• Adopting a Healthy Lifestyle in Middle Age is Not Too Late

Where many diseases are concerned, no information is available as to whether we can reduce the risk of acquiring them, and if so how.  On the other hand, some healthy lifestyle choices are indeed associated with a subsequent risk reduction.  For example: adhering to a Mediterranean-style diet, moderate consumption of alcohol, physical activity and non-smoking is associated with a 65% lower risk of all-cause mortality and a similar reduction in cardiovascular disease.  Since less than 10% of middle-aged adults practice healthy lifestyles, an important question is whether adopting a healthy lifestyle later in life will also have a beneficial effect. 

To answer this question, King et al performed a prospective study of almost 16,000 people between the ages of 45 and 64 years. She found that a switch to a healthy lifestyle that includes

1. a diet of at least 5 fruits and vegetables daily
2. exercise comprising at least walking and a minimum of 2.5 hours per week
3. maintaining a healthy weight (BMI between 18.5 and 30 kg/m²)
4. not smoking

results in a substantial reduction in mortality (40%) and cardiovascular disease (35%) after only 4 years compared to people with less healthy lifestyles. The benefit was independent of age, race, gender, socioeconomic status, a history of hypertension, hypercholesterolemia, diabetes, or previous cardiovascular disease.  Men, African-Americans, and individuals with less than college education, lower income, or a history of hypertension or diabetes were less likely to adopt a healthy lifestyle past the age of 45.

King DE, Mainous AG, Geesy ME. Turning Back the Clock: Adopting a Healthy Lifestyle in Middle Age.
Am J Med 2007;120:598-603

• Vitamin D

Humans get vitamin D from exposure to sunlight, from their diet, and from dietary supplements. It has been estimated that at least 40% of U.S. and European elderly people, children and adults are deficient in vitamin D.

Vitamin D is important for the intestinal absorption and deposition of calcium in the skeleton.  Vitamin D deficiency plays a role in causing osteopenia, osteoporosis, osteomalacia and muscle weakness.  Osteoporosis increases the risk of bone fractures.  Osteomalacia may cause bone pain and muscle aches, and therefore be misdiagnosed as fibromyalgia, chronic fatigue syndrome and depression. Muscle weakness increases the risk of falls and consequently of fractures.
Vitamin D controls more than 200 genes, including genes responsible for the regulation of cell proliferation, differentiation, apoptosis, and angiogenesis.  Moreover, vitamin D is also a potent immunomodulator.

Studies indicate that vitamin D deficiency is associated with a 30-50% increased risk of incidental colon, prostate, and breast cancer, and with higher mortality from these cancers. Vitamin D intake has been shown to decrease the risk of developing multiple sclerosis, rheumatoid arthritis and osteoarthritis.  For diabetes mellitus type I, an 80% reduced risk was found in people who had vitamin D supplementation in their first year of life, whereas vitamin D deficiency increased the risk by 200%. The risk for diabetes mellitus type II could be decreased by 33% with daily intake of calcium and vitamin D. Vitamin D status has been found to be associated also with hypertension, congestive heart failure, schizophrenia and depression.

Vitamin D intoxication is extremely rare. Doses of 10,000 IU of vitamin D3 per day for up to 5 months do not cause toxicity. Caution is needed for patients with granulomatous disorders (e.g. sarcoidosis) as they are more sensitive to vitamin D, resulting in hypercalciuria and hypercalcemia.

Much evidence suggests that recommended adequate intakes of vitamin D are actually inadequate and need to be increased to at least 800 IU of vitamin D3 per day unless a person eats oily fish frequently.  

Holick MF. Vitamin D Deficiency. New Engl J Med 2007;357:266-81