NEW YORK: In a first, researchers have identified six new genetic variants associated with habitual coffee drinking, suggesting why some people love to have coffee while others hate to sip it.
The genome-wide large study, led by the Harvard School of Public Health and Brigham and Women's Hospital, helps explain why a given amount of coffee or caffeine has varied effects on different people.
"Our findings identifies sub-groups of people most likely to benefit from increasing or decreasing coffee consumption for optimal health," said Marilyn Cornelis, research associate in department of nutrition at Harvard School of Public Health.
To reach this conclusion, researchers, part of the Coffee and Caffeine Genetics Consortium, conducted a genome-wide meta-analysis of more than 120,000 regular coffee drinkers of European and African-American ancestry.
They identified six variants that mapped to genes in areas involved in caffeine metabolism, influencing the rewarding effects of caffeine and involved in glucose and lipid metabolism.
"The findings suggest that people naturally modulate their coffee intake to experience the optimal effects exerted by caffeine and that the strongest genetic factors linked to increased coffee intake likely work by directly increasing caffeine metabolism," Cornelis explained.
Genetics have long been suspected of contributing to individual differences in response to coffee and caffeine.
"Like previous genetic analyses of smoking and alcohol consumption, this research serves as an example of how genetics can influence some types of habitual behaviour," added Daniel Chasman, associate professor at the Brigham and Women's Hospital.
The study appeared online in the journal Molecular Psychiatry.
Watafiti wamegundua aina sita za chembe za urithi zinazohusiana na kunywa kahawa, na kugundua ni kwa nini watu fulani hupenda kunywa kahawa wakati wengine hawapendi. Utafiti huo uliofanywa na Chuo cha Afya ya Umma cha Harvard na Hospitali ya Brigham na Wanawake, ulisaidia kueleza kwa nini kiasi fulani cha kahawa au kafeini huwa na athari tofauti kwa watu tofauti. """Ugunduzi wetu unafahamisha vikundi vidogo vya watu ambao wanaweza kufaidika zaidi na kuongeza au kupunguza matumizi ya kahawa kwa afya bora,"" alisema Marilyn Cornelis, msaidizi wa utafiti katika idara ya lishe katika Shule ya Afya ya Umma ya Harvard." Kwa mujibu wa utafiti uliofanywa na utafiti wa Coffee and Caffeine Genetics Consortium, utafiti huo ulijumuisha watu zaidi ya 120,000 wa asili ya Ulaya na Afrika. Watafiti waligundua aina sita za chembe za urithi zinazohusika katika metabolism ya caffeine, na kuathiri athari za faida za caffeine na kushiriki katika metabolism ya glukosi na lipid. "Matokeo ya utafiti huo yanaonyesha kwamba watu huongeza kiasi cha kahawa wanachokunywa ili kupata athari bora za caffeine, na kwamba sababu kubwa za maumbile zinazohusiana na kuongezeka kwa kiasi cha kahawa zinafanya kazi kwa kuongeza moja kwa moja kimetaboliki ya caffeine,"" alisema Cornelis." Kwa muda mrefu watu wamedhani kwamba chembe za urithi huchangia tofauti za mtu mmoja-mmoja katika kujibu kahawa na kafeini. "Kama vile uchambuzi wa zamani wa maumbile ya uvutaji sigara na unywaji pombe, utafiti huu unatumika kama mfano wa jinsi maumbile yanaweza kuathiri aina fulani za tabia ya kawaida, ""aliongeza Daniel Chasman, profesa msaidizi katika Hospitali ya Brigham na Wanawake." Utafiti huo ulichapishwa mtandaoni katika jarida la Molecular Psychiatry.