Friday, July 29, 2011

Red wine may protect against breast cancer for some women at increased risk

As we have discussed here before, the question of alcohol consumption and breast cancer is a volatile one, but a new study helps to shed some light on the subject. It becomes especially difficult for a subset of women with a genetic trait that places them at increased risk. Two genes, called BRCA1 and BRCA2, are mutations of genes that normally code for tumor suppression. When one of these mutations is present, the chances of developing breast cancer are substantially increased, and it is now routine to test for them when there is a family history of breast cancer. And given the consensus that alcohol consumption further increases the odds of developing breast cancer, it might make sense that the BRCA gene and drinking would be an especially dangerous mix. But when it comes to red wine, the story takes a different turn.

This new study, from the University of Ottawa in Montreal, looked at a large population of women with breast cancer, and tested them for BRCA. Additionally, drinking habits were determined by questionnaire. Interestingly, women with BRCA1 who were primarily red wine drinkers had about half of the expected incidence, and alcohol had no correlation at all. For BRCA2 positive women, alcohol was independently associated with breast cancer but red wine had no relationship.

So for BRCA-positive women, the effect of red wine really depends on which type; BRCA2 women should probably seriously consider avoiding alcohol of any type (unless they choose to have prophylactic mastectomy with reconstruction) while BRCA1 women might seriously consider cultivating a taste for cabernet. It’s a confused message, since the original purpose of the study was to clarify the magnitude of alcohol as a risk factor for BRCA-positive women, but the unexpected benefit for wine drinkers adds a layer of complexity. It’s not the first crack in the consensus about wine and breast cancer though, since populations where wine is regularly consumed there is a much lower incidence of breast cancer. The difficulty is statistically teasing out the true wine drinkers from the mixed and erratic drinking patterns in most populations.

Saturday, July 23, 2011

How wine helps diabetes

If current trends continue, an epidemic of diabetes is looming over the country. Are wine drinkers exempt? There is good evidence that wine drinkers are less likely to develop type 2 (non insulin-dependent) diabetes, and recent research may help explain why: wine derived compounds work in much the same way as popular diabetes medications.

To begin with, type 2 diabetes is typically associated with obesity, a main reason for the upward trend in developed countries. Wine drinkers tend to have healthier lifestyles overall so a certain amount of the benefit relates to healthier eating and exercising regularly. However, there seems to be more to it than that, and now we have biochemical evidence to back us up. One way that diabetes drugs work is to make cells more sensitive to insulin, which in turn helps them take in sugar. (Type 2 diabetics have a problem with insulin sensitivity, not a lack of insulin as in type 1.) Fat cells in particular become resistant to insulin.

Diabetes drugs such as Avandia (rosiglitazone) make cells more responsive to insulin by binding a receptor call PPAR. Red wine contains at least 2 compounds, ellagic acid and epicatechin gallate, that also bind PPAR. On average, a glass of red wine is equivalent (experimentally) to a full dose of Avandia (which by the way cautions against taking it with alcohol.) Other studies have found resveratrol from red wine to have anti-diabetic effects.

Of course anyone on diabetes medication should discuss their alcohol consumption with their doctor, but it helps to be independently informed as well. Alcohol, despite the calories, is metabolized differently from carbohydrates such as sugar; so wine, whose only calories come from alcohol, is less likely to cause problems with blood sugar levels.

Friday, July 8, 2011

Let them drink wine: A Bastille Day toast to healthy drinking

Marie Antoinette may be popularly credited with spurring the French revolution (and losing her head) with her response to the shortage of bread, but a closer look at the events leading up the storming of the Bastille on July 14, 1789 reveals that access to affordable wine was perhaps an even more important factor. In May a national assembly was convened to air grievances of the common people and demand formation of a constitution. A series of poor harvests and widespread food shortages contributed to general unrest, but the Bastille became a target both because “political” prisoners were housed there on arbitrary orders from the king, and also because it was an armory. But it was not the storming of the Bastille that was the first act of civil unrest in the French revolution, it was attacks on the customs houses where duties on wine were collected.

Wine, however, was not in particularly short supply in the 1780’s. The issue was a tax that was collected on wine as it was brought into the city, which had created an opportunity for enterprising publicans who set up shop just outside the Paris city gates. Affordable wine had thereby been generally available without a long journey at the end of a day’s work in the city. As one member of the legislature, Etienne Chevalier put it in 1789: “Wine is the basis of survival for the poor citizens of Paris. When bread, meat, and other foods are too expensive, he turns to wine; he nourishes and consoles himself with it.” But Paris, a walled city at the time, was growing, and as the walls were moved outward it became increasingly difficult for the “poor citizens of Paris” to maintain easy access to this important source of nutrition and comfort. So it was the customs houses at the gates of Paris that were targeted first in the revolution.

Some 300 years later, the French paradox would confirm the health benefits of regular consumption of wine with the evening meal. If there is a lesson in this historical nugget, perhaps it is this: Let them drink wine. A good baguette wouldn’t hurt either.

Friday, July 1, 2011

Space: The next frontier for wine and health?

Spaceflight has a number of deleterious effects on health, but recent evidence suggests that resveratrol – a polyphenol antioxidant from red wine – might help to offset some of these effects. If you ask me, not having access to wine with dinner is bad enough, but there is a long list of physical deteriorations that occur with prolonged zero gravity. These include muscle wasting and decrease in bone density, but there are also physiologic alterations such as insulin resistance and a shift from fat metabolism to carbohydrate utilization. These are issues with a months-long stay in the international space station, but extrapolating to the time required for planetary exploration they become serious problems.

A study on rats suggests how resveratrol may help protect against these changes. While the animals were not launched into space, there is an experimental model that mimics the effects to some degree by “unloading” the hind leg. This results in loss of muscle mass, decrease in bone density, and the associated metabolic changes. With resveratrol added to the diet, these changes were completely prevented, including insulin sensitivity and dietary fat processing.

What this means for us terrestrials may be the more intriguing question. Is wine a subsitute for exercise? Previous studies have suggested that resveratrol enhances athletic performance, and slows age-related muscle loss (again in mice only.) There is some evidence that muscle wasting from cancer may also be slowed with resveratrol supplementation. However, several studies  support the use of another wine polyphenol, quercetin, for boosting athletic performance and endurance, and the optimal combinations and dosages remain to be determined.
It is of course important to recognize that people are not rats (at least metabolically if not behaviorally) and this notion is completely untested in humans. Absorption and the biological availability of resveratrol in people is different than in rats and so we can’t read too much into this. What we do know is that wine drinkers are healthier and live longer on average, and it appears to be related to a number of things besides resveratrol. The real trick of course will be stocking the space cellar.