The first few months of 2006 saw week after week of seemingly negative or unimpressive results of large trials in a number of areas championed by many alternative healthcare practitioners and "liberal" allopathic doctors. Things began with the apparent failure of a low-fat diet to reduce cancer and heart disease in women^1,2,3 and then progressed to negative reports on calcium and vitamin D^4,5, glucosamine⁶ and chondroitin⁶, saw palmetto⁷, homocysteine^8,9, and vitamins C & E¹⁰.

Last month, (See Dynamic Chiropractic, May 8, 2006) we went beyond the headlines of a major Glucosamine and Chondroitin study. This month, we will again look past the headlines in which proclaimed the failure of low fat diets to reduce the risk of breast cancer, colorectal cancer, and cardiovascular disease in women.

Information is not Bad
Studies labeled as bad by groups disappointed in the outcome still contain a wealth of information. In a given study, when we know the amount, type, form or duration that a given substance is prescribed or a habit change is implemented, we can then analyze the ability to increase, decrease, resolve, or promote a given result, response, or effect in the species, race, gender, or age group that is studied. If we know the specifics of how the information from a study is obtained, we can apply it in proper context. Information gets the "bad" tag when, in actuality, it is simply misleading due to an incomplete presentation in the press caused by a number of reasons. For example, the vast majority of journalists do not read the entire scientific paper they report on. Rather, they base their conclusion on the abstract or a press release. Of the few who do read the entire article, many lack the training to properly interpret scholarly publications. Finally, headlines often exclude the basic data (described above) that is required for the layperson (who has neither the time or the desire to research the topic in depth) to correctly apply the information.

The Women’s Health Initiative Randomized Controlled Dietary Modification Trial
Between 1993 and 1998 women at 40 centers across the United States were recruited to participate in a dietary modification trial. The last intervention was held in August of 2004 and the statistical analysis was concluded in March of 2005. The mean followup time was 8.1 years with a maximum of 11.2 years. In the intervention group there were 19,541 women. In the comparison or control group there were 29,294 women. Ages of the women ranged from 50 to 79. In general they were overweight and/or obese. The mean average body weight for both groups was 169 pounds.

In the first year, the dietary intervention group received 18 intensive small group counseling sessions to educate them on the reduction of dietary fat and to increase daily servings of fruits, vegetables, and whole grains. Over the next (on average) 7 years the intervention sessions were every 3 months (4 times per year). There were a total of 46 meetings with certified nutritionists trained in the prioritizing of the study, including the top goal of reducing dietary fat to 20% calories.

Diets were monitored by food frequency questionnaires. All participants completed a questionnaire at baseline and after the first year. Then, one third of each group on a rotating basis completed a food frequency questionnaire each year. Thus, each participant had 2 more food frequency questionnaires over a 6-year period. All of the women also had a medical questionnaire update every 6 months throughout the intervention period. Mammographies were done every 2 years. Electrocardiograms were done every 3 years. The participants’ personal physicians monitored the colorectal examinations.

Caffeine and/or caffeine-containing beverages (specifically coffee) have been shown to be both linked to and have no association with, a variety of ailments including hypertension and heart disease. The evidence continues to be contradictory and, in a new study on caffeine and hypertension, even paradoxical.

Caffeine and Hypertension
Researchers looked at data from the Nurse’s Health Studies, Part I (NHS I, started in 1976 with over 120,000 RNs ages 30 to 55) and Part II (NHS II, started in 1989 with over 116,000 RNs ages 25 to 42).¹ The authors began by selecting all women in NHS I who were free of hypertension in 1990 (over 53,000) and all of the women in NHS II who were free of hypertension in 1991 (over 94,000). Records were analyzed for 12 years. In 2002 over 19,000 in NHS I had developed hypertension. In 2003 over 13,000 in NHS II were hypertensive. Dietary records from NHS I (1990, 1994, and 1998) and NHS II (1991, 1995, and 1999) were reviewed. The findings are in tables 2-4.

As you can see from Table 2, the results of this trial exhibit U-shaped curve with regard to caffeine and hypertension indicate there was a lower risk of hypertension at higher and lower intakes of caffeine with an increased risk in the middle. In Table 3, the risk of hypertension with coffee declined after one cup to a level where those who drank 6 or more cups daily had a 9 to 12% reduction compared to non-users. Tea confirmed the coffee results in NHI I but was contradictory in NHS II with risk paralleling consumption. (See Table 4).

Cola Surprise
Note that both sweetened and diet cola intake were the strongest predictors of increased risk for hypertension in both studies. (See Table 5 & 6). Confused? Well it may take genetics to sort this out. For example, a new study found an increased risk of caffeine related heart disease only in those who are genetically "slow" metabolizers. Those who are "rapid" caffeine metabolizers did not have a heart disease connection.² It turns out that people who carry the 1F allele on the liver enzyme cytochrome P4501A2 metabolize caffeine and have an increased risk of heart disease compared to those who carry the 1A allele. There could be some type of genetic influence on how certain people metabolize coke ingredients both individually and in combinations. In the meantime this research adds one more reason for both doctors and patients to reduce soft drink consumption. As far as coffee and tea, these findings indicate the need for further study.