Diet

Effects of Diet

We will now consider diet as it relates to improving or preventing disease. As previously mentioned, behavioral changes started early in life will have the greatest impact in health in later years, but it is never to late to effect a positive change.

First, let's consider the eating/cooking challenges facing the elderly. Those with arthritis may find reduced fine motor skills make food preparation difficult. Living on a fixed income leads to constraints on quality and quantity of food purchased. Depression and loneliness may affect food prepared or even eaten. Finally, some elderly will face a limited selection of food possibilities due to decreased salvia production leading to difficulty in swallowing. Poor dental health affects chewing, again decreasing food choices.

To address these challenges, suggest that the elderly person buy prepared food or use government programs like meals-on-wheels, eat with friends or at congregate meal programs, drink water even when not thirsty and maintain good dental health.

Osteoporosis

When you think of bones, the mineral calcium should come to mind. Calcium absorption relates to age, body stores, dietary intake, and presence of calcium enhancers or blockers. An acid stomach environment also aids calcium absorption. Calcium received during a meal is better absorbed due to the stimulation of gastric secretions and other components of the meal which may promote absorption. The current Dietary Reference Intake for calcium for those 51 to 70 and those 70+ years is 1200 milligrams as opposed to 1000 milligrams for younger adults. White elderly consume more calcium than Mexican Americans or African Americans and men consume more than women. Lactose intolerance may be an issue among the African American and Asian communities. Men tend to take in more calories and therefore have more opportunities to consume calcium-rich foods.

The best source of calcium is from milk and dairy products. The lactose sugar in the milk enhances absorption as does the vitamin D it is fortified with. The same holds true for yogurt. Calcium-fortified orange juice is another opportunity to add calcium to the diet. The acidic nature of orange juice enhances absorption and it is fortified with the highly soluble calcium-citrate-maltate calcium salt.

Supplements would also be an option. While anyone in the field of nutrition will always recommend that nutrients be delivered by eating the food that contains them, rather than in pill form, supplements should not be ruled out for the aging population. Physical exercise also promotes calcium absorption.

Obesity

Obesity is related to the incidence and severity of cardiovascular disease, hypertension and diabetes. Before considering each of these individually, you can see from the above graph the increase in obesity among elderly men and women from the 1970s onward.

Chart source: Federal Interagency Forum on Aging-Related Statistics. Older Americans 2004: Key Indicators of Well-Being. Federal Interagency Forum on Aging-Related Statistics. Washington, DC: U.S. Government Printing Office. November 2004.

Image: Human Heart

Cardiovascular Disease

In the late 1940s, public health messages aimed at reducing total fat consumption and replacing animal fats (saturated) with vegetable fats (unsaturated) led to a concomitant decrease in heart disease 10 to 15 years later. This lag time of 10 to15 years can be a motivator for young and middle-aged people to make positive changes.

Considering cardiac disease risk, we know that smoking, hypertension and high blood cholesterol, obesity and impaired glucose tolerance all contribute. High blood cholesterol is set at over 240 mg/dl total cholesterol or 160 mg/dl Low Density Lipoprotein (LDL) cholesterol. Total cholesterol is less of a predictor of heart risk than the individual components of LDL and High Density Lipoprotein (HDL). One myth is that these risk factors only apply to those middle-aged, not the elderly. Smoking does not significantly increase cardiovascular risk after age 65; hypertension and possibly high blood lipids do increase cardiovascular risk. The probability of death from heart disease increases with the number of risk factors one has. The good news is, the reverse is true. As the elderly control blood lipids, reduce weight, etc., their risk decreases.

In men, serum cholesterol increases with age until 65 and then decreases. Serum cholesterol levels in women peak higher and later in life, age 75. Serum total cholesterol value is strongly correlated with cardiac risk in the middle-aged and older. However, in those older than 75 its predictive value becomes questionable to the point that those in their late 70s and older are no longer advised to be screened. There may be a survivor phenomenon occurring here in that those who have made it into their late 70s have survived the period of greatest risk and are unlikely at this point to succumb to heart disease. One could also argue a quality of life issue: Is it worth a marked change in diet (lifestyle) in these elderly to try to affect a questionable predictor of risk?

