Thursday, November 08, 2007

Social Influences On Diet

A few more thoughts on why I believe social influences play a role in health and disease:

I have a friend who has serious weight and health problems. If he was born in Abkhasia or Okinawa, would he have turned out similarly? My feeling is he wouldn't.

By the same token, if a person from Okinawa, a place that experiences extraordinary health and longevity, were to migrate to the West, would they die earlier and experience our diseases?

One study found they would:

Impact Of Diet On The Cardiovascular Risk Profile Of Japanese Immigrants Living In Brazil

Study Basics
  • Cross-sectional study
  • Participants: 234 Okinawans living in Okinawa (OO) and 160 Okinawan immigrants living in Brazil (OB) (aged 45–59 years)
  • "Japanese immigrants from Okinawa living in Brazil have a higher mortality from cardiovascular diseases and have their mean life expectancy shortened compared with their counterparts living in Japan."
  • OO had 37% less obesity than OB.
  • OO had 50% less hypertension than OB. The OB subjects used threefold more antihypertensive medication than OO.
  • Meat intake was 34% higher in OB than OO.
  • Fish intake was sevenfold higher in OO than OB. Urinary taurine (an index of seafood intake) was 43% higher in OO than OB.
  • Serum potassium levels were 10% higher in OO than OB.
  • Urinary isoflavones (an index of the intake of soy products) were significantly lower in OB than in OO.
  • Omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were two- and threefold higher in OO than OB.
  • The rate of ischemic ECG changes in OO subjects was only 50% of that of OB subjects.
  • There were no differences in the smoking rate between OO and OB subjects.
  • "The results of the present study suggest that coronary risk factors and cardiovascular health are not only regulated by genetic factors, but that the impact of lifestyle (mainly diet) can be large enough to modulate the expression of genes."

Addendum: Since I'm talking about the Okinawans, and since my mind has been on cancer the last few weeks, I thought I'd post this excerpt from a book I'm reading, "Healthy At 100":
"When it comes to cancer, the medical data for these fortunate people are nothing short of amazing. Despite living to such extremely old ages compared to North Americans, their cancer rates are orders of magnitude better than those found in the West. Compared to someone in the United States, an Okinawan elder is:
  • 85% less likely to die from breast cancer.
  • 88% less likely to die from prostate cancer.*
  • 70% less likely to die from ovarian cancer.
  • 70% less likely to die from colon cancer."
* While prostate cancer is the most common cancer in males in North America and Europe, and the second leading cause of death from cancer among males in the modern industrialized world, it is extremely rare in Okinawa. When researchers in the Department of Urology at Ryukyus University conducted a study on prostate cancer in Okinawa, they found so few cases that they never bothered to publish the results. Most Okinawan men have never even heard of the disease.
And this:
"The extremely low rate of cancer among the elders in Okinawa cannot be explained by lack of chemicals or pollution, nor by shortened life spans. Three of Okinawa's rivers now rank among the five most polluted rivers in Japan."
Photo of 89-year-old Zen-ei Nakamura from Okinawa, via National Geographic.

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