The latest health research offers good reasons to raise a glass to toast your health: Drinking alcohol in moderation has been shown to reduce the risk of heart disease, diabetes, rheumatoid arthritis, osteoporosis, and even kidney stones.

But there is a “Goldilocks Effect” when it comes to drinking. Knowing how much is too much is the key to maximizing the health benefits of alcohol. Research suggests, for most men, that just-right sweet spot is two drinks per day; for women, it’s one.

Experts note, however, that even these one-size-fits-all guidelines aren’t appropriate for everyone and that other individual factors must also be taken into account.

For instance, a new study published last month in the American Journal of Public Health found that the heart-healthy benefits of moderate drinking are not the same for whites as blacks and vary by sex.

The findings, based on the long-running National Health Interview Survey run by the Centers for Disease Control and Prevention, indicate that black men who drink no alcohol have a lower death risk than those who consume alcohol in moderation, while white men who imbibe up to two drinks a day have a lower heart-disease risk than teetotalers. For black and white women, the variation is even greater.

Chandra Jackson, a Harvard School of Public Health epidemiologist, says the new research should prompt a new review of federal recommendations regarding alcohol consumption.

"Current dietary guidelines recommend moderate consumption for adult Americans who consume alcoholic beverages,” notes Jackson. “Our study suggests that additional refinements based on race/ethnicity may be necessary."

For the new study, the researchers analyzed the medical records and drinking habits of more than 25,800 black adults and more than 126,300 whites from 1997 to 2006. Thirteen percent of white men and 24 percent of black men said they never drank. The researchers also found that 23 percent of white women and 42 percent of black women were teetotalers.

The results showed:

• Among white men, the lowest risk of death was among whites who had one to two drinks a day, three to seven days a week.
• For black men, the lowest risk of death was among those who didn't drink at all.
• White women who consumed one drink a day, three to seven days a week, had the lowest risk of death.
• For black women, the lowest risk of death was among those who had one to two drinks, but only twice a week or less.

The researchers noted the results held true regardless of the type of alcohol participants consumed. For the study, one standard-sized drink was defined as 12-ounce bottle or can of beer, a five-ounce glass of wine, or a liquor drink including a 1.5-ounce shot of 80-proof spirits.

"Among white men and women, moderate alcohol consumption on most days of the week was associated with lowest mortality risk, but black men and women with similar drinking patterns did not have the same risk reduction compared with those who abstained or drank infrequently," the researchers concluded.

Addressing differences that might explain the results, the researchers said: "The rapid metabolism of alcohol among blacks resulting from potential genetic differences could reduce cardiovascular benefits, yet we found a suggestion of benefit for light consumption among black women, but not among black men.

"It would be particularly interesting to investigate racial/ethnic differences in reasons for consuming alcohol."

The findings add to the large body of scientific evidence that indicates a variety of genetic, biological, and lifestyle factors play a role in the connection between alcohol and death risk. These include diet, physical activity levels, sleep, income, genetics, and gender.

For example, past studies have shown that women with increased risks of developing cardiovascular problems — because of genetics, family background, or lifestyle factors — may benefit from a daily glass of wine, beer, or liquor. But for those at risk for breast cancer, having more than an occasional alcoholic drink may raise their risks.

In addition, many studies show that alcoholism runs in families and may exacerbate some mental-health issues, such as depression, so individuals who may be prone to such problems would do well to steer clear of alcohol altogether.

While Jackson said the findings help qualify and quantify the health benefits of alcohol, the research raises new questions worth exploring.

"The divergent findings between white and black men and women in this and other [studies] raise the unresolved question of whether the apparent cardio-protective effect of alcohol is real, differs for people of African ancestry, or is confounded by the varying lifestyle characteristics of drinkers versus nondrinkers," the researchers said.

They added that more research is needed to compile and evaluate factors that vary across different groups of people to explain direct and indirect links between health and alcohol consumption. Among them:

• How alcohol interacts with lifestyle factors — such as diet, physical activity, and sleep — so the benefits of drinking can be assessed in connection with those aspects.
• If the downsides of consuming alcohol as a result of "youthful experimentation” or to “cope with hardships" outweigh the potential benefits.
• Whether differences in physical, chemical, and social exposures to alcohol — in occupational and residential environments — are a factor.
• How variations in body composition and gastric absorption of alcohol affect its potential benefits.