Tuesday, 22 February 2011

Food for thought

Healthy eating and living is not only good for the ageing body, but also, good for the mind.

TODAY, as we get used to the idea of people living longer lives, we have also learned to accept the changes in our bodies and minds as inevitable developments we have to deal with when we age.

The physical changes are usually obvious. We have more aches and pains. We need more time to recover after pulling all-nighters. We no longer have the strength to move heavy boxes around the house.
Changes in the way our minds function (cognition), however, are subtler. Over time, we may notice that we take more time to learn new skills.

We need written checklists as we forget easily. Simple calculations make us reach for our mobile phones.
While we may be familiar with the ways we can slow or delay physical decline, we often overlook that the same measures can also help us slow and delay cognitive decline.

Cognitive decline may not be preventable, but there is much that can be done to delay or slow the decline,” said US Northeastern University Professor of Health Science Dr Katherine L. Tucker.

Keeping the mind active with Sudoku and mahjong is only a part of it. “Eat healthy foods, be physically and cognitively active, and avoid obesity, smoking and excessive alcohol,” Dr Tucker continued, as she wrapped up the presentation of her paper, Cognitive Decline with Aging: Can it be Prevented?, at the International Symposium of Health Sciences in Kuala Lumpur recently.

“Although we do not yet have enough data to confirm causal relationships between diet and cognitive decline, we are accumulating considerable evidence,” she said.

Eat well
Cognitive decline can be caused by infections and degenerative changes in the brain (when brain cells are diseased or damaged) or the lack of blood flow to the brain (which may cause brain cells to die).
But before science backed them up, factors that contribute to the acceleration of ageing have been largely observational. For instance, we notice that people who lead highly stressful lifestyles seem to age, physically and mentally, faster than those who lead simple, peaceful lives.

But why, and how? Researchers like Dr Tucker and her team at the Northeastern University, and formerly, at the Tufts University in Boston, are finally getting some clues. And Dr Tucker thinks it has a lot to do with good diet choices.

The strongest evidence for a dietary component supports a role for omega-3 fatty acids or fish consumption, wrote Dr Tucker in her abstract. There is a catch, though. As there is increasing evidence that omega-3 fatty acids interact with processes that are influenced by certain genes in the body, our genes may determine whether we will enjoy the protective benefits conferred by consuming it.

Other nutrients with compelling evidence include vitamins B6, B12 and folate from diet, although clinical trials with these as supplements have been disappointing, she continued.

“We know from history that the deficiency of several B vitamins can cause neurological deficits and dementia,” explained Dr Tucker. The chronic deficiency of vitamin B12, for instance, can cause peripheral neuropathy – damage to the nerves outside the brain and spinal cord.

Also, as the B vitamins and folate play a role in breaking down homocysteine, its deficiency can result in higher levels of the protein, which is associated with a higher risk of coronary heart disease, stroke, and lower cognitive function.

Studies of nutrients with antioxidant properties like vitamin E, vitamin C, and beta-carotene show conflicting results, but there has been increasing support for the role of an overall healthy dietary pattern.
Participation in physical and social activities, and the avoidance of tobacco use, too, has been shown to be protective.

“Other risk factors include diabetes, the metabolic syndrome, and depression, so it is likely that nutritional factors associated with these conditions contribute indirectly to cognitive decline,” Dr Tucker wrote in the report.

Live well, with less stress
A systematic review of research that looked into the link of health behaviours and cognitive decline by Korean researcher Lee Yunhwan and his team have found the following:
·Leisure-time physical activity, even of moderate levels, showed protective effects against dementia, whereas smoking elevated the risk of Alzheimer’s disease (the most common form of dementia).

·Moderate alcohol consumption tended to be protective against cognitive decline and dementia, but non-drinkers and frequent drinkers exhibited a higher risk for dementia and cognitive impairment.

·Midlife obesity had an adverse effect on cognitive function in later life.

·Analysis showed vegetable and fish consumption to be of benefit, whereas, persons consuming a diet high in saturated fat had an increased dementia risk.

However, besides these dietary factors, there are also other lifestyle factors that researchers have found important to maintain cognitive health as we age, said Dr Tucker.

“Things like keeping your mind active, continuing to work, and keeping a positive attitude can also help delay cognitive decline. So, being under stress and having a lot of concerns can take a toll on you as well,” she noted.

In a 2009 study that assessed the association between food insecurity and lower cognitive performance in 1,300 Puerto Rican adults in Massachusetts, Dr Tucker and a team of researchers also studied the interaction between stress and nutrition.

“When you have more stress in your life, your requirements for vitamins are even higher. And so it is even more important for people under high stress to have a good diet – because the processes in the body that are activated (under stress) need to be controlled with vitamins and antioxidants,” she explained.

Unfortunately, most of the time, the last thing on these people’s minds is eating well.

“That’s another reason why stress is harmful,” said Dr Tucker. “It has an effect directly on the body in terms of its utilisation of nutrients, and it also affects people because they tend not to eat as well,” she elaborated.

Education appears to count, too. “We don’t know completely why, but individuals with higher education tend to retain their cognitive function better when they age,” said Tucker. “It may be because people with higher education continue to be actively learning, and tend to have better diets as well,” she reasoned.

It’s a combination
With a reported 63,000 patients with dementia living in the country, and the Health Ministry’s expectation that this number is to double in 10 years, prevention is one of the important things we should look into.

The good news is, we don’t have to be nutritionists, PhD holders, or Zen masters to improve our chances at retaining our mental capabilities as we age, as any effort in the right direction counts.

This is because when researchers take into account all the promising results of separate studies done on diet, exercises and activities that build mental muscles, the evidence remains largely non-conclusive for any single factor.

They do, however, suggest what we have observed so far: that like any chronic condition, following a healthy lifestyle with a good quality diet, physical activity and social engagement can delay cognitive decline, Dr Tucker concluded.

The next step, then, is to find out how these measures can be tailored to fit current society needs. “More research is needed to develop effective interventions,” she said.

SOURCES FOOD sources of nutrients that may help cognitive decline:
Omega-3 fatty acids
Fatty fish (like salmon, mackarel, anchovies and sardines)
Vitamin B6
Organ meats, fortified cereals, fortified soy products
Vitamin B12
Fish, poultry, meat, fortified cereals
Folate (Folic acid)
Dark, leafy vegetables; enriched and whole grain breads; fortified cereals
Vitamin C
Raw guava, red pepper, kiwi fruit, orange, green pepper, brussels sprouts, strawberries, papaya
Vitamin E
Fortified cereals, sunflower seeds, almonds, peanut butter, vegetable oils
Carrot juice, pumpkin, sweet potato, spinach
1. Food sources for Vitamins and Minerals, WebMD.com
2. Food sources of Selected Nutrients, Dietary Guidelines for Americans 2005, USDA.gov.
3. USDA National Nutrient Database for Standard Reference, Release 22 Nutrient Lists, US Department of Agriculture Food and Information center.
 Above article is extracted from the star online dated 20th Feb 2011

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