Homocysteine

Scrabble Tip

Cholesterol or homocysteine?

Scrabble players know the answer to that one: homocysteine. (It earns 6 more points than cholesterol does.)

HSI members also know that homocysteine levels are more valuable than cholesterol levels in providing an accurate assessment of cardiovascular health.

So why isn’t “homocysteine” a household word? That’s also simple: Drug makers don’t have a drug that will lower homocysteine, so you don’t hear the word repeated 50 times a day in a barrage of TV commercials.

Nevertheless, this amino acid must be kept low to help prevent plaque buildup on blood vessel walls. A new study reveals that adequate intake of two nutrients can help that effort considerably.

Measuring up

According to Harvard Medical School researchers, food composition databases that recently became available now make it possible to study the effects of nutrients like choline on disease prevention.

Choline is a B vitamin that the body uses to make a neurotransmitter that facilitates memory storage and muscle control. Choline deficiency has been associated with insomnia, fatigue, poor kidney function and memory loss. Extreme cases of deficiency may prompt anemia, high blood pressure, cardiovascular disease and kidney failure.

In a study published in the American Journal of Clinical Nutrition, the Harvard team examined food frequency questionnaires submitted by more than 1,900 subjects (average age: 54) who participated in the Framingham Offspring Study. Using the new food composition databases from Harvard, the Department of Agriculture and the Journal of Nutrition, researchers were able to assess the total intake of choline and betaine. (Choline is oxidized to betaine.) Blood samples provided total homocysteine measurements for each subject.

Researchers found that subjects with the highest intake of choline had nearly 10 percent lower total homocysteine compared to subjects with the lowest choline intake. When highest and lowest betaine levels were included in the analysis, homocysteine levels dropped even lower in the highest intake group.

This homocysteine reduction might have been more dramatic if the subjects had actually been getting the recommended daily intake for choline, which is 550 mg per day for men and 425 mg per day for women. The highest choline intake recorded in the study was 401 mg per day, and the average for all subjects was just over 310 mg per day.

The best sources of choline are meat, eggs and milk. Betaine is found mostly in spinach, broccoli and beets.

Folate factor

An interesting wrinkle in the Harvard study involved the folate factor.

Researchers found that choline and betaine intake reduced homocysteine even when intakes of folate and other B vitamins were low.

As many HSI members are aware, folate plays a key role in managing homocysteine. Research has shown that homocysteine metabolism requires folate, vitamin B6 and B12. So for most people, increasing dietary folate intake by eating asparagus, lentils, chickpeas, most varieties of beans, and especially spinach and other leafy green vegetables, will lower their homocysteine.

If diet doesn’t do the trick, vitamin supplements often will. HSI Panelist Allan Spreen, M.D., recommends 1.6 mg of folic acid daily, and as much as 5 mg daily for patients with cardiovascular problems. (Be sure to talk to your doctor before adding new supplements or higher doses to your regimen.)

To get the most out of folate, Dr. Spreen also recommends 1 mg per day of B12, 100 mg per day of B6, and 400-500 mg per day of magnesium (to make the B6 more effective).

For more information about homocysteine, heart health and the benefits of B vitamins, see the e-Alert “The B List” (2/2/04).
http://www.hsionline.com/ealerts/ea200402/ea20040202.html

Sources:
“Dietary Choline and Betaine Assessed by Food-Frequency Questionnaire in Relation to Plasma Total Homocysteine Concentration in the Framingham Offspring Study” American Journal of Clinical Nutrition, Vol. 83, No. 4, April 2006, ajcn.org
“Increased Choline Intake Could Cut CVD Risk, Suggests Study” NutraIngredients, 6/22/06, nutraingredients.com