Increasing HDL levels appear to be more important than decreasing LDL levels in those already with symptoms of heart disease and in women. African Americans have higher HDL levels than Caucasians. Smoking, obesity and alcohol use decreases HDL. Note that heart disease occurs 10 to 15 years later in women than in men. The National cholesterol education Program (NCEP) recommends the following guidelines as protective for heart health:

Saturated fat <10% of total calories

Polyunsaturated fat 10% or less of total calories

Monounsaturated fat 10% to 15% of total calories

Replacing saturated fats with unsaturated fats produces lower total cholesterol. Our goal, however, is to reduce total cholesterol by reducing LDLs only and maintaining HDL level or optimally raising it. Oleic acid found in monounsaturated fats lowers LDLs without lowering HDLs. Trans fats increase LDLs and decrease HDLs. Polyunsaturated omega 3 fatty acids decrease VLDLs and also decrease the “stickiness” of blood platelets and therefore their ability to stick to plaques and form clots.

To raise HDLs, the following may be effective:

increase aerobic activity
loose weight
stop smoking
decrease trans fats
drink alcohol 1 to 2 drinks daily (those who do not drink are not encouraged to start)
increase monounsaturated fatty acids
increase soluble fiber
take niacin in high doses (prescribed by physician)

Risk Assessment Tool developed by the Framingham Heart Study to predict an individual’s chance of having a heart attack within the next 10 years. The Framingham Risk Assessment Tool can be found at: http://hin.nhlbi.nih.gov

In summary, when defining a diet plan, consider the age group of the person, whether young-old or old-old. Recent retirees would be candidates for aggressive therapy, especially if they present with low HDLs, and other risk factors of smoking, hypertension, impaired glucose tolerance and high CRP. Given that the heart healthy diet may be more nutritionally sound in protein, calcium and other nutrients, than their previous diet, there is no reason to decline diet changes for this group. The old-old, or those for whom a diet restriction would negatively affect quality of life, should not be counseled drastic changes. Data show that the elderly do respond to diet and medication as well as younger people do with a decrease in disease rates after treatment.

Hypertension

The National Heart, Lung and Blood Institute defines hypertension as a systolic blood pressure (the top number of the fraction) equal to or greater than 160 ml of mercury and a diastolic pressure (the bottom number of the fraction) less than 90 ml of mercury (normal for diastolic pressure). If both systolic and diastolic blood pressure is over the normal range, and continues into old age, it is called essential hypertension. In developed countries, both systolic and diastolic pressures rise until age 60. After that systolic may continue to rise while diastolic remains stable or drops. Depending on your data source, 44 to 76 percent of those 65 and over have hypertension. Seventy-five percent of African American women 60 to 80 plus have hypertension. African Americans and Native Americans or more likely to have hypertension and its complications. Equal numbers of men and women have elevated blood pressure.

Hypertension is a better predictor for stroke and cardiovascular disease than is serum cholesterol level. Weight gain, especially if it occurs in the 30s and 40s, leading to obesity, is associated with hypertension. Degree of obesity as measured by Body Mass Index (BMI), as well as central body fatness, correlate with hypertension. Weight reduction, logically, would lower blood pressure. A 5 kg loss is associated with a 5mm Hg decline in blood pressure. Weight loss in addition to sodium restriction would bring about an even greater reduction (11mm Hg decrease). Exercise is generally a vehicle to achieve weight loss.

In sodium-sensitive persons, which the elderly and African Americans are more likely to be, high sodium intake increases hypertension risk. Only 9 to 20% of the total U.S. population is sodium sensitive. Since it is not possible through testing to determine who is or isn’t sodium sensitive it appears sensible for all elderly with hypertension to reduce sodium intake to about 2 grams per day. This would translate into a 5 gram salt diet. Seven grams of sodium is prudent for those not sodium sensitive. Note: Be aware of sodium content from obvious sources of canned and prepared foods as well as use of sodium-containing drugs.

