12.1 Diet and Health: Degenerative Diseases


– WELCOME TO THE INFORMATION ON CHAPTER 11 COVERING DIET
AND HEALTH. I’M GOING TO START
WITH A DISCUSSION OF WHAT
A DEGENERATIVE DISEASE IS. WHEN YOU THINK OF
A DEGENERATIVE DISEASE THIS IS A CHRONIC DISEASE, WHICH MEANS IT TAKES A LONG TIME
TO DEVELOP. IT’S MOSTLY IRREVERSIBLE. I SAY MOSTLY
BECAUSE THERE ARE SOME DISEASES NOW WE REALIZING
THAT WE CAN’T JUST MANAGE THEM, BUT SOME CAN ACTUALLY
BE (INAUDIBLE) CURED. BUT FOR THE MOST PART IT’S
TAKING A LONG TIME TO DEVELOP AND MOST OF
THOSE DISEASES ARE MANAGED, AND IT’S CHARACTERIZED
BY A DEGENERATION OF THE ORGANS INVOLVED. WHAT THAT MEANS IS
THAT THE ORGANS ARE SOMEWHAT DESTROYED
OR PARTS OF THEM BREAKDOWN; THEY’RE NOT FUNCTIONING AS WELL. AND THERE ARE MANY
CONTRIBUTING FACTORS, SO IT’S NOT JUST ONE FACTOR THAT WILL CONTRIBUTE TO
THE DEVELOPMENT. IT COULD BE FOOD CHOICES,
ENVIRONMENTAL FACTORS, SMOKING, THE AMOUNT OF PHYSICAL ACTIVITY,
THE USE OF ALCOHOL. THERE ARE A NUMBER OF
DIFFERENT FACTORS THAT WILL CONTRIBUTE TO DISEASE
DEVELOPMENT OVER TIME. NOW, WE TRY TO
FIGURE OUT THE CAUSES OR MAIN CONTRIBUTING FACTORS
TO DEGENERATIVE DISEASES. WE LOOK TO A LOT OF
POPULATION STUDIES, THOSE EPIDEMIOLOGIC
STUDIES THAT WE DISCUSSED AT THE BEGINNING
OF THE SEMESTER. AND THIS IS WHERE WE
FIND CORRELATIONS, WHICH ARE ASSOCIATIONS. A CORRELATION BETWEEN A
RISK FACTOR AND DISEASE DOES NOT MEAN THE RISK
FACTOR CAUSED THE DISEASE. SO WHAT WE WILL SEE IS A LOT
OF ASSOCIATIONS OR FACTORS THAT MIGHT CONTRIBUTE TO
THE DEVELOPMENT OR JUST BE A MARKER OF THAT DISEASE,
BUT NOT ALWAYS CAUSATIVE. AND IT’S VERY EASY TO
GET CONFUSED BY THIS. CAUSATION REALLY MEANS
THAT IT PRODUCES AN EFFECT. IT’S AN ACT OR AN AGENT
THAT RESULTS IN AN EFFECT. AND AN EXAMPLE IS, IF YOU
HAD STAPHYLOCOCCUS AUREUS, WHICH IS A BACTERIA
KNOWN AS STAPH, CAUSE A SKIN INFECTION. IF YOU CUT YOURSELF THEN YOU
HAD A SKIN INFECTION THAT WAS CAUSED BY STAPHYLOCOCCUS
AUREUS YOU KNOW THE CAUSE. THE CAUSE IS A BACTERIA. THAT MAKES IT EASY
TO TREAT BECAUSE WE GIVE AN ANTIBIOTIC TO
TREAT THE BACTERIA, DESTROY THE BACTERIA THEN
WE RESOLVE THE INFECTION. IT’S MUCH MORE
DIFFICULT WHEN WE HAVE A LOT OF ASSOCIATED
RISK FACTORS. WE DON’T HAVE ONE SINGLE
AGENT THAT CAUSED IT AND THAT MEANS WE HAVE TO
LOOK AT A WIDE VARIETY OF RISK FACTORS THAT
CONTRIBUTE TO CHRONIC DISEASE. BUT REMEMBER, THEY DON’T
NECESSARILY CAUSE IT. SO THE KEY IS THAT CORRELATION
DOES NOT EQUAL CAUSATION. I’M GOING TO GO THROUGH
A COUPLE OF EXAMPLES. I’M GOING TO START
WITH THIS ONE. THIS FIRST GRAPH HERE IS THE NUMBER OF DEATHS
FROM HEART DISEASE, AND YOU CAN SEE A DOWNWARD
TREND FROM 1980-2000. THIS OCCURRED, WE THINK, BECAUSE OF THE ADVANCES
IN MEDICAL CARE. THE MORE ADVANCED
DIAGNOSTIC TECHNIQUES, MEANING THAT EARLIER DIAGNOSIS. SO WE HAVE THIS DOWNWARD TREND, BUT WHAT IF WE LOOKED AT
SOME OTHER INFORMATION. THIS IS THE NUMBER OF
CABLE SYSTEMS THAT INDIVIDUALS PURCHASED
BETWEEN 1980-2000, AND THERE’S A
