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One of the dreaded afflictions of getting older is age-related macular degeneration (AMD), which is a leading cause of vision loss in Americans 60 years and older. It has no cure. Thus this study finding that eating a Mediterranean diet, and especially lots of fruit, was associated with a lower risk of macular degeneration was welcome news. They also found a protective effect from drinking caffeinated beverages - about 78 mg of caffeine per day (about one cup of coffee or one shot of espresso). A Mediterranean diet stresses eating fruits, vegetables, nuts, whole grains, legumes, fish, seeds, and olive oil. From Science Daily:

Fruit-rich Mediterranean diet with antioxidants may cut age-related macular degeneration risk by more than a third

People who closely follow the Mediterranean diet -- especially by eating fruit -- may be more than a third less likely to develop age-related macular degeneration, a leading cause of blindness, according to a study presented at AAO 2016, the 120th annual meeting of the American Academy of Ophthalmology. The study is the first to identify that caffeine may be especially protective against AMD.

Many studies have confirmed the health benefits of the Mediterranean diet, which emphasizes eating fruits, vegetables, whole grains, legumes, nuts, healthy fats and fish, and limiting red meat and butter. The diet has been shown to improve heart health and reduced risk of cancer, but there has been little research on whether its benefits can extend to eye disease. To determine this, researchers studied a Portuguese population to see whether adherence to the diet impacted people's risk of AMD. Their findings revealed a significant reduction in risk in those who ate a Mediterranean diet most frequently, and particularly among those who consumed more fruit and caffeine.

Researchers at the University of Coimbra in Portugal studied 883 people age 55 or older in the central region of the country between 2013 and 2015. Of those, 449 had AMD in its early stages before vision loss, and 434 did not have AMD. Researchers assessed their diets based on a questionnaire asking how often they ate foods associated with the Mediterranean diet. The more they ate foods associated with the diet, the higher the score, from 0-9. Those who closely followed the diet scored a 6 or greater. Their findings were as follows:

Higher diet adherence scores meant lower AMD risk Of those who did not closely follow the diet (scored below a 6), 50 percent had AMD. Of those who did closely follow the diet (scored 6 or above), only 39 percent had AMD. This represents a 35 percent lower risk compared to those who did not adhere to the diet.

Fruits were especially beneficial Researchers analyzed consumption of foods and found that people who consumed higher levels of fruit were significantly less likely to have AMD. Of those who consumed 150 grams (about five ounces) or more of fruit a day: 54.5 percent did not have AMD and 45.5 percent had AMD. Overall, people who ate that much fruit or more each day were almost 15 percent less likely to have AMD, based on an odds ratio calculation.

Caffeine and antioxidants also were protective Researchers used a computer program to analyze the participants' consumption of micronutrients, according to their answers on the questionnaire. They found higher consumption of antioxidants such as caffeine, beta-carotene and vitamins C and E was protective against AMD. Of those who consumed high levels of caffeine (about 78 mg a day, or the equivalent of one shot of espresso): 54.4 percent did not have AMD and 45.1 percent had AMD....The researchers opted to look at caffeine because it is a powerful antioxidant that is known to be protective against other conditions, such as Alzheimer's disease.

Coffee consumption overall seems to be beneficial to health in various ways, such as lowering the risk of colorectal cancer. But there are times one should limit how much one drinks, such as during the  preconception period for both the male and female, and also during pregnancy, to lower the risk of miscarriage.

From Science Daily: Coffee consumption linked to decreased risk of colorectal cancer

Researchers have found that coffee consumption, including decaf, instant and espresso, decreases the risk of colorectal cancer. Moreover, these benefits increase the more coffee you drink. The study examined over 5,100 men and women who had been diagnosed with colorectal cancer within the past six months, along with an additional 4,000 men and women with no history of colorectal cancer to serve as a control group. Participants reported their daily consumption of boiled (espresso), instant, decaffeinated and filtered coffee, as well as their total consumption of other liquids.....

The data showed that even moderate coffee consumption, between one to two servings a day, was associated with a 26 percent reduction in the odds of developing colorectal cancer after adjusting for known risk factors. Moreover, the risk of developing colorectal cancer continued to decrease to up to 50 percent when participants drank more than 2.5 servings of coffee each day. The indication of decreased risk was seen across all types of coffee, both caffeinated and decaffeinated.

Coffee contains many elements that contribute to overall colorectal health and may explain the preventive properties. Caffeine and polyphenol can act as antioxidants, limiting the growth of potential colon cancer cells. Melanoidins generated during the roasting process have been hypothesized to encourage colon mobility. Diterpenes may prevent cancer by enhancing the body's defense against oxidative damage. "The levels of beneficial compounds per serving of coffee vary depending on the bean, roast and brewing method," said first author Stephanie Schmit, PhD, MPH. 

Colorectal cancer is the third most common cancer that is diagnosed in both men and women in the United States, with nearly five percent of men and just over four percent of women developing the disease over their lifetime. The American Cancer Society (ACS) estimates that in the United States, over 95,000 new cases of colon cancer and 39,000 new cases of rectal cancer will be diagnosed in this year alone.

Both males and females should limit coffee consumption in the preconception period to no more than 2 caffeinated drinks daily to lower the female's risk of miscarriage. From Medscape:

Even Men Need to Cut Back on Coffee Before Pregnancy

Women already know they need to cut back on coffee during pregnancy, if not sooner, to lower the risk of miscarriage. But a new study suggests the men in their lives need to limit caffeine too. Pregnant women who had more than two caffeinated drinks a day while trying to conceive had a 74% higher risk of miscarriage than their peers who drank less coffee, tea, soda and energy drinks, the study found.

When their husbands and boyfriends had more than two caffeinated drinks a day during the preconception phase, however, these pregnant women ended up with almost the same increased risk of miscarriage they would get from drinking coffee or soda themselves...."We did not find drinking one to two daily caffeinated beverages to increase the risk of miscarriage." Scientists aren't sure how caffeine contributes to miscarriage, but it's possible it affects egg or sperm production, implantation of the fertilized egg, or the ability of the embryo to grow in the uterus.

To assess how lifestyle choices may influence miscarriage risk, Louis and colleagues followed 344 couples in Texas and Michigan through the first seven weeks of pregnancy....Overall, 98 women, or 28%, experienced a miscarriage during the study, as reported March 24 in the journal Fertility and Sterility. Women 35 or older had nearly double the miscarriage risk of younger women, the study found. When women took daily multivitamins, their miscarriage risk was 55% lower than for their peers who didn't do this.

One surprise in the study is that researchers didn't find an increased miscarriage risk associated with smoking or alcohol, however. This doesn't mesh with previous research, noted Dr. Jeffrey Goldberg, a reproductive health researcher at Cleveland Clinic in Ohio who wasn't involved in the study.