, middle and high doses of apple extracts (the equivalent of one, three and six apples a day in humans), respectively, during the 24-week study.

"That reflects potent anti-proliferative [rapid decrease] activity," said
Liu.

The studies highlight the important role of phytochemicals, known as phenolics or flavonoids, found in apples and other fruits and vegetables. Of the top 25 fruits consumed in the United States, Liu reported in the same journal (56:18) that apples provide 33 percent of the phenolics that Americans consume annually.In a study of apple peel published in the same journal (56:21), Liu reported on a variety of new phenolic compounds that he discovered that also have "potent antioxidant and anti-proliferative activities" on tumours. And in yet another study in the same journal (56:24), he reported on his discovery of the specific modulation effects that apple extracts have on cell cycle machinery. Recently, Liu's group also reported the finding that apple phytochemicals inhibit an important inflammation pathway (NFkB) in human breast cancer cells.

Breast cancer is the most frequently diagnosed invasive cancer and the second leading cause of cancer deaths in women in the United States, said Liu.

"These studies add to the growing evidence that increased consumption of fruits and vegetables, including apples, would provide consumers with more phenolics, which are proving to have important health benefits. I would encourage consumers to eat more and a wide variety of fruits and vegetables daily."

For imaginative ideas and practical tuition in how to incorporate more fruit and vegetables in your diet, come along to a Cooking for Health course, held throughout the year in Somerset, UK.

Lowering cholesterol may reduce prostate cancer risk

High cholesterol not only leads to atherosclerosis and heart disease, but may also contribute to cancer growth and progression. Prostate cancer is the most common non-skin cancer in the United States, affecting approximately 1 in 6 men. Prostate tumours accumulate high levels of cholesterol, and tumour incidence correlates with eating a high fat/high cholesterol diet "Western" diet. In addition, prostate tumour progression has been linked to serum cholesterol levels.

To examine the role of high cholesterol in prostate cancer, Dr. Keith Solomon and colleagues fed mice a high fat/high cholesterol "Western" diet. They found that high cholesterol levels promoted tumour growth and that Ezetimibe (Zetia™), which blocks the absorption of cholesterol from the intestine, could prevent this increased tumour growth. Ezetimibe also blocked a cholesterol-mediated increase in angiogenesis, the growth of new blood vessels required for tumor progression. These data suggest that reducing cholesterol levels may inhibit prostate cancer growth specifically by inhibiting tumour angiogenesis.

The article from Solomon et al suggests "that cholesterol reduction, which is routinely accomplished pharmacologically in humans, may reduce angiogenesis, ultimately leading to less aggressive tumors." "Lowering cholesterol levels whether through diet, exercise, or the use of safe cholesterol-lowering drugs is known to provide a substantial benefit to patients—in the future it may be possible to add reduced risk of serious prostate cancer to that list of benefits" says Solomon. "We are in the process of working with clinicians to translate these findings into potential human studies. If we can demonstrate the effects noted in our pre-clinical studies in human patients we may be save lives and improve the quality of life," adds Dr. Michael Freeman, senior author of the study.

Diets rich in whole grains, pulses, vegetables, fruit, nuts and seeds, and low in animal products, are low in cholesterol. Learn how to lower cholesterol naturally at Cooking for Health classes held throughout the year in Somerset, UK.

Reference

Solomon et al. Ezetimibe Is an Inhibitor of Tumor Angiogenesis. American Journal Of Pathology, 2009; 174 (3): 1017