CLEAR UPWARD TREND. YOU COULD SEE THERE’S CLEARLY
AN INVERSE ASSOCIATION HERE. AS PEOPLE BOUGHT
MORE CABLE SYSTEMS, THE RISK OF DEATH FROM
HEART DISEASE DECREASED. SO CAN WE SAY THAT PURCHASING
A CABLE SYSTEM FOR YOUR HOME IS GOING TO DECREASE YOUR
RISK OF HEART DISEASE? I MEAN, YOU WOULD THINK
THAT WAS CRAZY, RIGHT, TO GIVE YOU THAT ASSOCIATION
AND MAKE IT CAUSATIVE. SO THERE’S A DIFFERENCE. THERE’S AN ASSOCIATION. WE CAN LOOK THROUGH
A LOT OF FACTORS TO FIGURE OUT WHY WE
HAVE THESE TRENDS. THEY COULD BE
COMPLETELY INDEPENDENT. THEY COULD HAVE SOME OVERLAP, BUT PURCHASING A CABLE SYSTEM
DOES NOT PREVENT HEART DISEASE. WE CAN LOOK TO A LOT OF OTHER
FACTORS THAT PROBABLY DECREASED THE DEATH RATE FROM HEART
DISEASE DURING THIS TIME. I’M GOING TO GO OVER
ANOTHER EXAMPLE HERE. NOW, LET’S LOOK AT THE
PREVALENCE OF DIABETES. YOU CAN SEE IT
INCREASED FROM 80-90 WITH A SHARP
UPTREND DURING 2010. NOW, A NOT AS CLEAR LINE,
WHICH IS APPLE COMPUTER SALES. YOU CAN SEE THE
TREND IS SIMILAR. WE’RE GOING WITH SLOPES
EARLY FROM 1980-1990 LOWER SALES AND THEN
IT SPIKES UP TO 2010; VERY SIMILAR. SO BASED ON THIS
DATA COULD WE SAY THAT BUYING A MAC
CAUSES DIABETES? NO.
I MEAN, AGAIN, THAT IS RIDICULOUS,
BUT I’M GIVING THIS INFORMATION THAT LOOKS
COMPLETELY RIDICULOUS. NOW, OF COURSE WE COULD
POSTULATE SOME THEORIES THAT DURING THIS TIME PEOPLE
BECAME MORE SEDENTARY, THEY PLAYED VIDEO GAMES, THE SAME TIME THEY’RE
PURCHASING COMPUTERS. SO, AGAIN, THERE COULD
BE SOME RISK FACTORS, SOME ASSOCIATED FACTORS
THAT CONTRIBUTE TO IT, BUT AGAIN IT’S NOT CAUSATIVE. SO THESE ARE VERY
OBVIOUS EXAMPLES, BUT WHEN WE START LOOKING AT
MORE DIET AND LIFESTYLE FACTORS SOMETIMES THAT
LINE BECOMES MORE BLURRED. SO YOU ALWAYS WANT TO REMEMBER, CORRELATION DOES
NOT EQUAL CAUSATION. NOW, ANOTHER CONFUSING
BIT OF TERMINOLOGY IS THE DIFFERENCE BETWEEN A
RISK FACTOR AND A RISK. VARIABLES, AND THAT’S WHEN YOU
READ STUDIES JUST LIKE YOU’LL SEE THEM TALK ABOUT VARIABLES,
ARE ESSENTIALLY RISK FACTORS. AND THAT MEANS THEY’RE
ASSOCIATED WITH AN INCREASE RISK OF
DISEASE DEVELOPMENT. SMOKING IS ASSOCIATED
WITH THE RISK OF DEVELOPING HEART
DISEASE OR LUNG CANCER. SEDENTARY BEHAVIOR IS ASSOCIATED WITH AN INCREASED
RISK OF DIABETES. BUT THEN THERE’S THE
RISK OF HAVING A DISEASE. SO THAT’S A COMPLICATIONS ASSOCIATED WITH
HAVING THE DISEASE. NOW, IF WE TOOK DIABETES,
THE RISK OF HAVING DIABETES– ONCE YOU HAVE A DISEASE,
YOU’RE AT RISK OF DEVELOPING NUMBNESS IN YOUR FEET,
OPEN SORES, INFECTIONS ON YOUR FEET,
AMPUTATIONS, KIDNEY FAILURE, LOSS OF YOUR VISION,
HEART DISEASE. SO THERE ARE A LOT OF RISKS
OF JUST HAVING THAT DISEASE. SO A SEDENTARY DISEASE
IS A RISK FACTOR FOR THE DEVELOPMENT OF DIABETES. THAT’S AN EXAMPLE OF A
RISK FACTOR OR A VARIABLE, BUT ONCE YOU HAVE THE
DISEASE YOU HAVE A RISK OF DEVELOPING CERTAIN
PROBLEMS FOR DIABETICS. IT’S AMPUTATIONS,
KIDNEY FAILURE, VISION PROBLEMS. AND THAT IS THE
END OF OUR SECTION ON DEGENERATIVE DISEASES.