There is clinical evidence that high potassium diets and possibly high calcium intakes (800mg) are associated with blood pressure in the normal range. The DASH (Dietary Approaches to Stop Hypertension) is one way to follow this diet recommendation. This food plan is low in sodium (2.5 to 3 grams/day) and rich in fruits, vegetables, and low-fat dairy foods which lead to a reduction in total fat, saturated fat and cholesterol. The kidneys of the elderly are less able to conserve sodium so a level no lower of 2 grams/day is advised. See more at: www.cspinet.org/nah/dashdiet.htm

Given that borderline systolic hypertension (140-159 mmHg) which often goes undetected, and therefore untreated, is associated with an increased risk of cardiovascular disease, the following intervention is recommended.

Weight reduction by 5 kg
Sodium intake at 2 to 3 grams
Alcohol consumption no greater than 1 ounce daily
Exercise to induce weight loss
At least five servings of fruits and vegetables daily
Calcium at DRI values of 1200 milligrams and magnesium at DRI values of 420 milligrams (men) and 320 milligrams (women).

Alcohol consumption at two drinks or more a day is associated with hypertension; caffeine consumption is not. Obesity, high alcohol intake (over 2 ounces/day) and high salt intake in the salt sensitive are the most important contributors to hypertension. Other contributors in the elderly are:

atherosclerotic disease (the arteries become less elastic)
hyperthyroidism
thiamin deficiency
renal disease
fever

Diabetes

The incidence of noninsulin-dependent diabetes mellitus (NIDDM) tracks age with the majority of patients being over 65. About 13% of people over 65 have diabetes. The disease will accelerate the aging process, to the point that the person is physiologically 10 years older than his or her chronological age.

The effects of diabetes are exacerbated in old age. Changes in blood capillary vessels lead to the following effects:

vision problems
neural problems which increase pain and decrease cognitive function
renal problems
increased infections
reduced circulation in the lower extremities.

An older person’s ability to function will be affected by the above conditions.

In terms of diet compliance, older persons rather than younger are more willing to make lifestyle changes, possibly due to more control over and flexibility with their time. The current diet for diabetes does not differ substantially from the dietary guidelines for all healthy persons: fat at 30% of calories or less, protein at 10 to 35%, alcohol at two or fewer drinks per day, carbohydrates emphasizing the complex, high fiber, rather than sugars, and an individualized approach to achievable weight loss.

Obesity is associated with insulin resistance in muscle and adipose tissue. Weight loss of 10 to 20 pounds that approaches a healthy body weight improves blood glucose levels. Weight gain, on the other hand, of 10 pounds between the ages of 40 and 60 can increase risk two fold. Intensive endurance rather than resistance training is associated with the improvement of the diabetic condition. This effect holds even in those who experience no change in body fat.

Aerobic exercise (20 minutes sessions using large muscle groups at least three times a week) can help regulate blood sugar, and change body fat pattern (decrease central abdominal fat). Strength training can reduce insulin resistance, although the effect is seen more often in men than women. It can also aid in changing fat pattern.

Nutritional Screening Instruments

The Nutritional Risk Index (NRI) is a list of 16 questions that help the clinician to identify those needing nutrition intervention or further assessment.

The Nutrition Screening Initiative (NSI) is a collaborative effort of the American Dietetic Association, The American Academy of Family Physicians and the National Counsel on Aging. The goals of the NSI are:

To develop a common tool to screen for nutritional risk
To develop a common approach to nutritional assessment
To develop ways to combine nutrition screening with medical practice.

The NSI consists of three instruments, where each successive tool involves a greater degree of qualitative and quantitative information than the previous. The first is a checklist using the mnemonic device—D-E-T-E-R-M-I-N-E—the purpose of which is to help the older person evaluate their eating habits, and also inform the clinician of the warning signs of poor nutritional status.

The next step would be the Level I screen. Depending on the results, the older person would continue on to the Level II screen, or given dietary advice appropriate to the risk factors identified. The Level II screen is done by or in cooperation with a physician because it involves biochemical testing and mental status evaluations. Information on this initiative is available online at: www.ltcnutrition.org

Another screening tool available for identifying nutritional risk, and especially protein-energy malnutrition, is called SCALES, an acronym for sadness, cholesterol, albumin, (weight) loss, eating problems and shopping.

Conclusion: Although one can argue that the current aged population has missed the opportunity to get the maximum benefit from diet, exercise and lifestyle changes, the elderly can surprisingly derive substantial benefit from these changes, even the oldest-old!